Abstract
Purpose:
Bioscaffolds, supporting survival and guiding axonal growth, holds great promise for the advancement of cell-based therapies for retinal neurodegenerative diseases. Increased knowledge is required on the effect of nanotopographies, extracellular matrix (ECM) proteins and neurotrophic factors on retinal cell survival, cell fate and axonal guidance. Hence, we here investigated the influence of nanotopography, laminin (ECM protein) and neurotrophic factors on retinal ganglion cells (RGC), photoreceptors (PR) and glial cells.
Methods:
Post-natal day 4 mouse retinas were isolated and dissociated into single cells and cultured for 7 days in vitro, at either Poly-L-Lysine-coated chamber slides or electrospun polycaprolactone (PCL) fiber substrates with random or aligned orientation. Non-coated and laminin-coated substrates were used. Either basic (DMEM-F12, B27 supplement) or the enriched Full-SATO (Neurobasal, CNTF, BDNF, Forskolin, Insulin) medium was used. Analysis parameters: survival, quantification and morphology assessment of RGC (RBPMS+, NeuN+, β-tubulin III+)-, PR (rhodopsin+) and glial (GFAP+) cells, and neurite length and orientation.
Results:
Nanotopography per se significantly affected the formation of retinal cells morphologies, exemplified by larger fractions of multipolar cells found on flat surfaces and random fibers and uni- and bipolar cells on aligned fibers. Addition of laminin and use of Full-SATO medium in all three substrates promoted both RGC and PR maturation, demonstrated by complex neuronal morphologies and extended neurite outgrowth. Notably, laminin induced cell neurites to grow along the fibers and not perpendicular to their orientation, as occurred on non coated fibers. Preliminary results also suggest increased numbers of RGC, PR and glial cells in cultures with laminin and Full-SATO medium.
Conclusions:
With a future cell-based retinal therapy in mind, we here provide further in-depth knowledge on control of retinal cells fate using electrospun PCL fibers, ECM-guiding proteins and a supportive enriched culture media. Controlled neural development and axonal guidance was improved by using laminin-coated aligned fibers and Full-SATO medium.