Mechanical stimulation of a bioactive, functionalized PVDF-TrFE scaffold provides electrical signaling for nerve repair applications

Abstract

Traumatic nerve injuries have limited success in achieving full functional recovery, with current clinical solutions often including implementation of nerve grafts or the use of nerve conduits to guide damaged axons across injury gaps. In search of alternative, and complimentary solutions, piezoelectric biomaterials demonstrate immense potential for tissue engineering applications. Piezoelectric poly(vinylidene fluoride-triflouroethylene) (PVFD-TrFE) scaffolds can be harnessed to non-invasively stimulate and direct function of key peripheral nervous system (PNS) cells in regeneration strategies. In this study, electrospun PVDF-TrFE was characterized, fabricated into a 3D scaffold, and finally rendered bioactive with the incorporation of a cell-secreted, decellularized extracellular matrix (dECM). PVDF-TrFE scaffolds were characterized extensively for piezoelectric capacity, mechanical properties, and cell-material interactions with fibroblasts and Schwann cells. Through functionalization of PVDF-TrFE scaffolds with a native, cell-assembled dECM, the ability to promote cell adhesion and enhanced viability was also demonstrated. Additionally, incorporation of bioactive functionalization improved the assembly of key regenerative ECM proteins and regenerative growth factors. PVDF-TrFE scaffolds were then fabricated into a conduit design that retained key physical, chemical, and piezoelectric properties necessary for PNS repair. This work shows great promise for multi-cue, electrospun biomaterials for regeneration of the PNS in traumatic injury.

Keywords: Biomaterial; Extracellular matrix; PNS injury; Piezoelectricity; Schwann cells; Tissue engineering.