Photoinduced Gelatin-Methacrylate Scaffolds to Examine the Impact of Extracellular Environment on Trabecular Meshwork Cells

Abstract

Glaucoma is the leading cause of irreversible blindness in the world, currently impacting 80 million people. Patients suffering from primary open-angle glaucoma experience aqueous humor accumulation within the eye causing an increase in intraocular pressure (IOP). The main cause of this rise in IOP is due to poor outflow of aqueous humor through the trabecular meshwork (TM), a tissue composed of collagen and glycosaminoglycans (GAGs) embedded with TM cells. The behavior of TM cells is impacted by their microenvironment, and studies conducted on two-dimensional plastic substrates do not necessarily reflect how TM cells would behave in their native setting. Here, we cultured human TM (hTM) cells on 3D biocompatible hydrogels composed of gelatin methacrylate (GelMA) incorporated with the glycosaminoglycans (GAGs) chondroitin sulfate (CS) and hyaluronic acid (HA). Mechanical properties were quantified by storage moduli and viscosity data. Cellular response was measured by quantifying cellular proliferation and expression of an important extracellular matrix protein, fibronectin. We have shown substrate mechanical properties to impact hTM cell proliferation over 2 weeks. It was found that the incorporation of GAGs impacted cell proliferation and fibronectin expression in hTM cells. This work will help elucidate hTM cell response with changes in their microenvironment.

Glycosaminoglycans Influence Extracellular Matrix of Human Trabecular Meshwork Cells Cultured on 3D Scaffolds

“…Increased bioavailability of dex to the hTM cells as a result of continuous media supply may be causing the transcriptional changes observed. Previously, we have also reported fibronectin expression to be increased in the presence of dex in both collagen-GAG scaffolds and GelMA/GAG hydrogels. , Current findings in conjunction with previous results are suggestive of these ECM proteins’ role in pressure gradient changes in in vitro TM models.…”

“…Previously, we have also reported fibronectin expression to be increased in the presence of dex in both collagen-GAG scaffolds and GelMA/GAG hydrogels. 25,27 Current findings in conjunction with previous results are suggestive of these ECM proteins' role in pressure gradient changes in in vitro TM models.…”

“…Our group has previously reported the feasibility of collagen-GAG scaffolds and GelMA hydrogels as a model system for in vitro study of hTM cells. 24,25,27 The scaffolds also provide different matrix compositions to explore hTM cell and ECM behavior. In this work, we have employed three-dimensional collagen and collagen-GAG scaffolds as in vitro hTM cell study systems.…”

“…To understand the role of ECM in glaucoma pathogenesis, various groups have studied TM cell behavior on tissue culture (TC) plates, scaffolds, hydrogels, Matrigel, coated SU-8 scaffolds, and collagen- and elastin-like polypeptides. − In 2D environments, cells are more restricted in their morphological development and motility than in the 3D environment, making the 3D environment more reflective of the complex native cellular microenvironment. Our group has previously reported the feasibility of collagen-GAG scaffolds and GelMA hydrogels as a model system for in vitro study of hTM cells. ,, The scaffolds also provide different matrix compositions to explore hTM cell and ECM behavior. In this work, we have employed three-dimensional collagen and collagen-GAG scaffolds as in vitro hTM cell study systems.…”

Cell‐instructive biomaterials in tissue engineering and regenerative medicine

“…70 million people worldwide, TM tissue engineering is still in its infancy. Our group has developed (Figure1) scaffolds using collagen and GelMA for in vitro study of human TM (hTM) cell behavior 30,31. Scaffold pore architecture influenced proliferation and fibronectin expression of hTM cells cultured in the scaffolds; with cells grown on scaffolds with larger pores displaying highest viability and fibronectin expression 32.…”