Table 4.

Molecular therapies for the creation of a conductive microenvironment.

	NGC	delivery method	model	gap	time	significant results	references
GDNF/NT-3	EVA NGC	luminal release	rat facial	5 mm	six weeks	NGC + GDNF showed highest nerve regeneration level.	Barras et al. [78]
VEGF	silicone NGC	suspension (matrigel)	rat sciatic	10 mm	one, two, four and 26 weeks	VEGF increased angiogenesis, SC migration and nerve regeneration.	Hobson [79]
NGF	poly(phenylene ethynylene) (PPE)	PPE microsphere release	rat sciatic	10 mm	12 weeks	NGF increased nerve regeneration versus control conduits.	Xu et al. [80]
GDNF	collagen + PLGA NGC	luminal release (various rates)	rat peroneal	3 mm	12 weeks	number of myelinated fibres tripled for all rates versus no GDNF group.	Piquilloud et al. [81]
NGF	porous PCL conduit	suspension/luminal release	rat sciatic	12 mm	four, eight weeks	NGF luminal release showed superior regeneration to suspension.	Chang [82]
GDNF + NGF	collagen + PLGA NGC	luminal release	rat sciatic	10 mm	two weeks	significant increase in early peripheral nerve regeneration.	Madduri et al. [9]
GDNF/NGF	silicone NGC	affinity-based fibrin matrix	rat sciatic	13 mm	four, eight, 12 weeks	12 weeks motor recovery of GDNF greater than isograft.	Wood et al. [83]
CNTF	chitosan/PLGA NGC	luminal release	dog tibial	25 mm	12 weeks	functional recovery comparable to that of autograft.	Shen et al. [84]
NGF	PLLA-CL fibrous NGC	core shell nanofibrous release	rat sciatic	10 mm	12 weeks	NGC showed similar functional recovery regeneration to autograft.	Liu et al. [85]