Fabrication of guanidinylated chitosan nanoparticles loaded with bioactive factors for facilitating wound healing

Developing wound dressings that improve healing and minimize scarring is of great importance. Chitosan, widely used in biomedical materials, and the chemicals, food and cosmetics fields, shows poor wound healing abilities. In addition, bioactive factors such as epidermal growth factor (EGF) and 1,25-dihydroxyvitamin D-3(VD3), which are significant for stimulating skin fibroblasts and keratinocyte proliferation, have limited applicability because they are unstable in wound dressing fabrication and storage. Here we prepared guanidinylated chitosan nanoparticles loaded with five different bioactive factors (CGNP), including EGF, ascorbic acid (VC), hydrocortisone, insulin and VD3, and evaluated their wound healing ability. The results show that the size of CGNPs was about 200 nm, which is suitable for cellular uptake. CGNPs were used to treat skin wounds induced on Wistar rats. With the treatment, complete healing was observed after 24 days, while untreated wounds and those treated with chitosan were irregular. Moreover, wounds treated with CGNP1 showed color and smoothness similar to normal skin after recovery after 28 days. CGNPs may be possible wound dressings for stable delivery of bioactive factors, enhancement of wound healing and avoidance scarring.