To investigate the cellular and molecular changes of cultured human retinal pigment epithelial (hRPE) cells when treated with different concentrations of platelet gel.

Confluent cultured hRPE cells in 3rd, 5th, and 7th were treated with 10%, 20%, and 30% platelet gels. Cultivated hRPE cells in 20% fetal bovine serum were considered as control. Cell viability was determined by MTT assay and by light microscopy. Total RNA was isolated and the gene expression profile was determined using real time RT-PCR. The real-time RT–PCR analysis was performed in duplicate as three independent experiments. Differences between the control and experimental groups were analyzed using the Student t test. P˂0.05 was considered statically significant.

Viability of cultivated hRPE cells treated with different concentrations of platelet gel was higher than the controls on day 7 (p value=0.044); however, it was comparable with control on day 3 (p value=0.108) and showed a borderline increase on day 1 (p value=0.074). The viability of hRPE cells was not significantly different between different concentrations of platelet gel on days 1, 3 and 7; however, hRPE cells demonstrated a significant increase of viability with 30% as compared to 10% platelet gel on day 7. hRPE cells treated with different concentrations of platelet gel did not show a significant change in the expression of Ki67, ?-SMA, and PAX6; however, expressions of MMP-9, MMP2 and KDR1 were not significantly changed with 10% platelet gel and a high expression of RPE65 was observed following 30% platelet gel treatment.

It seems that platelet gel as a 3D substrate has a positive effect on viability of cultivated hRPE cells; however, 10% platelet gel seems to be the proper concentration in terms of low risk of inflammation, angiogenesis, and induction of cell proliferation.