Near-Infrared Light-Triggered Nitric-Oxide-Enhanced Photodynamic Therapy and Low-Temperature Photothermal Therapy for Biofilm Elimination

A remotely controlled nanotherapeutic with immunomodulatory property for MRSA-induced bone infection

Osteomyelitis is a deep bone tissue infection caused by pathogenic microorganisms, with the primary pathogen being methicillin-resistant Staphylococcus aureus (MRSA). Due to the tendency of the infection site to form biofilms that shield drugs and immune cells to kill bacteria, combined with the severe local inflammatory response causing bone tissue destruction, the treatment of osteomyelitis poses a significant challenge. Herein, we developed a remotely controlled nanotherapeutic (TLBA) with immunomodulatory to treat MRSA-induced osteomyelitis. TLBA, combined with baicalin and gold nanorods, is positively charged to actively target and penetrate biofilms. Near-infrared light (808 nm) triggers spatiotemporal, controllable drug release, while bacteria are eliminated through synergistic interaction of non-antibiotic drugs and photothermal therapy, enhancing bactericidal efficiency and minimizing drug resistance. TLBA eliminated nearly 100 % of planktonic bacteria and dispersed 90 % of biofilms under NIR light stimulation. In MRSA-induced osteomyelitis rat models, laser irradiation raised the infection site temperature to 50 °C, effectively eradicating bacteria, promoting M2 macrophage transformation, inhibiting bone inflammation, curbing bone destruction, and fostering bone tissue repair. In summary, TLBA proposes a more comprehensive treatment strategy for the two characteristic pathological changes of bacterial infection and bone tissue damage in osteomyelitis.

D-Alanine functionalized Iridium(III) complexes as two-photon photo-antibiotics for bacteria-specific ablation in infected macrophages

The prevalence of bacterial resistance, driven by extensive antibiotic overuse, significantly threatens patient safety. Consequently, it is urgent and helpful for the clinician to develop new antibacterial therapy techniques. In this study, we designed a novel photodynamic antibacterial therapeutic strategy by functionalizing D-alanine on Iridium(III) complexes. The synergistic D-alanine metabolic labeling function and two-photon photodynamic eradication capacity of Ir(III) complexes enable bacterial imaging and elimination of bacterial pathogens within host cells. These two-photon photoantibiotics effectively inhibit bacterial biofilm formation and efficiently eliminate intracellular bacterial infections in macrophages, enabling real-time dynamic monitoring of antimicrobial efficacy. Furthermore, both in vitro and in vivo experiments demonstrated superior antibacterial performance compared to conventional antibiotics alone.

Vacancies-rich Z-scheme VdW heterojunction as H2S-sensitized synergistic therapeutic nanoplatform against refractory biofilm infections

Encapsulated in a self-produced negatively charged extracellular polymeric substance (EPS) matrix, the wound infected bacterial biofilms exhibit formidable resistance to conventional positively charged antibiotics and host's immune responses, which can undoubtedly lead to persistent infections and lethal complications. Nevertheless, developing efficacious strategies to root out stubborn biofilm and promote tissue regeneration still remains a challenge. To resolve this dilemma, a versatile vacancies-rich Z-scheme MoSSe Van der Waals heterojunction (MoSSe VdW HJ) is rationally fabricated as nanoplatform for hydrogen sulfide (H2S)-sensitized synergistic therapy of wound bacterial biofilm infection. The rich anion vacancies and Z-scheme heterostructure make the fabricated MoSSe VdW HJ can effectively augment H2S, localized hyperthermia, and reactive oxygen species production under the stimulation of biofilm microenvironments (BME) and irradiation of 808 nm near-infrared (NIR) light. Therefore, MoSSe VdW HJ is capable to integrate H2S gas, chemodynamic, photothermal, and photodynamic therapies to effectively destroy eDNA and polysaccharides in the EPS matrix, thereby breaching the biofilm barrier to eradicate bacteria and facilitate wound healing. The synergistic strategy exhibits superior anti-biofilm and wound repair effects both in vivo and in vitro, thus providing guideline for the development of BME and NIR light activated synergistic therapeutics to fight against refractory biofilm infections.

Mucus-penetrating nanomotor system strengthens mucosal immune response to in situ bacterial vaccine against severe bacterial pneumonia

Pathogens causing major infectious diseases primarily invade through mucosal tissues. Promptly killing these pathogens at the mucosal site and constructing mucosal vaccines in situ can prevent further infections and induce robust mucosal immune responses and memory to prevent reinfection. In this study, we utilized chemotherapy, sonodynamic therapy, and gas therapy to eliminate Streptococcus pneumoniae (S. pneumoniae) colonizing the nasal mucosa. Simultaneously, an in situ pneumococcal vaccine was constructed to elicit specific immune responses and memory. Poly-l-arginine (PArg)-modified ZIF-8 metal-organic frameworks (MOFs) loaded with the ultrasonic sensitizer protoporphyrin IX (PpIX) killed S. pneumoniae in the nasal cavity by multiple mechanisms in the presence of ultrasound. When stimulated by ultrasound, PpIX not only generates reactive oxygen species (ROS) for antimicrobial effect, but these ROS also catalyze the release of nitric oxide (NO) from PArg. NO exerts a motor-like effect that facilitates more efficient passage of nanoparticles through the mucus layer of the alveoli. The immunogenic bacterial debris formed a vaccine formulation by complexing with PArg, which adhered electrostatically to the mucosal surface, facilitating in situ vaccination and inducing mucosal immune responses and memory. This cascade-based combination therapy enabled rapid bacterial eradication and long-term immune prevention. It shortens the traditional vaccine development process, eliminates the spatial distance from pathogen invasion to vaccine development, significantly cuts costs, and addresses vaccine failure due to pathogen mutations. This approach offers a groundbreaking strategy for mucosal vaccine development and the prevention of major infectious diseases.

A multifunctional trap-capture-kill antibacterial system for enhanced wound healing via modified decellularized mushroom aerogels

Wound infections are prevalent and can result in prolonged healing times. In this study, we referred to the "trap-capture-kill" antibacterial strategy to create a wound dressing (DS/PDA@GO-L) by coupling graphene oxide (GO) with lysine and coating it onto the decellularized mushroom stem (DS) using polydopamine (PDA). The mechanism of action of the bacteria-killing process involves lysine chemotaxis and the siphoning effect of DS aerogel, with the process of killing the bacteria being initiated via near-infrared photothermal treatment. In vitro studies demonstrated that DS/PDA@GO-L exhibited excellent blood and cell compatibility, while in vivo experiments revealed its remarkable efficacy in combating bacterial infections. Specifically, the combination of DS/PDA@GO-L with photothermal therapy led to the elimination of over 95 % of S. aureus, E. coli, and Pseudomonas aeruginosa. Furthermore, the aerogel, when used in conjunction with photothermal therapy, significantly reduced bacterial infection at the wound site and accelerated wound healing. During the wound's proliferative phase, it notably enhanced vascularization and extracellular matrix deposition. Furthermore, immunohistochemical staining revealed that bacterial clearance led to a reduction in pro-inflammatory responses and a decrease in the expression of pro-inflammatory cytokines, thereby restoring the wound's inflammatory environment to a pro-regenerative state. Taken together, the developed DS/PDA@GO-L holds great potential in the field of infected skin wound healing.

Multifunctional targeted nanosystem based on aggregation-induced emission: Enhanced synergistic mild-photothermal chemotherapy of prostate cancer via downregulation of heat shock protein 70 under NIR-II imaging

Prostate cancer is the second most common malignancy in men, often presents at advanced stages, where treatment options are limited due to surgical intolerance and resistance to androgen deprivation therapy. Mild photothermal therapy (PTT) at 42-49°C selectively eliminates tumors while sparing normal tissues, but its efficacy is reduced by heat shock protein (HSP70) upregulation, which inhibits apoptosis. To address these limitations, we developed 2TToD@NPs, a multifunctional nanosystem combining second near-infrared (NIR-II) fluorescence imaging, mild PTT, and chemotherapy. The nanosystem, comprising an aggregation-induced emission agent (2TT-oC26B) and doxorubicin (DOX), targets prostate cancer cells via folic acid modification. Upon laser irradiation, 2TT-oC26B generates strong NIR-II fluorescence and thermal energy for imaging and mild PTT. Concurrently, DOX enhances tumor sensitivity to PTT by downregulating HSP70, reduces thermal resistance, induces DNA damage, and generates reactive oxygen species, triggering apoptosis. This synergistic approach overcomes the limitations of single-modality therapies. Our findings suggest that the multifunctional nanosystem effectively integrate precise imaging and targeted therapy, offering a promising strategy for advanced prostate cancer diagnosis and treatment.

Coaxially fabricated electrospinning near-infrared light-responsive nanofibrous membranes for combating drug-resistant bacteria

Nowadays, the rapid emergence of drug-resistant bacteria has posed a global threat to the public health, leading to increased cost of environmental hygiene and healthcare treatment, which urges the development of safe and efficient antibacterial strategies. Here, coaxially fabricated electrospun nanofibrous membrane (ENMs) consisted of quercetin (Qu) stabilized selenium nanoparticles (Qu@SeNPs) and electro-synthesized molybdenum disulfide (MoS2) nanosheets were facilely formed as core/shell structure with polyvinyl alcohol (PVA) and α-Lipoic acid (LA) as cross-linker. The obtained ENMs formed by core-shell PVA/MoS2/LA/Qu@SeNPs (PMLQS) showed good air permeability and near-infrared-light photothermal responsiveness to kill bacteria efficiently. Moreover, the obtained ENMs resembling extracellular matrix-like properties showed superior biocompatibility with negligible development toxicity of zebrafish. The antibacterial experiments indicated that the produced PMLQS fibrous membrane exhibited more pronounced bactericidal activity against Gram-positive (G+) Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) as compared to that of Gram-negative (G-) Escherichia coli (E. coli). Furthermore, transcriptomic analysis revealed MRSA inactivation by PMLQS ENMs involved disruption of ion transport, antioxidant system, carbohydrate metabolism and energy metabolism. Notably, the MRSA ADI pathway was also blocked supporting the minimized antibiotic resistance development. Therefore, the constructed near-infrared light-responsive PMLQS nanofibrous membrane held promise in tackling drug-resistant bacteria with enormous environmental and biomedical utilizations.

Cyclodextrin-based self-assembling hydrogel for Photothermal-controlled nitric oxide release in stage-specific treatment of MRSA-induced arthritis

MRSA-induced arthritis is a prevalent and highly debilitating orthopedic condition. The inflammatory response induced by bacterial infection hinders tissue repair and exacerbates bone loss. Traditional antibiotic therapies are limited by low bioavailability, substantial side effects, and narrow efficacy, rendering them inadequate for comprehensive treatment of arthritis. Nitric oxide (NO) has demonstrated considerable potential in overcoming bacterial resistance, modulating immune responses, and facilitating tissue repair. Therefore, a stage-specific NO release strategy, tailored to the distinct phases of bacterial arthritis, is essential for effective treatment. In this study, mesoporous polydopamine nanoparticles were utilized as NO donors (mPDA/NONOate) and encapsulated within a supramolecular hydrogel formed via the host-guest interaction between α-cyclodextrin (α-CD) and Pluronic F127. The injectable nature of the resulting NO/PDA-Gel hydrogel ensured uniform distribution within irregular bone joint infection sites, minimizing NO donor loss and enhancing local bioavailability. Notably, upon near-infrared (NIR) irradiation, the hydrogel induces a rapid increase in local temperature, facilitating rapid NO release. At the same time, the synergistic photothermal effect effectively kills bacteria and rapidly controls the infection. Without light irradiation, NO is sustainably and stably released from the NO/PDA-Gel, modulating the bone immune microenvironment, alleviating inflammation, promoting chondrocyte proliferation and differentiation, and accelerating bone tissue repair, thus significantly shortening the healing time of MRSA-induced arthritis. In conclusion, the injectable self-assembled NO/PDA-Gel offers a precise, stage-matched therapeutic approach for MRSA-induced arthritis and holds promise for the treatment of deep-seated infections caused by other multidrug-resistant pathogens.

Synergistic photothermal and photodynamic therapy to promote bacteria-infected wound healing using ZnO@PDA/Ag-integrated waterborne polyurethane films

Light-induced antibacterial effects aim to overcome the limitations of antibiotic-resistant bacteria and provide an effective solution for wound healing applications. This research focuses on developing a multifunctional wound dressing based on waterborne polyurethane (WPU) adorned with a hybrid photo nano-sensitizer (ZnO@PDA/Ag) that demonstrates near-infrared (NIR)-triggered synergistic photothermal and photodynamic effects. Through a facile synthesis process, zinc oxide (ZnO) nanoparticles were coated with polydopamine (PDA) to enhance biocompatibility, photothermic effect, and charge transfer efficiency due to a surface sensitization and passivation strategy. The synthesis was followed by the in situ reduction and decoration of plasmon silver nanoparticles (Ag NPs) to augment photodynamic activity. The structure, chemical composition, and morphology of the ZnO@PDA/Ag nano-sensitizer were examined and the results confirmed the successful synthesis. Furthermore, based on photo-thermal and fluorescence signal measurements under near-infrared (NIR) irradiation, the ZnO@PDA/Ag nanoparticles in aqueous dispersions exhibit effective light-to-heat conversion, as well as a strong ability for NIR-induced singlet oxygen generation. The WPU films incorporating the ZnO@PDA/Ag nano-sensitizer exhibit complete phototherapy inhibition of both Gram-negative E. coli and Gram-positive S. aureus bacteria. In addition, the films exhibited an appropriate biocompatibility in contact with L929 fibroblast cells. Moreover, in vivo studies in a rat wound model demonstrated accelerated wound healing and tissue regeneration with the application of ZnO@PDA/Ag in WPU nanocomposite film, particularly under NIR light irradiation. Histological analysis confirmed the formation of mature epithelial layers and minimal inflammatory response, indicating the potential of this film for clinical wound management.

Cu2+/Zn2+ "Antimicrobial Chamber" with Self-Enhanced Photothermal Activity Supports Infected Wound Healing

Wound healing of drug-resistant bacterial infection is a major challenge in clinical practice, and existing treatments suffer from the drawbacks of high dosage, low efficiency, and insufficient biosafety. Herein, we coated ultrasmall copper sulfide nanoparticles (CuS NPs) into zeolitic imidazolate framework-8 (ZIF-8) and modified them with polydopamine (PDA) to obtain CuS@ZIF-8@PDA NPs for bacterial infection wound treatment. Due to the presence of CuS and the degradability of ZIF-8, CuS@ZIF-8@PDA NPs can continuously release Cu2+ and Zn2+ in a slightly acidic environment under near-infrared (NIR) irradiation. Furthermore, the introduction of PDA endows it with an excellent photothermal property. The synergistic effect of dual ions/photothermal enables it to effectively eradicate Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Moreover, in vivo experimental results confirm that released Cu2+ and Zn2+ can promote epithelial regeneration, thereby accelerating wound healing. In the bacterially infected mouse model, CuS@ZIF-8@PDA NPs exhibit excellent synergistic antimicrobial and wound healing effects, while having no toxic side effects on major organs. The study of the dual-ion/photothermal synergistic antibacterial strategy based on CuS@ZIF-8@PDA NPs provides a new insight into bacterial infection wound repair.

Microenvironment-responsive recombinant collagen XVII-based composite microneedles for the treatment of androgenetic alopecia

Androgenetic alopecia (AGA) is the most prevalent form of hair loss worldwide. Growth factors have been used to treat hair loss, but their intradermal delivery remains challenging. Type XVII collagen (COL17) has been reported to regulate the aging process of hair follicles (HFs). We reason that combining the therapeutic efficacy of growth factors and collagen biomaterials will provide maximal hair regeneration. Here, we design a microenvironment-responsive recombinant human COL17 microneedle (MRrhCOL17 MN) system for the transdermal delivery of the insulin-like growth factor-1 (IGF-1) to stimulate hair growth. We load IGF-1 into mesoporous polydopamine nanoparticles (MPDAs) to allow for continuous release of the growth factor. When applied to the skin, the composite MNs penetrate the skin, release IGF-1 and rhCOL17 in response to the alteration of the microenvironment and photothermal effect, and stimulate hair growth in a mouse model of AGA. Compared with the clinical drug minoxidil, our MN system more effectively enhances neovascularization, alleviates tissue inflammatory responses, and promotes hair regeneration in AGA mice. These therapeutic effects have been linked to the activation of the VEGF/VEGFR and Src/p38 MAPK signaling pathways. Taken together, the composite MRrhCOL17 MN thereby offers a new option for intractable AGA patients. STATEMENT OF SIGNIFICANCE: Growth factors hold the potential to effectively stimulate the growth of hair follicles; however, their transdermal delivery remains a formidable challenge. In this study, recombinant human type XVII collagen (rhCOL17) is employed as the primary scaffolding material to fabricate microneedles (MNs) for the delivery of insulin-like growth factor 1 (IGF-1), with the aim of promoting hair follicle regeneration. Additionally, the concept of microenvironmental responsiveness is integrated to enable the controlled release of IGF-1 from the MNs. Moreover, the low-temperature photothermal effect of nanoparticles is harnessed to optimize the process of hair regeneration, thereby maximizing the outcome of hair follicle rejuvenation.

Engineered Probiotics with Low Oxygen Targeting Porphyromonas gingivalis and Gingival Fibroblasts for the Treatment of Periodontitis

The overuse of antibiotics has increased the prevalence of drug-resistant bacteria in periodontitis. "Sentinel" gingival fibroblasts, stimulated by pathogenic bacteria, continue to release signaling factors that affect stem cell repair and recruit immune cells, resulting in persistent inflammation in periodontal tissues, eventually leading to the loosening and loss of teeth. Periodontal pathogenic bacteria cause surface hypoxia, and gingival fibroblasts in the inflammatory microenvironment express HIF-1α, promoting hypoxic areas in periodontal pockets. No drug delivery system is available for the hypoxic region of periodontal pockets. We synthesized BI NPs via berberine (BBR) and indocyanine green (ICG) and formed BIP NPs by wrapping BI NPs with polydopamine (PDA), and the BIP NPs were delivered to the hypoxic region of the periodontal pocket by hitchhiking with the anaerobic probiotic Bifidobacterium bifidum (Bif). The BIP NPs released berberin (BBR) under near-infrared (NIR) irradiation, which inhibited the sulfur metabolism of Porphyromonas gingivalis via mild photothermal action and BBR-targeted serine acetyltransferase, resulting in a decrease in resistance to oxidative stress, thus exerting a nonantibiotic bacteriostatic effect. This mild photothermal effect facilitated the uptake of BIP NPs bygingival fibroblasts. Moreover, BBR targeted nuclear factor-erythroid 2-related factor 2 (NRF2) to reduce ferroptosis, and the gingival fibroblast supernatant modulated macrophage polarization through the NF-κB pathway. In the periodontitis rat model, Bif@BIP+NIR treatment carried the drug to deep periodontal pockets, decreasing local gingival ferroptosis and alleviating periodontitis symptoms. To summarize, engineered probiotics target low-oxygen periodontal pockets for drug delivery, P. gingivalis for nonantibiotic bacterial inhibition, and gingival fibroblasts to mitigate ferroptosis, thus alleviating periodontitis to reduce periodontitis.

Nanomedicines as disruptors or inhibitors of biofilms: Opportunities in addressing antimicrobial resistance

The problem of antimicrobial resistance (AMR) has caused global concern due to its great threat to human health. Evidences are emerging for a critical role of biofilms, one of the natural protective mechanisms developed by bacteria during growth, in resisting commonly used clinical antibiotics. Advances in nanomedicines with tunable physicochemical properties and unique anti-biofilm mechanisms provide opportunities for solving AMR risks more effectively. In this review, we summarize the five "A" stages (adhesion, amplification, alienation, aging and allocation) of biofilm formation and mechanisms through which they protect the internal bacteria. Aimed at the characteristics of biofilms, we emphasize the design "THAT" principles (targeting, hacking, adhering and transport) of nanomedicines in their interactions with biofilms and internal bacteria. Furthermore, recent progresses in multimodal antibacterial nanomedicines, including biofilms disruption and bactericidal activity, and the types of currently available antibiofilm nanomedicines contained organic and inorganic nanomedicines are outlined and highlighted their potential applications in the development of preclinical research. Last but not least, we offer a perspective for the effectiveness of nanomedicines designed to address AMR and challenges associated with their clinical translation.

Bioinspired programmed antibiofilm strategies for accelerated wound healing via spatiotemporally controlled enzyme nanoreactors

Biofilms, protected by their dense, self-produced matrix, pose a significant clinical challenge due to their antibiotic resistance, leading to persistent infections and delayed wound healing, particularly in diabetic patients. Tailored to the biofilm life cycle, a double-layered nanoreactor was developed for rapid and complete antibiofilm therapy. The inner layer, cross-linked with poly(allylamine hydrochloride) (PAH)/phosphate, dimeric indocyanine green (dICG), and bromothymol blue (BTB), shields glucose oxidase (GOx) and β-glucanase (β-DEX) from unfavorable environment. The outer layer is coated with bacteria-targeted gold nanozymes (AuNEs). The healing of biofilm-infected diabetic wounds progresses three spatiotemporal stages activated by light irradiation and pH changes. Initially, the photothermal effect of dICG triggers nitric oxide (NO)-mediated biofilm dispersion and lowers the wound pH via a GOx/AuNEs cascade reaction. The resulting acidic environment then induces nanoreactor disassembly, releasing β-DEX to degrade the biofilm matrix and facilitate deeper penetration. Finally, AuNEs specifically recognize and eliminate planktonic bacteria, further disrupting the biofilms and accelerating wound healing by generating reactive oxygen species (ROS) and more toxic reactive nitrogen species (RNS). The wound status can be monitored in real-time using BTB's colorimetric pH analysis for visual feedback on treatment progress. This multifunctional design offers a programmed antibiofilm strategy for dynamic wound management.

Mechanism of selenium-doped black phosphorus nanosheets wrapped with biomimetic tumor cell membrane for prostate cancer immunotherapy

Prostate cancer (PCa) is commonly considered a "cold tumor" due to its immunosuppressive microenvironment. Cold tumors are typically identified by the absence of T-cell infiltration within the tumor, while other immune populations and myeloid cells can be observed in these tumors. To achieve light-heat combined immunotherapy checkpoint inhibitor treatment for castration-resistant prostate cancer, we aimed to transforming "cold tumors" into "hot tumors". We designed and synthesized a two-dimensional material, selenium-doped black phosphorus (BP), to enhance the photothermal conversion efficiency, and formed Se@BPNSs by liquid-phase exfoliation. To address the issue of enhanced permeability and retention effect, and to achieve efficient targeting, we coated the Se@BPNSs with RM-1 cell membrane derived from mouse prostate cancer cells. By injecting a certain dose of Se@BPNSs into the tumor and irradiating with a 808 nm laser, the Se@BPNSs converted light energy into heat to kill tumor cells at high temperatures while releasing antigens captured by dendritic cells. In addition, we combined the immunotherapy checkpoint inhibitor anti-PD1 to enhance the immune response and promote immune cell infiltration. The successful preparation of Se@BPNSs was verified through material characterization, cell-level and animal-level experiments, and the antitumor effect was meanwhile verified, which further provided guidance for prostate cancer treatment by photothermal synergistic immunotherapy.

HSP90 inhibitor-loaded hollow mesoporous nanoparticles for enhanced synergistic mild photothermal/chemotherapy in triple negative breast cancer

The combination of mild-temperature photothermal and chemotherapy represents a promising therapeutic strategy capable of maximizing anti-cancer efficacy while minimizing adverse reactions, particularly when integrated with multi-modal treatments. Nevertheless, the increase in heat shock protein (HSP) expression induced by mild hyperthermia may significantly influence the therapeutic efficacy. In this study, Isoliensinine (Iso) and the heat shock protein 90 (HSP90) inhibitor ganetespib were loaded into MPDA nanoparticles (NPs) to form GI-MPDA@BSA NPs, establishing a multi-modal therapeutic nanoplatform. The synthesized GI-MPDA@BSA NPs exhibit excellent photothermal conversion performance and favorable biocompatibility. Under 808 nm laser irradiation, the mild photothermal therapy (PTT) generated by MPDA facilitates the rapid release of drugs from BSA, resulting in an effective synergistic cytotoxic effect on cancer cells. Concurrently, the released ganetespib suppressed HSP90 expression, thereby potentiating the effects of mild photothermal/chemotherapy. In vitro and in vivo experimental results indicate that GI-MPDA@BSA exhibits low cytotoxicity while conspicuously inhibiting tumor growth under laser irradiation and eliciting an immune response. Furthermore, the application of two-dimensional ultrasound (2D US) and contrast-enhanced ultrasound (CEUS) to monitor post- tumor treatment changes elucidates the evolutionary process following combined mild-temperature photothermal/chemotherapy, presenting a novel strategy for the treatment and monitoring of triple negative breast cancer (TNBC) in clinical practice.

Thiolated chitosan hydrogel combining nitric oxide and silver nanoparticles for the effective treatment of diabetic wound healing

Nitric oxide (NO) has shown significant potential in chronic wound healing due to its ability of promoting blood circulation. However, excessive NO can trigger local inflammatory response, potentially hindering wound healing. Therefore, controlled and sustained NO release to minimize pro-inflammation effects during treatment is in great demand for diabetic wounds. Herein, an injectable thiolated chitosan hydrogel loaded with NO donors (GNO) and silver nanoparticles (AgNPs) is presented for effective diabetic wound treatment, from which NO was released stably and sustainably responsive to reactive oxygen species (ROS) at the wound site. The combination of NO and AgNPs demonstrated robust antibacterial activity and biofilm dissipation. During diabetic wound treatments, the sustained release of NO promoted blood vessel regeneration while inhibiting inflammatory factors, thereby accelerating wound healing. This combined approach achieves efficient antibacterial action, biofilm prevention, inflammation suppression, vascular repair, improved local blood circulation, ultimately facilitating the reconstruction of epithelial structures at the wound site, thereby providing a promising solution for the diabetic chronic wound healing.

A Smart Injectable Hydrogel with Dual Responsivity to Arginine Gingipain A and Reactive Oxygen Species for Multifunctional Therapy of Periodontitis

Distinct clinical phenotypes of periodontitis are associated with specific microbiome profiles and diverse inflammatory conditions. Current drug delivery systems face challenges in precisely modulating this dynamic microenvironment. Effective inhibition of bone resorption can only be achieved through a strategic response to bacterial infections and inflammation within the periodontal pocket, followed by prompt treatment tailored to disease severity. In this study, tannic acid (TA) is loaded into hollow mesoporous silica nanoparticles (HMSNs) that are functionalized with positively charged polyarginines (R8) and negatively charged human serum albumin (HSA). These HMSNs-R8@TA-HSA (HRT) nanoparticles are then encapsulated within an injectable Nap-Gly-Phe-Phe-Tyr-OH (NapGFFY) hydrogel (NHRT). The intermediate linker R8 can interact with both arginine gingipain A (RgpA) and reactive oxygen species (ROS), which serve as markers of bacterial infections and inflammation, respectively. HSA, arginine, TA, and nitric oxide are differentially released from the hydrogel in response to varying concentrations of RgpA and ROS, demonstrating excellent antibacterial, antioxidant, and anti-inflammatory properties. This smart RgpA/ROS dual-responsive and injectable hydrogel with multifunctional therapy provides new prospects for the management of periodontitis.

Temperature-Triggered Reversible Adhesion Hydrogel with Responsive Drug Release, Mild Photothermal Therapy, and Biofilm Clearance for Skin Infection Healing

Bacterial infection gives rise to a hypoxic, H2O2-abundant, and acidic local microenvironment at the site of inflammation, which prevents the healing of skin tissues. In this work, gelatin and oxidized carboxymethyl cellulose were developed as the framework of hydrogels. Tannic acid and 3-formylphenylboronic acid served as small-molecule anchors. Through the introduction of multiple dynamic cross-linkings, the hydrogel was endowed with various functions. These functions encompassed mechanical compatibility with the skin, reversible adhesion characteristics, and rapid self-healing capabilities. In addition, nanoflower-like MnO2 microparticles loaded with berberine hydrochloride were embedded. MnO2 has the ability not only to kill bacteria through the photothermal effect (PTT) but also to catalyze the decomposition of H2O2 and release oxygen, effectively improving the inflammatory microenvironment. Remarkably, based on the drug/PTT synergistic strategy, the hydrogel exhibited significant antibacterial activity and biofilm removal ability under mild conditions (<50 °C), avoiding thermal damage to healthy tissues. Consequently, the hydrogels demonstrate favorable biocompatibility, significant cell proliferation, migration, angiogenesis, collagen deposition, and tissue regeneration. Therefore, the multifunctional antimicrobial hydrogel is expected to be a skin-friendly medical dressing with enormous potential in the treatment of skin and soft tissue infections.

Nanozyme based ultra-stretchable, low-hysteresis, and dual-mode antibacterial composite hydrogels for wound healing

Wound care always presents challenges as they are susceptible to bacterial infections and have mechanical compatibility issues with wound dressings, leading to a delayed recovery of the structure and functional integrity of skin tissue. Herein, an iron-based metal-organic framework loaded with gold (Fe-MIL-88NH2-Au) nanozyme based composite hydrogel (HMAux) with excellent mechanical compatibility and dual-mode antibacterial properties was designed for wound care. To obtain HMAux, Fe-MIL-88NH2-Au nanozyme with photothermal properties and peroxidase-like and oxidase-like activities was prepared. Then it was introduced into the hydrogel system with a sea-island structure which was prepared via the copolymerization of acrylamide and acryloyl Pluronic F127 (PF127-DA) in the aqueous solution. Using dynamic micelles as the energy dissipation mechanism, double bonds and intermolecular interactions as two crosslinking methods in HMAux make it possess good stretchability (3244 %-4524 %), toughness (593.8 kJ/m3 to 421.5 kJ/m3), and low hysteresis (0.13-0.15). Furthermore, the synergistic photothermal and chemodynamic effects provide good antibacterial performance under mild conditions, with killing rates of approximately 95.02 % and 97.28 % for S. aureus and E. coli, respectively. In vivo experiments have proved that HMAux can effectively adapt to the contour of the wound and treat wound infections.

NIR photo-responsive injectable chitosan/hyaluronic acid hydrogels with controlled NO release for the treatment of MRSA infections

Due to resistance to common antibiotics, methicillin-resistant Staphylococcus aureus (MRSA) infections pose a significant threat to human health. In this study, we developed an injectable, adhesive, and biocompatible hydrogel with multiple functions. Specifically, carboxymethyl chitosan (CMCS) crosslinked with hyaluronic acid (HA) forms the primary framework of the hydrogel. Subsequently, polydopamine (PDA), 5,10,15,20-tetrakis (4-aminophenyl) porphyrin (TAPP), and L-arginine (L-Arg) are incorporated as a photothermal agent, photosensitizer, and nitric oxide (NO) donor, respectively, resulting in the CHDTA hydrogel. Under the combined irradiation of 660 nm and 808 nm near-infrared (NIR) light, the CHDTA hydrogel exhibits both photodynamic therapy (PDT) and photothermal therapy (PTT) effects. Simultaneously, L-Arg reacts with singlet oxygen (1O2), generated via the PDT effect, leading to the production of NO. The CHDTA hydrogel effectively inhibits the activity of Staphylococcus aureus (S. aureus) and MRSA, achieving bactericidal rates of 99.4 % and 98.8 %, respectively, through a combination of PDT, PTT, and NO synergistic antibacterial mechanisms. In vivo studies demonstrate the excellent antibacterial properties and wound healing promotion of the CHDTA hydrogel in MRSA-infected animal wound models. The hydrogel system developed in this study integrates multiple functional design concepts and serves as a potential therapeutic platform for combating MRSA infections.

From Autonomous Chemical Micro-/Nanomotors to Rationally Engineered Bio-Interfaces

Developing micro-/nanomotors that convert a chemical energy input into a local gradient field and motion is an appealing but challenging task that holds particular promise for the intersection of materials and nanoengineering. Over the past two decades, remarkable advancements have refined these out-of-equilibrium chemically powered micro-/nanomotors, enabling them to orchestrate in situ chemical transformations that dynamically change local environments. The ionic products, radicals, gases, and electric fields from these active materials reshape the microenvironment, paving the way for ecofriendly disease interventions. This review discusses the state-of-the-art reactions that propel these energy-consuming micro-/nanomotors and elucidates the emerging implications of their products on biological systems. Particular emphasis has been placed on their potential for neural modulation, reactive oxygen species (ROS) regulation, synergistic tumor therapy, antibacterial strategies, and tissue regeneration. Collectively, these sketches provide a landscape of therapeutic modalities, heralding a new era of biomedicine. By harnessing the in situ product field of this active matter, we envision a paradigm shift toward active therapies that transcend conventional approaches, promising breakthroughs in disease diagnosis, treatment, and prevention.

Nanohybrid Hydrogel with Dual Functions: Controlled Low-Temperature Photothermal Antibacterial Activity and Promoted Regeneration for Treating MRSA-Infected Bone Defects

Methicillin-resistant Staphylococcus aureus (MRSA)-related bone defects pose significant clinical challenges due to treatment failures. Here, an injectable nanohybrid hydrogel (FND-ZHD) is developed that combines controlled low-temperature photothermal antibacterial therapy with enhanced bone regeneration. The hydrogel uses Pluronic F-127 as the matrix, incorporating polydopamine-coated nano-hydroxyapatite and zinc oxide nanoparticles encapsulated with polydopamine and hyaluronic acid, forming a sophisticated nanostructured composite. Under near-infrared (NIR) irradiation, the FND-ZHD hydrogel exhibits efficient photothermal properties, enabling precise low-temperature photothermal therapy to eliminate MRSA infections. The photothermal process generates reactive oxygen species (ROS), contributing to potent antibacterial activity, while the hydrogel design allows self-elimination of excess ROS to minimize cytotoxicity. Simultaneously, the hydrogel enhances bone regeneration by upregulating heat shock protein 70 (HSP70), promoting osteogenic differentiation and accelerating bone repair. In vitro and in vivo experiments demonstrate that the FND-ZHD hydrogel not only possesses strong antibacterial efficacy against MRSA but also significantly improves bone healing in infected bone defect models. This dual-function strategy leverages the synergistic effects of nanomaterials at the nano- and microscale, achieving simultaneous antibacterial action and bone regeneration. The work highlights the potential of nanotechnology-based multifunctional biomaterials in addressing complex medical problems, paving the way for advanced therapies in orthopedic and regenerative medicine.

NIR-triggered programmable nanomotor with H2S and NO generation for cascading oncotherapy by three-pronged reinforcing ICD

Gas therapy (GT) and/or phototherapy have been recently employed as immunogenic cell death (ICD) agents for activating immunotherapy, whereas the effective activation of sufficient immune responses remains an enormous challenge in such single therapeutic modality. In this study, a near-infrared (NIR)-triggered programmable nanomotor with hydrogen sulfide (H2S) and nitric oxide (NO) generation is well designed to achieve oncotherapy by cascading mild photothermal, gas, and reactive oxygen species (ROS)-reinforced immunogenic cell death. In brief, a gas signal molecule donor NOSH with H2S and NO capable of on-demand H2S and NO release was synthesized and then loaded into hollow mesoporous copper sulfide nanoparticles (termed as HCuSNPs) with an inherent NIR absorption and surface modification activity to obtain the programmable nanomotor (termed as NOSH@PEG-HCuSNPs). In particular, NOSH@PEG-HCuSNPs can effectively achieve the simultaneous spatiotemporal co-delivery of NOSH and HCuSNPs, thereby exerting the synergistic effects of GT and mild photothermal therapy (mPTT). It is worth noting that the anti-tumor response of mPTT is effectively enhanced by GT by disrupting the mitochondrial respiratory chain, inhibiting ATP production, and promoting tumor cell apoptosis. One by one, a large number of peroxynitrite anion (ONOO-) radicals are generated by the interactions of ROS from mPTT and NO from NOSH. Meanwhile, the unique protective mechanism of H2S is utilized to induce tumor thermal ablation by reducing the overexpression of heat shock protein 90 (HSP 90) and minimize the unnecessary damage toward normal tissues. Finally, ICD is markedly augmented by the cascading effects of mPTT, ONOO⁻radicals, and H2S. Concurrently, the immunosuppressive tumor microenvironment is reprogrammed, effectively inhibiting distant tumor tissues and preventing metastasis and tumor recurrence. Taken together, this study provides a new perspective for innovation in the field of oncotherapy.

Aggregation-induced emission-based phototheranostics to combat bacterial infection at wound sites: A review

The healing of chronic wounds infected by bacteria has attracted increasing global concerns. In the past decades, antibiotics have certainly brought hope to cure bacteria-infected chronic wounds. However, the misuse of antibiotics leads to the emergence of numerous multidrug-resistant bacteria, which aggravate the health threat to clinical patients. To address these increasing challenges, scientists are committed to creating novel non-antibiotic strategies to kill bacteria and promote bacteria-infected chronic wound healing. Fortunately, with the quick development of nanotechnology, the representatives of phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), exhibit promising possibilities in promoting bacteria-infected wound healing. Well-known, photothermal agents and photosensitizers largely determine the effects of PTT and PDT. A common problem for these molecules is the aggregation-induced quenching effect, which highly limits their further applicability in biomedical and clinical fields. Fortunately, the occurrence of aggregation-induced emission luminogens (AIEgens) efficiently overcomes the photobleaching and exhibit advantages, such as strongly aggregated emission, superior photostability, aggregation-enhanced reactive oxygen species (ROS), and heat generation, which makes great sense to the development of PTT and PDT. This article reviews various studies conducted on novel AIEgen-based materials that can mediate potent PDT, PTT, and a combination of PDT and PTT to promote bacteria-infected chronic wound healing.

Design and application of antimicrobial nanomaterials in the treatment of periodontitis

Periodontitis is a chronic inflammatory disease induced by the microbiome, leading to the destruction of periodontal structures and potentially resulting in tooth loss. Using local drug delivery systems as an adjunctive therapy to scaling and root planning in periodontitis is a promising strategy. However, this administration method's effectiveness is constrained by the complexity of the periodontal environment. Nanomaterials have demonstrated significant potential in the antibacterial treatment of periodontitis, attributed to their controllable size, shape, and surface charge, high design flexibility, high reactivity, and high specific surface area. In this review, we summarize the complex periodontal microenvironment and the difficulties of local drug delivery in periodontitis, explicitly reviewing the application and design strategies of nanomaterials with unique properties in the distinct microenvironment of periodontitis. Furthermore, the review discusses the limitations of current research, proposes feasible solutions, and explores prospects for using nanomaterials in this context.

Exosome-decorated bio-heterojunctions reduce heat and ROS transfer distance for boosted antibacterial and tumor therapy

Photothermal and photodynamic therapies represent effective modalities for combatting bacteria and tumor cells. However, therapeutic outcomes are constrained by limitations related to the heat and reactive oxygen species (ROS) transfer distance from photosensitizers to targets. To address this issue, we have devised and developed exosome-decorated bio-heterojunctions (E-bioHJ) consisted of MXene (Ti3C2), liquid metal (LM) and exosomes sourced from CT26 cells to enhance the phototherapeutic consequences. Engineering E-bioHJ enhances phototherapeutic effect in antibacterial and anti-tumor treatment, which is ascribed to reducing transfer distance of the heat and ROS. When adorned with exosomes, E-bioHJ is targetedly delivered into the cytoplasm of tumor cells to generate amount heat and ROS under 808 nm near-infrared radiation, which further induces mitochondrial dysfunction and apoptosis/necroptosis. As envisaged, this study presents a novel tactic to enhance the antibacterial and anti-tumor efficacy of biomaterials through reducing the heat and ROS delivery travel distance.

Harnessing Nanoreactors with Coupled Optical and Molecular Modalities for Photoenzymatic Modulation of Active Species in Cancer Photo-Immunotherapy

The dynamic process in tumor ablation requires both the generation of reactive oxygen species (ROS) to elicit immunogenic cell death (ICD) and the subsequent reduction of ROS levels to maintain the stimulatory activity of signaling proteins and recover T cells' immune function. Inspired by the regulation mechanism of redox homeostasis in myeloid-derived suppressor cells and the high-selectivity in alcohols/aldehydes conversions of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and Fe(III) synergistic catalysis, photoenzymatic modulators with contradictory but synergistic functions are developed for adaptive photo-immunotherapy of cancer. In particular, poly(caffeic acid) (PCA) nanospheres are synthesized by highly efficient oxidative polymerization of CA. The obtained π-conjugated structures have an extended absorbance in the near-infrared (NIR) region, narrow band energy (0.86 eV), and low exciton binding energy (43.56 meV) that lead to polymerization-enhanced type I photosensitization and photostability. Meanwhile, abundant semiquinone radicals existing in PCA bestow them with superior antioxidant function. Under NIR irradiation, the elevated superoxide radical yields (3.5-fold compared with CA) and heat stress elicit robust ICD. When irradiation ceases, active species downregulation and the infiltration of T lymphocytes increase by 2.7-fold compared with conventional photosensitizers. As envisaged, this work demonstrates a novel tactic to remodel redox and immune homeostasis for effective inhibition of tumor growth and metastasis.

Enhanced cGAS-STING Activation and Immune Response by LPDAM Platform-Based Lapachone-Chemical-Photothermal Synergistic Therapy for Colorectal Cancer

The cGAS-STING signaling pathway is a pivotal immune response mechanism that bridges tumor and immune cell interactions. This study describes a multifunctional LPDAM nanoplatform integrating Lapachone, polydopamine (PDA), and Mn2+, which synergistically kills tumor cells and activates the cGAS-STING pathway, thereby inducing DC maturation and T cell activation to achieve potent antitumor immunity. In the tumor microenvironment, Lapachone generates H2O2 via the NAD(P)H:quinone oxidoreductase 1 (NQO1 enzyme), while Mn2+ catalyze H2O2 conversion into •OH through chemodynamic effects (CDT). The photothermal effects (PTT) of PDA further amplify this cascade reaction, producing reactive oxygen species (ROS) that damage tumor mitochondria and release mitochondrial DNA (mtDNA). The released mtDNA activates the cGAS-STING pathway, while Mn2+ enhances the sensitivity of cGAS to mtDNA, leading to robust antitumor immunity. Concurrently, photothermal-induced immunogenic cell death (ICD) promotes dendritic cells (DCs) maturation, further strengthening immune responses. Moreover, Mn2⁺ also serves as a contrast agent for T1-weighted magnetic resonance imaging (MRI), offering precise tumor visualization. This study demonstrates that the LPDAM nanoplatform facilitates Lapachone/CDT/PTT synergistic therapy under MRI guidance, showcasing its potential as an innovative strategy for combined immunotherapy in clinical oncology.

Self-propelling intelligent nanomotor: A dual-action photothermal and starvation strategy for targeted deep tumor destruction

Delivering nanoparticles to deep tumor tissues while maintaining high therapeutic efficacy and minimizing damage to surrounding tissues has long posed a significant challenge. To address this, we have developed innovative self-propelling bowl-shaped nanomotors MSLA@GOx-PDA composed of mesoporous silica loaded with l-arginine and polydopamine, along with glucose oxidase (GOx). These nanomotors facilitate the generation of hydrogen peroxide through GOx-catalyzed glucose oxidation, thereby initiating nitric oxide production from l-arginine. This dual mechanism equips MSLA@GOx-PDA with the robust motility required for deep tumor tissue penetration while depleting essential nutrients necessary for tumor growth, consequently impeding tumor progression. In addition, near-infrared lasers have the significant advantage of being depth-penetrating and non-invasive, allowing real-time fluorescence imaging and guiding dopamine-mediated mild photothermal therapy. Notably, starvation therapy depletes intracellular adenosine triphosphate and inhibits the synthesis of heat shock proteins, thus overcoming the Achilles' heel of mild photothermal therapy and significantly enhancing the efficacy of this therapy with encouraging synergistic anti-tumour effects. Overall, the integration of biochemical and optics strategies in this nanomotor platform represents a significant advancement in deep-tissue tumor therapy. It has substantial clinical translational value and is expected to have a transformative impact on future cancer treatments.

Photonic hydrogels combining the slow photon effect and NO gas therapy for synergetic enhanced photodynamic antibacterial therapy

Photodynamic therapy (PDT) offers potential for combating bacterial infections through the generation of reactive oxygen species (ROS). However, the antibacterial efficiency of PDT is largely impeded by the limited photon absorption of photosensitizers and the short diffusion length and lifespan of ROS. Herein, we present a light-harvesting platform based on l-arginine-modified photonic hydrogels loaded with new indocyanine green (PG@Arg/IR820) for synergizing the slow photon effect with NO gas therapy to enhance PDT antibacterial efficiency. Upon near-infrared (NIR) light irradiation, PG@Arg/IR820 can maximize the utilization of photons via the slow photon effect to generate sufficient ROS, which not only acts as the primary bactericidal agent in PDT but also triggers l-arginine to generate NO. NO exhibits a long diffusion distance and lifespan and can freely diffuse to inhibit distant bacterial growth, demonstrating a vital complementary advantage in bacterial inactivation by ROS. The synergistic effect of the slow photon effect combined with NO gas therapy allows PG@Arg/IR820 to intensify bacterial destruction and enhance PDT antibacterial efficiency. This antibacterial system sheds light on an advisable design principle for efficient antibacterial activities in photodynamic inactivation.

Dual-responsive polydopamine-embellished Zn-MOFs enabling synergistic photothermal and antibacterial metal ion therapy for oral biofilm eradication

Oral biofilms are associated with various oral diseases causing pain and discomfort, and pose a severe threat to general health. Conventional surgical debridement and antibacterial therapy often yield unsatisfactory outcomes because they either fail to fully and painlessly eliminate biofilms or increase the risk of bacterial resistance. In this study, we synthesized polydopamine-embellished Zn-MOFs (ZIF-8@PDA NPs), which can degrade under mildly acidic conditions to release Zn2+. These nanoparticles also convert near-infrared light energy into heat, thereby enabling synergistic photothermal and antibacterial metal ion therapy for oral biofilm eradication. Our findings reveal that therapy with ZIF-8@PDA NPs, when exposed to near-infrared radiation, demonstrates exceptional antibacterial efficacy and is highly effective in eradicating oral biofilms both in vitro and ex vivo. Furthermore, we used an in vivo rodent tooth biofilm model to demonstrate the suppression of dental caries. This work presents a promising solution for preventing and suppressing dental caries as well as other treating diseases linked to oral biofilm infections.

Antibiotic-free responsive biomaterials for specific and targeted Helicobacter pylori eradication

Gastric cancer is highly correlated with Helicobacter pylori (H. pylori) infection. Approximately 50 % of the population worldwide is infected with H. pylori. However, current treatment regimens face severe challenges including drug resistance and gut microbiota disruption. An integrative treatment with slight negative influences on intestinal flora, conforming with concepts of integrative prevention of gastric cancer, is urgently needed. Non-antibiotic responsive biomaterials can respond to different stimuli, including pH, enzymes, light, ultrasound and magnetism, under which biomaterials are specifically activated to perform antibacterial capabilities, while neutral intestinal microenvironments differ from gastric microenvironments or inflammatory sites and have no or minimal irradiation via precisely controlled exogenous stimuli, which may not only overcome antibiotic resistance but also avoid gut microbiota disorders. First, the latest progress in responsive biomaterials against H. pylori without gut microbiome disturbance and their anti-H. pylori performances are profoundly summarized. Second, the mechanisms against planktonic bacteria, biofilms and intracellular bacteria are discussed respectively. Finally, the strategies of specific and targeted H. pylori elimination by responsive biomaterials are introduced. Additionally, the challenges and the focus of future research on translation into clinical application are fully proposed. Antibiotic-free responsive biomaterials for specific and targeted H. pylori eradication represent an innovative approach.

Ultrathin high-entropy hydrotalcites-based injectable hydrogel with programmed bactericidal and anti-inflammatory effects to accelerate drug-resistant bacterial infected wound healing

Drug-resistant bacteria infected wounds often bring high risks of delayed healing process and even death. Sonodynamic therapy (SDT) can efficiently kill drug-resistant bacteria. However, superabundant reactive oxygen species (ROS) generated during SDT inevitably trigger significant inflammatory responses, hindering tissue remodeling. Herein, we develop intelligent ultrathin high-entropy hydrotalcites (UHE-HTs)-based injectable thermal-responsive hydrogel loaded with nicotinamide mononucleotide (UHE-HTs/PFN), aiming to achieve programmed antibacterial and anti-inflammatory effects. In the early infection stage, sonosensitive UHE-HTs/PFN hydrogel simultaneously can trigger rapid production of singlet oxygen (1O2) under ultrasound and efficient MDR bacterial sterilization. After halting ultrasonic irradiation, oxidoreductase-mimicking catalysis and nicotinamide mononucleotide release of UHE-HTs/PFN hydrogel effectively reduce ROS levels at wound sites, dampening the NF-κB inflammatory pathway. Such inhibited NF-κB expression can not only reduce the production of pro-inflammatory cytokines and inflammatory responses, but also significantly down-regulate the pyroptosis pathways (NLRP3/ASC/Casp-1) and inhibit pyroptosis that leads to inflammation. Moreover, significantly reduced ROS levels and synergistic release of Mg2+ reverse pro-inflammatory immune microenvironment. Both in vitro and in vivo assays demonstrate that UHE-HTs/PFN hydrogel can transform the adverse infected wound environment into a regenerative one by eradicating drug-resistant bacteria, scavenging ROS, and synergistic anti-inflammation. Therefore, this work develop an intelligent UHE-HTs/PFN hydrogel act as a "lever" that effectively achieve a balance between ROS generation and annihilation, rebuilding harmonious bactericidal and anti-inflammatory effects to remedy drug-resistant bacteria infected wound.

Synergistic effects of NO/H2S gases on antibacterial, anti-inflammatory, and analgesic properties in oral ulcers using a gas-releasing nanoplatform

Oral mucosal wounds are more prone to inflammation due to direct exposure to various microorganisms. This can result in pain, delayed healing, and other complications, affecting patients' daily activities such as eating and speaking. Consequently, the overall quality of life for patients is significantly reduced. To address these challenges, we developed a multifunctional therapeutic nanoplatform, DATS@Arg-EA-SA, through the self-assembly of guanidinated dendritic peptides (Arg-EA-SA) that encapsulate diallyl trisulfide (DATS), a hydrogen sulfide (H2S) donor. The guanidine-rich surface of DATS@Arg-EA-SA efficiently neutralizes reactive oxygen species (ROS) in the ulcer microenvironment, generating nitric oxide (NO), which acts as the primary antimicrobial agent by disrupting bacterial membranes. Concurrently, the presence of glutathione triggers the release of H2S from DATS, providing supplementary antibacterial support. DATS@Arg-EA-SA effectively kills all bacteria, achieving results comparable to those of penicillin, a classical antibiotic. Moreover, it demonstrates superior sterilization efficacy against drug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), significantly outperforming penicillin. Following the initial antimicrobial phase, the nanoplatform transitions into an anti-inflammatory stage. H2S, in synergy with NO, facilitates the conversion of M1 macrophages to M2 macrophages, thereby reducing the expression of inflammatory factors. Importantly, the combination of H2S and NO provides effective analgesia by downregulating the expression of TRPV1 and TRPV4, thus restoring normal dietary behaviors and improving the overall quality of life. This system ultimately promotes collagen fiber deposition and accelerates the re-epithelialization of the ulcer wound, positioning DATS@Arg-EA-SA as a promising gas-delivery nanoplatform for rapid wound repair in the clinical treatment. STATEMENT OF SIGNIFICANCE: Oral mucosal wounds are highly susceptible to microbial infections, leading to inflammation, pain, delayed healing, and a significant decline in quality of life. We developed a multifunctional therapeutic nanoplatform (DATS@Arg-EA-SA) via the self-assembly of guanidinated dendritic peptides encapsulating the H2S donor DATS, which exhibited antibacterial, anti-inflammatory, and analgesic properties. In the oral ulcer microenvironment, DATS@Arg-EA-SA generates substantial NO under elevated ROS levels, while glutathione triggers the controlled release of H2S. NO disrupts bacterial membranes as the primary antibacterial agent, with H2S providing synergistic antibacterial effects. Furthermore, H2S and NO synergistically promote the transformation of M1 to M2 macrophages, attenuating inflammation. Importantly, the combined action of H2S and NO alleviates pain by downregulating TRPV1 and TRPV4, supporting the restoration of normal dietary behavior and improving quality of life.

Engineering Gas-Releasing Nanomaterials for Efficient Wound Healing

The escalating prevalence of tissue damage and its associated complications has elicited global apprehension. While nanomaterial-based wound healing exhibits significant potential in terms of curbing infections and surpassing conventional methods, unresolved concerns regarding nanomaterial controllability and precision remain unresolved, jeopardizing its practical applications. In recent years, a unique strategy for creating gas-releasing nanomaterials for wound repair has been proposed, involving the creation of gas-releasing nanomaterials to facilitate wound repair by generating gas donor moieties. The operational spatiotemporal responsiveness and broad-spectrum antibacterial properties of these gases, combined with their inability to generate bacterial resistance like traditional antibiotics, establish their efficacy in addressing chronic non-healing wounds, specifically diabetic foot ulcers (DFUs). In this review, we delve into the intricacies of wound healing process, emphasizing the chemical design, functionality, bactericidal activity, and potential of gas-release materials, encompassing NO, CO, H2S, O2, CO2, and H2, for effective wound healing. Furthermore, we explore the advancements in synergistic therapy utilizing these gases, aiming to enhance our overall comprehension of this field. The insights gleaned from this review will undoubtedly aid researchers and developers in the creation of promising gas-releasing nanomaterials, thus propelling efficient wound healing in the future.

Enhanced anti-tumor efficacy of berberine-loaded mesoporous polydopamine nanoparticles for synergistic chemotherapy and photothermal therapy

The development of innovative therapeutic strategies that combine multiple treatment modalities is essential for effective cancer therapy. In this study, we engineered berberine (BER)-loaded mesoporous polydopamine (MPDA) nanoparticles (BER-MPDA) to enhance anti-tumor efficacy through synergistic chemotherapy and photothermal therapy (PTT). The mesoporous structure of MPDA allowed for a high loading capacity of BER, a natural isoquinoline alkaloid with known anticancer properties. Upon near-infrared laser irradiation, BER-MPDA exhibited marked photothermal conversion efficiency, leading to effective tumor cell ablation. Both in vitro and in vivo experiments indicated that the combined treatment of BER-MPDA with near-infrared laser irradiation resulted in superior tumor inhibition compared to monotherapy. The synergistic effect was attributed to the enhanced cellular uptake and the simultaneous induction of chemo- and photothermal cytotoxicity. Our findings suggest that BER-MPDA represents a promising platform for multimodal cancer therapy, offering a potent approach to overcoming the limitations of conventional chemotherapy and PTT.

Engineered nanoplatform mediated gas therapy enhanced ferroptosis for tumor therapy in vivo

The high glutathione (GSH) environment poses a significant challenge for inducing ferroptosis in tumor cells, necessitating the development of nanoplatforms that can deplete intracellular GSH. In this study, we developed an engineered nanoplatform (MIL-100@Era/L-Arg-HA) that enhances ferroptosis through gas therapy. First, we confirmed that the Fe element in the nanoplatform undergoes valence changes under the influence of high GSH and H2O2 in tumor cells. Meanwhile, L-Arg generates NO gas in the presence of intracellular H2O2, which reacts with GSH. Additionally, Erastin depletes GSH by inhibiting the cystine/glutamate antiporter system, reducing cystine uptake and impairing GPX4, while also increasing intracellular H2O2 levels by activating NOX4 protein expression. Through these combined GSH-depletion mechanisms, we demonstrated that MIL-100@Era/L-Arg-HA effectively depletes GSH levels, disrupts GPX4 function, and increases intracellular lipid ROS levels in vitro. Furthermore, this nanoplatform significantly inhibited tumor cell growth and extended the survival time of tumor-bearing mice in vivo. This engineered nanoplatform, which enhances ferroptosis through gas therapy, shows significant promise for ferroptosis-based cancer therapy and offers potential strategies for clinical tumor treatment.

Glucose oxidase: An emerging multidimensional treatment option for diabetic wound healing

The healing of diabetic skin wounds is a complex process significantly affected by the hyperglycemic environment. In this context, glucose oxidase (GOx), by catalyzing glucose to produce gluconic acid and hydrogen peroxide, not only modulates the hyperglycemic microenvironment but also possesses antibacterial and oxygen-supplying functions, thereby demonstrating immense potential in the treatment of diabetic wounds. Despite the growing interest in GOx-based therapeutic strategies in recent years, a systematic summary and review of these efforts have been lacking. To address this gap, this review article outlines the advancements in the application of GOx and GOx-like nanozymes in the treatment of diabetic wounds, including reaction mechanisms, the selection of carrier materials, and synergistic therapeutic strategies such as multi-enzyme combinations, microneedle structures, and gas therapy. Finally, the article looks forward to the application prospects of GOx in aiding the healing of diabetic wounds and the challenges faced in translating these innovations to clinical practice. We sincerely hope that this review can provide readers with a comprehensive understanding of GOx-based diabetic treatment strategies, facilitate the rigorous construction of more robust multifunctional therapeutic systems, and ultimately benefit patients with diabetic wounds.

Near-infrared light-enhanced polydopamine-based multifunctional nanoparticles for combination of chemodynamic and NO gas therapy in the treatment of osteosarcoma

The emergence of treatment approaches that integrate conventional phototherapy with additional adjuvant treatments has garnered considerable interest. In this study, we proposed a complex utilizing Fe and polydopamine as a carrier, co-loaded with the nitric oxide initiator L-arginine (L-Arg) and the photosensitizer indocyanine green (ICG), as a potential strategy for the "photothermal/photodynamic/Chemodynamic/nitric oxide gas therapy" of osteosarcoma. Nanoparticles have the ability to undergo degradation within the mildly acidic conditions present in the tumor microenvironment. Consequently, the resulting release of Fe ions facilitates the consumption of hydrogen peroxide through Fenton/Fenton-like reactions, thereby generating hydroxyl radicals (•OH) that possess potent cytotoxic properties. L-Arg can also be catalyzed by reactive oxygen species (ROS) or NO synthase overexpressed in cancer cells to generate NO, which is not only used for gas therapy (GT), but also as a biological messenger to regulate vasodilation to relieve tumor hypoxia. More importantly, the addition of low-dose near-infrared laser can not only promote the efficiency of the above two reactions, but also achieve PTT/PDT and obtain good synergistic tumor treatment effects. The anti-tumor efficacy of nanoparticles was verified in the 143B mouse osteosarcoma model. This "PTT/PDT/CDT/GT" strategy expands bone tumor treatment options through nanoparticle-mediated enhanced therapy.

A self-supplied hydrogen peroxide and nitric oxide-generating nanoplatform enhances the efficacy of chemodynamic therapy for biofilm eradication

Bacterial biofilms present a profound challenge to global public health, often resulting in persistent and recurrent infections that resist treatment. Chemodynamic therapy (CDT), leveraging the conversion of hydrogen peroxide (H2O2) to highly reactive hydroxyl radicals (•OH), has shown potential as an antibacterial approach. Nonetheless, CDT struggles to eliminate biofilms due to limited endogenous H2O2 and the protective extracellular polymeric substances (EPS) within biofilms. This study introduces a multifunctional nanoplatform designed to self-supply H2O2 and generate nitric oxide (NO) to overcome these hurdles. The nanoplatform comprises calcium peroxide (CaO2) for sustained H2O2 production, a copper-based metal-organic framework (HKUST-1) encapsulating CaO2, and l-arginine (l-Arg) as a natural NO donor. When exposed to the acidic microenvironment within biofilms, the HKUST-1 layer decomposes, releasing Cu2+ ions and l-Arg, and exposing the CaO2 core to initiate a cascade of reactions producing reactive species such as H2O2, •OH, and superoxide anions (•O2-). Subsequently, H2O2 catalyzes l-Arg to produce NO, which disperses the biofilm and reacts with •O2- to form peroxynitrite, synergistically eradicating bacteria with •OH. In vitro assays demonstrated the nanoplatform's remarkable antibiofilm efficacy against both Gram-positive Methicillin-resistant Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa, significantly reducing bacterial viability and EPS content. In vivo mouse model experiments validated the nanoplatform's effectiveness in eliminating biofilms and promoting infected wound healing without adverse effects. This study represents a breakthrough in overcoming traditional CDT limitations by integrating self-supplied H2O2 with NO's biofilm-disrupting capabilities, offering a promising therapeutic strategy for biofilm-associated infection.

Corrole-based photothermal nanocomposite hydrogel with nitric oxide release for diabetic wound healing

The management of chronic diabetic wounds remains a significant challenge due to persistent bacterial infections and impaired angiogenesis. Herein, we reported a nanocomposite hydrogel (M/P-SNO/G) incorporated with M/P-SNO nanoparticles engineered by supramolecular assembly of the photosensitizing mono-carboxyl corrole (MCC) and S-nitrosothiol-modified polyethylene glycol (mPEG-SNO) for synergistic photothermal therapy (PTT)/nitric oxide (NO) treatment of diabetic wounds. The strong π-π interaction among aggregated MCC in M/P-SNO enhances the optical absorption and photothermal ability, thereby facilitating the precise release of NO upon laser irradiation. The hydrogel matrix, composed of oxidized hyaluronic acid and carboxymethyl chitosan crosslinked by Schiff-base, demonstrates good injectability and self-healing characteristics, providing an ideal environment for wound repair. As expected, M/P-SNO/G exhibits a desirable photothermal performance and a controlled laser-responsive NO release, realizing enhanced bactericidal effect and anti-biofilm ability in vitro. In a full-thickness skin defect model on diabetic mice, M/P-SNO/G has proven effective in bacteria clearance and angiogenesis, significantly accelerating wound healing. This study presents a feasible supramolecular strategy to develop diabetic wound dressings with synergistic PTT/NO treatment. STATEMENT OF SIGNIFICANCE: Developing advanced dressings that simultaneously eliminate bacteria and accelerate wound recovery is essential for treating diabetic wounds. This study developed a nanocomposite hydrogel (M/P-SNO/G) featuring the synergistic effect of photothermal therapy (PTT) and nitric oxide (NO) treatment to accelerate infected diabetic wound healing. M/P-SNO nanoparticles within the hydrogel are self-assembled through the hydrophobic photosensitizing mono-carboxyl corrole (MCC) and the hydrophilic NO-releasing polymer (mPEG-SNO), where highly aggregated MCC molecules ensure superior photothermal performance. Meanwhile, the temperature increase induced by the photothermal effect activates NO release from the hydrogel. Under 660 nm laser irradiation, M/P-SNO/G demonstrates a PTT/NO synergy to effectively inhibit bacterial proliferation and promote angiogenesis, offering significant benefits in diabetic wound repair and further expanding the biomedical applications of corroles.

Co-delivery of antimicrobial peptide and Prussian blue nanoparticles by chitosan/polyvinyl alcohol hydrogels

Altered skin integrity increases the chance of infection, and bacterial infections often lead to a persistent inflammatory response that prolongs healing time. Functional artificial hydrogels are receiving increasing attention as suitable wound dressing barrier. However, the antimicrobial effect of the new dressing still needs to be explored in depth. In this work, the antimicrobial peptide MSI-1 was covalently attached to chitosan-modified poly (vinyl alcohol) hydrogels mixed with Prussian blue nanoparticles (PBNPs) via a primary amine group coupled to a carboxyl group. The synthesized hydrogel has a long-lasting antimicrobial surface and is able to maintain its bactericidal effect on Staphylococcus aureus and Escherichia coli for 24 h. Due to the presence of PBNPs, the hydrogel was able to rise to 48.3 °C within 10 min under near infrared (NIR) light irradiation at a wavelength of 808 nm and maintain this mild temperature to avoid bacterial biofilms. The hydrogel showed >90 % survival in co-culture with cells for 3 d and did not damage major organs in animal experiments. Thus, the photothermal dual-mode antimicrobial hydrogel synthesized in this study increases the selectivity as a safe and efficient wound dressing for the treatment of infected skin defects.

NIR-Activated Hydrogel with Dual-Enhanced Antibiotic Effectiveness for Thorough Elimination of Antibiotic-Resistant Bacteria

Antibiotic resistance has become a critical health crisis globally. Traditional strategies using antibiotics can lead to drug-resistance, while inorganic antimicrobial agents can cause severe systemic toxicity. Here, we have developed a dual-antibiotic hydrogel delivery system (PDA-Ag@Levo/CMCS), which can achieve controlled release of clinical antibiotics levofloxacin (Levo) and classic nanoscale antibiotic silver nanoparticles (AgNPs), effectively eliminating drug-resistant P. aeruginosa. Benefiting from the photothermal (PTT) effect of polydopamine (PDA), the local high temperature generated by PDA-Ag@Levo/CMCS can quickly kill bacteria through continuous and responsive release of dual-antibiotics to restore sensitivity to ineffective antibiotics. Moreover, AgNPs could significantly improve the efficiency of traditional antibiotics by disrupting bacterial membranes and reducing their toxicity to healthy tissues. A clever combination of PTT and drug-combination therapy can effectively eliminate biofilms and drug-resistant bacteria. Mechanism studies have shown that PDA-Ag@Levo might eliminate drug-resistant P. aeruginosa by disrupting biofilm formation and protein synthesis, and inhibit the resistance mutation of P. aeruginosa by promoting the expression of related genes, such as rpoS, dinB, and mutS. Collectively, the synergistic effect of this dual-antibiotic hydrogel combined with PTT provides a creative strategy for eliminating drug-resistant bacteria in chronic infection wounds.

Stimuli-responsive and targeted nanomaterials: Revolutionizing the treatment of bacterial infections

Bacterial infections have emerged as a major threat to global public health. The effectiveness of traditional antibiotic treatments is waning due to the increasing prevalence of antimicrobial resistance, leading to an urgent demand for alternative antibacterial technologies. In this context, antibacterial nanomaterials have proven to be powerful tools for treating antibiotic-resistant and recurring infections. Targeting nanomaterials not only enable the precise delivery of bactericidal agents but also ensure controlled release at the infection site, thereby reducing potential systemic side effects. This review collates and categorizes nanomaterial-based responsive and precision-targeted antibacterial strategies into three key types: exogenous stimuli-responsive (including light, ultrasound, magnetism), bacterial microenvironment-responsive (such as pH, enzymes, hypoxia), and targeted antibacterial action (involving electrostatic interaction, covalent bonding, receptor-ligand mechanisms). Furthermore, we discuss recent advances, potential mechanisms, and future prospects in responsive and targeted antimicrobial nanomaterials, aiming to provide a comprehensive overview of the field's development and inspire the formulation of novel, precision-targeted antimicrobial strategies.

Recent Advances in Porphyrin-Based Covalent Organic Frameworks for Synergistic Photodynamic and Photothermal Therapy

Porphyrin's excellent biocompatibility and modifiability make it a widely studied photoactive material. However, its large π-bond conjugated structure leads to aggregation and precipitation in physiological solutions, limiting the biomedical applications of porphyrin-based photoactive materials. It has been demonstrated through research that fabricating porphyrin molecules into nanoscale covalent organic frameworks (COFs) structures can circumvent issues such as poor dispersibility resulting from hydrophobicity, thereby significantly augmenting the photoactivity of porphyrin materials. Porphyrin-based COF materials can exert combined photodynamic and photothermal effects, circumventing the limitations of photodynamic therapy (PDT) due to hypoxia and issues in photothermal therapy (PTT) from heat shock proteins or the adverse impact of excessive heat on the protein activity of normal tissue. Furthermore, the porous structure of porphyrin COFs facilitates the circulation of oxygen molecules and reactive oxygen species and promotes sufficient contact with the lesion site for therapeutic functions. This review covers recent progress regarding porphyrin-based COFs in treating malignant tumors and venous thrombosis and for antibacterial and anti-inflammatory uses via combined PDT and PTT. By summarizing relevant design strategies, ranging from molecular design to functional application, this review provides a reference basis for the enhanced phototherapy application of porphyrin-based COFs as photoactive materials. This review aims to offer valuable insights for more effective biomedical applications of porphyrin-based COFs through the synthesis of existing experimental data, thereby paving the way for their future preclinical utilization.

Photothermal-Triggered Extracellular Matrix Clearance and Dendritic Cell Maturation for Enhanced Osteosarcoma Immunotherapy

Osteosarcoma, a predominant malignant tumor among adolescents, exhibits high mortality and suboptimal immunotherapy efficacy due to a collagen-dense extracellular matrix (ECM) that hinders cytotoxic T lymphocyte (CTL) infiltration. Herein, we developed mesoporous polydopamine (MPDA) nanoparticles encapsulating bromelain and the immune adjuvant R848 (M@B/R), aimed at enhancing photothermal immunotherapy. These nanoparticles efficiently accumulate at the tumor site following injection. Upon near-infrared (NIR) light irradiation, photothermal therapy (PTT) induces immunogenic cell death in tumor cells and, with the aid of R848, efficiently promotes dendritic cell maturation, activating antitumor immunity and leading to CTL infiltration into the tumor. Concurrently, NIR-induced heating activates bromelain, resulting in ECM degradation and improved CTL penetration into the tumor. Our in vivo evaluations demonstrate potent antitumor effects in osteosarcoma-bearing mice. This integrated approach offers a promising strategy for overcoming physical barriers in ECM-rich tumors, marking a significant advancement in the treatment of osteosarcoma.

Outer Membrane Vesicle-Cancer Hybrid Membrane Coating Indocyanine Green Nanoparticles for Enhancing Photothermal Therapy Efficacy in Tumors

Cell membrane-coated nanomaterials are increasingly recognized as effective in cancer treatment due to their unique benefits. This study introduces a novel hybrid membrane coating nanoparticle, termed cancer cell membrane (CCM)-outer membrane vesicle (OMV)@Lip-indocyanine green (ICG), which combines CCMs with bacterial OMV to encapsulate ICG-loaded liposomes. Comprehensive analyses were conducted to assess its physical and chemical properties as well as its functionality. Demonstrating targeted delivery capabilities and good biocompatibility, CCM-OMV@Lip-ICG nanoparticles showed promising photothermal and immunotherapeutic effects in tumor models. By inducing hyperthermia-induced tumor therapy and bolstering antitumor immunity, CCM-OMV@Lip-ICG nanoparticles exhibit a synergistic therapeutic effect, providing a new perspective for the management of cancer.

Emerging nitric oxide gas-assisted cancer photothermal treatment

Photothermal therapy (PTT) has garnered significant attention in recent years, but the standalone application of PTT still faces limitations that hinder its ability to achieve optimal therapeutic outcomes. Nitric oxide (NO), being one of the most extensively studied gaseous molecules, presents itself as a promising complementary candidate for PTT. In response, various nanosystems have been developed to enable the simultaneous utilization of PTT and NO-mediated gas therapy (GT), with the integration of photothermal agents (PTAs) and thermally-sensitive NO donors being the prevailing approach. This combination seeks to leverage the synergistic effects of PTT and GT while mitigating the potential risks associated with gas toxicity through the use of a single laser irradiation. Furthermore, additional internal or external stimuli have been employed to trigger NO release when combined with different types of PTAs, thereby further enhancing therapeutic efficacy. This comprehensive review aims to summarize recent advancements in NO gas-assisted cancer photothermal treatment. It commences by providing an overview of various types of NO donors and precursors, including those sensitive to photothermal, light, ultrasound, reactive oxygen species, and glutathione. These NO donors and precursors are discussed in the context of dual-modal PTT/GT. Subsequently, the incorporation of other treatment modalities such as chemotherapy (CHT), photodynamic therapy (PDT), alkyl radical therapy, radiation therapy, and immunotherapy (IT) in the creation of triple-modal therapeutic nanoplatforms is presented. The review further explores tetra-modal therapies, such as PTT/GT/CHT/PDT, PTT/GT/CHT/chemodynamic therapy (CDT), PTT/GT/PDT/IT, PTT/GT/starvation therapy (ST)/IT, PTT/GT/Ca2+ overload/IT, PTT/GT/ferroptosis (FT)/IT, and PTT/GT/CDT/IT. Finally, potential challenges and future perspectives concerning these novel paradigms are discussed. This comprehensive review is anticipated to serve as a valuable resource for future studies focused on the development of innovative photothermal/NO-based cancer nanotheranostics.

Amino Acid Functionalized SrTiO3 Nanoarrays with Enhanced Osseointegration Through Programmed Rapid Biofilm Elimination and Angiogenesis Controlled by NIR-Driven Gas Therapy

Bacterial biofilm formation is closely associated with persistent infections of medical implants, which can lead to implantation failure. Additionally, the reconstruction of the vascular network is crucial for achieving efficient osseointegration. Herein, an anti-biofilm nanoplatform based on L-arginine (LA)/new indocyanine green (NICG) that is anchored to strontim titanium oxide (SrTiO3) nano-arrays on a titanium (Ti) substrate by introducing polydopamine (PDA) serving as the interlayer is designed and successfully fabricated. Near-infrared light (NIR) is used to excite NICG, generating reactive oxygen species (ROS) that react with LA to release nitric oxide (NO) molecules. Utilizing the concentration-dependent effect of NO, high power density NIR irradiation applied during the early stage after implantation to release a high concentration of NO, which synergized with the photothermal effect of PDA to eliminate bacterial biofilm. Subsequently, the irradiation power density can be finely down-regulated to reduce the NO concentration in subsequent treatment for accelerating the reconstruction of blood vessels. Meanwhile, SrTiO3 nano-arrays improve the hydrophilicity of the implant surface and slowly release strontium (Sr) ions for continuously optimizing the osteogenic microenvironment. Effective biofilm elimination and revascularization alongside the continuous optimization of the osteogenic microenvironment can significantly enhance the osseointegration of the functionalized Ti implant in in vivo animal experiments.