Human Bone Derived Collagen for the Development of an Artificial Corneal Endothelial Graft. In Vivo Results in a Rabbit Model

Abstract

Corneal keratoplasty (penetrating or lamellar) using cadaveric human tissue, is nowadays the main treatment for corneal endotelial dysfunctions. However, there is a worldwide shortage of donor corneas available for transplantation and about 53% of the world’s population have no access to corneal transplantation. Generating a complete cornea by tissue engineering is still a tough goal, but an endothelial lamellar graft might be an easier task. In this study, we developed a tissue engineered corneal endothelium by culturing human corneal endothelial cells on a human purified type I collagen membrane. Human corneal endothelial cells were cultured from corneal rims after corneal penetrating keratoplasty and type I collagen was isolated from remnant cancellous bone chips. Isolated type I collagen was analyzed by western blot, liquid chromatography -mass spectrometry and quantified using the exponentially modified protein abundance index. Later on, collagen solution was casted at room temperature obtaining an optically transparent and mechanically manageable membrane that supports the growth of human and rabbit corneal endothelial cells which expressed characteristic markers of corneal endothelium: zonula ocluddens-1 and Na+/K+ ATPase. To evaluate the therapeutic efficiency of our artificial endothelial grafts, human purified type I collagen membranes cultured with rabbit corneal endothelial cells were transplanted in New Zealand white rabbits that were kept under a minimal immunosuppression regimen. Transplanted corneas maintained transparency for as long as 6 weeks without obvious edema or immune rejection and maintaining the same endothelial markers that in a healthy cornea. In conclusion, it is possible to develop an artificial human corneal endothelial graft using remnant tissues that are not employed in transplant procedures. This artificial endothelial graft can restore the integrality of corneal endothelium in an experimental model of endothelial dysfunction. This strategy could supply extra endothelial tissue and compensate the deficit of cadaveric grafts for corneal endothelial transplantation.

Silk Fibroin Films for Corneal Endothelial Regeneration: Transplant in a Rabbit Descemet Membrane Endothelial Keratoplasty

“…Several groups, including our own, 56 have already developed different artificial endothelial grafts that allow the recovery of endothelial functionality in different in vivo models. 18,27,29,57,58 From our point of view, SF films present several advantages, such as having better mechanical properties than other biomaterials, being a biomaterial that has been used for centuries in medicine and that could be easily accessible and have a lower cost of production than other biomaterials in some countries.…”

Design of a Novel Two‐Component Hybrid Dermal Scaffold for the Treatment of Pressure Sores

“…Various properties of silicones make them favorable for biomedical uses, especially for wound dressings, including low liquid surface tension, high permeability, pressure sensitivity, mechanical resistance, and ease of sterilization . Moreover, there are several documented cases of using silicone to enhance the mechanical properties of more fragile biomaterials, especially in the case of wound dressings . As an example, Pires and Moares demonstrated the enhanced tensile strength and flexibility of chitosan–alginate membranes following incorporation of the liquid silicone rubber Silpuran 2130 A/B .…”

Experimental design of a culture approach for corneal endothelial cells

“…In regards of area and perimeter drop upon confluence, further studies required to determine if a stabilization or compaction process occurs as observed with human CECs [4,28,29] Total Protein, Pro-collagen I And Na/K-ATPase Concentration Total protein, pro-collagen I, and NA/K-ATPase concentrations were higher in CECs. A heterogeneous amount of CECs per group were evaluated due to their challenging isolation and culture.…”

“…The clarity and nutrition of the cornea rely on these functions, given that it is an avascular tissue [3]. The damage to the corneal endothelium can lead to blindness because CECs are arrested in the G 1 cell cycle phase [4][5][6]. Corneal blindness can only be treated through transplantation, however, this procedure faces the shortage of tissue donors [3,[7][8][9][10].…”