Functionalization of electrospun PLA fibers using amphiphilic block copolymers for use in carboxy-methyl-cellulose hydrogel composites

Carboxy-methyl-cellulose (CMC) hydrogels, prepared in the presence of a crosslinker and photoinitiator, were reinforced with 3.7 wt% electrospun PLA fibers to create CMC hydrogel composites. To improve fiber-matrix adhesion, electrospun fiber mats based on hybrids of PLA and amphiphilic block copolymer (BCP) poly(D,L-lactide)-block-poly[2-(dimethylamino)ethyl methacrylate] (PLA-b-PDMAEMA) were produced. The presence of PDMAEMA at the fiber surface induced hydrophilic surface properties, which could be controlled by varying the PDMAEMA chain length. PDMAEMA was quaternized and co-electrospun with PLA fibers, which further enhanced the interaction between fibers and hydrogel matrixviaionic interactions. Physicochemical properties of the electrospun fiber mats and their CMC hydrogel based composites were assessed and revealed a nearly two orders of magnitude increase in modulus. Continuous electrospun fiber mats were chopped into discontinuous fibers to create short fiber reinforced CMC hydrogels. Rheological properties of these reinforced hydrogels incorporating 0.5 wt% discontinuous fibers were evaluated and showed potential as injectable composite systems for biomedical applications.