Damage of peripheral nervous system directly interferes with the communication network between brain, spinal cord and the rest of the body, and around 20 million people in United States suffer this
[1]. Donor site morbidity and limited graft material are limitations confronted by solutions such as allograft and autograft
[2]. Otherwise nerve conduits have the capacity to develop a successful nerve recovery , and most important return a better quality of life to patients. The lost of extracellular matrix (ECM), local growth factors and cells is what limits the regeneration of nerves.The proposed research consists of the engineer of 3D collagen nanofiber scaffold through electrospinning, a versatile technique for nanofibers development . The scaffold, composed of the most abundant protein in our body collagen, mimics ECM and facilitates cell adhesion and elongation to promote nerve regeneration, providing biological and mechanical support
[3][4]. The development of the collagen nanofiber structure is optimized via electrospinning parameters in order to modify nanofiber orientation which is directly related towards the direction of nerve regeneration. A random and aligned pattern has been developed and confirmed by Scanning Electron Microscope (SEM). In vitro assays and fluorescene microscope analysis with Schwann and PC-12 cells, both key cell lines in nerve tissue regeneration, resulted on successful cell adhesion to electrospun collagen nanofiber, random and aligned. Cellular tissue has been observed on collagen scaffold through SEM, after 24h cell culture and proper cell fixation method. Present experiments consist on the addition of nerve growth factor (NGF) to PC-12 cell line in order to promote differentiation. The differentiation of PC-12 cells will be analyzed towards the influence of collagen scaffold orientation on the direction of cell growth elongation. A future approach is a co-culture between Schwann and PC-12 ,on collagen scaffold,with the vision to prove that the naturally secreated NGF by Schwann cells promote the differentiation of PC-12 . Results from this co-culture will validate the use of collagen electrospun nanofiber scaffold impregnated with Schwann cells as a vehicle to deliver the proper natural components in a injured nerve and achieve nerve regeneration.
References:
1. National Institute of Neurological Disorders and Stroke: Peripheral Neuropathy Fact Sheet (Bethesda, Maryland, 2014).
2. W. Z. Ray and S. E. Mackinnon: Management of nerve gaps: Autografts, allografts, nerve transfers, and end-to-side neurorrhaphy. Exp. Neurol. 223(1), 77 (2010).
3. S. Previtali, M. Malaguti, N. Riva, M. Scarlato, P. Dacci, G. Dina, D. Triolo, E. Porrello, I. Lorenzetti, R. Fazio, G. Comi, A. Bolino, and A. Quattrini: The extracellular matrix affects axonal regeneration in peripheral neuropathies. Neurology 71(322–331) (2008).
4. G. a. Di Lullo, S. M. Sweeney, J. Körkkö, L. Ala-Kokko, and J. D. San Antonio, “Mapping the ligand-binding sites and disease-associated mutations on the most abundant protein in the human, type I collagen,†J. Biol. Chem., vol. 277, no. 6, pp. 4223–4231, (2002).
