The article Fiber reinforced GelMA hydrogel to induce the regeneration of corneal stroma by Kong et al., discusses the development of a 3D fiber hydrogel build by fabricating a grid poly (ε-caprolactone)-poly (ethylene glycol) (PECL) microfibrous scaffold and infusing it with gelatin methacrylate (GelMA) hydrogel. Because of its complex structure and keratocyte-fibroblast transition, corneal stroma regeneration has always been difficult. The cornea plays an essential role in the visual system by supplying two-thirds’ of optical power, protecting the intraocular structures, and refracting light onto the retina. The functions of the cornea may be impaired by injuries, infections, and congenital or degenerative conditions. This leads to corneal damage being the second leading cause of blindness. Currently, penetrating keratoplasty is the most commonly used transplanting procedure to improve visual impairment. However, the global demand for corneal tissue cannot be met due to a lack of donor corneal tissue. Therefore, developing clinical alternatives to corneal transplantation, such as cell-based therapy and bioengineered constructs, is critical and imminent.
The fiber spacing is calibrated to create an optimum build that mimics the stromal structure and has properties that are most similar to those of the natural cornea. In this study, the effects of direct writing different fiber topological structures on mechanical power, light transmittance, and mass swelling ratio are analyzed in order to find the right fiber hydrogel to use as a corneal equivalent. Also, the study discusses the effects of topological structure (3D fiber hydrogel, 3D GelMA hydrogel, and 2D culture dish) and chemical factors (serum, ascorbic acid, insulin, and β-FGF) on limbal stromal stem cell (LSSC) differentiation and phenotype maintenance, in vitro and in vivo tissue regeneration. That is done by measuring the expression of keratocyte- and fibroblast-specific proteins and genes. The findings indicate that in vitro and in vivo, the engineered fiber hydrogel and serum-free media work together to create an ideal environment for keratocyte phenotype maintenance and the regeneration of damaged corneal stroma.
Reference:
Kong, B., Chen, Y., Liu, R. et al. Fiber reinforced GelMA hydrogel to induce the regeneration of corneal stroma. Nat Commun 11, 1435 (2020). https://doi.org/10.1038/s41467-020-14887-9