Abstract
Purpose: :
To evaluate the in vitro interactions between primary photoreceptors and collagen vitrigel biomaterial substrates.
Methods: :
Cells were isolated from the neural retina of Nrl-GFP mice at postnatal stages ranging from P1 to P10 and plated onto collagen vitrigels (CVs) and poly-D-lysine (PDL) controls. These primary cells were cultured for up to 14 days. Cell morphology, total cell number and percentage of total cells expressing GFP were evaluated for the duration of in vitro culture. Cultures were also immunostained for photoreceptor markers, including rhodopsin.
Results: :
Almost all cultures on CV exhibited improved cell viability and increased gene expression over the entire culture period compared to PDL control, regardless of post-natal stage. Morphological examination of the cultures revealed that at P4 postnatal stage, GFP-positive cells formed distinct aggregates. This unexpected finding was noted on CV biomaterial, but not on the PDL control plates. These aggregates or cell clusters formed during the first 24 hours in culture and elaborated their neural cytoarchitecture until days 7-10. Preliminary immunostaining demonstrated that P5 cells plated onto CV expressed rhodopsin after 4 days in culture and that this expression is segregated to one side of the cell.
Conclusions: :
Improved cell viability and GFP expression in the CV cultures suggest that the biomaterial may provide an in vitro environment that better mimics the photoreceptor’s natural environment, compared to PDL coated plates. Furthermore, the aggregation behavior observed exclusively on the CV suggests a unique interaction between this biomaterial and the photoreceptor cells at specific developmental stages. Our findings indicate that CV may hold promise for future applications including in vitro retinal modeling and cell transplantation.
Keywords: retinal culture