An innovative route to prepare in situ graded crosslinked PVA graphene electrospun mats for drug release

We present a fast, one step method to obtain PVA/graphene/chlorhexidine nanofibrous membranes, with a crosslinking gradient along their cross-section. Briefly, polymeric solutions were electrospun onto a heated plate, enabling the in situ crosslinking of PVA macromolecules. Of course, the crosslinking degree of such structures was found to decrease upon the distance from the plate during deposition. The outcomes reveal the crucial role of graphene, capable of promoting heat transfer throughout the entire structure, thus leading to 70-80% crosslinking degrees and preventing delamination issues. Such membranes were compared to untreated and oven thermally treated ones, and a robust relationship between processing, structure and properties was outlined, with a special focus on the release behaviour of such materials, which proved to be tuneable from instantaneous/burst to sustained release (up to 500 hours) by adjusting formulation and preparation technique.