Electrospun Nanofibers for Tissue Repair and Regeneration

Electrospun nanofibers have been widely applied for tissue repair and regeneration because of their advantages of mimicking the structure and composition of extracellular matrix to a certain extent. We have developed a series of scaffolds based on electrospun nanofibers to promote the repair and regeneration of peripheral nerve, bone, and skin. To improve the repair efficacy of peripheral nerve injury, we have constructed a nerve guidance conduit based on electrospun nanofibers in a bionic design to simulate the microenvironment required for nerve repair. Nerve growth factor and indocyanine green were loaded in phase change material particles and then deposited between two layers of electrospun nanofiber membranes to obtain a photothermal responsive scaffold. Upon the irradiation of a near-infrared laser, nerve growth factor was triggered to be released from the scaffold, promoting the axon extension. In addition, we deposited a density gradient of bioactive nanoparticles on the surface of uniaxially aligned fibers to guide the axon extension and accelerate cell migration along the direction of increasing the density of the nanoparticles. We further constructed degradable hydrogels in the lumen and regulated the degradation rate of the hydrogel to be increased from the proximal to distal position, allowing for the long-term delivery of growth factor loaded in the hydrogel and promoting the regeneration of sciatic nerve in rat. Additionally, we conducted large animal experiments in sheep to explore the effects of multi-channel nanofibrous nerve conduit on sheep nerve injury repair. For the repair of skin wounds, according to the demand of various growth factors in each stage of repair period, we constructed a multi-layered nanofibrous scaffold with a radially aligned nanofibrous inner surface. The scaffold effectively integrated multiple induced signals such as topography, bioactive factors and photothermal response to achieve spatiotemporally controlled delivery and accelerated wound healing. Combined with photothermal effects, we constructed a multifunctional bone repair scaffold to recruit stem cells and induce their osteogenic differentiation to improve the repair of bone defects. We also developed gradient self-assembled activated fiber scaffolds to induce osteogenic differentiation of stem cells. In summary, electrospun nanofibers can be applied to construct multifunctional tissue repair materials to promote tissue injury repair and regeneration.