Effect of human autologous serum and fetal bovine serum on human corneal epithelial cell viability,migration and proliferation in vitro

AIM： To analyze the concentration-dependent effects of autologous serum （AS） and fetal bovine serum （FBS） on human corneal epithelial cell （HCEC） viability, migration and proliferation. METHODS： AS was prepared from 13 patients with non- healing epithelial defects Dulbecco＇s modified eagle medium/ Ham＇s F12 （DMEM/F12） with 5% FBS, 0.5% dimethyl sulphoxide （DMSO）, 10 ng/mL human epidermal growth factor, 1% insulin-transferrin-selenium, then were incubated in serum media： DMEM/F12 supplemented by 5%, 10%, 15% or 30% AS or FBS. HCEC viability was analyzed using cell proliferation kit XTI＇, migration using a wound healing assay, proliferation by the cell proliferation enzyme-linked immunosorbent assay （ELISA） BrdU kit. Statistical analysis was performed using the generalized linear model, the values at 30% AS or 30% FBS were used as the baselines. RESULTS： HCEC viability was the highest at 30% AS or 15% FBS and the lowest at 10% AS or 30% FBS application. HCEC migration was the quickest through 30% AS or 30% FBS and the slowest through 5% AS or 5% FBS concentrations. Proliferation was the most increased through 15% AS or 5% FBS and the least increased through 30% AS or 30% FBS concentrations. HCEC viability at 10% and 15% AS was significantly worse （P=0.001, P=0.023） compared to baseline and significantly better at 15% FBS （P=0.003） concentrations. HCEC migration was significantly worse （P〈0.007） and HCEC proliferation significantly better （P〈0.001） in all concentration groups compared to baseline. CONCLUSION： For the best viability of HCEC 30% AS or 15% FBS, for HCEC migration 30% AS or 30% FBS, for proliferation 15% AS or 5% FBS should be used. Therefore, we suggest the use of 30% AS in clinical practice.

Impact of crosslinking/riboflavin-UVA-photodynamic inactivation on viability,apoptosis and activation of human keratocytes in vitro

Riboflavin-UVA photodynamic inactivation is a potential treatment altemative in therapy resistant infectious keratitis. The purpose of our study was to determine the impact of riboflavin-UVA photodynamic inactivation on viability, apop- tosis and activation of human keratocytes in vitro. Primary human keratocytes were isolated from human corneal buttons and cultured in DMEM/Ham＇s F12 medium supplemented with 10% fetal calf serum. Keratocytes underwent UVA light illumination （375 nm） for 4.10 minutes （2 J/cm2） during exposure to different concentrations of riboflavin. Twenty-four hours after treatment, cell viability was evaluated photometrically, whereas apoptosis, CD34 and alpha-smooth muscle actin （α-SMA） expression were assessed using flow cytometry. We did not detect significant changes in cell viability, apoptosis, CD34 and α-SMA expression in groups only treated with riboflavin or UVA light. In the group treated with riboflavin-UVA-photodynamic inactivation, viability of keratocytes decreased significantly at 0.1% riboflavin （P〈0.01） while the percentage of CD34 （P〈0.01 for both 0.05% and 0.1% riboflavin） and alpha-SMA positive keratocytes （P〈0.01 and P〈0.05 for 0.05% and 0.1% riboflavin, respectively） increased significantly compared to the controls. There was no significant change in the percentage of apoptotic keratocytes compared to controls at any of the used ribo- flavin concentrations （P=0.09 and P=0.13）. We concluded that riboflavin-UVA-photodynamic-inactivation decreases viability of myofibroblastic transformation and multipotent haematopoietic stem cell transformation; however, it does not have an impact on apoptosis of human keratocytes in vitro.