Retinal cell regeneration using tissue engineered polymeric scaffolds

Abstract

Highlights  There is no approved treatment for dry AMD or for the advanced GA of the retina.  Tissue engineering is promising to repair damaged human retina, and restore its functions.  Polymeric scaffolds allow cells to grow & proliferate to regenerate damaged retinal tissues.  Integration of tissue engineering with drug delivery to regenerate retinal cells is yet to be realized. Degenerative retinal diseases, such as age-related macular degeneration (AMD), can lead to permanent sight loss. Although intravitreal anti-vascular endothelial growth factor (VEGF) and steroid injections are effective for the management of early stages of wet and/or neovascular AMD (nAMD), no proven treatments currently exist for dry AMD or for the advanced geographic atrophy of the retina that follows. Tissue engineering (TE) has recently emerged as a promising alternative to repair retinal damaged and restore its functions. Here, we review recent advances in TE, with a particular emphasis on retinal regeneration. We provide an overview of retinal diseases, followed by a comprehensive review of TE techniques, cells, and polymers used in the fabrication of scaffolds for retinal cell regenerations, in particular the retinal pigment epithelium (RPE).

Microfluidic and Microscale Assays to Examine Regenerative Strategies in the Neuro Retina

“…While, emerging transplantable biomaterials have generated excitement to bolster outcomes of cell replacement therapy, their tissue engineering methodologies rely largely upon chemical interactions rather than microfluidics with the notable exceptions of microfabricated scaffolds. The reader is, here, directed to current reviews of emerging retinal biomaterials [215,216].…”

“…As a result, several bio-scaffolds have emerged that produce lattices of retinal matrix proteins to support retinal cell viability and interconnectivity. While, the wealth of emerging retinal biomaterials remains outside the scope of the current article, select contemporary articles can be found here [215,216].…”

“…The innovation of 3D microstructured scaffolds has dramatically altered delivery of replacement cells into adult retina [215,282]. Microfabrication techniques have been employed to create artificial tissue constructs comprising microfibers, microparticles, and hydrogel building blocks.…”

“…This so-called wine glass scaffold design promoted efficient capture of hiPSC-derived photoreceptor cell bodies and guidance of basal axon extensions. The system provided significant contributions to cell replacement therapy because experiments ultimately achieved a uniform level of photoreceptor organization and polarization that has not been possible using conventional bolus injections or previously-described bio-scaffolds [215].…”

Nanocarriers, Progenitor Cells, Combinational Approaches, and New Insights on the Retinal Therapy

“…Although therapeutic drugs for controlling myopia progression have been utilized, such as atropine and pirenzepine, molecular mechanisms for their therapeutic actions persist as the subject of debate [10]. Since the retina is a fragile light-sensing tissue, promoting alternative strategies to healing damaged tissues of the eye and returning its functions plays an essential role for the degenerative disease [11].…”