3D Porous poly(lactic acid)/regenerated cellulose composite scaffolds based on electrospun nanofibers for biomineralization

One of the serious challenges in bone tissue engineering is the construction of biomimetic scaffolds, which can bridge the gap between mechanical strength and porous structure requirements. Although electrospinning technology can be used to create nanofibrous networks with a structure of artificial extracellular matrix (ECM), the restricted shapes and pore sizes block its application. Herein, we combine technologies of freeze-drying and crosslinking to fabricate a novel three-dimensional (3D) poly(lactic acid)/regenerated cellulose (PLA/RC) scaffold. Owing to the introduction of RC nanofibers, the hydrophilicity and biological activity has been improved. Moreover, citric acid works as a non-toxic crosslinker to participate in the esterification-crosslinking reaction with RC nanofibers, and its unreacted - COOH groups can also endow the 3D scaffolds with apatitenucleating capacity to further boost osteogenic potential. The resulting PLA/RC nanofiber-reconfigured scaffolds present the characteristics of high water absorption, hierarchical cellular structure and fast recovery from 80% strain. Notably, the well-designed PLA/RC scaffolds with abundant hydroxyl groups and carboxyl groups exhibit the excellent biomineralization ability in the SBF solution. And the formation of bonelike apatite not only can buffer the acid degradation products from PLA, but also will be beneficial to scaffold-to-bone bonding in the process of implantation. It is significant that the whole preparation process is safe, green and economical, which can well satisfy the demands of biomedical materials. Thus, the developed 3D PLA/RC scaffold is promising in the field of bone tissue engineering application.