Optimization of Oligomer Chitosan/Polyvinylpyrrolidone Coating for Enhancing Antibacterial, Hemostatic Effects and Biocompatibility of Nanofibrous Wound Dressing.

A synergistic multilayer membrane design is necessary to satisfy a multitude of requirements of an ideal wound dressing. In this study, trilayer dressings with asymmetric wettability, composed of electrospun polycaprolactone (PCL) base membranes coated with oligomer chitosan (COS) in various concentrations of polyvinylpyrrolidone (PVP), are fabricated for wound dressing application. The membranes are expected to synergize the hygroscopic, antibacterial, hemostatic, and biocompatible properties of PCL and COS. The wound dressing was coated by spraying the solution of 3% COS and 6% PVP on the PCL base membrane (PVP6-3) three times, which shows good interaction with biological subjects, including bacterial strains and blood components. PVP6-3 samples confirm the diameter of inhibition zones of 20.0 ± 2.5 and 17.9 ± 2.5 mm against Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The membrane induces hemostasis with a blood clotting index of 74% after 5 min of contact. In the mice model, wounds treated with PVP6-3 closed 95% of the area after 10 days. Histological study determines the progression of skin regeneration with the construction of granulation tissue, new vascular systems, and hair follicles. Furthermore, the newly-growth skin shares structural resemblances to that of native tissue. This study suggests a simple approach to a multi-purpose wound dressing for clinical treatment.

Fabrication of chitosan oligomer-coated electrospun polycaprolactone membrane for wound dressing application.

Wound dressings are typically used to provide a favorable environment supporting the intricate process of wound healing. This research aims to fabricate and evaluate an electrospun polycaprolactone (EsPCL) membrane coated with various densities of chitosan oligomers (COS) - a biological agent - for application as bioactive wound dressing. Weight calculation was employed to investigate the density of COS coated onto the electrospun PCL membrane. Physicochemical characteristics of the prepared membranes, such as hydrophilicity and mechanical properties were demonstrated and evaluated through standard experimental methods. In vitro assays and mice model were used to investigate the antibacterial activities, cytocompatibility, hemostasis and the in vivo interaction of the membranes. The results showed that COS was coated successfully on the surface of the polymeric membrane, altering its morphology and associated characteristics. The greater concentration of COS led to an increase in the thickness of the membrane, which resulted in stronger antibacterial activities. Moreover, the increase of chitosan oligomers density in the membrane induced faster hemostasis and affected the re-epithelialization and wound healing in mice. Thus, the membrane as a whole and particularly chitosan oligomers were shown to be potential for further studies regarding wound dressing.