Polyurethane/natural polymer blends nanofibers for application as electrospun wound dressings

The skin, as the first defense barrier against the entry of pathogens into the body, helps to heal the wounds through four stages including homeostasis, inflammation, proliferation, and regeneration. Today, various wound dressings have been introduced to help the body's immune system to improve the speed and quality of wound healing. Conventional wound dressings include polyurethane foams and elastomers, hydrocolloids, hydrogels, semipermeable films, alginate wound dressings, and electrospun polymer nanofibers. Wound dressings based on polymer nanofibers have received a lot of attention for reasons such as similarity to the extracellular matrix (ECM), the desired cell adhesion, high surface-to-volume ratio, gas exchange capability, nutrient supply, and fluid evaporation control. So far, the use of electrospun polyurethanes for the preparation of wound dressings has been reported in various studies. However, the results of studies on a wide range of wound dressings have shown that almost no polymer alone can heal different wounds, effectively. For this reason, many efforts have been made recently to develop polyurethane wound dressings to heal various types of wounds. In this regard, natural polymers have been used due to properties such as biological activity, biocompatibility, and biodegradability along with polyurethanes with desirable physical and mechanical properties. In this article, after introducing the the mechanism of wound healing and describing the characteristics of an ideal wound dressing, the polyurethane/natural polymer blends nanofibers for use as electrospun wound dressings will be discussed.