Photothermal 2D Nanosheets Combined With Astragaloside IV for Antibacterial Properties and Promoting Angiogenesis to Treat Infected Wounds

Immunomodulatory Effects and Mechanisms of Two-Dimensional Black Phosphorus on Macrophage Polarization and Bone Regeneration

The repair of bone defects poses a significant challenge within the realm of clinical medicine. However, with the advent of various emerging biotechnologies, bone tissue engineering (BTE) has emerged as a promising discipline that offers innovative therapeutic strategies to address bone defects. Among the novel biomaterials being explored, two-dimensional (2D) black phosphorus (BP) has attracted considerable attention due to its advantageous properties, which include antimicrobial activity, drug delivery capabilities, and effective photothermal conversion. These properties render BP an excellent candidate for BTE applications. Recent studies have indicated that BP possesses remarkable immunomodulatory properties that influence bone regeneration, profoundly impacting the transformation of the osteoimmune microenvironment, thereby guiding the process of bone remodeling. Macrophage is a principal component of the osteoimmune microenvironment, and evidence suggests that BP significantly influences the polarization of macrophage M1 and M2 phenotypes. This review aims to present the regulatory effects and underlying mechanisms of 2D BP on macrophage polarization in the immune microenvironment. It highlights the ability of BP to systematically modulate the inflammatory environment and to facilitate the metabolic reprogramming of macrophages. The review concludes with a discussion of the potential applications and limitations of BP nanomaterials in the field of BTE.

Engineering Two-Dimensional Nanomaterials for Photothermal Therapy

Two-dimensional (2D) nanomaterials offer a transformative platform for photothermal therapy (PTT) due to their unique physicochemical properties and exceptional photothermal conversion efficiencies. This Minireview summarizes the photothermal mechanisms of common 2D nanomaterials and details their synthesis, surface modification, and optimization strategies. Recent advances leveraging 2D nanomaterials for enhanced PTT are highlighted, with particular emphasis on synergistic therapeutic modalities. Despite the significant potential of 2D nanomaterials in PTT, challenges persist, including scalable and reproducible manufacturing, precise targeted delivery, understanding of the underlying biological interactions, and comprehensive assessment of long-term biocompatibility and toxicity. Looking forward, emerging technologies such as machine learning are expected to play a crucial role in accelerating the design and optimization of 2D nanomaterials for PTT, enabling the prediction of optimal structures, properties, and therapeutic efficacy, and ultimately paving the way for personalized nanomedicine.

Black Phosphorus Nanoflakes: An Emerging Nanomaterial for Clinical Wound Management and Biomedical Applications

Black phosphorus (BP), a two-dimensional material, has gathered significant attention over the last decade, primarily due to its unique physiochemical properties and potential role in various biomedical applications. This review provides an in-depth overview of the synthesis, nanomaterial properties, interactions, and biomedical uses of BP, with a particular focus on wound management. The structure, synthesis methods, and stability of BP are discussed, highlighting the high degree of nanomaterial biocompatibility and cytotoxicity. The antimicrobial properties of BP, including mechanisms of action and preclinical studies to date, are examined, emphasizing the effectiveness of BP against various clinical pathogens relevant to wound management. Additionally, the versatility of BP in biomedical implementations is highlighted through utilization in drug delivery, imaging, and photothermal therapy, with a focus on scalability and reproducibility with outlined future perspectives. Despite identified challenges for translation in clinical uses, BP nanomaterial has significant potential as a versatile platform in biomedical applications, especially in wound management.

Advances and Challenges in Immune-Modulatory Biomaterials for Wound Healing Applications

Wound healing progresses through three distinct stages: inflammation, proliferation, and remodeling. Immune regulation is a central component throughout, crucial for orchestrating inflammatory responses, facilitating tissue repair, and restraining scar tissue formation. Elements such as mitochondria, reactive oxygen species (ROS), macrophages, autophagy, ferroptosis, and cytokines collaboratively shape immune regulation in this healing process. Skin wound dressings, recognized for their ability to augment biomaterials' immunomodulatory characteristics via antimicrobial, antioxidative, pro- or anti-inflammatory, and tissue-regenerative capacities, have garnered heightened attention. Notwithstanding, a lack of comprehensive research addressing how these dressings attain immunomodulatory properties and the mechanisms thereof persists. Hence, this paper pioneers a systematic review of biomaterials, emphasizing immune regulation and their underlying immunological mechanisms. It begins by highlighting the importance of immune regulation in wound healing and the peculiarities and obstacles faced in skin injury recovery. This segment explores the impact of wound metabolism, infections, systemic illnesses, and local immobilization on the immune response during healing. Subsequently, the review examines a spectrum of biomaterials utilized in skin wound therapy, including hydrogels, aerogels, electrospun nanofiber membranes, collagen scaffolds, microneedles, sponges, and 3D-printed constructs. It elaborates on the immunomodulatory approaches employed by these materials, focusing on mitochondrial and ROS modulation, autophagic processes, ferroptosis, macrophage modulation, and the influence of cytokines on wound healing. Acknowledging the challenge of antibiotic resistance, the paper also summarizes promising plant-based alternatives for biomaterial integration, including curcumin. In its concluding sections, the review charts recent advancements and prospects in biomaterials that accelerate skin wound healing via immune modulation. This includes exploring mitochondrial transplantation materials, biomaterial morphology optimization, metal ion incorporation, electrostimulation-enabled immune response control, and the benefits of composite materials in immune-regulatory wound dressings. The ultimate objective is to establish a theoretical foundation and guide future investigations in the realm of skin wound healing and related materials science disciplines.

Nanomaterial strategies in wound healing: A comprehensive review of nanoparticles, nanofibres and nanosheets

Wound healing is a complex process that orchestrates the coordinated action of various cells, cytokines and growth factors. Nanotechnology offers exciting new possibilities for enhancing the healing process by providing novel materials and approaches to deliver bioactive molecules to the wound site. This article elucidates recent advancements in utilizing nanoparticles, nanofibres and nanosheets for wound healing. It comprehensively discusses the advantages and limitations of each of these materials, as well as their potential applications in various types of wounds. Each of these materials, despite sharing common properties, can exhibit distinct practical characteristics that render them particularly valuable for healing various types of wounds. In this review, our primary focus is to provide a comprehensive overview of the current state-of-the-art in applying nanoparticles, nanofibres, nanosheets and their combinations to wound healing, serving as a valuable resource to guide researchers in their appropriate utilization of these nanomaterials in wound-healing research. Further studies are necessary to gain insight into the application of this type of nanomaterials in clinical settings.

Advances in the Application of Black Phosphorus-Based Composite Biomedical Materials in the Field of Tissue Engineering

Black Phosphorus (BP) is a new semiconductor material with excellent biocompatibility, degradability, and optical and electrophysical properties. A growing number of studies show that BP has high potential applications in the biomedical field. This article aims to systematically review the research progress of BP composite medical materials in the field of tissue engineering, mining BP in bone regeneration, skin repair, nerve repair, inflammation, treatment methods, and the application mechanism. Furthermore, the paper discusses the shortcomings and future recommendations related to the development of BP. These shortcomings include stability, photothermal conversion capacity, preparation process, and other related issues. However, despite these challenges, the utilization of BP-based medical materials holds immense promise in revolutionizing the field of tissue repair.

Injectable Antiswelling and High-Strength Bioactive Hydrogels with a Wet Adhesion and Rapid Gelling Process to Promote Sutureless Wound Closure and Scar-free Repair of Infectious Wounds

Developing injectable antiswelling and high-strength bioactive hydrogels with wet tissue adhesiveness and a rapid gelling process to meet the requirements for rapid hemostasis, sutureless wound closure, and scar-free repair of infected skin wounds continues to have ongoing challenges. Herein, injectable, antibacterial, and antioxidant hydrogel adhesives based on poly(citric acid-co-polyethylene glycol)-g-dopamine and amino-terminated Pluronic F127 (APF) micelles loaded with astragaloside IV (AS) are prepared. The H2O2/horseradish peroxidase (HRP) system is used to cause cross-linking of the hydrogel network through oxidative coupling between catechol groups and chemical cross-linking between the catechol group and the amino group. The hydrogels exhibit a rapid gelling process, high mechanical strength, an antiswelling effect, good antioxidant property, H2O2 release behavior, and degradability. In addition, the hydrogels present good wet tissue adhesiveness, high bursting pressure, excellent antibacterial activity, long-term sustained release of AS, and good biocompatibility. The hydrogels perform good hemostasis on mouse liver, rat liver, and rabbit femoral vein bleeding models and achieve much better closure and healing of skin incisions than biomedical glue and surgical sutures. Furthermore, the hydrogel dressing significantly improved the scar-free repair of MRSA-infected full thickness skin defect wounds by modulating inflammation, regulating the ratio of collagen I/III, and improving the vascularization and granulation tissue formation. Thus, AS-loaded hydrogels show huge potential as multifunctional dressings for in vivo hemostasis, sutureless wound closure, and scar-free repair of infected skin wounds.

Black Phosphorus - A Rising Star in the Antibacterial Materials

Antibiotics are the most commonly used means to treat bacterial infection at present, but the unreasonable use of antibiotics induces the generation of drug-resistant bacteria, which causes great problems for their clinical application. In recent years, researchers have found that nanomaterials with high specific surface area, special structure, photocatalytic activity and other properties show great potential in bacterial infection control. Among them, black phosphorus (BP), a two-dimensional (2D) nanomaterial, has been widely reported in the treatment of tumor and bone defect due to its excellent biocompatibility and degradability. However, the current theory about the antibacterial properties of BP is still insufficient, and the relevant mechanism of action needs to be further studied. In this paper, we introduced the structure and properties of BP, elaborated the mechanism of BP in bacterial infection, and systematically reviewed the application of BP composite materials in the field of antibacterial. At the same time, we also discussed the challenges faced by the current research and application of BP, which laid a solid theoretical foundation for the further study of BP in the future.

Fucoidan promotes angiogenesis and accelerates wound healing through AKT/Nrf2/HIF-1α signalling pathway

After skin injury, wound repair involves a complex process in which angiogenesis plays a crucial role. Previous research has indicated that fucoidan may aid in wound healing; we therefore hypothesised that fucoidan may speed up the process by promoting angiogenesis. In this study, we investigated the potential molecular mechanism underlying fucoidan's ability to accelerate wound healing by promoting angiogenesis. Using a full-cut wound model, we observed that fucoidan significantly intensified wound closure and promoted granulation formation and collagen deposition. Immunofluorescence staining revealed that fucoidan also promoted wound angiogenesis, specifically by accelerating the migration of new blood vessels to the middle area of the wound. Furthermore, fucoidan demonstrated the ability to enhance the proliferation of human umbilical vein endothelial cells (HUVECs) damaged by hydrogen peroxide (H2 O2 ) and to improve the formation of endothelial tubes. Mechanistic studies revealed that fucoidan upregulated the protein levels of the AKT/Nrf2/HIF-1α signalling pathway, which plays a crucial role in angiogenesis. This was further confirmed using the inhibitor LY294002, which reversed the promotion of endothelial tube formation by fucoidan. Overall, our findings suggest that fucoidan can promote angiogenesis via the AKT/Nrf2/HIF-1α signalling pathway and accelerate wound healing.

Recent Progress of Photothermal Therapy Based on Conjugated Nanomaterials in Combating Microbial Infections

Photothermal therapy has the advantages of non-invasiveness, low toxicity, simple operation, a broad spectrum of antibacterial ability, and non-proneness to developing drug resistance, which provide it with irreplaceable superiority in fighting against microbial infection. The effect of photothermal therapy is closely related to the choice of photothermal agent. Conjugated nanomaterials are potential candidates for photothermal agents because of their easy modification, excellent photothermal conversion efficiency, good photostability, and biodegradability. In this paper, the application of photothermal agents based on conjugated nanomaterials in photothermal antimicrobial treatment is reviewed, including conjugated small molecules, conjugated oligomers, conjugated polymers, and pseudo-conjugated polymers. At the same time, the application of conjugated nanomaterials in the combination of photothermal therapy (PTT) and photodynamic therapy (PDT) is briefly introduced. Finally, the research status, limitations, and prospects of photothermal therapy using conjugated nanomaterials as photothermal agents are discussed.

Nanotherapeutics with immunoregulatory functions for the treatment of bacterial infection

The advent of drug-resistant pathogens results in the occurrence of stubborn bacterial infections that cannot be treated with traditional antibiotics. Antibacterial immunotherapy by reviving or activating the body's immune system to eliminate pathogenic bacteria has confirmed promising therapeutic strategies in controlling bacterial infections. Subsequent studies found that antimicrobial immunotherapy has its own benefits and limitations, such as avoiding recurrence of infection and autoimmunity-induced side effects. Current studies indicate that the various antibacterial therapeutic strategies inducing immune regulation can achieve superior therapeutic efficacy compared with monotherapy alone. Therefore, summarizing the recent advances in nanomedicine with immunomodulatory functions for combating bacterial infections is necessary. Herein, we briefly introduce the crisis caused by drug-resistant bacteria and the opportunity for antibacterial immunotherapy. Then, immune-involved multimodal antibacterial therapy for the treatment of infectious diseases was systematically summarized. Finally, the prospects and challenges of immune-involved combinational therapy are discussed.

Nanofiber Scaffolds as Drug Delivery Systems Promoting Wound Healing

Nanofiber scaffolds have emerged as a revolutionary drug delivery platform for promoting wound healing, due to their unique properties, including high surface area, interconnected porosity, excellent breathability, and moisture absorption, as well as their spatial structure which mimics the extracellular matrix. However, the use of nanofibers to achieve controlled drug loading and release still presents many challenges, with ongoing research still exploring how to load drugs onto nanofiber scaffolds without loss of activity and how to control their release in a specific spatiotemporal manner. This comprehensive study systematically reviews the applications and recent advances related to drug-laden nanofiber scaffolds for skin-wound management. First, we introduce commonly used methods for nanofiber preparation, including electrostatic spinning, sol-gel, molecular self-assembly, thermally induced phase separation, and 3D-printing techniques. Next, we summarize the polymers used in the preparation of nanofibers and drug delivery methods utilizing nanofiber scaffolds. We then review the application of drug-loaded nanofiber scaffolds for wound healing, considering the different stages of wound healing in which the drug acts. Finally, we briefly describe stimulus-responsive drug delivery schemes for nanofiber scaffolds, as well as other exciting drug delivery systems.