Customizable Collagen Vitrigel Membranes and Preliminary Results in Corneal Engineering

Abstract

Corneal opacities are a leading cause of visual impairment that affect 4.2 million people annually. The current treatment is corneal transplantation, which is limited by tissue donor shortages. Corneal engineering aims to develop membranes that function as scaffolds in corneal cell transplantation. Here, we describe a method for producing transplantable corneal constructs based on a collagen vitrigel (CVM) membrane and corneal endothelial cells (CECs). The CVMs were produced using increasing volumes of collagen type I: 1X (2.8 μL/mm2), 2X, and 3X. The vitrification process was performed at 40% relative humidity (RH) and 40 °C using a matryoshka-like system consisting of a shaking-oven harboring a desiccator with a saturated K2CO3 solution. The CVMs were characterized via SEM microscopy, cell adherence, FTIR, and manipulation in an ex vivo model. A pilot transplantation of the CECs/CVM construct in rabbits was also carried out. The thickness of the CVMs was 3.65–7.2 µm. The transparency was superior to a human cornea (92.6% = 1X; 94% = 2X; 89.21% = 3X). SEM microscopy showed a homogenous surface and laminar organization. The cell concentration seeded over the CVM increased threefold with no significant difference between 1X, 2X, and 3X (p = 0.323). The 2X-CVM was suitable for surgical manipulation in the ex vivo model. Constructs using the CECs/2X-CVM promoted corneal transparency restoration.

Emerging alternatives to keratoplasty for corneal endothelial cell dysfunction

“…These CEC-like cells can be implanted by either direct injection to the anterior chamber or as part of a tissue engineered endothelial keratoplasty (TEEK) using a substrate, some of which are based on human donor tissues [66,67 ,68] while others use synthetic polymers [69][70][71][72] and xenografts [73]. Interesting candidates include decellularized femtosecond laser-cut ultrathin stromal lamellae and anterior lens capsule which have shown some potential in rabbit models [66] as well as decellularized small incision lenticule extraction lenticules which were found effective in an ex vivo human donor cornea model [67 & ].…”

Recent advances in cell-based regenerative therapies for corneal disease

“…Most studies use cultivated CEC, but the proposed scaffolds are diverse. Some use human ophthalmic tissue, such as decellularized femtosecond laser-cut ultrathin stromal lamellae or anterior lens capsule [71], while others use nonophthalmic or nonhuman tissues, such as cross-linked amniotic membrane [72], xenografts, such as acellular porcine corneal stroma [73], or natural and synthetic polymers [74,75].…”