Electrospun polycarbonate urethane nanofibrous scaffold for dural repair: physico-chemical characterization and in vivo biocompatibility assessment

Dural repair of the native dura following trauma or surgery is often challenging due to limitations such as the poor extensibility, regenerative capacity, and the structural integrity of the dura mater. This has led to the rise of dura substitutes, both biological and synthetic, that aim to match the native dura in its strength and elasticity. While the biological dura substitutes are met with immune rejection, scarring or disease transmission risks, scar tissue formation is a major concern in synthetic dura substitutes. In revision surgeries, the chaotic extraction of the scar tissue-encapsulated material causes severe damage to the patient's tissues. This work aims to develop a biologically inert dura substitute by electrospinning biostable polycarbonate urethane. The membrane was characterized in terms of its mechanical strength, stiffness, suture pullout strength, and porosity. The in-vitro cytotoxicity was evaluated in L929 cells by direct contact, MTT and Alamar blue assay. In accordance with ISO 10993, toxicological safety evaluation procedures such as acute systemic toxicity, sensitization, skin irritation, and genotoxicity studies were performed. The material was implanted in rabbit dural defects, with a commercially available Neuro-patch as the control for six months. The gross and histological investigations revealed that the membrane was mechanically resilient with good intraoperative handling characteristics. Furthermore, it was non-toxic, and had minimal to moderate tissue adhesion and did not elicit any chronic inflammatory responses, indicating its potential role in future dura substitute applications.