A Perfect Pair: Stabilized Black Phosphorous Nanosheets Engineering with Antimicrobial Peptides for Robust Multidrug Resistant Bacteria Eradication

Synergistic Enhancement of Antibacterial and Osteo-Immunomodulatory Activities of Titanium Implants via Dual-Responsive Multifunctional Surfaces

Bone implant-associated infections and inflammations, primarily caused by bacteria colonization, frequently result in unsuccessful procedures and pose significant health risks to patients. To mitigate these challenges, the development of engineered implants with spatiotemporal regulation capabilities, designed to inhibit bacterial survival and modulate immune responses in the early stage, while promoting bone defect healing in the late stage is proposed. The implants are functionalized with ε-poly-l-lysine-phenylboronic acid (PP) via dynamic boronic ester bonds, which facilitate its release through a reactive oxygen species (ROS) and pH-responsive strategy, thereby establishing an antibacterial microenvironment on and around the implants. Additionally, the dynamic metal coordination interaction facilitates the loading and sustained release of Sr2+ under an acidic environment, providing immunomodulatory and osteogenic effects. The ROS/pH-responsive feature, coupled with the implant-bone tissue integration process, affords precise spatiotemporal regulation of the Ti-TA-Sr-PP implants. This strategy represents a promising approach for the preparation of advanced bone implants.

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.

Imidazole-Rich, Four-Armed Host-Defense Peptidomimetics as Promising Narrow-Spectrum Antibacterial Agents and Adjuvants against Pseudomonas Aeruginosa Infections

The development of narrow-spectrum antimicrobial agents is paramount for swiftly eradicating pathogenic bacteria, mitigating the onset of drug resistance, and preserving the homeostasis of bacterial microbiota in tissues. Owing to the limited affinity between the hydrophobic lipid bilayer interior of bacterial cells and most hydrophilic, polar peptides, the construction of a distinctive class of four-armed host-defense peptides/peptidomimetics (HDPs) is proposed with enhanced specificity and membrane perturbation capability against Pseudomonas aeruginosa by incorporating imidazole groups. These groups demonstrate substantial affinity for unsaturated phospholipids, which are predominantly expressed in the cell membrane of P. aeruginosa, thereby enabling HDPs to exhibit narrow-spectrum activity against this bacterium. Computational simulations and experimental investigations have corroborated that the imidazole-rich, four-armed peptidomimetics exhibit notable selectivity toward bacteria over mammalian cells. Among them, 4H10, characterized by its abundant and densely distributed imidazole groups, exhibits impressive activity against various clinically isolated P. aeruginosa strains. Moreover, 4H10 has demonstrated potential as an antibiotic adjuvant, enhancing doxycycline accumulation and exerting effects on intracellular targets by efficiently disrupting bacterial cell membranes. Consequently, the hydrogel composed of 4H10 and doxycycline emerged as a promising topical agent, significantly diminishing the skin P. aeruginosa burden by 97.1% within 2 days while inducing minimal local and systemic toxicity.

Carboxymethyl chitosan nanoparticle-modulated cationic hydrogels doped with copper ions for combating bacteria and facilitating wound healing

The simultaneous administration of antibacterial treatment and acceleration of tissue regeneration are crucial for the effective healing of infected wounds. In this work, we developed a facile hydrogel (PCC hydrogel) through coordination and hydrogen interactions by polymerizing acrylamide monomers in the presence of carboxymethyl chitosan nanoparticles and copper ions. The prepared PCC hydrogel demonstrated effective bacterial capture from wound exudation and exhibited a potent bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Furthermore, slow release of copper ions from the hydrogel facilitated wound healing by promoting cell migration, collagen deposition and angiogenesis. Additionally, the PCC hydrogel possessed excellent biocompatibility and hemostatic properties. The practical effectiveness of PCC hydrogel in addressing bacterial infections and facilitating wound healing was verified using a mouse model of MRSA-induced wound infections. Overall, this work presents a simple yet efficient multifunctional hydrogel platform that integrates antibacterial activity, promotion of wound healing, and hemostasis for managing bacteria-associated wounds.

Emerging Trends in Dissolving-Microneedle Technology for Antimicrobial Skin-Infection Therapies

Skin and soft-tissue infections require significant consideration because of their prolonged treatment duration and propensity to rapidly progress, resulting in severe complications. The primary challenge in their treatment stems from the involvement of drug-resistant microorganisms that can form impermeable biofilms, as well as the possibility of infection extending deep into tissues, thereby complicating drug delivery. Dissolving microneedle patches are an innovative transdermal drug-delivery system that effectively enhances drug penetration through the stratum corneum barrier, thereby increasing drug concentration at the site of infection. They offer highly efficient, safe, and patient-friendly alternatives to conventional topical formulations. This comprehensive review focuses on recent advances and emerging trends in dissolving-microneedle technology for antimicrobial skin-infection therapy. Conventional antibiotic microneedles are compared with those based on emerging antimicrobial agents, such as quorum-sensing inhibitors, antimicrobial peptides, and antimicrobial-matrix materials. The review also highlights the potential of innovative microneedles incorporating chemodynamic, nanoenzyme antimicrobial, photodynamic, and photothermal antibacterial therapies. This review explores the advantages of various antimicrobial therapies and emphasizes the potential of their combined application to improve the efficacy of microneedles. Finally, this review analyzes the druggability of different antimicrobial microneedles and discusses possible future developments.

Black phosphorus, an advanced versatile nanoparticles of antitumor, antibacterial and bone regeneration for OS therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor. In the clinic, usual strategies for OS treatment include surgery, chemotherapy, and radiation. However, all of these therapies have complications that cannot be ignored. Therefore, the search for better OS treatments is urgent. Black phosphorus (BP), a rising star of 2D inorganic nanoparticles, has shown excellent results in OS therapy due to its outstanding photothermal, photodynamic, biodegradable and biocompatible properties. This review aims to present current advances in the use of BP nanoparticles in OS therapy, including the synthesis of BP nanoparticles, properties of BP nanoparticles, types of BP nanoparticles, and modification strategies for BP nanoparticles. In addition, we have discussed comprehensively the application of BP in OS therapy, including single, dual, and multimodal synergistic OS therapies, as well as studies about bone regeneration and antibacterial properties. Finally, we have summarized the conclusions, limitations and perspectives of BP nanoparticles for OS therapy.

Recent design strategies for boosting chemodynamic therapy of bacterial infections

The emergence of drug-resistant bacteria poses a significant threat to people's lives and health as bacterial infections continue to persist. Currently, antibiotic therapy remains the primary approach for tackling bacterial infections. However, the escalating rates of drug resistance coupled with the lag in the development of novel drugs have led to diminishing effectiveness of conventional treatments. Therefore, the development of nonantibiotic-dependent therapeutic strategies has become imperative to impede the rise of bacterial resistance. The emergence of chemodynamic therapy (CDT) has opened up a new possibility due to the CDT can convert H2O2 into •OH via Fenton/Fenton-like reaction for drug-resistant bacterial treatment. However, the efficacy of CDT is limited by a variety of practical factors. To overcome this limitation, the sterilization efficiency of CDT can be enhanced by introducing the therapeutics with inherent antimicrobial capability. In addition, researchers have explored CDT-based combined therapies to augment its antimicrobial effects and mitigate its potential toxic side effects toward normal tissues. This review examines the research progress of CDT in the antimicrobial field, explores various strategies to enhance CDT efficacy and presents the synergistic effects of CDT in combination with other modalities. And last, the current challenges faced by CDT and the future research directions are discussed.

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.

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.

Injectable Zn2+ and Paeoniflorin Release Hydrogel for Promoting Wound Healing

As more and more superbugs emerge, wounds are struggling to heal due to the inflammation that accompanies infection. Therefore, there is an urgent need to reduce the abuse of antibiotics and find nonantibiotic antimicrobial methods to counter infections to accelerate wound healing. In addition, common wound dressings struggle to cover irregular wounds, causing bacterial invasion or poor drug release, which reduces the wound healing rate. In this study, Chinese medicinal monomer paeoniflorin which can inhibit inflammation is loaded in mesoporous zinc oxide nanoparticles (mZnO), while Zn²⁺ released from mZnO degradation can kill bacteria and facilitate wound healing. The drug-loaded mZnO was encapsulated by a hydrogel formed from oxidized konjac glucomannan and carboxymethyl chitosan via rapid Schiff base reaction to obtain an injectable drug-releasing hydrogel wound dressing. The immediate-formation hydrogel allows the dressing to cover any wound shape. In vitro and in vivo studies have demonstrated that the dressing has good biocompatibility and superior antibacterial properties, which can promote wound healing and tissue regeneration by promoting angiogenesis and collagen production, providing a promising perspective for the further development of multifunctional wound dressings.

Functional nano-systems for transdermal drug delivery and skin therapy

Transdermal drug delivery is one of the least intrusive and patient-friendly ways for therapeutic agent administration. Recently, functional nano-systems have been demonstrated as one of the most promising strategies to treat skin diseases by improving drug penetration across the skin barrier and achieving therapeutically effective drug concentrations in the target cutaneous tissues. Here, a brief review of functional nano-systems for promoting transdermal drug delivery is presented. The fundamentals of transdermal delivery, including skin biology and penetration routes, are introduced. The characteristics of functional nano-systems for facilitating transdermal drug delivery are elucidated. Moreover, the fabrication of various types of functional transdermal nano-systems is systematically presented. Multiple techniques for evaluating the transdermal capacities of nano-systems are illustrated. Finally, the advances in the applications of functional transdermal nano-systems for treating different skin diseases are summarized.

Recent advances in 2D material-based phototherapy

Phototherapy, which generally refers to photothermal therapy (PTT) and photodynamic therapy (PDT), has received significant attention over the past few years since it is non-invasive, has effective selectivity, and has few side effects. As a result, it has become a promising alternative to traditional clinical treatments. At present, two-dimensional materials (2D materials) have proven to be at the forefront of the development of advanced nanomaterials due to their ultrathin structures and fascinating optical properties. As a result, much work has been put into developing phototherapy platforms based on 2D materials. This review summarizes the current developments in 2D materials beyond graphene for phototherapy, focusing on the novel approaches of PTT and PDT. New methods are being developed to go above and beyond conventional treatment to fully use the potential of 2D materials. Additionally, the efficacy of cutting-edge phototherapy is assessed, and the existing difficulties and future prospects of 2D materials for phototherapy are covered.