Mechanical Force Induced Self-Assembly of Chinese Herbal Hydrogel with Synergistic Effects of Antibacterial Activity and Immune Regulation for Wound Healing

Network pharmacological study and in vitro studies validation-Molecular dynamics simulation of Cistanche deserticola in promoting periodontitis and bone remodeling

OBJECTIVE

Periodontitis is a chronic infectious disease, characterized by loss of alveolar bone and supporting tissues. Cistanche deserticola(Cd), a local medicinal herb in Xinjiang, possesses favorable biological characteristics and potential applications. Our aim is to investigate the remodeling properties of Cd extract and elucidate the specific mechanisms underlying its therapeutic effects on periodontitis, by employing a combination of basic experimental and network pharmacology approaches.

METHODS

Firstly, UHPLC-QTOF-MS analysis was conducted on Cd extract to identify its main components, with several compounds were identified by standard. Subsequently, in vitro studies were performed using the Cd extract on MC3T3-E1 cells. Cell proliferation viability was assessed using CCK-8 and apoptosis assays, while ALP and ARS staining and quantitative experiments, qRT-PCR, and Western blot assays were employed to evaluate the osteogenic differentiation capability. Network pharmacology analysis was then carried out using the identified compounds to establish a database of Cd components and targets, along with a database of periodontitis. The intersection of these databases revealed the network relationship between Cd components-mapped genes-signaling pathways. KEGG/GO pathway analysis of the targets was performed to filter potential enriched pathways. PPI/CytoHubba protein interaction network analysis was utilized to identify hub genes. Molecular docking and molecular dynamics simulations were employed to analyze the docking and interaction between core gene and Cd components.

RESULTS

We detected 38 major components in the Cd extract, with Echinacoside, Acteoside, Tubuloside A, and Cistanoside A undergoing standard substance verification. In vitro studies indicated that the Cd, at concentrations below 100 μg/ mL, did not affect cell proliferation and inhibited apoptosis. Osteogenesis assays demonstrated that Cd at concentrations of 1 μg/ mL, 10 μg/ mL, and 100 μg/ mL significantly promoted the osteogenic differentiation ability of MC3T3-E1 cells. It also notably upregulated the mRNA and protein levels of Alp, Bmp2, Runx2, and Opn, and the optimal concentration was 10 μg/mL. Network pharmacology results revealed the network relationship between Cd's components, crossed targets and signaling pathways. Combined with KEGG/GO pathway analysis and PPI/CytoHubba protein interaction network analysis. The key pathway and hub genes of Cd regulating periodontitis are both related to hypoxia pathway and HIF-1α. Molecular docking results showed a strong binding affinity between Cd compounds and hub genes, and molecular dynamics simulation results indicated the stability of the complexes formed between HIF-1α and several Cd compounds.

CONCLUSION

Cistanche deserticola exhibits a notable capacity to promote bone regeneration, and its mechanism of action in regulating periodontitis is associated with the hypoxia signaling pathway. HIF-1α may serve as a potential core gene. Future research will focus on exploring the mechanism of Cd in intervene periodontitis and promoting bone remodeling in hypoxic environment.

Self-Healing Guar Gum-Based Nanocomposite Hydrogel Promotes Infected Wound Healing through Photothermal Antibacterial Therapy

Preventing bacterial infections is a crucial aspect of wound healing. There is an urgent need for multifunctional biomaterials without antibiotics to promote wound healing. In this study, we fabricated a guar gum (GG)-based nanocomposite hydrogel, termed GBTF, which exhibited photothermal antibacterial therapy for infected wound healing. The GBTF hydrogel formed a cross-linked network through dynamic borate/diol interactions between GG and borax, thereby exhibiting simultaneously self-healing, adaptable, and injectable properties. Additionally, tannic acid (TA)/Fe3+ nanocomplexes (NCs) were incorporated into the hydrogel to confer photothermal antibacterial properties. Under the irradiation of an 808 nm near-infrared laser, the TA/Fe3+ NCs in the hydrogel could rapidly generate heat, leading to the disruption of bacterial cell membranes and subsequent bacterial eradication. Furthermore, the hydrogels exhibited good cytocompatibility and hemocompatibility, making them a precandidate for preclinical and clinical applications. Finally, they could significantly promote bacteria-infected wound healing by reducing bacterial viability, accelerating collagen deposition, and promoting epithelial remodeling. Therefore, the multifunctional GBTF hydrogel, which was composed entirely of natural substances including guar gum, borax, and polyphenol/ferric ion NCs, showed great potential for regenerating infected skin wounds in clinical applications.

The Combination of Bioactive Herbal Compounds with Biomaterials for Regenerative Medicine

Regenerative medicine aims to restore the function of diseased or damaged tissues and organs by cell therapy, gene therapy, and tissue engineering, along with the adjunctive application of bioactive molecules. Traditional bioactive molecules, such as growth factors and cytokines, have shown great potential in the regulation of cellular and tissue behavior, but have the disadvantages of limited source, high cost, short half-life, and side effects. In recent years, herbal compounds extracted from natural plants/herbs have gained increasing attention. This is not only because herbal compounds are easily obtained, inexpensive, mostly safe, and reliable, but also owing to their excellent effects, including anti-inflammatory, antibacterial, antioxidative, proangiogenic behavior and ability to promote stem cell differentiation. Such effects also play important roles in the processes related to tissue regeneration. Furthermore, the moieties of the herbal compounds can form physical or chemical bonds with the scaffolds, which contributes to improved mechanical strength and stability of the scaffolds. Thus, the incorporation of herbal compounds as bioactive molecules in biomaterials is a promising direction for future regenerative medicine applications. Herein, an overview on the use of bioactive herbal compounds combined with different biomaterial scaffolds for regenerative medicine application is presented. We first introduce the classification, structures, and properties of different herbal bioactive components and then provide a comprehensive survey on the use of bioactive herbal compounds to engineer scaffolds for tissue repair/regeneration of skin, cartilage, bone, neural, and heart tissues. Finally, we highlight the challenges and prospects for the future development of herbal scaffolds toward clinical translation. Overall, it is believed that the combination of bioactive herbal compounds with biomaterials could be a promising perspective for the next generation of regenerative medicine.

A Mesoporous Silica-Loaded Multi-Functional Hydrogel Enhanced Tendon Healing via Immunomodulatory and Pro-Regenerative Effects

Tendon injuries are pervasive orthopedic injuries encountered by the general population. Nonetheless, recovery after severe injuries, such as Achilles tendon injury, is limited. Consequently, there is a pressing need to devise interventions, including biomaterials, that foster tendon healing. Regrettably, tissue engineering treatments have faced obstacles in crafting appropriate tissue scaffolds and efficacious nanomedical approaches. To surmount these hurdles, an innovative injectable hydrogel (CP@SiO2), comprising puerarin and chitosan through in situ self-assembly, is pioneered while concurrently delivering mesoporous silica nanoparticles for tendon healing. In this research, CP@SiO2 hydrogel is employed for the treatment of Achilles tendon injuries, conducting extensive in vivo and in vitro experiments to evaluate its efficacy. This reults demonstrates that CP@SiO2 hydrogel enhances the proliferation and differentiation of tendon-derived stem cells, and mitigates inflammation through the modulation of macrophage polarization. Furthermore, using histological and behavioral analyses, it is found that CP@SiO2 hydrogel can improve the histological and biomechanical properties of injured tendons. This findings indicate that this multifaceted injectable CP@SiO2 hydrogel constitutes a suitable bioactive material for tendon repair and presents a promising new strategy for the clinical management of tendon injuries.

Developing Chinese herbal-based functional biomaterials for tissue engineering

The role of traditional Chinese medicine (TCM) in treating diseases is receiving increasing attention. Chinese herbal medicine is an important part of TCM with various applications and the active ingredients extracted from Chinese herbal medicines have physiological and pathological effects. Tissue engineering combines cell biology and materials science to construct tissues or organs in vitro or in vivo. TCM has been proposed by the World Health Organization as an effective treatment modality. In recent years, the potential use of TCM in tissue engineering has been demonstrated. In this review, the classification and efficacy of TCM active ingredients and delivery systems are discussed based on the TCM theory. We also summarized the current application status and broad prospects of Chinese herbal active ingredients in different specialized biomaterials in the field of tissue engineering. This review provides novel insights into the integration of TCM and modern Western medicine through the application of Chinese medicine in tissue engineering and regenerative medicine.

Enhancing Chronic Wound Healing through Engineering Mg2+-Coordinated Asiatic Acid/Bacterial Cellulose Hybrid Hydrogels

Infectious chronic wounds have gradually become a major clinical problem due to their high prevalence and poor treatment outcomes. The urgent need for wound dressings with immune modulatory, antibacterial, and angiogenic properties has led to the development of innovative solutions. Asiatic acid (AA), derived from herbs, has demonstrated excellent antibacterial, anti-inflammatory, and angiogenic effects, making it a promising candidate for incorporation into hydrogel carriers for wound healing. However, there is currently no available report on AA-based self-assembled hydrogels. Here, a novel hybrid hydrogel dressing consists of interpenetrating polymer networks composed of self-assembled magnesium ion (Mg2+) coordinated asiatic acid (AA-Mg) and bacterial cellulose (BC) is developed to promote infected chronic wound healing. A natural carrier-free self-assembled AA-Mg hydrogel with good injectable and self-healing properties could maintain the sustained release of AA and Mg2+ over an extended period. Notably, the introduction of Mg2+ boosted some pharmacological effects of self-assembled hydrogels due to its excellent anti-inflammatory and angiogenesis. In vitro studies confirmed the exceptional biocompatibility, antibacterial efficacy, and anti-inflammatory potential of the AA-Mg/BC hybrid hydrogel, which also exhibited a commendable mechanical strength. Furthermore, in vivo biological results displayed that the hybrid hydrogel significantly accelerated the wound healing process by boosting dense and organized collagen deposition and the granulation tissue and benefiting revascularization. The introduced self-assembled AA-Mg-based hydrogel offers a promising solution for the effective management of chronic wounds. This universal strategy for the preparation of self-assembled hydrogels modulated with bioactive divalent metal ions is able to excavate more herbal small molecules to construct new self-assembled biomaterials.

Construction of antibacterial bone implants and their application in bone regeneration

Bacterial infection represents a prevalent challenge during the bone repair process, often resulting in implant failure. However, the extensive use of antibiotics has limited local antibacterial effects at the infection site and is prone to side effects. In order to address the issue of bacterial infection during the transplantation of bone implants, four types of bone scaffold implants with long-term antimicrobial functionality have been constructed, including direct contact antimicrobial scaffold, dissolution-penetration antimicrobial scaffold, photocatalytic antimicrobial scaffold, and multimodal synergistic antimicrobial scaffold. The direct contact antimicrobial scaffold involves the physical penetration or disruption of bacterial cell membranes by the scaffold surface or hindrance of bacterial adhesion through surface charge, microstructure, and other factors. The dissolution-penetration antimicrobial scaffold releases antimicrobial substances from the scaffold's interior through degradation and other means to achieve local antimicrobial effects. The photocatalytic antimicrobial scaffold utilizes the absorption of light to generate reactive oxygen species (ROS) with enhanced chemical reactivity for antimicrobial activity. ROS can cause damage to bacterial cell membranes, deoxyribonucleic acid (DNA), proteins, and other components. The multimodal synergistic antimicrobial scaffold involves the combined use of multiple antimicrobial methods to achieve synergistic effects and effectively overcome the limitations of individual antimicrobial approaches. Additionally, the biocompatibility issues of the antimicrobial bone scaffold are also discussed, including in vitro cell adhesion, proliferation, and osteogenic differentiation, as well as in vivo bone repair and vascularization. Finally, the challenges and prospects of antimicrobial bone implants are summarized. The development of antimicrobial bone implants can provide effective solutions to bacterial infection issues in bone defect repair in the foreseeable future.

Hydrogel-Functionalized Bandages with Janus Wettability for Efficient Unidirectional Drug Delivery and Wound Care

Chronic wounds have imposed a severe physical and economic burden on the global healthcare system, which are usually treated by the delivery of drugs or bioactive molecules to the wound bed through wound dressings. In this work, we have demonstrated a hydrogel-functionalized bandage with Janus wettability in a bilayer structure to achieve unidirectional drug delivery and multifunctional wound care. The Janus patterned bandage with porous gradient wetting channels on the upper layer is responsible for the unidirectional transport of the drug from the outside to the wound bed (up to 90% drug transport efficiency) while preventing drug diffusion in unwanted directions (<8%). The hydrogel composed of chitosan quaternary ammonium salt (HACC), poly(vinyl alcohol) (PVA), and poly(acrylic acid) (PAA) at the bottom layer further functionalized such a bandage with biocompatibility, excellent antibacterial properties, and hemostatic ability to promote wound healing. Especially, the hydrogel-functionalized bandage with Janus wettability exhibits excellent mechanical flexibility (∼198% strain), which can comply well with skin deformation (stretching, bending, or twisting) and maintain unidirectional drug delivery behavior without any leakage. The in vivo full-thickness skin wound model confirms that the hydrogel-functionalized bandage can significantly facilitate epithelialization and collagen deposition and improve drug delivery efficiency, thus promoting wound closure and healing (the wound healing ratio was 98.10% at day 15). Such a synergistic strategy of unidirectional drug delivery and multifunctional wound care provides a more efficient, economical, and direct method to promote wound healing, which could be used as a potential high-performance wound dressing for clinical application.

MOF-derived Co-Ni layered double hydroxides/polyethyleneimine modified chitosan micro-nanoreactor for high-efficiency capture of uranium from seawater

The preparation of powder adsorbent into microsphere adsorbent is one of the effective methods for the industrialization of uranium extraction from seawater. Herein, a MOF-derived Co-Ni layered double hydroxides/polyethyleneimine modified chitosan micro-nanoreactor (DNPM) was prepared by a simple method in this work. The microstructure and chemical structure of DNPM were comprehensively characterized. The pH value, adsorption time, initial solution concentration, temperature, competitive ions, regeneration performance, and bed column heights were investigated for the adsorption performance of DNPM by batch adsorption and fixed-bed column continuous adsorption experiments. When the contact time was 8 h, the initial concentration was 150 mg/L, and the pH value was 6, the adsorption capacity of DNPM was 334.67 mg/g. The uranium adsorption by DNPM fits with the pseudo-second-order kinetic and Langmuir models, which was a spontaneous and endothermic process. In addition, DNPM has good adsorption selectivity and reusability. The fixed-bed column continuous adsorption experiment shows that the adsorption capacity increased with the increase of bed column height. The adsorption mechanism can be attributed to coordination chelation and electrostatic interaction. In general, this work provides an effective strategy for developing environmentally friendly uranium adsorbent that can be industrially used.

Wool keratin/zeolitic imidazolate framework-8 composite shape memory sponge with synergistic hemostatic performance for rapid hemorrhage control

Uncontrollable hemorrhage and subsequent wound infection pose severe threats to life, especially in the case of deep, non-compressible, massive bleeding. Here, a wool keratin/zeolitic imidazolate framework-8 (WK/ZIF-8) composite shape memory sponge is prepared by incorporating ZIF-8 nanoparticles into wool keratin. The combination of keratin and ZIF-8 particles not only reduces the effect of ZIF-8 particles on cell viability but also bolsters the mechanical properties of the keratin sponge and endows it with antibacterial efficacy. Due to the synergistic effect of the excellent hemostatic performance of keratin and Zn2+ release from ZIF-8 nanoparticles, the porous structure suitable for blood cell adhesion and the shape recovery ability of sponges, the WK/ZIF-8 composite sponge exhibits superior hemostatic performance to commercial medical sponges in SD rat and rabbit hemorrhage models. In addition, in vitro and in vivo antibacterial experiments demonstrate the anti-infection activity of the composite sponge. Overall, the WK/ZIF-8 composite sponge provides a promising approach to rapidly control bleeding and promote wound healing.

Hydrophobic Tetracycline Immobilized in Fibrous Hyaluronan Regulates Adhesive Collagen-Based Hydrogel Stability for Infected Wound Healing

Collagen-based hydrogels have a significant impact on wound healing, but they suffer from structural instability and bacterial invasion in infected wounds. Here, electrospun nanofibers of esterified hyaluronan (HA-Bn/T) are developed to immobilize the hydrophobic antibacterial drug tetracycline by π-π stacking interaction. Dopamine-modified hyaluronan and HA-Bn/T are employed simultaneously to stabilize the structure of collagen-based hydrogel by chemically interweaving the collagen fibril network and decreasing the rate of collagen degradation. This renders it injectable for in situ gelation, with suitable skin adhesion properties and long-lasting drug release capability. This hybridized interwoven hydrogel promotes the proliferation and migration of L929 cells and vascularization in vitro. It presents satisfactory antibacterial ability against Staphylococcus aureus and Escherichia coli. The structure also retains the functional protein environment provided by collagen fiber, inhibits the bacterial environment of infected wounds, and modulates local inflammation, resulting in neovascularization, collagen deposition, and partial follicular regeneration. This strategy offers a new solution for infected wound healing.

Microenvironment-responsive Cu-phenolic networks coated nanofibrous dressing with timely macrophage phenotype transition for chronic MRSA infected wound healing

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a pressing clinical issue that impedes wound healing. Pro-inflammatory M1 macrophages is required to clear bacteria and recruit various cell types during the initial phase of wound healing, but timing of this process is crucial. Herein, a microenvironment-responsive nanofibrous dressing capable of timely macrophage phenotype transition in vivo is constructed by coating copper ions (Cu2+)-polydopamine (PDA) networks on poly (ε-caprolactone) fiber (PCL-fiber) membrane. During the initial post-implantation period, the nanofibrous dressing show pH-sensitive Cu2+ release in the acidic infection microenvironment. The release Cu2+ have a direct killing effect on MRSA, and promote the proinflammatory M1 phenotype of macrophages to enhance the antibacterial macrophage response. Later, PDA to become a reactive oxygen species (ROS) scavenger when in microenvironments with elevated ROS levels, which conferred the dressing with an immunomodulatory activity that convert M1 macrophages into M2 macrophages. In vivo examination in an MRSA infected full-thickness skin wounds of rat model demonstrates that this dressing significantly facilitated infection eradication and wound healing through modulating local inflammatory phenotype. Overall, this study offers a simple and effective approach for timely manipulation of inflammation progression to promote infected wound healing.

Animal tissue-derived biomaterials for promoting wound healing

The skin serves as the primary barrier between the human body and external environment, and is therefore susceptible to damage from various factors. In response to this challenge, animal tissue-derived biomaterials have emerged as promising candidates for wound healing due to their abundant sources, low side-effect profiles, exceptional bioactivity, biocompatibility, and unique extracellular matrix (ECM) mimicry. The evolution of modern engineering technology and therapies has allowed these animal tissue-derived biomaterials to be transformed into various forms and modified to possess the necessary properties for wound repair. This review provides an overview of the wound healing process and the factors that influence it. We then describe the extraction methods, important properties, and recent practical applications of various animal tissue-derived biomaterials. Our focus then shifts to the critical properties of these biomaterials in skin wound healing and their latest research developments. Finally, we critically examine the limitations and future prospects of biomaterials generated from animal tissues in this field.

An Integrally Formed Janus Hydrogel for Robust Wet-Tissue Adhesive and Anti-Postoperative Adhesion

Facile fabrication of asymmetrically adhesive hydrogel with robust wet tissue adhesion simultaneously with effective anti-postoperative adhesion still remains a great challenge. In this work, an integrally formed Janus hydrogel is facilely fabricated in one step by controlling the interfacial distribution of free carboxyl groups on the two sides of hydrogels. At a lower stirring speed, the generated bigger sized emulsion droplets mainly occupy the top surface of hydrogel, which effectively hinders the exposition of carboxyl groups on the top surface, driving them to be more distributed on the bottom surface, ultimately resulting in the poor adhesion of top surface but robust adhesion of bottom surface to various wet tissue even underwater. The difference in adhesive strength achieves as high as 20 times between the two surfaces. In vivo rabbit experiment outcomes clearly validate that the bottom surface of hydrogel firmly adheres to the stomach defect, and the other opposite surface can efficiently address the postoperative adhesion problem. Besides, this hydrogel exhibits superior mechanical toughness and conductivity which has been used as a highly adhesive strain sensor to real-time monitor the beating heart in vivo. This simple yet effective strategy provides a much more feasible approach for creating Janus hydrogels bioadhesives.

Bioinspired Polyacrylic Acid-Based Dressing: Wet Adhesive, Self-Healing, and Multi-Biofunctional Coacervate Hydrogel Accelerates Wound Healing

Polyacrylic acid (PAA) and its derivatives are commonly used as essential matrices in wound dressings, but their weak wet adhesion restricts the clinical application. To address this issue, a PAA-based coacervate hydrogel with strong wet adhesion capability is fabricated through a facile mixture of PAA copolymers with isoprenyl oxy poly(ethylene glycol) ether and tannic acid (TA). The poly(ethylene glycol) segments on PAA prevent the electrostatic repulsion among the ionized carboxyl groups and absorbed TA to form coacervates. The absorbed TA provides solid adhesion to dry and wet substrates via multifarious interactions, which endows the coacervate with an adhesive strength to skin of 23.4 kPa and 70% adhesion underwater. This coacervate achieves desirable self-healing and extensible properties suitable for frequently moving joints. These investigations prove that the coacervate has strong antibacterial activity, facilitates fibroblast migration, and modulates M1/M2 polarization of macrophages. In vivo hemorrhage experiments further confirm that the coacervate dramatically shortens the hemostatic time from hundreds to tens of seconds. In addition, full-thickness skin defect experiments demonstrate that the coacervate achieves the best therapeutic effect by significantly promoting collagen deposition, angiogenesis, and epithelialization. These results demonstrate that a PAA-based coacervate hydrogel is a promising wound dressing for medical translation.

Synthesis and evaluation of water-soluble imidazolium salt chitin with broad-spectrum antimicrobial activity and excellent biocompatibility for infected wound healing

Infections caused by bacteria have long constituted a major threat to human health and the economy. Therefore, there is an urgent need to design broad-spectrum antibacterial materials possessing good biocompatibility to treat such infections. Herein, inspired by the good biocompatibility of chitin and antibacterial properties of imidazolium salts, a polysaccharide-based material, imidazolium salt chitin (IMSC), was homogeneously prepared using a facile method with epichlorohydrin as a chemical crosslinker to combine chitin with imidazole to enhance Staphylococcus aureus (S. aureus)-infected wound healing. The characteristics, antimicrobial properties, and biosafety of IMSC were evaluated. The results demonstrated successful grafting of imidazole onto chitin. Furthermore, IMSC exhibited good water solubility, broad-spectrum antimicrobial activity, hemocompatibility, and biocompatibility. Moreover, IMSC enabled complete healing of S. aureus-infected wound in Sprague-Dawley rats within 15 days of application, thus demonstrating that IMSC could reduce wound inflammation and remarkably accelerate wound healing owing to its efficient antibacterial activity and ability to promote collagen deposition in and around the wound area. Therefore, this study provides a promising and potential therapeutic strategy for infected wound healing by synthesizing a water-soluble and broad-spectrum antimicrobial material exhibiting good biocompatibility.

Why traditional herbal medicine promotes wound healing: Research from immune response, wound microbiome to controlled delivery

Impaired wound healing in chronic wounds has been a significant challenge for clinicians and researchers for decades. Traditional herbal medicine (THM) has a long history of promoting wound healing, making them culturally accepted and trusted by a great number of people in the world. However, for a long time, the understanding of herbal medicine has been limited and incomplete, particularly in the allopathic medicine-dominated research system. The therapeutic effects of individual components isolated from THM are found less pronounced compared to synthetic chemical medicine, and the clinical efficacy is always inferior to herbs. In the present article, we review and discuss underlying mechanisms of the skin microbiome involved in the wound healing process; THM in regulating immune responses and commensal microbiome. We additionally propose few pioneer ideas and studies in the development of therapeutic strategies for controlled delivery of herbal medicine. This review aims to promote wound care with a focus on wound microbiome, immune response, and topical drug delivery systems. Finally, future development trends, challenges, and research directions are discussed.

An injectable hydrogel combining medicine and matrix with anti-inflammatory and pro-angiogenic properties for potential treatment of myocardial infarction

One of the main illnesses that put people's health in jeopardy is myocardial infarction (MI). After MI, damaged or dead cells set off an initial inflammatory response that thins the ventricle wall and degrades the extracellular matrix. At the same time, the ischemia and hypoxic conditions resulting from MI lead to significant capillary obstruction and rupture, impairing cardiac function and reducing blood flow to the heart. Therefore, attenuating the initial inflammatory response and promoting angiogenesis are very important for the treatment of MI. Here, to reduce inflammation and promote angiogenesis in infarcted area, we report a new kind of injectable hydrogel composed of puerarin and chitosan via in situ self-assembly with simultaneous delivery of mesoporous silica nanoparticles (CHP@Si) for myocardial repair. On the one hand, puerarin degraded from CHP@Si hydrogel modulated the inflammatory response via inhibiting M1-type polarization of macrophages and expression of pro-inflammatory factors. On the other hand, silica ions and puerarin released from CHP@Si hydrogel showed synergistic activity to improve the cell viability, migration and angiogenic gene expression of HUVECs in both conventional and oxygen/glucose-deprived environments. It suggests that this multifunctional injectable CHP@Si hydrogel with good biocompatibility may be an appropriate candidate as a bioactive material for myocardial repair post-MI.

On-Demand Removable Self-Healing and pH-Responsive Europium-Releasing Adhesive Dressing Enables Inflammatory Microenvironment Modulation and Angiogenesis for Diabetic Wound Healing

Current diabetic wound treatments remain unsatisfactory due to the lack of a comprehensive strategy that can integrate strong applicability (tissue adhesiveness, shape adaptability, fast self-healability, and facile dressing change) with the initiation and smooth connection of the cascade wound healing processes. Herein, benefiting from the multifaceted bonding ability of tannic acid to metal ions and various polymers, a family of tannin-europium coordination complex crosslinked citrate-based mussel-inspired bioadhesives (TE-CMBAs) are specially developed for diabetic wound healing. TE-CMBAs can gel instantly (< 60 s), possess favorable shape-adaptability, considerable mechanical strengths, high elasticity, considerable wet tissue adhesiveness (≈40 kPa), favorable photothermal antimicrobial activity, excellent anti-oxidant activity, biocompatibility, and angiogenetic property. The reversible hydrogen bond crosslinking and sensitive metal-phenolic coordination also confers TE-CMBAs with self-healability, pH-responsive europium ion and TA releasing properties and on-demand removability upon mixing with borax solution, enabling convenient painless dressing change and the smooth connection of inflammatory microenvironment modulation, angiogenesis promotion, and effective extracellular matrix production leveraging the acidic pH condition of diabetic wounds. This adhesive dressing provides a comprehensive regenerative strategy for diabetic wound management and can be extended to other complicated tissue healing scenarios.