Logic-Based Diagnostic and Therapeutic Nanoplatform with Infection and Inflammation Monitoring and Microenvironmental Regulation Accelerating Wound Repair

Elastic sac-shaped hydrogel dressing with responsive antibacterial and pro-healing in movable wounds via MOF activated ink spraying

In daily life, sports frequently cause skin injuries, particularly in movable parts such as joints. However, the frequent movement of joints can impede the proper fitting of dressings, resulting in re-tearing of the wound, an increased infection risk, and prolonged healing. Moreover, demand for skin wound dressings in movable parts has risen, as around 2.4 million joint surgeries are performed annually. Therefore, it is crucial to design an elastic wound dressing that can accommodate repeated joint movements and control wound infection responsively. In this study, a biomimetic hydrogel dressing was designed based on the inkjet behaviour of the elastic ink sac of cuttlefish through repeated extrusion. This dressing comprises a highly elastic polyether F127 diacrylate-based ink sac with micro-nozzles, along with antibacterial and pro-healing ink, metal-organic framework modified gelatin, possessing responsive release properties. With the movement rhythm, the super-elastic dressing perfectly conforms to the wounds in joints or other movable parts to absorb exudation and release therapeutic ink in response to the microenvironment to prevent infection. In conclusion, the biomimetic dressing demonstrates excellent mechanical properties with a deformation of approximately 400 %, and attains an antibacterial rate exceeding 95 %. Compared with the control group, collagen production increases by 2.6 times, and the wound healing speed is enhanced by over 20 %. Therefore, the application of the biomimetic dressing is anticipated to offer a novel approach for managing skin infection wounds in movable parts.

Near-infrared light-triggered silk fibroin hydrogels integrated with polydopamine-modified nanoparticles for enhanced wound healing and infection control

This study presents the development and evaluation of a novel silk fibroin (SF)-based hydrogel composite, SiPDA/Ag-C, enhanced with polydopamine (PDA)-modified silver nanoparticles (Ag@PDA) and PDA-modified curcumin (Cur-PDA), for skin wounds treatment and infection control. Dopamine readily oxidizes and reacts with SF to form hydrogels. By in-situ synthesizing silver nanoparticles (Ag NPs) on the surface of PDA nanospheres, Ag@PDA achieves a dual antibacterial effect. It combines the photothermal antibacterial property of PDA with the ability of Ag NPs to disrupt bacterial membranes and DNA. Coating PDA on the surface of curcumin creates Cur-PDA nanoparticles, which not only enhance curcumin's bioavailability but also integrate curcumin's anti-inflammatory and antioxidant properties with PDA's antioxidant and photothermal antibacterial capabilities. Combining Ag@PDA and Cur-PDA into the SF hydrogel matrix results in the SiPDA/Ag-C hydrogel. The hydrogel leverages the photothermal properties of PDA to achieve non-invasive wound healing under near-infrared (NIR) light irradiation. The SiPDA/Ag-C hydrogel could significantly inhibit the growth of Staphylococcus aureus and Escherichia coli in vitro and in vivo, and promote wound healing by reducing inflammation, enhancing antioxidant capacity, and stimulating tissue regeneration. In vivo study shows that compare with the treatment of SiPDA/Ag-C hydrogel alone, the combined treatment with NIR irradiation could significantly inhibit bacterial growth and improve tissue repair. The hydrogel also exhibited excellent biocompatibility, biodegradability, and minimal cytotoxic effects, making it a promising candidate for advanced wound care and tissue engineering applications.

Copper doped carbon dots modified bacterial cellulose with enhanced antibacterial and immune regulatory functions for accelerating wound healing

The microenvironment of wound healing is susceptible to bacterial infection, chronic inflammation, oxidative stress, and inadequate angiogenesis, requiring the development of innovative wound dressings with antibacterial, anti-inflammatory, antioxidant, and angiogenic capabilities. This research crafted a new multifunctional bacterial cellulose composite membrane infused with copper-doped carbon dots (BC/Cu(II)-RCDs). Findings validated the successful loading of copper-doped carbon dots onto the BC membrane via hydrogen bonding interactions. Compared to the pure BC membrane, the BC/Cu(II)-RCDs composite membrane exhibited significantly enhanced hydrophilicity, tensile properties, and thermal stability. Diverse in vitro assays demonstrated excellent biocompatibility and antibacterial activity of BC/Cu(II)-RCDs composite membranes, alongside their ability to expedite the inflammatory phase and stimulate angiogenesis. In vivo trials corroborated the membrane's ability to foster epithelial regeneration, collagen deposition, and tissue regrowth in full-thickness skin wounds in rats while also curbing inflammation in infected full-thickness skin wounds. More importantly, the treatment of the BC/Cu(II)-RCDs composite membrane may result in the activation of VEGF and MAPK signaling proteins, which are key players in cell migration, angiogenesis, and skin tissue development. In essence, the developed BC/Cu(II)-RCDs composite membrane shows promise for treating infected wounds and serves as a viable alternative material for medicinal bandages.

Concanavalin-conjugated zinc-metal-organic framework drug for pH-controlled and targeted therapy of wound bacterial infection

Wounds are prone to infection which may be fatal to the life of the patient. The use of antibiotics is essential for managing bacterial infections in wounds, but the long-term use of high doses of antibiotics may lead to bacterial drug resistance and even to creation of superbacteria. Therefore, the development of targeted antimicrobial treatment strategies and the reduction in antibiotic usage are of utmost urgency. In this study, a multifunctional nanodrug delivery system (Cef-rhEGF@ZIF-8@ConA) for the treatment of bacteriostatic infection was synthesized through self-assembly of Zn2+, cefradine (Cef) and recombinant human epidermal growth factor (rhEGF), then conjugated with concanavalin (ConA), which undergoes pH-responsive degradation to release the drugs. First, ConA can specifically combine with bacteria and inhibit the rapid release of Zn2+ ions, thus achieving a long-acting antibacterial effect. Cef exerts its antibacterial effect by inhibiting the synthesis of bacterial membrane proteins. Finally, Zn2+ ions released from the Zn-metal-organic framework (MOF) demonstrate bacteriostatic properties by enhancing the permeability of the bacterial cell membrane. Furthermore, rhEGF upregulates angiogenesis-associated genes, thereby promoting angiogenesis, re-epithelialization and wound healing processes. The results showed that Cef-rhEGF@ZIF-8@ConA has good biocompatibility, with antibacterial efficacy against Staphylococcus aureus and Escherichia coli of 99.61 % and 99.75 %, respectively. These nanomaterials can inhibit the release of inflammatory cytokines and promote the release of anti-inflammatory cytokines, while also stimulating the proliferation of fibroblasts to facilitate wound healing. Taken together, the Cef-rhEGF@ZIF-8@ConA nanosystem is an excellent candidate in clinical therapeutics for bacteriostatic infection and wound healing.

A Hydrogel Dressing Comprised of Silk Fibroin, Ag Nanoparticles, and Reduced Graphene Oxide for NIR Photothermal-Enhanced Antibacterial Efficiency and Skin Regeneration

Bacterial infection, inflammation, and excessive oxidative stress are the primary factors that contribute to delayed healing of skin wounds. In this study, a multifunctional wound dressing (SF/Ag@rGO hydrogel) is developed to promote the healing of infected skin wounds by combining the inherent antibacterial activity of Ag nanoparticles (NPs) with near-infrared (NIR)-assisted antibacterial therapy. Initially, L-ascorbic acid is used as a reducing agent and PVP-K17 as a stabilizer and dispersant, this facilitates the synthesis of reduced graphene oxide loaded with Ag NPs (Ag@rGO). Ag@rGO is then blended with a silk fibroin (SF) solution to form an instantly gelling SF/Ag@rGO hydrogel that exhibits rapid self-healing, injectability, shape adaptability, NIR responsiveness, antioxidant, high tissue adhesion, and robust mechanical properties. In vitro and in vivo experiments show that the SF/Ag@rGO hydrogel demonstrates strong antioxidant and photothermal antibacterial capabilities, promoting wound healing through angiogenesis, stimulating collagen generation, alleviating inflammation, antioxidant, and promoting cell proliferation, indicating that the SF/Ag@rGO hydrogel dressing is an ideal candidate for clinical treatment of full-thickness bacterial-stained wounds.

Mechanochemically Reprogrammed Tantalum Interfaces Enhance Osseointegration Via Immunomodulation

Bone and tooth defects can considerably affect the quality of life and health of patients, and orthopedic implants remain the primary method of addressing such defects. However, implant materials cannot coordinate with the immune microenvironment because of their biological inertness, which may lead to implant loosening or failure. Motivated by the microstructure of nacre, we engineered a biomimetic micro/nanoscale topography on a tantalum surface using a straightforward method. This comprised an organized array of tantalum nanotubes arranged in a brick wall structure, with epigallocatechin gallate acting as "mortar." The coating improved the corrosion resistance, biocompatibility, and antioxidant properties. In vitro and in vivo evaluations further confirmed that coatings can create a favorable bone immune microenvironment through the synergistic effects of mechanochemistry and enhance bone integration. This research offers a new viewpoint on the creation of sophisticated functional implants, possessing vast potential for use in the regeneration and repair of bone tissue.

ZIF-8-Modified Black Phosphorus Nanosheets Incorporated into Injectable Dual-Component Hydrogels for Enhanced Photothermal Antibacterial and Osteogenic Activities

The development of growth factor-free biomaterials for bone tissue regeneration with anti-infection and anti-inflammatory activities remains challenging. Black phosphorus nanosheets (BPNs), with distinctive attributes, including photothermal conversion and calcium ion chelation, offer potential for use in bone tissue engineering and infection prevention. However, BPNs are prone to oxidation and degradation in aqueous environments, and methods to stabilize BPNs for long-term bone repair remain insufficient. Herein, zeolitic imidazolate framework-8 (ZIF-8) was used to stabilize BPNs via in situ crystallization onto the surface of BPNs (BP@ZIF-8 nanocomposite). A novel injectable dual-component hydrogel comprising gelatin methacryloyl (GelMA) and methacrylate-modified hyaluronic acid (HAMA) was used as a BP@ZIF-8 nanocomposite carrier (GelMA/HAMA/BP@ZIF-8). The BP@ZIF-8 nanocomposite could effectively protect internal BPNs from oxidation and enhance the long-term photothermal performance of the hydrogel in both in vitro and in vivo settings. The GelMA/HAMA/BP@ZIF-8 hydrogel was injectable and exhibited outstanding performance for photothermal conversion, mechanical strength, and biodegradability, as well as excellent photothermal antibacterial activity against Staphylococcus aureus and Escherichia coli in vitro and in an in vivo rat model. The GelMA/HAMA/BP@ZIF-8 hydrogel also provided a microenvironment conducive to osteogenic differentiation, promoting the transformation of M2 macrophages and inhibiting inflammatory responses. Furthermore, the hydrogel promoted bone regeneration and had a synergistic effect with near-infrared irradiation in a rat skull-defect model. Transcriptome sequencing analysis revealed that the PI3K-AKT- and calcium-signaling pathways may be involved in promoting osteogenic differentiation induced by the GH-BZ hydrogel. This study presents an innovative, multifaceted solution to the challenges of bone tissue regeneration with antibacterial and anti-inflammatory effects, providing insights into the design of smart biomaterials with dual therapeutic capabilities.

Iron-doped nanozymes with spontaneous peroxidase-mimic activity as a promising antibacterial therapy for bacterial keratitis

The development of non-antibiotic pharmaceuticals with biocompatible and efficient antibacterial properties is of great significance for the treatment of bacterial keratitis. In this study, we have developed antibacterial iron-doped nanozymes (Fe3+-doped nanozymes, FNEs) with distinguished capacity to fight against bacterial infections. The iron-doped nanozymes are composed of Fe3+ doped zeolitic imidazolate framework-8 (Fe/ZIF-8) and polyethylene imide (PEI), which were functionally coated on the surface of Fe/ZIF-8 and imparted the FNEs with improved water dispersibility and biocompatibility. FNEs possess a significant spontaneous peroxidase-mimic activity without the need for external stimulation, thus elevating cellular reactive oxygen species level by catalyzing local H2O2 at the infection site and resulting in bacteria damaged to death. FNEs eliminated 100% of Staphylococcus aureus within 6 h, and significantly relieved inflammation and bacterial infection levels in mice bacterial keratitis, exhibiting higher bioavailability and a superior therapeutic effect compared to conventional antibiotic eye drops. In addition, the FNEs would not generate drug resistance, suggesting that FNEs have great potential in overcoming infectious diseases caused by antimicrobial resistant bacteria.

Developing a Selection Framework for Zinc Ion-Based Biomaterial Design: Guided by the Biosafety Assessment of ZIF-8 and ZnO

In recent years, nanomaterials have gained widespread use in the biomedical field, with ZIF-8 and ZnO emerging as promising candidates due to their remarkable performance in osteogenesis, angiogenesis, and antimicrobial therapy. However, before advancing these nanomaterials for clinical applications, it is imperative to evaluate their biocompatibility. In particular, comparing nanomaterials with similar biomedical functions is crucial for identifying the most suitable nanomaterials for further development and market entry. Our study aimed to compare the biocompatibility of nano-ZIF-8 and nano-ZnO under the same conditions. We found that nano-ZIF-8 exhibited lower toxicity both in vitro and in vivo compared to nano-ZnO. To gain insights into the underlying mechanisms responsible for this difference, we conducted further experiments to investigate lysosome damage, mitochondrial change, and the occurrence of ferroptosis. Additionally, we performed transcriptome sequencing to analyze the expression of relevant genes, thereby providing robust validation for our findings. In summary, our study highlighted the importance of evaluating nanomaterials with similar biomedical effects. Through this comparative study, we have not only shed light on the superior biocompatibility of nano-ZIF-8 over nano-ZnO, but also contributed valuable insights and methodological references for future material screening endeavors. Ultimately, our study served as a stepping stone toward the development of safer and more effective nanomaterials for various biomedical applications.

Advances in Immunomodulatory MOFs for Biomedical Applications

Given the crucial role of immune system in the occurrence and progression of various diseases such as cancer, wound healing, bone defect, and inflammation-related diseases, immunomodulation is recognized as a potential solution for treatment of these diseases. Immunomodulation includes both immunosuppression in hyperactive immune conditions and immune activation in hypoactive conditions. For these purposes, metal-organic frameworks (MOFs) are investigated to modulate immune responses either by their own bioactivities or by delivering immunomodulatory agents due to their excellent biodegradability and high delivery capacity. This review starts with an overview of the synthesis strategies of immunomodulatory MOFs, followed by a summarization on the latest applications of immunomodulatory MOFs in cancer immunomodulatory, wound healing, inflammatory disease, and bone tissue engineering. A variety of design considerations, in order to optimize immunomodulatory properties and efficacy of MOFs, is also involved. Last, the challenges and perspectives of future research, which are expected to provide researchers with new insight into the design and application of immunomodulatory MOFs, are discussed.

Multifunctional hydrogel bioscaffolds based on polysaccharide to promote wound healing: A review

Various types of skin wounds pose challenges in terms of healing and susceptibility to infection, which can have a significant impact on physical and mental well-being, and in severe cases, may result in amputation. Conventional wound dressings often fail to provide optimal support for these wounds, thereby impeding the healing process. As a result, there has been considerable interest in the development of multifunctional polymer matrix hydrogel scaffolds for wound healing. This review offers a comprehensive review of the characteristics of polysaccharide-based hydrogel scaffolds, as well as their applications in different types of wounds. Additionally, it evaluates the advantages and disadvantages associated with various types of multifunctional polymer and polysaccharide-based hydrogel scaffolds. The objective is to provide a theoretical foundation for the utilization of multifunctional hydrogel scaffolds in promoting wound healing.

Therapeutic Potential Evaluation of Silk Sericin Stabilized Fisetin to Ulcerative Colitis

Ulcerative colitis is a chronic inflammatory bowel disease with a high recurrence rate. Natural phytochemical compounds are increasingly being considered as preventative and supportive treatments for this condition. However, the poor water solubility and stability of many of these compounds limit their effectiveness in vivo. To address this issue, fisetin (FT), a natural phytochemical with poor solubility, is stabilized using silk sericin (SS) to create a composite (SS/FT). The therapeutic potential of the SS/FT on ulcerative colitis is extensively investigated, and the results showed that it effectively alleviated the body weight loss and colon length shortening induced by dextran sulfate sodium. Notably, SS/FT downregulated the immune response, decreased colonic histopathological lesions, and reduced the cGAS/STING signal activation. This suggests that SS/FT may offer a promising therapy for treating ulcerative colitis.

Quorum Sensing Interference Assisted Therapy-Based Magnetic Hyperthermia Amplifier for Synergistic Biofilm Treatment

Biofilms offer bacteria a physical and metabolic barrier, enhancing their tolerance to external stress. Consequently, these biofilms limit the effectiveness of conventional antimicrobial treatment. Recently, quorum sensing (QS) has been linked to biofilm's stress response to thermal, oxidative, and osmotic stress. Herein, a multiple synergistic therapeutic strategy that couples quorum sensing interference assisted therapy (QSIAT)-mediated enhanced thermal therapy with bacteria-triggered immunomodulation in a single nanoplatform, is presented. First, as magnetic hyperthermia amplifier, hyaluronic acid-coated ferrite (HA@MnFe2 O4 ) attenuates the stress response of biofilm by down-regulating QS-related genes, including agrA, agrC, and hld. Next, the sensitized bacteria are eliminated with magnetic heat. QS interference and heat also destruct the biofilm, and provide channels for further penetration of nanoparticles. Moreover, triggered by bacterial hyaluronidase, the wrapped hyaluronic acid (HA) decomposes into disaccharides at the site of infection and exerts healing effect. Thus, by reversing the bacterial tissue invasion mechanism for antimicrobial purpose, tissue regeneration following pathogen invasion and thermal therapy is successfully attained. RNA-sequencing demonstrates the QS-mediated stress response impairment. In vitro and in vivo experiments reveal the excellent antibiofilm and anti-inflammatory effects of HA@MnFe2 O4 . Overall, QSIAT provides a universal enhancement strategy for amplifying the bactericidal effects of conventional therapy via stress response interference.

Multifunctional MXene-doped photothermal microneedles for drug-resistant bacteria-infected wound healing

Skin injuries and drug-resistant bacterial infections pose serious challenges to human health. It is essential to establish a novel multifunctional platform with good anti-infection and wound-healing abilities. In this study, a new MXene-doped composite microneedle (MN) patch with excellent mechanical strength and photothermal antibacterial and ROS removal properties has been developed for infected wound healing. When the MN tips carrying the MXene nanosheets are inserted into the cuticle of the skin, they will quickly dissolve and subsequently release the nanomaterials into the subcutaneous infection area. Under 808 nm NIR irradiation, the MXene, as a "nano-thermal knife", sterilizes and inhibits bacterial growth through synergistic effects of sharp edges and photothermal antibacterial activity. Furthermore, ROS caused by injury and infection can be cleared by MXene-doped MNs to avoid excessive inflammatory responses. Based on the synergistic antibacterial and antioxidant strategy, the MXene-doped MNs have demonstrated excellent wound-healing properties in an MRSA-infected wound model, such as promoting re-epithelialization, collagen deposition, and angiogenesis and inhibiting the expression of pro-inflammatory factors. Therefore, the multifunctional MXene-doped MN patches provide an excellent alternative for clinical drug-resistant bacteria-infected wound management.

Nanosized Silk-Magnesium Complexes for Tissue Regeneration

Metal ions provide multifunctional signals for cell and tissue functions, including regeneration. Inspired by metal-organic frameworks (MOFs), nanosized silk protein aggregates with a high negative charge density are used to form stable silk-magnesium ion complexes. Magnesium ions (Mg ions) are added directly to silk nanoparticle solutions, inducing gelation through the formation of silk-Mg coordination complexes. The Mg ions are released slowly from the nanoparticles through diffusion, with sustained release via tuning the degradation or dissolution of the nanosized silk aggregates. Studies in vitro reveal a dose-dependent influence of Mg ions on angiogenic and anti-inflammatory functions. Silk-Mg ion complexes in the form of hydrogels also stimulate tissue regeneration with a reduced formation of scar tissue in vivo, suggesting potential utility in tissue regeneration.

Porous Silicon Carrier Endowed with Photothermal and Therapeutic Effects for Synergistic Wound Disinfection

Drug carriers endowed with photothermal effects will allow the drug delivery system to release drugs in a thermal-stimuli manner. In addition, the photothermal therapy (PTT) will also interplay with therapeutic drugs loaded in the carrier to exhibit synergistic bioactivity for various disease treatment. However, endowing the drug carrier with photothermal and synergistic therapeutic effects still has challenge. Herein, we demonstrate that surface modification of porous silicon (PSi) with polydopamine (PDA) could endow the classical drug carrier with a significant photothermal effect for advanced antibacterial therapy and wound disinfection. Specifically, the PSi surface interacts with a Cu²⁺/PDA complex via a simple and fast surface reduction-induced deposition method, forming the unique CuPDA coated PSi microcarrier (CuPPSi) without blocking the mesoporous structure. The CuPPSi carrier generates a higher near-infrared (NIR) photothermal efficiency and improved drug loading capacity owing to the abundant functional groups of PDA. Stimuli-responsive release of antibacterial Cu²⁺ and loaded curcumin (Cur) from CuPPSi can be realized under multiple stimuli including pH, reactive oxygen species and NIR laser irradition. Benefited from the carrier's intrinsic multimodal therapy, the CuPPSi-Cur platform exhibits amplified, broad-spectrum, and synergistic antibacterial effect, killing more than 98% for both Staphylococcus aureus and Escherichia coli at a mild PTT temperature (∼45 °C). Notably, the combined therapy promotes migration of fibroblasts with no significant cytotoxicity as revealed through cell experiments in vitro. In bacteria-infected mice model, efficient bacterial ablation and wound healing are further demonstrated with negligible side effects in vivo. Overall, the rational design of a drug carrier with photothermal and therapeutic effects provides a novel intervention for amplifing wound disinfection clinically.