Abstract:

Significance Wound healing is a dynamic, complex and multicellular process. The healing process of skin involves four distinct stages: hemostasis, inflammation, proliferation, and tissue remodeling. Although the skin has the ability to regenerate itself, certain types of wounds such as extensive injuries or chronic wounds are difficult to self-heal, so it is very important to develop wound dressings that promote self-healing. Micro-nanofibers have a high surface area-to-volume ratio area and high porosity, and have a similar structure to extracellular matrix, which is conducive to cell adhesion and proliferation, thus promoting wound healing. Growth factor is a signaling protein that regulates cell growth, differentiation, proliferation, migration and metabolism during different wound healing processes. The use of growth factors and their combination on the basis of the dressing is considered to be a promising treatment method to promote active healing.

Progress Firstly, the three growth factors and their functions are summarized. At present, the most studied growth factors are basic fibroblast growth factor, epidermal growth factor and platelet-derived growth factor. Growth factors are involved in the four stages of skin wound healing. Growth factors play a key role in granulation tissue formation, regulating inflammatory response, and promoting angiogenesis. In addition, growth factors can also promote the proliferation and migration of wound cells to accelerate or improve the wound healing process. Secondly, growth factor delivery strategies are explored. In order to avoid degradation or inactivation of growth factors at the wound site and to maintain their continuous release at the wound site, a large number of studies have explored the effective loading mode of growth factors and developed excellent growth factor delivery systems. These methods include micro-nanofiber scaffolds, microspheres combined with nanoparticles and heparin, which avoid the burst release of growth factors and are conducive to its long-term effect. Finally, the micro/nanofiber dressings loaded with basic fibroblast factor, epidermal growth factor, platelet-derived growth factor, and multiple growth factors were described. The textile materials, preparation process and experimental results of micro-nanofiber dressings were summarized.

Conclusion and Prospect Micro/nanofiber dressings are one of the ideal wound repair materials, and the introduction of growth factors and their combinations can better promote active wound healing. It was found that the role of growth factors has been widely proved, and the use of a single growth factor can no longer meet people's needs for wound healing. Because different growth factors participate in different stages of wound healing, the use of multiple growth factors to promote wound healing has become the future trend. Secondly, in order to match the release of multiple growth factors in different wound healing stages, the delivery methods of growth factors are no longer single, but are developing towards the direction of combination of multiple delivery methods. At present, the burst release in the initial stage and the sustained release in the subsequent stage are the main delivery methods. Finally, with the increasing availability of textile materials for the preparation of micro/nanofibers, the co-application of natural and synthetic polymer materials is being extensively investigated so as to meet the needs of appropriate delivery of growth factors. At present, although most of the related research is still in the stage of animal experiments, micro/nanofiber dressings loaded with growth factors have a wide application prospect in the field of skin healing and repair materials, and it is believed that this repair material will be widely used in clinical practice.

Key words: growth factor, micro-nanofiber, medical dressing, basic fibroblast growth factor, epidermal growth factor, platelet-derived growth factor