Nanotechnology promotes the full-thickness diabetic wound healing effect of recombinant human epidermal growth factor in diabetic rats

We utilized a modified double-emulsion method with poly(lactic-co-glycolic acid) as the carrier to prepare recombinant human epidermal growth factor (rhEGF) nanoparticles. The morphology of the nanoparticles was detected by a transmission electron microscope. The particle size distribution was measured by a laser analyzer with a zeta potential meter. Enzyme-linked immunosorbent assays were performed to determine the rhEGF encapsulation efficiency and release model, and the proliferation of the mouse fibroblasts was analyzed by the MTT method. Diabetic rats with full-thickness wounds were divided into four groups according to different treatments: rhEGF nanoparticles, rhEGF stock solution, empty nanoparticles, and phosphate-buffered saline. Photographs were taken after the treatments to calculate the wound healing rates, and the granulation tissue of the wounds was sampled for pathologic slides. Proliferating cell nuclear antigen was assayed by immunohistochemistry. Our results showed that the rhEGF nanoparticles were around 193.5 nm (diameter), and the particle size distribution was uniform and dispersible. The encapsulation efficiency was 85.6% and rhEGF release lasted 24 hours. Compared with other groups, the rhEGF nanoparticles promoted the highest level of fibroblast proliferation, and this group showed the fastest healing rate. The number of proliferating cell nuclear antigen positive cells in the rhEGF nanoparticles group was higher than the other groups. We concluded that controlled release of rhEGF encapsulated in the nanoparticles enhanced rhEGF effects to stimulate cell proliferation and shorten the wound healing time.