Figure 3.

Schematic of cellular and molecular-based therapies used for the creation of a more conductive nerve microenvironment. Examples of molecular therapies include growth factors (VEGF and bFGF) and neurotrophic factors (NT3 and NGF). Likewise cell therapies involve the use of SCs, stem cells (ASCs and MSCs) and genetically modified cells (SCs overexpressing GDNF). These can be delivered by a number of means including: (i) suspension within solution or a biomaterial matrix (hydrogel, sponge), (ii) released via a diffusion-based systems (controlled released via cross-linking, slow degrading polymer coatings etc. from luminal wall), (iii) the use of affinity-based delivery systems (factors conjugated to a fibrin matrix), and (iv) microsphere (e.g. collagen, fibrin) encapsulation which can either be suspended within the lumen or released from the luminal wall.