Leucine-activated nanohybrid biofilm for skin regeneration via improving cell affinity and neovascularization capacity

The accumulation of skin diseases has increased the need for biomimicking materials with high bioactivity and biosafety for wound healing, where how to improve the cell affinity of the skin regenerative materials as well as their neovascularization capacity is a key factor for rapid regeneration of the injured skin tissue. In the current study, we developed an advanced type of biodegradable nanofibrous biofilm which can attract skin-related cells and accelerate blood vessel formation for skin regeneration. Firstly, bioactive nanohybrids (LEU@LP) were fabricated via in situ doping of the nutrient amino acid leucine (beneficial for fibroblast proliferation and protein synthesis) into LAPONITE® nanodisks (enriched in Mg and Si favorable for vascularization). LEU@LP nanoparticles were then hybridized with a biodegradable polylactide (PLA) nanofibrous mesh via an airbrushing technique, followed by a subsequent ammonia plasma surface treatment to improve PLA's hydrophilicity to increase cell affinity. The resulting hybrid biofilms with skin-biomimicking nanofibrous structural networks can promote cell adhesion, spreading, migration and proliferation of fibroblasts, leading to the ideal skin wound healing (with blood vessel formation and hair follicle regeneration), probably attributed to their better hydrophilicity to promote cell affinity and the capacity of sustainable release of leucine (beneficial for fibroblasts proliferation) and the composition provision (Mg and Si which are beneficial for neovascularization).