Multifunctional Chitosan-Based Ointment Supplemented With Cannabimimetic N-Stearoylethanolamine for Wound Healing

Multifunctionality is a principal property of polymer-based materials for medical application. Chitosan is the most popular biocompatible and biodegradable natural biopolymer with hemostatic and wound healing activities that is also used as a platform for delivery of medicines, nucleic acids and other bioactive compounds. Here, we prepared chitosan-based ointment-like product containing ampicillin, polyvinylpyrrolidone and 1,2-propylene glycol. It can be easily mixed with water-soluble substances (e.g., antibiotics, antioxidants) as well as with plant oils (linseed) which provided a possibility of incorporation of biologically active water-insoluble ingredients (e.g., the cannabimimetic N-stearoylethanolamine (NSE)). The last was previously shown to act as an anti-burn agent. Scanning electron microscopy revealed coarse-mesh structure of created ointments, which was less expressed in sample of chitosan without ampicillin. The conducted FTIR analysis revealed an appearance of additional peak in spectrum of chitosan-ampicillin complex, suggesting formation of ion bonds between amide groups of chitosan and carboxylic groups of ampicillin. The antioxidant activity of obtained ointments (DPPH assay) depended on their composition. Such a multifunctional ointment demonstrated a potent wound healing effect in experiments of wound treatment in mice. It was confirmed by faster closure of wounds, shortening of their complete epithelization and enhanced remodelling of collagen fibres. Topical application of NSE-containing ointment hindered wound-induced inflammation, as revealed by time-dependent changes in the immune cell pattern. Thus, we produced a novel chitosan-based platform possessing amphiphilic properties that are favourable for wound healing activity in this ointment formulation.