Spatiotemporal release of NGF and GDNF from nanofibrous scaffolds

Abstract

Controlled release of growth factors can drastically enhance tissue regeneration. Nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) are known to promote peripheral nerve regeneration. In this investigation, NGF and GDNF were incorporated through emulsion electrospinning into PDLLA fibers and PLGA fibers, respectively. The deposition of PDLLA and PLGA nanofibers via dual-source dual-power electrospinning was programmed along the bicomponent scaffold thickness. The structure and properties of bicomponent scaffolds were studied. Core-shell structures were observed in both types of fibers. Both NGF and GDNF were incorporated in fibers with relatively high encapsulation efficiency. The in vitro degradation of scaffolds and in vitro release of growth factors were studied for up to 42 days. PDLLA nanofibers were more stable during degradation, resulting in slower release of NGF from scaffolds. Sustained and spatially confined release of both growth factors was achieved. Sequential release of growth factors could also be obtained.