Abstract

   Owing to high rates of antibiotic resistance, the elimination of
   periodontal plaque biofilms has become a significant clinical
   challenge. In this context, metal–organic framework (MOF)-based
   photodynamic therapy (PDT) has emerged as a novel antimicrobial
   treatment option. However, this therapeutic strategy suffers from
   drawbacks such as the insufficient generation of reactive oxygen
   species and the lack of targeted biofilm clearance, which greatly
   hinder its clinical application. Here, a multifunctional MOF-based
   nanocomposite (ICG@Uio-66-UBI) was developed by modifying MOFs
   (Uio-66-NH[2]) with an antimicrobial peptide (UBI29-41) to enhance PDT
   efficiency. Our findings showed that the UBI29-41 targets EPS and
   selectively binds to lipopolysaccharide (LPS) on bacterial surfaces via
   electrostatic interactions, enabling precise delivery of ICG-generated
   ROS under 808-nm near-infrared irradiation, which disrupts bacterial
   membranes and inhibits biofilm formation. Subsequently, UBI29-41 blocks
   LPS-TLR4 binding, suppressing NF-κB signaling and reducing
   pro-inflammatory cytokine production. Furthermore, the nanocomposite
   significantly downregulates the LuxS/AI-2 quorum sensing (QS) system,
   reducing AI-2 synthesis and virulence gene expression, thereby
   inhibiting biofilm formation. In vivo studies confirmed the platform's
   efficacy in inhibiting biofilm formation and preventing collagen
   degradation in gingival tissue. By synergistically combining targeted
   antimicrobial action, anti-inflammatory effects, and QS modulation,
   ICG@Uio-66-UBI represents a breakthrough in precision periodontal
   therapy, offering a potent solution for biofilm-associated infections.

   Keywords: Metal–organic frameworks, Photodynamic therapy, Antimicrobial
   peptides, Inhibiting biofilms formation, LuxS/AI-2

Graphical abstract

   A multifunctional MOF-based nanocomposite (ICG@Uio-66-UBI) was
   developed by modifying MOFs (Uio-66-NH[2]) with an antimicrobial
   peptide (UBI29-41) to remove periodontal plaque biofilms. UBI29-41
   could target both lipopolysaccharide (LPS) and lipoteichoic acid (LTA)
   on the surface of bacteria through electrostatic interactions.
   Meanwhile, the MOFs generated ROS under 808-nm near-infrared
   irradiation, disrupting bacterial cell membranes and inhibiting biofilm
   formation. Subsequently, the interaction between UBI29-41 and LPS could
   inhibit NF-κB signaling pathway activation. Furthermore, the
   nanocomposite significantly down-regulated the activity of the
   LuxS/AI-2 quorum sensing system and the expression of related genes.

   Image 1
   [37]Open in a new tab

   A multifunctional MOF-based nanocomposite (ICG@Uio-66-UBI) was
   developed by modifying MOFs (Uio-66-NH[2]) with an antimicrobial
   peptide (UBI29-41) to remove periodontal plaque biofilms. UBI29-41
   could target both lipopolysaccharide (LPS) and lipoteichoic acid (LTA)
   on the surface of bacteria through electrostatic interactions.
   Meanwhile, the MOFs generated ROS under 808-nm near-infrared
   irradiation, disrupting bacterial cell membranes and inhibiting biofilm
   formation. Subsequently, the interaction between UBI29-41 and LPS could
   inhibit NF-κB signaling pathway activation. Furthermore, the
   nanocomposite significantly down-regulated the activity of the
   LuxS/AI-2 quorum sensing system and the expression of related genes.

Highlights

     * •
       We first successfully developed multifunctional MOF-based
       nanocomposite (ICG@Uio-66-UBI) was developed by modifying MOFs
       (Uio-66-NH[2]) with an cationic antimicrobial peptide (UBI29-41) to
       enhance PDT efficiency.
     * •
       Our findings showed that the UBI29-41 could target both LPS and LTA
       on the surface of bacteria through electrostatic interactions.
       Meanwhile, the MOFs generated ROS under 808nm near-infrared
       irradiation, disrupting bacterial cell membranes and inhibiting
       biofilm formation.
     * •
       The potential mechanism by which ICG@Uio-66-UBI inhibits biofilm
       formation could involve the nanocomposite significantly
       downregulating the activity of the LuxS/AI-2 quorum sensing (QS)
       system and the expression of associated genes (RadD, FadA, FomA,
       Fap2,RgpA, RgpB, HagA, HagB, and Kgp).
     * •
       We showed that cationic antimicrobial peptide UBI29-41 specifically
       targets the LPS on the surface of bacteria and inhibiting the NF-κB
       signaling pathway, thereby ultimately exerting anti-inflammatory
       effects.
     * •
       This study offers a novel strategy for the precise treatment of
       periodontal disease and compensates for the issue of inadequate
       targeting in conventional periodontitis treatment. Since QS
       promotes biofilm formation and virulence expression, it can be
       considered a potential target against bacterial infection.

1. Introduction

   Periodontal infection is a chronic disease caused by bacteria and
   induces an inflammatory response in the host that results in
   periodontal tissue destruction and bone resorption [[38]1,[39]2].
   Numerous studies have confirmed that in dental plaque—a complex
   microbial biofilm that contains a variety of gram-positive and
   gram-negative bacteria—the microorganisms and their metabolites
   interact with the host's immune defenses, contributing to an
   inflammatory response [[40]3,[41]4]. Thus, developing effective
   strategies to prevent plaque formation and inflammation is critical for
   periodontal disease management. The current treatment approach for
   periodontal disease typically involves mechanical debridement,
   including tooth brushing, or non-surgical periodontal treatment and
   antibiotic therapy to inhibit bacterial growth and reduce bacterial
   colonization [[42]5]. However, complete plaque removal is challenging
   to achieve with traditional treatments owing to the presence of deep
   structures such as periodontal pockets and dental roots [[43]6]. These
   limitations of traditional treatments have prompted the search for new
   alternatives to effectively control inflammation and inhibit the
   formation of plaque biofilms.

   Antimicrobial photodynamic therapy (aPDT) is a relatively new and
   promising strategy for the treatment of several diseases, including
   peri-implantitis, periodontitis, and other oral lesions [[44]7,[45]8].
   In aPDT, photosensitizers are excited by specific wavelengths of light
   and react with endogenous oxygen to produce cytotoxic reactive oxygen
   species (ROS), which damage bacterial plasma membranes and DNA and
   induce cell death [[46]9]. However, the clinical application of free
   photosensitizers is limited by poor water solubility, low
   photostability, and inefficient ROS generation [[47]10]. To address
   these challenges, nanotechnology-based aPDT strategies have gained
   attention due to the superior water solubility of nanoparticles (NPs)
   and their ability to regulate ROS release. Metal–organic frameworks
   (MOFs), particularly Uio-66, have shown promise as photosensitizer
   carriers because of their tunable pore sizes, large surface areas, and
   excellent biocompatibility [[48][11], [49][12], [50][13]].
   Uio-66-NH[2], an amino-modified variant, enhances ROS production even
   under low oxygen conditions, making it effective against periodontal
   pathogens resistant to conventional PDT [[51]14]. Nevertheless,
   exogenous MOF-based nanomaterials lack mechanisms for actively
   targeting bacteria and thereby trigger an immune response. Thus, it is
   particularly important to develop nano-delivery systems that target
   both periodontal pathogens and inflammation.

   Cationic antimicrobial peptides (CAMPs) are key components of the
   innate immune system and represent a potential source of novel
   antibiotics. In addition to their direct antimicrobial effects, CAMPs
   modulate immune responses, making them attractive for therapeutic
   applications [[52]15]. Recent studies have explored the use of CAMPs to
   achieve targeted antimicrobial effects through interactions with
   negatively charged bacterial components, such as lipopolysaccharide
   (LPS) in gram-negative bacteria and lipoteichoic acid (LTA) in
   Gram-positive bacteria [[53]16,[54]17]. These interactions disrupt
   bacterial membranes and enhance the penetration of antimicrobial agents
   [[55][18], [56][19], [57][20], [58][21]]. Notably, LPS activates
   Toll-like receptor4 (TLR4), triggering MyD88-dependent NF-κB signaling.
   This pathway upregulates inflammatory mediators, including
   interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and
   cyclooxygenase-2 (COX-2) [[59][22], [60][23], [61][24]]. CAMPs such as
   UBI29-41 not only neutralize LPS but also inhibit NF-κB activation,
   offering dual therapeutic benefits [[62]25,[63]26]. With exceptional
   thermal stability and pH resilience, UBI29-41 is uniquely suited for
   constructing multifunctional nanoparticles [[64]27].

   In recent years, with the development of nanotechnology, treatment
   strategies such as chemodynamic therapy, phototherapy, and sonodynamic
   therapy (SDT) have gained prominence as alternatives to antibiotic
   therapy [[65][28], [66][29], [67][30]]. However, the double-membrane
   structure of Gram-negative bacteria, including Fusobacterium nucleatum
   and Porphyromonas gingivalis, limits the penetration of ROS, reducing
   the effectiveness of single therapies [[68]31,[69]32]. Combining CAMPs
   with aPDT presents a synergistic strategy that targets both bacterial
   membranes and metabolic pathways, thereby improving treatment
   efficiency.

   In this study, we developed a dual-functional nano-platform combining
   aPDT with the targeting peptide UBI29-41 to achieve enhanced
   antimicrobial and anti-inflammatory effects under 808nm near-infrared
   (NIR) irradiation. Unlike previous studies that primarily focused on
   biofilm inhibition, our work investigates the underlying mechanisms of
   action. Bacterial biofilm formation and virulence are regulated by
   quorum sensing (QS), a communication system mediated by signaling
   molecules such as autoinducer-2 (AI-2), synthesized by the LuxS enzyme
   [[70]33,[71]34]. We hypothesize that our nanoplatform could disrupt the
   LuxS/AI-2 QS system, thereby inhibiting both biofilm formation and
   virulence factor expression.

   To test this hypothesis, we encapsulated the photosensitizer
   indocyanine green (ICG) within Uio-66 to form a core-shell structure
   and modified the surface with UBI29-41, creating a NIR therapeutic
   platform ([72]Fig. 1). This platform, termed ICG@Uio-66-UBI, combines
   targeted aPDT with anti-inflammatory effects, demonstrating favorable
   biosafety both in vitro and in vivo. Our design achieves the following
   objectives: 1) Specific targeting of pathogenic bacteria through
   interactions between UBI29-41 and negatively charged LPS/LTA, while ROS
   generated by ICG under NIR irradiation penetrates bacterial membranes,
   enhancing aPDT efficacy. 2) Suppression of the NF-κB pathway by
   UBI29-41, which inhibits LPS-induced inflammation and modulates the
   local inflammatory microenvironment. 3) Regulation of the LuxS/AI-2 QS
   system to reduce virulence factor secretion and inhibit biofilm
   formation. This platform, termed ICG@Uio-66-UBI, combines targeted aPDT
   with anti-inflammatory effects, demonstrating favorable biosafety and
   synergistic efficacy in vitro and in vivo. This work advances
   periodontal therapy by combining bacterial targeting, inflammation
   control, and QS inhibition—a multifunctional platform addressing the
   complex nature of periodontal disease. By overcoming the limitations of
   conventional treatments, our platform offers a precise,
   mechanism-driven approach for managing deep-seated dental infections.

Fig. 1.

   [73]Fig. 1
   [74]Open in a new tab

   Schematic illustration of synthesis of ICG@Uio-66-UBI NPs and their
   remarkable ability to enhance target anti-biofilm and immunomodulation
   against periodontal diseases.

2. Materials and methods

2.1. Preparation of ICG@Uio-66 composites

   To synthesize the ICG@Uio-66 composites, 90 mg of amino terephthalic
   acid, 115 mg of zirconium chloride, 1.8 g of benzoic acid, and 80 μL of
   concentrated hydrochloric acid were dissolved in 35 mL of
   N,N-dimethylformamide (DMF) under continuous stirring. The homogeneous
   mixture was transferred to a hydrothermal kettle and heated at 120 °C
   for 10 h. After cooling to room temperature, the mixture was
   centrifuged at 15,000 ×g for 30 min, and the resulting precipitate was
   washed three times with ethanol to remove impurities. To ensure
   complete removal of unreacted organic solvents, the material was soaked
   in ethanol for 3 days. The purified product was then centrifuged, and
   the collected precipitate was freeze-dried for subsequent use. For the
   loading of ICG, ICG (100 mg) was mixed with Uio-66 (50 mg) in ethanol
   (200 mL) and stirred for 24 h. All subsequent experiments were
   performed using ICG-loaded nanoplatforms as intended.

2.2. Introduction of UBI target

   The carboxyl groups on the UBI peptide were activated by dissolving UBI
   (1 mg/mL) in deionized water and adding
   1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) (5 mg/mL, pH 5.6).
   The solution was stirred at 37 °C for 2 h to facilitate activation.
   Next, an equal volume of moxifloxacin-adsorbed Uio-66 (2 mg/mL) was
   added to the activated UBI solution. To promote covalent bonding
   between the amino groups of Uio-66 and the carboxyl groups of UBI,
   5 mg/mL of N-hydroxysuccinimide (NHS) solution was introduced, and the
   mixture was gently agitated at room temperature for 24 h. After the
   reaction, the resulting material was collected, lyophilized, and stored
   at -80 °C for further use.

2.3. Characterization of NPs

   The ultrastructure of drug-free Uio-66, ICG@Uio-66, and ICG@Uio-66-UBI
   samples was examined using field emission transmission electron
   microscopy (TEM). NP size and zeta potential were measured using the
   Zetasizer Nano instrument (Malvern Instruments, Malvern, UK). The
   solutions (25 mg/mL) were then transferred to 1 mL polystyrene cuvettes
   for analysis. Nitrogen adsorption–desorption was conducted using a
   JW-BK112 surface area and porosity analyzer (JWGB Sci & Tech Co.,
   Beijing, China). The surface area was determined by employing the
   Brunauer–Emmett–Teller (BET) model, while the cumulative pore volume
   was calculated from the adsorption branch of the isotherm by employing
   the Barrette–Joyner–Halenda (BJH) model. Thermogravimetric analysis
   (TGA) was conducted in ambient air using an STA 6000 simultaneous
   thermal analyzer (PerkinElmer, Waltham, MA, USA) over a temperature
   range of 30–800 °C at a heating rate of 5 °C/min. UV–vis absorption
   spectra were obtained using a Lambda 950 UV–vis spectrophotometer
   (PerkinElmer, Lambda 950).

2.4. Photothermal performance evaluation of ICG@Uio-66-UBI NPs

   The photothermal performance of ICG@Uio-66-UBI NPs was evaluated in
   vitro by measuring temperature changes under 808 nm laser irradiation.
   NPs were prepared at concentrations of 2.5, 5, 10, 20, and 30 μg/mL and
   exposed to laser power densities of 0.5, 1.0, and 2.0 W/cm^2. Samples
   were placed in quartz dishes and irradiated for 10 min, with FLIR
   thermal imaging used to monitor temperature changes. Real-time
   temperature measurements were recorded every 2 min. Each experiment was
   performed in triplicate to ensure reproducibility. Additionally, the
   photothermal performance of ICG@Uio-66-UBI NPs at a fixed concentration
   was compared across different power densities (0.5, 1.0, and
   2.0 W/cm^2) using the same experimental protocol.

2.5. Detection of singlet oxygen (^1O[2]) from ICG@Uio-UBI nanocomposites

   The singlet oxygen (^1O[2]) generation capability of ICG@Uio-66 and
   ICG@Uio-66-UBI was assessed using 3,3′,5,5′-tetramethylbenzidine (TMB)
   as a substrate. Enzyme markers, such as horseradish peroxidase (HRP),
   were added to NP solutions (2.5, 5, 10, 20, and 30 μg/mL) to facilitate
   binding with target molecules (e.g., antigens or antibodies). TMB
   solution was then added, and 1 mL of the mixture was irradiated with
   808 nm near-infrared light at 1 W/cm^2 for 10 min. The absorbance of
   the resulting blue product was measured at 620–650 nm using UV–Vis
   spectrophotometry to quantify reaction intensity and target molecule
   concentration.

   To further evaluate ^1O[2] generation, methylene blue (MB) was used as
   a substrate. A 1 mL aqueous solution containing MB (1 mM) and
   ICG@Uio-66-UBI (30 μg/mL) was irradiated with 808 nm NIR light at
   1 W/cm^2 for 0, 5, 10, 15, 20, and 30 min. UV–Vis absorption spectra
   were recorded at 664 nm to monitor MB degradation, which correlates
   with ^1O[2] production.

2.6. Cytotoxicity assay

   L929 fibroblasts and human gingival fibroblasts (HGFs)were used to
   assess the cytocompatibility of Uio-66, ICG@Uio-66, and ICG@Uio-66-UBI
   NPs as aPDT agents for periodontal disease treatment. Cells were
   cultured in DMEM supplemented with 10% fetal bovine serum (FBS) and 1%
   penicillin–streptomycin (100 g/mL streptomycin and 100 U/mL
   penicillin). Then, the cells were incubated in a constant temperature
   incubator at 37 °C in 5 % CO[2]. Finally, the L929 cells were seeded at
   a density of 2.5 × 10^3 cells per well in 96-well plates for in vitro
   culture. The cells were incubated with various concentrations of
   Uio-66, ICG@Uio-66, and ICG@Uio-66-UBI (0 μg/mL to 50 μg/mL) for 24 h
   and 72 h. The viability of the cells at 24 h and 72 h was determined
   using a Cell Counting Kit-8 (CCK-8) assay and the optical density (OD)
   was measured using the SpectraMax M3 (Molecular Devices, USA)
   microplate reader at 450 nm.

2.7. Bacterial culture and biofilm formation

   For this study, Porphyromonas gingivalis (P. gingivalis, ATCC 33277),
   Fusobacterium nucleatum (F. nucleatum, ATCC 10953), and Streptococcus
   gordonii (S. gordonii, ATCC10558) were procured from the American Type
   Culture Collection (ATCC, Manassas, VA) for single-species biofilm
   formation. After culturing P. gingivalis, F. nucleatum, and S. gordonii
   in anaerobic conditions (5% CO[2], 10% H[2], and 85% N[2]) at 37 °C for
   3–7 days, the microbial concentration was adjusted to
   10^8 colony-forming units (CFU)/mL. Both types of bacteria were grown
   on Brain Heart Infusion (BHI) medium at 37 °C. The AI-2 reporter strain
   V. harveyi BB170 (ATCC BAA-1117) was aerobically cultured in 2216e
   medium at 30 °C with shaking.

2.8. Construction of saliva membrane

   Saliva samples were collected from volunteers without active caries and
   no history of antibiotic use within the past three months. The study
   protocol was approved by the Ethics Committee of Nanjing Stomatological
   Hospital (Approval No. NJSH-202023NL-43). The samples were filtered
   using bacterial filters, and hydroxyapatite slices were immersed in the
   filtered saliva for 2 h to form a salivary film. After incubation, the
   supernatant was discarded.

2.9. In vitro assessment of the efficacy of NPs against single-species
biofilms

   For the in vitro assessment of NPs efficacy against single-species
   biofilms, seven groups were set up as follows: control, control + NIR,
   Uio-66, ICG@Uio-66, ICG@Uio-66-UBI, ICG@Uio-66 + NIR, and
   ICG@Uio-66-UBI + NIR. Then, we placed hydroxyapatite slices that had
   been coated with a saliva film were placed at the bottom of a 24-well
   plate. P. gingivalis, F. nucleatum and S. gordonii were inoculated onto
   separate hydroxyapatite slices (10^8 CFU/mL) and were treated with
   various NPs (30 μg/mL), followed by NIR exposure (1 W/cm^2, 10 min) for
   3 days. The control group received neither NP treatment nor NIR
   exposure. To evaluate the efficacy of different NPs in inhibiting
   biofilm formation, live/dead fluorescent staining and standard plate
   counting assays were carried out. Moreover, biofilm biomass and
   extracellular polysaccharide production were quantified. Detailed
   procedures are listed in the Supporting Information.

2.10. Detection of bacterial cell membrane permeability

   To evaluate the permeability of bacterial cell membranes following
   treatment with different nanoparticles (NPs), the release of nucleic
   acids from the cytoplasm was measured. Three bacterial species—P.
   gingivalis, F. nucleatum, and S. gordonii—were cultured to the
   logarithmic phase and adjusted to a concentration of 1 × 10^8 CFU/mL.
   Equal volumes of the experimental materials, namely Uio-66, ICG@Uio-66,
   and ICG@Uio-66-UBI (each at a concentration of 60μg/mL), were added at
   twice the concentration of the bacterial suspension. The bacterial
   suspensions were then irradiated with an 808 nm NIR laser. The
   bacterial suspensions were immediately collected and filtered through a
   0.22 μm filter to remove bacterial cells. The supernatant was
   subsequently diluted, and the optical density (OD) at 260 nm was
   measured using a UV–Vis spectrophotometer.

2.11. In vitro assessment of the efficacy of NPs against multi-species
biofilms

   Seven identical groups of multi-species biofilms were established using
   the same procedure used for single-species biofilm experiments.
   Bacterial suspensions of F. nucleatum (10^8 CFU/mL), P. gingivalis
   (10^8 CFU/mL), and S. gordonii (10^8 CFU/mL) were combined in equal
   volumes to create a mixed bacterial suspension, which was then placed
   onto hydroxyapatite slices in 24-well plates. The suspensions were
   treated with various NPs (30 μg/mL) and exposed to NIR irradiation (808
   nm, 1 W/cm^2, 10 min) for 3 days. Live/dead fluorescent staining and
   scanning electron microscopy (SEM) were performed to examine the impact
   of NPs on multi-species biofilms.

2.12. Mechanism underlying the antibacterial effects of ICG@Uio-66-UBI

   Log-phase F. nucleatum cells were diluted to a concentration of
   1 × 10^8 CFU/mL and treated with ICG@Uio-66-UBI NPs (30 μg/mL),
   followed by NIR exposure (808 nm, 1 W/cm^2, 10 min), for 3 days. The
   control group did not receive any NP or NIR treatment. The bacterial
   suspensions were collected for total RNA extraction. Sequencing was
   performed on the Illumina NovaSeq 6000 platform by Suzhou Panomik
   Biomedical Technology Co. Ltd. The concentration and purity of the
   extracted RNA were evaluated using an Agilent 2100 Bioanalyzer. After
   rRNA removal, RNA fragmentation, cDNA synthesis, and polymerase chain
   reaction (PCR) enrichment, high-quality clean data were obtained for
   subsequent analyses. The reference genome was established using
   Bowtie2, and the filtered reads were aligned to the reference genome.
   The gene read count values were determined using HTSeq (version
   0.6.1p2) and represented the original expression levels of the
   respective genes. The gene expression levels in different samples were
   normalized using FPKM (fragments per kilobase of exon per million
   fragments mapped) values. DESeq (version 1.20.0) was employed to
   identify differentially expressed genes (DEGs), and genes with
   |log2FoldChange| > 1 and a p value of <0.05 were considered
   significant. GO enrichment analysis was performed using topGO to
   determine the main biological functions of the DEGs, and Gene Ontology
   (GO) terms with a p value of less than 0.05 were considered
   significantly enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG)
   pathway enrichment analysis was performed using clusterProfiler
   (version 3.4.4) software to identify significantly enriched pathways
   (p < 0.05).

2.13. mRNA expression of LuxS

   LuxS is a critical enzyme involved in regulating bacterial biofilm
   formation. As the bacterial density increases, LuxS induces the
   secretion of the AI-2 signal molecule, which in turn promotes
   intercellular signaling and bacterial aggregation, leading to the
   formation of biofilms. Therefore, the expression of LuxS gene — was
   quantitatively determined using the qRT‒PCR technique. Primers for the
   target genes were custom synthesized by GenScript (Nanjing, China);
   specific information is provided in [75]Table S2. The expression of
   mRNA was assessed using the 2^−ΔΔCt method. The 16S rRNA gene was
   utilized as the internal reference. All experiments were repeated three
   times.

2.14. AI-2 inhibitory activity of ICG@Uio-66-UBI

   The concentration of V. harveyi in fresh 2216e medium BB170 was
   adjusted to 1 × 10^6 CFU/mL. The F. nucleatum suspension
   (1 × 10^8 CFU/mL) was subsequently combined with ICG@Uio-66-UBI or left
   untreated, and the samples were divided into three groups: (1) Control
   group: The F. nucleatum suspension was cultured in a
   ICG@Uio-66-UBI-free medium; (2) ICG@Uio-66-UBI group: The F. nucleatum
   suspension and 30 μg/mL ICG@Uio-66-UBI were incorporated into the
   medium; (3) ICG@Uio-66-UBI + NIR group: The F. nucleatum suspension and
   30 μg/mL ICG@Uio-66-UBI NPs were incorporated into the medium and
   exposed to NIR irradiation (808 nm, 1 W/cm^2, 10 min). Subsequently,
   all samples were incubated at 37 °C for 1–12 h. Meanwhile, 1 mL of the
   culture medium was harvested at 4, 6, 8, 10, and 12 h and subsequently
   centrifuged for 10 min to obtain the supernatant. To assess the AI-2
   activity in each experimental group, 90 μL of BB170 was incubated with
   10 μL of the AI-2 supernatant (prepared using the aforementioned
   experimental samples) for 6 h at 28 °C. The bioluminescence values were
   measured at 490 nm using a Promega Luminometer. This experiment was
   conducted independently three times.

2.15. Expression of virulence factors in F. nucleatum

   F. nucleatum is an important bridge bacterium in the early and late
   stages of plaque pathogen colonization, playing an important role in
   biofilm formation. Therefore, the expression of its virulence factors —
   the Fap2, FomA, RadD, and FadA genes — was quantitatively determined
   using the RT‒qPCR technique. Primers for the target genes were custom
   synthesized by GenScript (Nanjing, China); specific information is
   provided in [76]Table S2. The expression of mRNA was assessed using the
   2^−ΔΔCt method. The 16S rRNA gene was utilized as the internal
   reference. All experiments were repeated three times.

2.16. Extraction of inflammatory stimulants and experimental grouping

   The anti-inflammatory effects of ICG@Uio-66-UBI were assessed using an
   inflammatory model based on RAW 264.7 murine macrophages. To prepare
   the inflammatory stimulus, a P. gingivalis suspension was adjusted to
   an optical density (OD600) of 0.2 and centrifuged at 7000 rpm for
   10 min to collect bacterial pellets. The pellets were washed with
   phosphate-buffered saline (PBS) to remove residual culture medium,
   resuspended in deionized water, and mixed with an equal volume of 90 %
   phenol solution. The mixture was heated at 65 °C for 15–30 min,
   followed by centrifugation at 7000 rpm for 20 min at 4 °C to isolate
   lipopolysaccharide (LPS). The aqueous phase was dialyzed to remove
   residual phenol and lyophilized to obtain LPS powder, with its
   concentration quantified using ultraviolet spectrophotometry at 260 nm.

   RAW 264.7 cells were seeded at a density of 1.2 × 10^5 cells per well
   in a 6-well plate and incubated in 2 mL of medium for 24 h.
   Subsequently, 200 μL of the 10 μg/mL LPS was added to each well, except
   for the control group, which received normal medium. After 6 h,
   ICG@Uio-66 or ICG@Uio-66-UBI NPs were added to the medium at a
   concentration of 30 μg/mL, while the control group remained untreated.
   The experimental groups were categorized as follows: 1) Control group:
   Cells cultured in LPS-free medium. 2) ICG@Uio-66 group: Medium
   supplemented with 10 μg/mL LPS and 30 μg/mL ICG@Uio-66. 3)
   ICG@Uio-66-UBI group: Medium supplemented with 10 μg/mL LPS and
   30 μg/mL ICG@Uio-66-UBI. 4) ICG@Uio-66 + NIR group: Medium supplemented
   with 10 μg/mL LPS and 30 μg/mL ICG@Uio-66, with NIR irradiation (808
   nm, 1 W/cm^2, 10 min) applied twice daily. 5) ICG@Uio-66-UBI + NIR
   group: Medium supplemented with 10 μg/mL LPS and 30 μg/mL
   ICG@Uio-66-UBI, with NIR irradiation (808 nm, 1 W/cm^2, 10 min) applied
   twice daily.

   Following treatment, all groups were cultured for an additional 12 h to
   evaluate the anti-inflammatory effects.

2.17. Gene and protein expression of inflammatory factors in RAW 264.7 cells

   The expression of proinflammatory cytokine genes IL-6, TNF-α, IL-1β,
   IL-8, iNOS, and COX-2 were investigated via qRT-PCR. The qPCR primers
   were designed as shown in [77]Table S3. Relative gene expression was
   assessed using the 2^−ΔΔCt method.

   Immunofluorescence staining for proinflammatory cytokines (IL-6, TNF-α,
   and iNOS) was performed as follows: RAW 264.7 cells were fixed with 4 %
   paraformaldehyde (PFA) for 20–30 min and incubated in 5 % blocking
   buffer (BSA). Then, the cells were incubated with mouse anti-IL-6,
   anti-TNF-α, and anti-iNOS primary antibodies (1:400) overnight at 4 °C.
   Immunofluorescence images were collected using confocal laser scanning
   microscopy (CLSM) after the cells were incubated with the secondary
   antibody (1:400) and DAPI. All experiments were repeated three times.

2.18. Evaluation of NF-κB activation in macrophages by NPs

   The transposition of NF-κB/p65 in RAW 264.7 cells was tested through
   immunofluorescence staining. Immunofluorescence staining for NF-κB/p65
   was performed as described for proinflammatory cytokines in section
   [78]2.11. The cells were fixed with 4% PFA for 20–30 min, permeabilized
   with 0.1% TritonX-100 for 5 min, and blocked with 5% BSA for 30 min.
   Subsequently, the cells were incubated overnight at 4 °C with mouse
   anti-NF-κB/p65 primary antibodies (1:400), followed by incubation with
   the secondary antibodies (1:800) and DAPI. The images were randomly
   acquired using CLSM.

2.19. Regulating the NF-κB pathway

   RAW 264.7 cells (1 × 10^6/well) were pretreated with 30 μg/mL
   ICG@Uio-66-UBI and 10 μg/mL LPS for 0,15,30,60,90 min. The protein
   level of p65, IκBα and TLR4 was quantitively investigated via western
   blot. In brief, the total protein was obtained in RIPA lysis buffer
   with PMSF with 30 min. Following a series of standardized procedures,
   including electrophoresis, membrane transfer, blocking, and incubation
   with primary antibodies (anti-p-p65, anti-p-IκBα, anti-TLR4) and
   HRP-conjugated secondary antibody incubation, the proteins were
   visualized with an ECL kit by a gel imaging analysis system. β-actin
   and α-tubulinwas used as internal control.

2.20. Development of a periodontal inflammation model and therapeutic
interventions

   Male Wistar rats (∼180 g) aged 7–8 weeks were utilized to establish a
   model of periodontal inflammation in vivo. All animal experiments were
   explicitly approved by the Nanjing Stomatological Hospital Ethics
   Committee (#IACUC-D2304013). The Wistar rats were anesthetized with
   10 % chloral hydrate (4 mL/kg of body weight). Then, a 100 μL
   suspension of P. gingivalis (OD[600] = 0.2) was injected into the
   vestibular groove of the mandibular incisor for 14 consecutive days.
   After the model was established, rats were randomized into five groups:
   Inflammatory control, ICG@Uio-66, ICG@Uio-66-UBI, ICG@Uio-66 + NIR, and
   ICG@Uio-66-UBI + NIR. Then, based on group allocation, various NPs
   (30 μg/mL, 0.1 mL) were injected at the same site as the P. gingivalis
   injection, and 808 nm NIR irradiation ( 1 W/cm^2, 10 min) was provided
   for 3 days. The control group received an equivalent dosage of PBS
   instead.

2.21. In vivo evaluation of antibacterial effects

   At the end of the treatment period, the bacterial counts of treated
   tissue were assessed using a standard plate counting assay to evaluate
   the antibacterial efficacy of NPs against periodontal inflammation. In
   brief, swabs were gently inserted into the infected site for 10 s and
   immediately placed in 2 mL of BHI medium and incubated for 48 h. The
   bacterial suspensions were diluted using the gradient dilution method
   and cultured on blood agar plates before the enumeration of bacterial
   colonies.

2.22. In vivo fluorescence imaging

   For the in vivo evaluation of the ROS levels in different groups,
   fluorescence imaging of live animals was performed following the
   administration of NPs. The ROS probe DCFH-DA (1.8 mg/kg) was initially
   administered via local injection at the treatment site. This was
   followed by a 30-min incubation period. Subsequently, an imaging system
   for small animals (excitation filter: 465 nm; emission filter: 520 nm;
   ColdSpring) was used to acquire images.

2.23. Histological evaluation

   All rats were euthanized, and the gingival tissues at the treatment
   sites were excised after 3 days of treatment. The specimens were fixed
   in 4% PFA for histological analysis. The inflammatory infiltration of
   the gingival tissue was further evaluated using hematoxylin and eosin
   (H&E) staining, Masson's trichrome staining, and immunohistochemistry
   (IHC). A light microscope (Olympus) was used to view the H&E-stained
   slides. At 100× magnification, the inflamed regions were identified,
   and collagen degradation was evaluated. IHC staining was employed for
   the evaluation of proinflammatory cytokine levels in the tissue
   following treatment with various NPs. Rabbit anti-IL-6 (GB11117,
   Servicebio) and rabbit anti-TNF-α (GB11188, Servicebio) were used as
   the primary antibodies (1:400). Stained regions were observed at
   100× and 400× magnification and the average fluorescence intensity was
   measured using Image J.

2.24. Statistical analysis

   GraphPad Prism 8.6, Origin 2018, and Image J-Fiji software were used
   for statistical analyses. One-way analysis of variance (ANOVA) was
   carried out to determine the significance of differences among groups.
   A value of p < 0.05 was deemed to be statistically significant.

3. Results and discussion

3.1. Preparation and characterization of ICG@Uio-66-UBI NPs

   To construct the multifunctional nanoplatform, a stepwise strategy was
   employed integrating photodynamic functionality, bacterial targeting,
   and structural support. First, Uio-66-NH[2] was synthesized as a
   zirconium-based MOF with high porosity and abundant surface amine
   groups. ICG, a negatively charged NIR-absorbing photosensitizer, was
   subsequently loaded into the MOF via electrostatic interactions and
   physical encapsulation, endowing the system with PDT capability.
   Finally, the antimicrobial peptide UBI29-41, known for its strong
   affinity to bacterial membranes due to its cationic and amphipathic
   properties, was covalently conjugated to the MOF surface through
   EDC/NHS-mediated amide bond formation with the terminal amine groups.
   This sequential modification results in a well-defined
   nanocomposite—ICG@Uio-66-UBI—that simultaneously possesses (i) stable
   MOF architecture for structural integrity and drug loading, (ii)
   ICG-mediated ROS generation upon NIR irradiation, and (iii)
   UBI29-41-mediated bacterial targeting.

   High-resolution TEM images ([79]Fig. 2b–d) revealed that the particles
   of the synthesized Uio-66 material were uniformly dispersed, and the
   dispersibility of the material remained good even after loading ICG.
   Furthermore, after modifying the surface of the material with UBI, a
   significant rough layer appeared. The NP sizes were further examined by
   dynamic laser scattering (DLS). Similar to TEM observations, DLS
   demonstrated the size of the hydrated particles was primarily
   distributed around 123.5 ± 18.6 nm ([80]Fig. 2g), this specific size
   enables effective interaction with bacterial cells, thereby enhancing
   its antimicrobial efficacy. X-ray diffraction (XRD) ([81]Fig. 3a) and
   the BET model were employed to analyze specific surface area and
   further characterize the structure of Uio-66 before and after ICG
   loading. The small-angle XRD data indicated that pure Uio-66,
   ICG@Uio-66, and ICG@Uio-66-UBI all exhibited a diffraction peak at
   7.3°. The nitrogen adsorption–desorption isotherms of Uio-66 and
   ICG@Uio-66 demonstrated type-I isotherm behavior, indicating the
   presence of micropores ([82]Fig. 2e). Nevertheless, the BET surface
   area and pore volume of ICG@Uio-66 (1523.43 m^2 g^−1 and
   0.46 cm^3 g^−1, respectively) were lower than those of pure Uio-66
   (1756.65 m^2 g^−1 and 0.59 cm^3 g^−1, respectively), we hypothesize
   that the predominant factor is the filling effect induced by ICG, which
   may lead to the compression or deformation of certain pores.
   Alternatively, the incorporation of ICG might disrupt the
   crystallization process of Uio-66, thereby diminishing the material's
   internal structural order and yielding a more irregular pore
   architecture. Despite the observed reductions in specific surface area
   and pore volume, this composite framework could potentially offer
   distinctive performance benefits in realms like photocatalytic
   degradation. [83]Fig. 3c shows that shows that the nanocomposite
   exhibits a Zeta potential of +13.6 mV indicating that while the
   incorporation of negatively charged ICG molecules does lead to a
   partial reduction in surface charge compared to bare Uio-66-NH[2]
   (typically ∼16.8 mV), the composite remains positively charged overall.
   Importantly, the observed increase in Zeta potential after subsequent
   conjugation with UBI29-41 is attributed to the positively charged
   nature of the peptide itself, which contains multiple basic residues
   such as lysine and arginine. This modification offsets the slight
   charge reduction from ICG and results in a final surface potential
   higher than that of the ICG-loaded MOF alone.Since periodontal
   pathogens carry a negative charge on their surfaces, this provides a
   favorable condition for the binding of this nanoplatform to periodontal
   pathogens. TGA showed that the loading rate of ICG was about 2 wt%
   ([84]Fig. 2f).

Fig. 2.

   [85]Fig. 2
   [86]Open in a new tab

   Characterization of Uio-66, ICG@Uio-66 and ICG@Uio-66-UBI NPs. (a)
   Schematic illustration of the synthesis of ICG@Uio-66-UBI NPs. (b–d)
   TEM images of various NPs, including Uio-66, ICG@Uio-66 and
   ICG@Uio-66-UBI NPs. (e) Nitrogen adsorption-desorption isotherms of
   Uio-66, ICG@Uio-66 NPs. (f) TGA of ICG@Uio-66 and ICG@Uio-66 NPs. (g)
   The size distribution of ICG@Uio-66-UBI NPs.

Fig. 3.

   [87]Fig. 3
   [88]Open in a new tab

   Characterization and in vitro evaluation on the ROS generation of NPs.
   (a) XRD pattern of various NPs. (b) UV–Vis spectra of ICG@Uio-66 and
   ICG@Uio-66-UBI NPs. (c) Zeta potential of different NPs. (d) UV–Vis
   absorption spectra of ICG@Uio-66-UBI mixed MB at different time. (e)
   UV–vis spectra of different concentrations of ICG@Uio-66 NPs. (f)
   UV–Vis spectra of different concentrations of ICG@Uio-66-UBI NPs. (g)
   Infrared thermal images of ICG@Uio-66-UBI at different light intensity
   under an 808 nm laser (0.5 W/cm^2, 1 W/cm^2, 2 W/cm^2, 10 min). (h)
   Temperature of ICG@Uio-66-UBI at different light intensity under an
   808 nm laser (0.5 W/ cm^2, 1 W/cm^2, 2 W/cm^2, 10 min).

   To confirm the photocatalytic activity of ICG@Uio-66 and
   ICG@Uio-66-UBI, standard assays based on the oxidation of TMB were
   performed. Since the presence of ROS facilitates the catalytic
   conversion of TMB, the reaction leads to the formation of a blue hue in
   an acetate buffer solution. As shown in ([89]Fig. 3e and f and S1b),
   the rapid oxidation of TMB was observed in the presence of ICG@Uio-66
   and ICG@Uio-66-UBI NPs. With increasing concentrations of ICG@Uio-66
   and ICG@Uio-66-UBI NPs, a progressive deepening in the coloration of
   the post-reaction solution is observed, which serves as a visual
   indicator of the escalating concentration of ROS produced. However, the
   color of MB faded upon reaction with ROS ([90]Fig. 3d). These findings
   conclusively indicate that the material exhibits significant
   photocatalytic activity. The photothermal effect of ICG@Uio-66-UBI is
   shown in [91]Fig. 3g and h. Notably, the solution temperatures rose
   from 26.5 °C to 29.1 °C under 0.5 W/cm^2 and from 26.7 °C to 30.3 °C
   under 1 W/cm^2 of near-infrared irradiation. The resultant temperature
   increments were found to be modest. This suggests that ICG@Uio-66-UBI
   possesses thermal stability, and its mechanism of action is attributed
   to the photodynamic generation of ROS, rather than photothermal
   effects. Thus, NIR with a power density of 1 W/cm^2 is suitable for
   conducting the follow-up experiments.

3.2. Biosafety assessment of different NPs

   To assess the clinical feasibility of Uio-66, ICG@Uio-66, and
   ICG@Uio-66-UBI ([92]Fig. S3), the in vitro biosafety of these
   nanoparticles (NPs) was evaluated using the CCK-8 assay in a mouse
   fibroblast cell line (L929). The results indicated that cell viability
   remained above 90% after 24 h when the NPs concentration was ≤40 μg/mL.
   However, a significant reduction in cell viability was observed at
   concentrations exceeding 40 μg/mL. After 72 h, cell viability was
   markedly inhibited at 40 μg/mL for all NPs ([93]Fig. S3a–c). Similar
   trends were observed in HGFs using the CCK-8 assay ([94]Fig. S3d–f).
   Based on these findings, 30 μg/mL was identified as a biosafe
   concentration for subsequent experiments. In vivo toxicity was further
   evaluated through histological examination of major organs, including
   the heart, liver, spleen, lungs, and kidneys. No significant
   histological changes were observed following treatment with the NPs
   ([95]Fig. S3g), confirming their biocompatibility at low
   concentrations. These results demonstrate that Uio-66, ICG@Uio-66, and
   ICG@Uio-66-UBI exhibit excellent biocompatibility and hold significant
   promise for clinical applications in the treatment of periodontal
   diseases.

3.3. Antibacterial efficacy of different NPs with respect to single-species
biofilm formation

   The in vitro antibiofilm efficacy of ICG@Uio-66-UBI NPs was
   investigated against F. nucleatum, P. gingivalis, and S. gordonii,
   which are representative periodontal pathogens and porphyrin-producing
   bacteria, respectively. The investigation was conducted following 808nm
   NIR irradiation given the significantly greater penetration depth of
   NIR light [[96]9,[97]35]. We established single-species biofilms and
   confirmed their successful formation using confocal microscopy
   ([98]Fig. S2). The results ([99]Fig. 4) illustrated the disruptive
   impact of various NPs on the formation of F. nucleatum, P. gingivalis,
   and S. gordonii biofilms. Following treatment, the antibacterial
   effects of different NPs on single-species biofilms were assessed based
   on EPS production, CFU counts and biofilm biomass. EPS, which protects
   cells from external stimuli and stabilizes microbial communities, also
   promotes microbial aggregation and biofilm formation. As shown in
   [100]Fig. 4f and S4, the EPS production in biofilms of F. nucleatum and
   P. gingivalis was significantly reduced in the ICG@Uio-66-UBI + NIR
   group compared to the control. However, the EPS production in S.
   gordonii biofilms did not show the most pronounced disruption under the
   combined action of antimicrobial peptides and aPDT. This resistance may
   stem from the higher curdlan content in the EPS of S. gordonii, a
   gram-positive bacterium, whose polysaccharide suspension coagulates at
   high temperatures, enhancing its resistance to antimicrobial agents.
   Following the disruption of the EPS in the biofilms, the OD260nm values
   of the three bacterial species in the ICG@Uio-66-UBI + NIR NPs group
   were significantly higher than those in any other experimental group,
   as illustrated in [101]Fig. 4g. This observation indicates the most
   pronounced leakage of DNA and RNA from the bacterial cells. The
   enhanced antibacterial effect can be attributed to the targeted
   interaction of cationic UBI29-41 with LPS on P. gingivalis and F.
   nucleatum and LTA on S. gordonii, altering the permeability of the
   bacterial cell membrane and causing the leakage of intracellular
   components, such as nucleic acids and proteins, ultimately leading to
   bacterial cell death [[102]36]. In the absence of NIR exposure, the
   growth of single-species biofilms in both the Uio-66 and ICG@Uio-66
   groups was similar to that in the control group. When NIR irradiation
   was provided, the growth of F. nucleatum, P. gingivalis and S. gordonii
   biofilms was significantly reduced in the ICG@Uio-66-UBI and
   ICG@Uio-66-UBI-mediated aPDT groups (p < 0.05), with the latter showing
   a remarkable 2 log reduction approximately in CFU ([103]Fig. 4a–d).
   Biomass production followed a similar trend to CFU counts ([104]Fig.
   S5), with the ICG@Uio-66-UBI group exhibiting a significant decline in
   biomass and CFU values compared to the control (p < 0.01).
   Additionally, [105]Fig. 4e provides a three-dimensional (3D)
   reconstruction of 3-day biofilms. 3D live/dead staining images
   demonstrated that the control group, which did not receive any
   nanomaterial treatment, exhibited the highest abundance of viable
   bacteria stained green irrespective of NIR exposure. Meanwhile, Uio-66
   and ICG@Uio-66 alone had no significant effect on biofilm formation. In
   contrast, the combination of aPDT and UBI29-41 in the ICG@Uio-66-UBI
   group significantly augmented the proportion of dead bacteria within
   the biofilm. Nevertheless, only partial bacterial cell death was
   observed in the ICG@Uio-66-UBI group without NIR irradiation and the
   ICG@Uio-66-mediated aPDT group.

Fig. 4.

   [106]Fig. 4
   [107]Open in a new tab

   Inhibition effect of ICG@Uio-66-UBI NPs on F. nucleatum, P. gingivalis
   and S. gordonii biofilm formation. The images of (a) F. nucleatum, (b)
   P. gingivalis and (c) S. gordonii clones. (d) Corresponding statistical
   data for biofilm colonies of F. nucleatum, P. gingivalis and S.
   gordonii biofilms. (e) The 3D live/dead images of 3-day biofilms (dead
   bacteria, stained red; live bacteria, stained green) for F. nucleatum,
   P. gingivalis and S. gordonii. (f) Statistical data for EPS of F.
   nucleatum P. gingivalis and S. gordonii. (g) Nucleic acid leakage of F.
   nucleatum, P. gingivalis and S. gordonii in different groups.
   n = 5,∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001, ns, not
   significant.

   ROS generated through the interaction of photoexcited NPs and light
   irradiation, play a critical role in eradicating periodontal pathogens
   by damaging cellular components such as proteins, nucleic acids, and
   lipids [[108][37], [109][38], [110][39]]. Therefore, the multi-target
   antibacterial therapy of aPDT makes it challenging for microorganisms
   to develop resistance. However, gram-negative bacteria like P.
   gingivalis and F. nucleatum, with their low-permeability outer
   membranes, exhibit greater ROS resistance than gram-positive bacteria.
   In the present study, the overall positive charge of UBI29-41
   facilitated the accumulation of NPs on the polyanionic surfaces of
   microbial cells containing LPS [[111]40]. The electrostatic interaction
   between UBI29-41 and LPS of P. gingivalis and F. nucleatum enhanced
   generation of ROS around the bacteria. TEM revealed that P. gingivalis
   in the control group presented normal morphology, but the bacterial
   cell wall was ruptured and there was content leakage in the
   ICG@Uio-66-UBI + NIR group ([112]Fig. S15). This demonstrated that UBI
   enhanced the antibacterial effects of aPDT. Interestingly, although S.
   gordonii was more ROS-sensitive than P. gingivalis and F. nucleatum,
   the findings in the ICG@Uio-66-UBI + NIR group suggest that modulating
   charge dynamics on gram-positive bacterial cell walls through cationic
   molecule binding to LTA also plays a pivotal role in inhibiting biofilm
   formation.

3.4. Antibacterial efficacy of different NPs with respect to multi-species
biofilm formation

   The pathogenesis of periodontal disease is not driven by a single
   pathogen but rather by the synergistic aggregation of multiple
   bacterial species and the formation of complex mixed biofilms
   [[113]41]. To evaluate the antibiofilm efficacy of ICG@Uio-66-UBI, we
   constructed a multi-species biofilm model comprising F. nucleatum, P.
   gingivalis, and S. gordonii. Quantitative analysis of bacterial
   viability via colony-forming unit (CFU) counts revealed that
   ICG@Uio-66-UBI exhibited a more pronounced bactericidal effect against
   multi-species biofilms compared to single-species biofilms, achieving
   an approximate 1 log reduction in CFU ([114]Fig. 5a, b). Notably, the
   combination of ICG@Uio-66-UBI with antimicrobial photodynamic therapy
   (aPDT) further enhanced this effect, resulting in a remarkable 2 log
   reduction in CFU.

Fig. 5.

   [115]Fig. 5
   [116]Open in a new tab

   Antibacterial effects on established multi-species biofilms. (a) The
   images of mixed bacteria clones. (b) Corresponding statistical data for
   multi-species biofilm colonies. (c) TEM images of multi-species
   following treatment with various nanoparticles (red represent the
   disruption of the cell membrane.) (d) The 3D live/dead images of 3-day
   multi-species biofilms (dead bacteria, stained red; live bacteria,
   stained green). n = 5,∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001,
   ∗∗∗∗p < 0.0001, ns, not significant.

   Scanning electron microscopy (SEM) was employed to assess the
   morphological changes in the three bacterial species following
   nanoparticle treatment. As depicted in [117]Fig. 5c, bacteria in the
   control, control + NIR, Uio-66, and ICG@Uio-66 groups maintained normal
   morphology. In contrast, bacteria in all treatment groups exhibited
   varying degrees of surface indentation, with significant biofilm
   dissipation observed in the ICG@Uio-66-UBI + NIR group. This phenomenon
   can be attributed to the localized generation of ROS, which induced
   protein and lipid denaturation, ultimately leading to bacterial
   membrane degradation.

   Further validation was provided by 3D live/dead staining of the
   multi-species biofilms ([118]Fig. 5d). Compared to the control groups,
   the ICG@Uio-66-UBI, ICG@Uio-66 + NIR, and ICG@Uio-66-UBI + NIR groups
   demonstrated a significantly higher proportion of dead bacteria within
   the biofilm. However, the extent of bacterial death in the
   multi-species biofilm was less pronounced than that observed in
   single-species biofilms, even after treatment with ICG@Uio-66-UBI
   combined with aPDT. This discrepancy may be explained by the unique
   role of F. nucleatum as a bridging bacterium, which facilitates the
   formation of multi-species biofilms by mediating interactions between
   P. gingivalis and S. gordonii [[119]42]. Additionally, multi-species
   biofilms inherently exhibit enhanced pathogenicity and resistance to
   antimicrobial agents due to their increased biomass and metabolic
   activity, potentially accounting for the reduced efficacy of
   ICG@Uio-66-UBI against these complex communities compared to
   single-species biofilms.

3.5. Antibacterial mechanisms of ICG@Uio-66-UBI

   To further explore the anti-biofilm mechanisms induced by
   ICG@Uio-UBI + NIR treatment, RNA-seq analysis was conducted to identify
   DEGs in F. nucleatum treated with ICG@Uio-UBI + NIR ([120]Fig. 6). As
   shown in the volcano plots ([121]Fig. 6a), a total of 1893 genes were
   co-expressed in both the control and ICG@Uio-66-UBI + NIR groups.
   Meanwhile, 42 genes were up-regulated and 75 genes were down-regulated
   in F. nucleatum. The expression levels of DEGs were analyzed using
   hierarchical clustering, and robust within-group repeatability was
   observed. However, there was a significant difference in the expression
   levels of these genes between the ICG@Uio-66-UBI + NIR group and the
   control group ([122]Fig. 6b).

Fig. 6.

   [123]Fig. 6
   [124]Open in a new tab

   RNA-seq analysis of F. nucleatum treated with ICG@Uio-66-UBI+NIR. (a)
   Volcano plots from RNA-seq analysis depicting differentially expressed
   genes between the Control and ICG@Uio-66-UBI+NIR groups. (b) Heatmap
   illustrating the differential expression of genes associated with
   bacterial biofilm formation. (c, d) KEGG pathways enrichment analysis
   of downregulated genes. (e) RT-qPCR analysis of the relative mRNA level
   of virulence factor genes in F. nucleatum biofilms. (f) ICG@Uio-66-UBI
   inhibits secretion of AI-2 signaling molecule by F. nucleatum.
   n = 5,∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001, ns, not
   significant.

   Subsequently, KEGG and GO functional enrichment analysis was performed.
   As depicted in [125]Fig. S6, during GO enrichment analysis, the
   functions of genes and proteins are typically categorized into three
   modules: molecular function, biological process, and cellular
   component. In this study, GO analysis revealed the significant
   enrichment of DEGs in amino acid metabolic processes, energy metabolism
   activities, biosynthetic process, and fatty acid metabolism. The amino
   acid metabolic activities included “nicotinamide nucleotide metabolic”
   and “nicotinamide nucleotide biosynthetic” processes. Meanwhile,
   “conversion from NAD to NADP” and “ATP-dependent activity” were related
   to energy metabolism. Simultaneously, we noted that the GO terms “DNA
   primase activity” and “transcription regulator activity” were also
   significantly altered, indicating that ICG@Uio-66-UBI + NIR treatment
   disrupts protein synthesis-associated processes ([126]Fig. S8a and b).
   KEGG pathway analysis was further performed to determine the
   antibacterial mechanisms underlying ICG@Uio-66-UBI, and the enrichment
   of 18 pathways was identified. As illustrated in [127]Fig. 6c and d, QS
   pathways were significantly enriched in the KEGG enrichment analyses
   and were downregulated by ICG@Uio-66-UBI + NIR treatment. The LuxS/AI-2
   QS system is a regulatory mechanism present in both Gram-negative and
   Gram-positive bacteria, with a particularly strong association with
   periodontal pathogens [[128]43]. During bacterial proliferation, the
   LuxS protease facilitates the upregulation of autoinducer AI-2
   synthesis, thereby modulating the formation of bacterial biofilms. As
   depicted in [129]Fig. 6e, the gene expression of LuxS decreased to
   21.6% in the ICG@Uio-66-UBI + NIR group. Meanwhile, as shown in
   [130]Fig. 6f, ICG@Uio-66-UBI significantly inhibited the production of
   AI-2 signaling molecules in F. nucleatum, and this inhibition increased
   as time extends. These findings demonstrated that the antibacterial
   effects of ICG@Uio-66-UBI are likely mediated by its interference with
   LuxS gene expression in the QS system of F. nucleatum. This reduces
   AI-2 secretion and attenuates bacterial virulence to inhibit biofilm
   formation. These result is consistent with those reported by Jang
   [[131]44].

   To further validate the role of the AI-2 signaling molecule, F.
   nucleatum AI-2 and its inhibitor, D-galactose were employed to
   investigate formation of F. nucleatum, P. gingivalis, and S. gordonii
   biofilms, utilizing crystal violet staining and confocal microscopy for
   assessment. As previously reported, semi-purified F. nucleatum AI-2
   triggered biofilm formation in periodontopathogens [[132]44],
   Consistent with this, the addition of purified F. nucleatum AI-2
   significantly increased biofilm production (p < 0.05) ([133]Fig. S10a,
   S11a and S12a). Conversely, the addition of D-galactose at varying
   concentrations (20 mM, 100 mM, and 200 mM) gradually reduced biofilm
   biomass in all three species, as quantified by crystal violet staining.
   Notably for P. gingivalis and S. gordonii, while D-galactose did not
   significantly suppress AI-2 activity at a concentration of 20 mM,
   biofilm formation was markedly inhibited by D-galactose at a
   concentration of 200 mM compared with the 20 mM groups (p < 0.01).
   Biofilm formation was also visualized through confocal imaging
   analysis. Compared with the control group, there was a notably elevated
   proportion of live bacteria following the treatment with ICG@Uio-66-UBI
   in the presence of F. nucleatum AI-2. Nevertheless, D-galactose
   significantly increased the proportion of dead bacteria within the
   biofilm of F. nucleatum, P. gingivalis, and S. gordonii when cultured
   with F. nucleatum AI-2 ([134]Fig. S10c, S11c and S12c). These results
   indicate that F. nucleatum AI-2, regulated by LuxS, is a key signaling
   molecule affecting the formation of periodontium plaque biofilm. Since
   QS promotes biofilm formation, it can be considered a potential target
   against bacterial infection. Additionally, above results also
   highlighted that ICG@Uio-66-UBI can effectively inhibit biofilm
   formation by targeting the QS system.

3.6. ICG@Uio-66-UBI modulates the LuxS/AI-2 quorum sensing pathway

   Studies have shown that as bacterial population density increases, the
   QS system upregulates AI-2 secretion via LuxS protease, enhancing the
   expression of genes related to bacterial adhesion and virulence
   factors, thereby promoting biofilm formation [[135]45]. Key virulence
   factors of F. nucleatum, such as adhesins RadD and FadA, play critical
   roles in epithelial cell adhesion and invasion [[136]46]. Additionally,
   virulence factors like heat-modified protein (FomA) and
   fatty-acid-binding protein 2 (Fap2) are closely associated with plaque
   biofilm formation [[137]47]. To further explore the impact of the
   LuxS/AI-2 system on bacterial virulence, qRT-PCR was performed to
   validate the expression of virulence-associated DEGs (RadD, FadA, FomA,
   Fap2). The results revealed significant downregulation of RadD, FadA,
   FomA, and Fap2 (p < 0.01) in the ICG@Uio-66-UBI + NIR group ([138]Fig.
   6e).

   Similarly, P. gingivalis, detected in 85.75% of subgingival plaques
   from chronic periodontitis patients, relies on virulence factors for
   microbial coaggregation, biofilm formation, and homeostasis
   [[139]47,[140]48]. In this study, the expression of haemagglutinins
   (HagA, HagB) and virulence factor genes (RgpA, RgpB, Kgp) in P.
   gingivalis was evaluated after treatment with ICG@Uio-66-UBI NPs. As
   shown in [141]Fig. S8a, the mRNA levels of RgpA, RgpB, HagA, HagB, and
   Kgp decreased significantly (p < 0.05) in the ICG@Uio-66-UBI + NIR
   group compared to the control. Notably, these virulence factors
   exhibited lower sensitivity to ICG@Uio-66-UBI alone than to
   ICG@Uio-66-UBI + NIR. Additionally, the secretion of AI-2 by P.
   gingivalis followed a similar trend to that of F. nucleatum ([142]Fig.
   S8c).

   These findings suggest that the combination of antimicrobial peptides
   and aPDT effectively inhibits plaque biofilm formation [[143]49]. This
   is attributed to the neutralization of P. gingivalis surface LPS by
   UBI29-41 and the penetration of ROS generated via aPDT through the
   bacterial outer membrane/cell wall, damaging DNA encoding virulence and
   adhesion factors [[144]50]. Collectively, these results demonstrate
   that ICG@Uio-66-UBI disrupts the LuxS/AI-2 system, modulates related
   gene expression, and inhibits periodontal plaque biofilm formation.

3.7. Immunomodulatory characteristics of ICG@Uio-66-UBI NPs

   The LPS produced by Porphyromonas gingivalis activates monocytes,
   macrophages, and other immune cells, triggering the release of
   pro-inflammatory cytokines such as IL-6, IL-1β, IL-8, TNF-α, and COX-2.
   These cytokines play pivotal roles in periodontal inflammation by
   inducing B-cell apoptosis and amplifying inflammatory cascades through
   mutual positive regulation [[145][51], [146][52], [147][53],
   [148][54]]. To evaluate the anti-inflammatory potential of our
   nanoplatform, RAW264.7 cells were stimulated with LPS for 6 h and
   treated with various nanoparticles (NPs) with or without 808-nm
   near-infrared (NIR) irradiation (1 W/cm^2, 10 min). Notably, LPS
   stimulation significantly upregulated the expression of IL-6, IL-1β,
   IL-8, iNOS, COX-2, and TNF-α in the inflammatory control group
   (ICG@Uio-66 group), but this effect was markedly attenuated in the
   ICG@Uio-66 + NIR group ([149]Fig. 7b). This suppression can be
   attributed to the ability of aPDT to eliminate periodontal pathogens
   and inhibit the release of virulence factors, thereby reducing
   pro-inflammatory cytokine production—a finding consistent with previous
   reports demonstrating aPDT-mediated inactivation of TNF-α and IL-1β
   [[150]55]. Furthermore, treatment with ICG@Uio-66-UBI significantly
   downregulated the expression of these inflammatory factors (p < 0.05),
   likely due to the electrostatic interaction between the cationic
   UBI29-41 peptide and anionic LPS, which mitigates LPS-induced
   macrophage activation [[151]56,[152]57].

Fig. 7.

   [153]Fig. 7
   [154]Open in a new tab

   ICG@Uio-66-UBI NPs exhibit inhibitory effects on bacterial-induced
   macrophage inflammatory response in vitro. (a) The diagram illustration
   of procedure for establishing an in vitro inflammation model. (b)
   qRT-PCR analysis of the relative mRNA level of pro-inflammatory
   cytokines including IL-1β, IL-6, IL-8, TNF-α, iNOS and COX-2 in a
   treatment model. (c) Immunofluorescence staining of IL-6, TNF-α and
   iNOS in a treatment model and (d) corresponding analysis of positive
   cells expression. (e) Immunofluorescence staining was performed to
   detect alterations in NF-κB/p65 protein levels in Raw 264.7 cells and
   images collected by CLSM. (f) Western Blot of TLR4, NF-κB/p65 and IκBα,
   β-actin and GADPH was used as internal control. (g) Schematic
   representation of the potential mechanis by which ICG@Uio-66-UBI NPs
   inhibit inflammation. Scale bar: 50 μm. n = 5, ∗p < 0.05, ∗∗p < 0.01,
   ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001, ns, not significant.

   In this study, the ICG@Uio-66-UBI + NIR group exhibited the highest
   inhibition of IL-6, IL-1β, IL-8, iNOS, COX-2, and TNF-α gene
   expression. In order to further validate these findings, cell-based
   immunofluorescence experiments were conducted and the protein
   expression of inflammatory factors was observed across different
   experimental groups. Immunofluorescence analysis ([155]Fig. 7c, d &
   S13) revealed the robust protein expression of IL-6, TNF-α, and iNOS in
   the ICG@Uio-66 group (inflammation group). However, the fluorescence
   signal for these inflammatory factors was attenuated upon treatment
   with ICG@Uio-66-UBI combined with 808nm NIR irradiation. This indicated
   that the expression of these proteins was downregulated in the
   ICG@Uio-66-UBI + NIR group, reaching levels comparable to those in the
   control group. This finding corroborated that the concurrent
   application of the antimicrobial peptide UBI29-41 with aPDT could
   effectively and synergistically impede the release of inflammatory
   factors for periodontitis treatment. Subsequently, an
   immunofluorescence assay was employed to determine the inhibition of
   the NF-κB pathway by ICG@Uio-66-UBI treatment and thereby assess immune
   response regulation. As shown in [156]Fig. 7e and S14, the ICG@Uio-66
   group displayed robust green fluorescence in the NF-κB/p65 subunit
   nuclear translocation assay. In contrast, the treatment groups
   (ICG@Uio-66-UBI, ICG@Uio-66 + NIR, and ICG@Uio-66-UBI + NIR) exhibited
   significantly fewer positive cells than the inflammation group
   (p < 0.001). The findings suggested that the aPDT/UBI29-41 nanoplatform
   could effectively inhibit the translocation of the NF-κB/p65 subunit,
   leading to the suppression of NF-κB activation and a subsequent
   reduction in the release of downstream inflammatory factors regulated
   by NF-κB.

   LPS, a pathogen-associated molecular pattern (PAMP), activates TLR4 and
   initiates the TLR4-NF-κB signaling pathway [[157]58]. UBI29-41
   specifically targets the core oligosaccharide and phosphate groups of
   LPS, disrupting its structural integrity and preventing the formation
   of the LPS-LBP-TLR4 trimer [[158]59]. This inhibition blocks NF-κB
   phosphorylation and subsequent pathway activation ([159]Fig. 7g).
   Time-course experiments revealed that LPS-induced phosphorylation of
   IκBα and NF-κB/p65 peaked at 15–30 min but was significantly suppressed
   by ICG@Uio-66-UBI + NIR treatment at 60–90 min (p < 0.005) ([160]Fig.
   7f). TLR4 expression followed a similar pattern, further confirming
   that ICG@Uio-66-UBI inhibits NF-κB signaling by suppressing IκB
   phosphorylation and preventing NF-κB/Rel complex nuclear translocation,
   particularly during later stages. Collectively, these results
   demonstrate that ICG@Uio-66-UBI, under NIR irradiation, effectively
   inhibits the NF-κB pathway and reduces inflammatory cytokine release,
   offering a promising strategy for controlling periodontal inflammation.

3.8. In vivo therapeutic performance of ICG@Uio-66-UBI for treating
periodontal inflammation

   To evaluate the antibiofilm and anti-inflammatory efficacy of
   ICG@Uio-66-UBI, we established a rat model of P. gingivalis-induced
   periodontitis ([161]Fig. 8a). Bacterial suspensions were injected into
   the gingival tissue of rat lower incisors for 14 days to induce
   inflammation, followed by treatment with various nanocomposites and
   808nm NIR irradiation for 3 consecutive days. The treatment effects
   were visually assessed based on enlarged facial and intraoral
   photographs of the rats. As shown in [162]Fig. 8e, the gingival tissue
   was dark red and the presence of swelling was apparent in the
   inflammatory control group. This indicated the presence of severe
   localized periodontal inflammation. Compared to the inflammatory
   control group, the ICG@Uio-66-UBI and ICG@Uio-66+NIR groups exhibited a
   slight alleviation of gingival inflammation. Meanwhile, the
   ICG@Uio-66-UBI + NIR group showed a significant improvement in the
   gingival status, with the gingiva almost appearing normal. As depicted
   in [163]Fig. 8f, after treatment with different NPs, the CFU counts all
   showed varying degrees of reduction in different groups when compared
   with the inflammatory control group. The aforementioned results implied
   a potential correlation between the mitigation of local inflammation
   and the antimicrobial activity of the ICG@Uio-66-UBI nanoplatform.
   Previous studies have demonstrated that UBI29-41 exhibits potent
   anti-inflammatory effects, thereby promoting wound healing by
   specifically targeting periodontal pathogens and effectively reducing
   the bacterial load [[164]60]. Recently, accumulating evidence has also
   demonstrated that aPDT can also regulate the development of
   inflammation. Hsing-Wen Sung and colleagues discovered that aPDT can
   decrease the production of nitric oxide and other byproducts from
   active macrophages, thereby mitigating the inflammatory response and
   minimizing damage to local tissues [[165]61]. Therefore, CAMPs may
   promote the effects of aPDT by targeting pathogenic bacteria to
   alleviate inflammation, thus achieving rapid and effective treatment.

Fig. 8.

   [166]Fig. 8
   [167]Open in a new tab

   Anti-bacterial and anti-inflammatory capacity of
   ICG@Uio-66-UBI-mediated aPDT in vivo. (a) Schematic illustration of
   experimental schedule. (b,c) The in vivo fluorescence imaging of ROS
   level at the infection site following treatment with various
   nanoparticles. (d) The quantification for local ROS level by
   calculating mean fluorescence intensity ratio. (e) Intraoral photos and
   colonies of bacteria isolated from gingival tissues were cultured on
   agar plates. (f) Corresponding statistical data for antibiofilm
   efficiency. n = 5,∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001,
   ns, not significant.

   To validate the production of ROS by the nanoplatform upon NIR
   irradiation in vivo, we conducted live imaging experiments in mice. As
   shown in [168]Fig. 8b, the inflammatory control group and ICG@Uio-66
   group (no NIR irradiation) exhibited significantly elevated
   fluorescence intensities, which were attributed to the excessive
   production of ROS due to localized periodontal inflammation caused by
   bacteria infection. Meanwhile, the attenuated fluorescence intensity in
   the ICG@Uio-66 + NIR group could be attributed to the rapid
   bactericidal effect of aPDT. However, the anti-inflammatory effect was
   suboptimal in this group since the generation of ROS following aPDT
   treatment did not have any other inherent anti-inflammatory components.
   In contrast, the fluorescence intensity was markedly reduced in the
   ICG@Uio-66-UBI + NIR group due to the multimodal therapeutic effect of
   aPDT/UBI29-41. In this group, the level of ROS was equivalent to that
   of the control group. Quantitative analysis ([169]Fig. 8,c d) provided
   statistical evidence supporting the aforementioned graphical findings.

   Then, an in vivo study was conducted to further corroborate the
   efficacy of intervention with ICG@Uio-66-UBI NPs with respect to
   immunoregulation ([170]Fig. 9). The amount of inflammatory cells in
   gingival tissues was analyzed through H&E staining. [171]Fig. 9a shows
   that the inflammatory control group and ICG@Uio-66 group exhibited a
   substantial infiltration of inflammatory cells in the gingival tissue
   and a significant reduction in fibroblast density. However, the
   ICG@Uio-66-UBI (no irradiation) and ICG@Uio-66 + NIR groups exhibited a
   remarkable reduction in inflammatory cells. Notably, the gingival
   tissue in the ICG@Uio-66-UBI + NIR irradiation group exhibited a
   resemblance to healthy tissue. This demonstrated the significant
   inhibitory effect of combined aPDT and antimicrobial peptide treatment
   on local inflammation. The statistical analysis of the number of
   inflammatory cells is presented in [172]Fig. 9d and reaffirms the
   aforementioned findings.

Fig. 9.

   [173]Fig. 9
   [174]Open in a new tab

   Evaluations of the anti-inflammatory efficacy following different NPs
   treatments under 808 nm NIR irradiation in vivo. (a) Images of H&E
   staining and (d) The statistical analysis of immune cell counts at the
   inflammatory site in gingival tissue. (b) Images of Masson staining and
   (e) The statistical analysis of collagen degradation in gingival
   tissue. (c) IHC staining images of gingival tissues including IL-6 and
   TNF-α. (f,g) Quantitation of IL-6, TNF-α levels in IHC staining
   samples. n = 5, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001,
   ns, not significant.

   Collagen integrity, a critical indicator of periodontal health, was
   evaluated using Masson's trichrome staining ([175]Fig. 9b,e). In the
   blank control group, collagen fibrils appeared densely packed and
   well-organized, as indicated by intense blue staining. In contrast, the
   inflammatory control and ICG@Uio-66 (no NIR) groups exhibited
   significant collagen degradation, reflecting advanced periodontal
   damage. Treatment with ICG@Uio-66-UBI or ICG@Uio-66+NIR markedly
   reduced collagen dissolution, with the ICG@Uio-66-UBI+NIR group showing
   the most pronounced preservation of collagen structure. Type I
   collagen, the primary component of periodontal ligaments, is a key
   biomarker of periodontal disease progression [[176]62].
   Pathogen-associated molecular patterns (PAMPs) trigger inflammatory
   responses, upregulating matrix metalloproteinases (MMPs) in fibroblasts
   and epithelial cells, which degrade collagen fibers [[177]63]. However,
   the ROS generated by aPDT not only enhance collagen maturation but also
   inhibit osteoclast formation, counteracting tissue destruction
   [[178]64]. The targeted delivery of ROS by UBI29-41 further amplifies
   these effects, localizing therapeutic action to pathogenic bacteria and
   minimizing collateral tissue damage. These findings underscore the dual
   role of ICG@Uio-66-UBI in preserving collagen integrity and mitigating
   inflammation, highlighting its potential to disrupt the vicious cycle
   of infection and tissue degradation.

   Pro-inflammatory cytokines, particularly IL-6 and TNF-α, play pivotal
   roles in periodontal pathogenesis. Gingipains and fimbriae from
   Porphyromonas gingivalis upregulate IL-1β, IL-8, IL-6, and TNF-α,
   exacerbating tissue destruction [[179]65]. IL-6 promotes collagen
   degradation, osteoclast activation, and bone resorption, while TNF-α
   amplifies inflammation by stimulating IL-1 and IL-6 production, further
   enhancing MMP activity and inhibiting collagen synthesis [[180]66].
   Immunohistochemical staining revealed strong expression of IL-6 and
   TNF-α in the inflammatory control and ICG@Uio-66 (no NIR) groups, as
   indicated by brownish-yellow staining ([181]Fig. 9c,f ＆g). In contrast,
   the ICG@Uio-66-UBI + NIR group exhibited minimal immunostaining
   (p < 0.01), confirming the nanoplatform's ability to suppress
   pro-inflammatory cytokine production. This reduction in IL-6 and TNF-α
   levels correlates with decreased collagen degradation and inflammation,
   demonstrating the therapeutic efficacy of ICG@Uio-66-UBI.

4. Conclusions

   This study developed ICG@Uio-66-UBI, a NIR light-responsive
   nanoplatform for precision treatment of periodontal infections. The
   UBI29-41-modified system enhances targeted ICG delivery to pathogens
   and synergizes with photodynamic therapy (PDT) to achieve dual
   antimicrobial and anti-inflammatory effects. UBI29-41 binds selectively
   to LPS and LTA on bacterial surfaces, amplifying localized singlet
   oxygen (^1O[2]) production under NIR irradiation to disrupt biofilms
   and inhibit plaque formation. Simultaneously, the platform suppresses
   LPS-TLR4 interactions and NF-κB activation, reducing inflammation and
   tissue damage. In vivo studies confirmed its therapeutic potential,
   showing reduced inflammatory cell infiltration, inhibited collagen
   degradation, and downregulated inflammatory mediators. Transcriptome
   analysis revealed downregulation of biofilm-related genes and the
   LuxS/AI-2 QS pathway, providing mechanistic insights.

   In summary, ICG@Uio-66-UBI offers a novel, dual-action strategy for
   periodontitis treatment, combining biofilm inhibition with inflammation
   control, and holds significant clinical promise.

CRediT authorship contribution statement

   Wen Li: Writing – original draft, Funding acquisition, Data curation.
   Fengqun You: Formal analysis. Jie Yang: Methodology, Investigation.
   Deao Gu: Supervision, Formal analysis. Yuyang Li: Supervision, Project
   administration. Xuan Zhang: Visualization, Project administration.
   Leiying Miao: Visualization, Funding acquisition. Weibin Sun:
   Conceptualization.

Declarations ethics approval and consent to participate

   Animal experiments was approved by the Ethical Review Board at Nanjing
   University (No. #IACUC-D2304013). Human clinical experiments was
   approved by the Ethical Review Board at Nanjing University
   (No.NJSH-202023NL-43). All respondents were informed comprehensively
   and provided written informed consent.

Data availability

   The data are available from the corresponding author on reasonable
   request.

Funding

   This work was supported by the Natural Science Foundation of Jiangsu
   under Grant (No.BK20221177), “2015” Cultivation Program for Reserve
   Talents for Academic Leaders of Nanjing Stomatological School Medical
   School of Nanjing Univeristy (No.0223A203), Postgraduate Research &
   Practice Innovation Program of Jiangsu Province (SJCX▁240009), the Key
   Project supported by Medical Science and Technology Development
   Foundation, Nanjing Department of Healthunder Grant (No.ZKX24056), the
   General Project supported by Medical Science and Technology Development
   Foundation, Nanjing Department of Healthunder Grant
   (No.YKK23183,YKK24198), High-Level Hospital Construction Project of
   Naniing Stomatological Hospital, Affiliated Hospital of Medical School,
   Institute of Stomatology, Nanjing University (No.0224C051, 0224C020,
   0224C006).

Declaration of competing interest

   The authors declare that they have no known competing financial
   interests or personal relationships that could have appeared to
   influence the work reported in this paper.

Acknowledgments