Current updates of macrophage-loaded nanodrug delivery systems for the treatment of wound healing

Clinically, due to the complexity of the wound microenvironment, it is difficult to achieve an ideal therapeutic effect with traditional wound healing treatments. In recent years, the rapid development of nanodrug-loading technology has significantly improved the therapeutic effects and reduced the adverse reactions of wound treatment modalities, thus showing good application prospects. Several types of nanomaterials can be used in drug loading, such as metals and metal oxides, lipids, and those that are carbon-based, ceramic-based, and polymer-based. However, due to their own chemical and physical properties and biocompatibility, there are some drawbacks that appear during the treatment process, such as cytotoxicity, uneven drug release and poor targeting, which limit the applications of nanoparticles as drug carriers to heal wounds. In such systems, macrophages have the advantages of strong targeting, immunogenicity and high drug loading. Therefore, the use of macrophage surface modification, phagocytosis pathways and macrophage membrane coating technology to develop macrophages and drug-loaded nanomaterials into a nanodrug-loaded system coated by macrophages can effectively compensate for these limitations and significantly improve the therapeutic effects on wounds. On the one hand, the unique phagocytic ability of macrophages makes internalization of these nanodrug carriers easier; on the other hand, combined with their immunotherapeutic properties, macrophages possess strong targeting capabilities. In addition, the controllable release and long-distance transportation of drugs are also effectively guaranteed. This review describes the active role of macrophages in wound repair and the types of nanoparticles used in wound healing. We focused on the role of macrophages in wound treatment by combining loaded nanoparticles in different ways as a drug delivery system, hoping to use the advantages of macrophage-coated nano drug delivery system to provide valuable reference information for wound treatment.