Protease-Loaded CuS Nanoparticles with Synergistic Photothermal/Dynamic Therapy against F. nucleatum-Induced Periodontitis

Abstract

Periodontitis is a chronic inflammatory disease induced by a plaque biofilm, which can lead to the destruction of the periodontal support tissue and even teeth loss. The common strategies of periodontitis treatment are to eliminate bacterial/ biofilm-related inflammation and subsequently inhibit alveolar bone resorption, for which antibiotic therapy is the most traditional one. However, impenetrable polymeric substances on bacterial biofilms make it difficult for traditional antimicrobial agents to take effect. In this study, a novel nanoparticle protease-loaded CuS NPs was developed, combining the advances of photodynamic and photothermal therapy from CuS and enzymatic degradation of the biofilm by a protease. The photothermal activity and the reactive oxygen generation capacity of the designed nanoparticles were verified by the experimental results, constituting the basis of antibacterial function. Next, the high antimicrobial activity of CuS@A NPs on Fusobacterium nucleatumand its biofilm was demonstrated. The proper hemo/cytocompatibility of CuS-based NPs was demonstrated by in vitro assays. Last, effective treatment against periodontitis was achieved in a rat periodontitis model through the significant efficacy of inhibiting bone resorption and alleviating inflammation. Thus, the developed CuS@A NPs prove a promising material for the management of periodontitis.

Sulfated Chitosan-Modified CuS Nanocluster: A Versatile Nanoformulation for Simultaneous Antibacterial and Bone Regenerative Therapy in Periodontitis

“…For instance, in the 250 μg/mL and 300 μg/mL CuS@MSN-SCS groups, the inhibition ratio exceeded 95% (Figure B), highlighting the antibacterial efficacy of CuS@MSN-SCS. Since plaque biofilm is the primary cause of periodontitis, the antibiofilm potential of the samples was further evaluated through crystal violet staining, where higher violet color intensity indicates greater biofilm biomass . Consistent with the colony count results, the control group and the 50 μg/mL CuS@MSN-SCS group exhibited a deep purple color (Figure A, middle row).…”

“…A ligature silk was placed around the maxillary second molar of the rats to induce inflammation, subsequently feeding them a high-sugar diet for 14 days . Afterward, CuS@MSN-SCS was locally applied for treatment 10 times, while minocycline (MiNo), a widely used antibiotic in clinical practice, served as the positive control group to compare therapeutic effects. As depicted in Figure B, in comparison to the blank group, the periodontitis group displayed significant bone loss, confirming the successful establishment of the periodontitis model.…”

“…Periodontitis, as a prevalent chronic inflammatory disease worldwide, is characterized by bacterial infection and progressive destruction of periodontium, including the alveolar bone, gingiva, periodontal ligament, and root cementum. − Bacteria directly contribute to the onset and progression of periodontitis by forming a subgingival microbiota, which later transforms into subgingival plaque biofilm. , The subgingival plaque biofilms induce an exaggerated proinflammatory immune reaction in the gingival connective tissue, resulting in paracrine signaling that leads to alveolar bone resorption . Progressive loss of alveolar bone can eventually result in tooth looseness and dental loss, significantly impacting the quality of patient’s life and imposing a substantial social and economic burden. − This indicates that control of bacteria biofilm and alveolar bone regeneration is crucial for the treatment of periodontitis.…”

“…Currently, clinical therapeutic strategies for periodontitis mainly consist of initial cause-related therapy, such as home care review, scaling and root planing, as well as regenerative periodontal surgery, including guided tissue regeneration and bone grafts . Despite significant achievements, the effectiveness of these strategies in clearing bacteria is often limited due to the abundance of bacteria present in inflamed gingiva and deep periodontal pockets. ,, Moreover, bone regeneration outcomes are variable and unpredictable, frequently lacking sufficient angiogenesis . For instance, scaling and root planing is unable to completely eradicate bacteria, leading to protracted periodontal inflammation. ,, Although antibiotics can be employed as adjunctive therapy to enhance bacterial clearance, they can induce bacterial drug resistance and disrupt the balance of oral microbial communities, resulting in unintended systemic side effects. , Furthermore, regenerative periodontal surgery commonly results in undesired angiogenesis for insufficient bone regeneration and no improvement in tooth stability.…”

“…Despite significant achievements, the effectiveness of these strategies in clearing bacteria is often limited due to the abundance of bacteria present in inflamed gingiva and deep periodontal pockets. ,, Moreover, bone regeneration outcomes are variable and unpredictable, frequently lacking sufficient angiogenesis . For instance, scaling and root planing is unable to completely eradicate bacteria, leading to protracted periodontal inflammation. ,, Although antibiotics can be employed as adjunctive therapy to enhance bacterial clearance, they can induce bacterial drug resistance and disrupt the balance of oral microbial communities, resulting in unintended systemic side effects. , Furthermore, regenerative periodontal surgery commonly results in undesired angiogenesis for insufficient bone regeneration and no improvement in tooth stability. As a consequence, developing a strategy that effectively clears bacteria, particularly in deep periodontal pockets and inflamed gingiva, while promoting angiogenesis for enhanced bone regeneration is fundamental for improving the clinical efficacy of periodontitis treatment.…”