Neural Tissue Engineering
Injuries of the nervous system occur commonly among people of many different ages and backgrounds. Recently, liver growth factor (LGF) has been used as a neural tissue regenerator. LGF administration stimulates neurogenesis and neuron survival and promotes migration of newly generated neurons. LGF treatment induces the outgrowth of striatal dopaminergic terminals in 6-hidroxydopamine-lesioned rats and protects dopaminergic neurons in hemiparkinsonian animals . However, there are still no effective strategies to improve neural regeneration. Currently, Neural tissue engineering provides a promising avenue for regeneration of nerves . Neural tissue engineering combining customized biomaterial scaffolds with cells offers an integrative approach to tackle the trauma, stroke, or degenerative diseases .
Since nanomaterials can be tailored at the molecular level and scaffold morphology may more closely resemble features of ECM components in terms of porosity, framing, and biofunctionalities, nanostructured scaffolds recently showed great promise in tissue engineering . Both carbon nanotube and graphene hold great potential in the biomedical field because of their extraordinary properties . Many novel biomaterials are being developed, such as multi-faceted nanoscaffolds built by the approaches and applications of self-assembling peptides and peptide amphiphiles for direct application to neural injury . Besides, among all the biomaterials, hyaluronic acid is a promising candidate for central neural tissue engineering because of its unique physico-chemical and biological properties .
Most popular cell candidates used for neural tissue engineering include glial cells and stem/stem-like cells. Glial cells can secrete neuroprotective agents that stimulate natural neural repair. Stem/stem-like cells have the additional potential to replace lost tissue via differentiating into neuronal cells [158, 163]. Most studies have examined the effects of soluble pharmacological factors on the cellular neurogenesis. On the other hand, it is now recognized that mechanical cues such as stretch and shear stress also have a strong potential to induce cellular neurogenesis . In addition, because patient-specific iPSC can be differentiated into disease-relevant cell types, including neurons, cellular reprogramming of somatic cells to human iPSC represents an efficient tool for in vitro modeling of human brain diseases and provides an innovative opportunity in the identification of new therapeutic drugs .