Abstract
Purpose :
Synthetic peptide hydrogels are promising scaffolds where cornea epithelium and other cell types can be grown into in vitro cultures. The aim of this study was to develop a corneal model employing a peptide hydrogel layer as a mimetic of corneal stroma. The model was used in the assessment of corneal cytotoxicity and penetration properties of prostaglandin analogs that are considered as first-line treatment for glaucoma.
Methods :
The hydrogel was produced from human collagen-mimetic peptides exhibiting relevant properties. The hydrogels were cast into microplate wells and cell culture inserts. Human corneal epithelial cells (HCE-T) were seeded on the hydrogels and multilayered for the permeability experiments using the air-liquid interface method. In the cell viability experiments, the plastic-based conventional microplate cultures were used as a control condition. Cytotoxicity of benzalkonium chloride (BAK) and prostaglandin analogs, bimatoprost, latanoprost, tafluprost and travoprost (50 mM), were assessed using PrestoBlue and lactate dehydrogenase release assays. The permeability of fluorescent reference molecules, i.e., FITC-dextran 70 kDa and 4 kDa, Rhodamine 123, 6-carboxyfluorescein and Rhodamine B, and prostaglandin analogs was measured.
Results :
There was a clear dose-response in the cytotoxicity at clinically relevant BAK concentrations. The IC50 values of BAK in HCE-T cells grown in plastic microplates were slightly lower (0.0056%) than on hydrogels (0.0079%). Latanoprost, tafluprost, travoprost and positive control BAK (0.01%) significantly decreased the cell viability on microplates (P<0.0001) and on hydrogels (P<0.05 latanoprost, P<0.01 tafluprost, P<0.01 travoprost, P<0.0001 BAK). Nevertheless, the cell viability was maintained relatively high (>72% on microplates, >86% on hydrogels) with all tested prostaglandin analogs. The apparent permeability coefficient (Papp) values between prostaglandin analogs were different. Tafluprost and travoprost showed very low Papp values. On the contrary, latanoprost and bimatoprost were identified as high permeability molecules with high Papp values.
Conclusions :
We provide evidence that the HCE-T cells grown on human collagen-mimetic peptide hydrogels that mimic the stroma is suitable as a corneal in vitro model. The model is convenient for the assessment of cytotoxicity and permeability of ophthalmic drugs in the preclinical phase of drug development
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.