Recreating a human trabecular meshwork outflow system on microfabricated porous structures

BIOTECHNOLOGY AND BIOENGINEERING | DECEMBER 2013

Volume 110, Issue 12, December 2013, Pages: 3205–3218

Karen Y. Torrejon, Dennis Pu, Magnus Bergkvist, John Danias, Susan T. Sharfstein and Yubing Xie

Abstract

Glaucoma is the leading cause of irreversible blindness, resulting from an increase in intraocular pressure (IOP). IOP is the only modifiable risk factor of glaucoma and is controlled by the outflow of the aqueous humor through the human trabecular meshwork (HTM). Currently, the lack of a proper in vitro HTM model impedes advances in understanding outflow physiology and discovering effective IOP-lowering anti-glaucoma therapeutics. Therefore, we designed and constructed an in vitro HTM model using micropatterned, porous SU-8 scaffolds, which support cells to recapitulate functional HTM morphology and allow the study of outflow physiology. The pore size of SU-8 scaffolds, surface coating, cell seeding density, and culture duration were evaluated for HTM cell growth. The bioengineered HTM was characterized by F-actin staining and immunocytochemistry of HTM markers. A stand-alone perfusion chamber with an integrated pressure sensing system was further constructed and used for the investigation of the outflow facility of the bioengineered HTM treated with latrunculin B—an IOP lowering agent. Cells in the in vitro model exhibited HTM-like morphology, expression of α-smooth muscle actin, myocilin, and αB-crystallin, outflow characteristics and drug responsiveness. Altogether, we have developed an in vitro HTM model system for understanding HTM cell biology and screening of pharmacological or biological agents that affect trabecular outflow facility, expediting discovery of IOP-lowering, anti-glaucoma therapeutics.

Biotechnol. Bioeng. 2013;110: 3205–3218. © 2013 Wiley Periodicals, Inc.