New Human Organotypic Corneal Tissue Model for Ophthalmic Drug Delivery Studies

Abstract

PURPOSE. The purpose of the current work was to develop a physiologically relevant, in vitro human three-dimensional (3D) corneal epithelial tissue model for use in ophthalmic drug development.METHODS. Normal human corneal epithelial cells were cultured at the air-liquid interface to produce the 3D corneal tissue model. Corneal barrier was determined by measuring transepithelial electrical resistance (TEER). Quantitative PCR arrays were utilized to investigate expression of 84 phase I/II metabolizing enzymes and 84 drug transporter genes. Permeability was evaluated using model compounds with a wide range of hydrophobicity, molecular weight, and excipients. Finally, different formulations of latanoprost and bimatoprost were administered and drug absorption and tissue viability and integrity were investigated.RESULTS. Histologic assessment and TEER of the corneal tissue model revealed tissue structure, thickness, and barrier formation (1000 6 146 XÁcm 2 ) comparable to native human corneal epithelium. The 3D corneal tissue expressed tight junctions, mucins, and key corneal epithelial detoxification enzymes. Drug-metabolizing enzyme and transporter gene expression in 3D corneal tissue and excised human corneal epithelium were highly correlated (r 2 ¼ 0.87). Coefficients of permeation for model drugs in the tissue model and excised rabbit corneas also showed a high correlation (r 2 ¼ 0.94). As expected, latanoprost and bimatoprost free acids had much lower permeability (Papp ¼ 1.2 3 10 À6 and 1.9 3 10 À6 ) than the corresponding prodrugs (Papp ¼ 2.5 3 10 À5 and 5.6 3 10 À5 ), respectively. The presence of 0.02% benzalkonium chloride in ophthalmic formulations significantly affected tissue barrier and viability.CONCLUSIONS. The newly developed 3D corneal tissue model appears to be very useful for evaluation of corneal drug permeability and safety during ophthalmic drug development.

Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano) for Ocular Delivery of Cyclosporine-A

“…In vitro Permeation Studies of CyA through Ocular Reconstituted Tissue COR-100 EpiCorneal TM reconstituted tissues were chosen as biological substrate to evaluate the capability of CyA loaded into ASMP-Nano formulations to permeate through corneal tissues [39]. For the experiment, COR-100 EpiCorneal TM reconstituted tissues were preliminary equilibrated overnight in culture medium (COR-100 ASY medium) at Standard Cell Culture Conditions (SCC, 37 • C, 5% CO 2 ) in line with the Mattek protocol.…”

Penetration Enhancers in Ocular Drug Delivery

“…One of the closest models to the real cornea involves reconstructed tissue cultures which comprise different types of cells that help mimic the three-layer structure including the epithelium, stroma, and endothelium. For example, Kaluzhny et al [67] recently developed an in vitro human three-dimensional corneal epithelial tissue model and demonstrated the applicability of this membrane for studies of drug permeability using several fluorescent markers, as well as latanoprost and bimatoprost.…”

Corneal Infection Models: Tools to Investigate the Role of Biofilms in Bacterial Keratitis

“…Therefore, many in vitro models have focused solely on the cultivation of human corneal epithelial cell (HCE) multilayers [111,112]. However, 3D organotypic models have also been developed which incorporate epithelial, stromal and endothelial cells, providing whole-tissue models [113][114][115]. The cornea has six distinct layers and the outermost layer is the corneal epithelium, which is made up of 5-7 rows of tightly packed corneal epithelial cells.…”