Over 596 million people live with low vision and blindness globally. Increases in population longevity largely drive the recent rise of degenerative retinal pathologies. Retinal cell transplantation is a novel regenerative therapy that shows great promise to treat retinal degeneration. Here, donor stem-like cells are transplanted into host retina to replace degenerated or dysfunctional neurons, such as photoreceptors, to restore visual function. While some successful outcomes have been measured, the limited cell motility of transplanted cells and their integration into host tissue remain key challenges. This project examined how in vitro cell migration upon transplantable matrix is affected by the modification of Topoisomerase II-beta (Top2b), a critical enzyme in neural development. We used in vitro transduction and transfection models to assess how Top2b knockdown and overexpression affect the behavior of retinal progenitor cells upon transplantable extracellular matrices and emerging transplant scaffolds. We demonstrated that Top2b knockdown impaired neuronal differentiation and reduced chemotactic migration via expression of key receptors. Top2b overexpression enhanced receptor expression; however, the resulting changes in adhesion, shape, and migration varied significantly depending upon the extracellular matrix. These data underline the influence of physical and biochemical properties of the environment on Top2b modulation. In complement, we applied an elastomeric flow device fabricated using rapid prototyping techniques, including resin stereolithography and fused deposition modeling, to study how flow influenced retinal cell behavior. Tests examined how interstitial flow conditions significantly impacted cell survival and morphology. Results showed that laminin coating within the microfluidic device improved cell adhesion and smoother microchannel surfaces to better support consistent cell behavior. Further, more physiologically relevant flow conditions of interstitial flow (Q=1ul/min) allowed cells to adapt, elongate, and adhere onto the microchannel. These studies together offer proof-of-concept for using rapid prototyping to examine cell behavior in physiological microenvironments and establish that Top2b shows promise to be a modulator in retinal cell motility, significant to transplantation.
Alexandra Caroline Dabrowski (Thu,) studied this question.