Self-assembling hydrogels and electrospun frames
Worldwide, an estimated 2.5 million people live with spinal cord injury, with more than 130,000 new injuries reported each year. Spinal cord injury has a significant impact on patient quality of life, life expectancy and economic burden, with considerable costs associated with primary care and loss of income. Stroke is currently the second leading cause of death in the Western world, ranking after heart diseases and before cancer, and could raise secondary dysfunctions too.
In the case of focal brain ischemia and chronic spinal cord injuries, namely whenever an extensive loss of tissue occurs, cell therapy is helpful but not sufficient for the regeneration of the lost tissues. Within these regions, mechanical substrates are needed in order to provide physical support for axonal regeneration and for the transplanted cells to effectively integrate within the host tissues.
Tissue engineering is an interdisciplinary field of medical science that brings together the principles of material science, biochemistry, cell biology, physics and medical science, aiming to develop biological “components” for the maintenance, regeneration or replacement of tissues and organs.
In the typical approach of tissue engineering cells, harvested from biopsies or obtained from cell banks, are cultured in vitro for their expansion, then seeded into polymeric scaffolds and implanted into the damaged tissue. Additionally, scaffolds my be loaded with drugs to provide a short- or medium term delivery in vivo.
In neural tissue engineering some of used approaches comprise pro-regenerative drugs like neurotrophic factors, neuroprotective compounds, chemotactic cytokines and anti-inflammatory agents. Scaffolds are also seeded with myelinating cells (Schwann cells, Olfactory Ensheathing cells ), genetically modified cells secreting neurotrophic factors in vivo, and, most importantly, stem cells, both embrionic and neural stem cells, rapidly becoming the most tested candidates for nervous tissue replacements. Notably, in both peripheral and central nervous systems an effective regenerative approach has to address the spatial re-organization of the tissue to be regenerated, to be achieved via chemotactic attraction nad/or physical guidance of the regenerating nervous tissues.