Poly-l/dl-lactic acid films functionalized with collagen IV as carrier substrata for corneal epithelial stem cells

Abstract

A B S T R A C TLimbal epithelial stem cells (LESCs) are responsible for the renewal of corneal epithelium. Cultivated limbal epithelial transplantation is the current treatment of choice for restoring the loss or dysfunction of LESCs. To perform this procedure, a substratum is necessary for in vitro culturing of limbal epithelial cells and their subsequent transplantation onto the ocular surface. In this work, we evaluated poly-L/DL-lactic acid 70:30 (PLA) films functionalized with type IV collagen (col IV) as potential in vitro carrier substrata for LESCs. We first demonstrated that PLA-col IV films were biocompatible and suitable for the proliferation of human corneal epithelial cells. Subsequently, limbal epithelial cell suspensions, isolated from human limbal rings, were cultivated using culture medium that did not contain animal components. The cells adhered significantly faster to PLA-col IV films than to tissue culture plastic (TCP). The mRNA expression levels for the LESC specific markers, K15, P63α and ABCG2 were similar or greater (significantly in the case of K15) in limbal epithelial cells cultured on PLA-col IV films than limbal epithelial cells cultured on TCP. The percentage of cells expressing the corneal (K3, K12) and the LESC (P63α, ABCG2) specific markers was similar for both substrata. These results suggest that the PLA-col IV films promoted LESC attachment and helped to maintain their undifferentiated stem cell phenotype. Consequently, these substrata offer an alternative for the transplantation of limbal cells onto the ocular surface.

Recent Approaches of Collagen Biomatrix Modification as a Corneal Biomatrix and its Cellular Interaction

“…Four studies investigated the interaction of corneal cells on collagen biomaterials with other biological molecules and cells [81][82][83][84]. Meanwhile, four studies exploited the biological benefit function of collagen by combination of different biomatrix to improve its function as a cell carrier [40,[85][86][87]. From these articles, several types of cells were used such as CECs, LESCs alone or co-culture of both cells and the combination of one of these cells with stromal cells (corneal stromal stem cell or limbal fibroblast).…”

“…De la Mata and colleagues [85] studied the biological properties of collagen IV by incorporating the collagen into a poly-L/DL-lactic acid (PLA) biomatrix. Functionalizing PLA films with collagen IV (70:30) improved LESCs attachment, selection, and enrichment and maintained the undifferentiated LESCs phenotype with homogenous polygonal morphology [85]. This finding was supported by Wright, De Bank, Luetchford, Acosta and Connon [40] who incorporated collagen IV into an oxidized alginate biomatrix.…”

Goals and Challenges of Stem Cell-Based Therapy for Corneal Blindness Due to Limbal Deficiency

“…Additionally, synthetic biodegradable PLA polymers have been recently used for the treatment of LSCD by serving as a substratum for freshly excised limbal tissue [ 143 ]. The use of PLGA membranes as substitute for amniotic membranes or fibrin for limbal epithelial transplantation is a novel technique that will potentially benefit patients, reduce costs, and avoid the risk of disease transmission.…”

Construction and Evaluation of Collagen-Based Corneal Grafts Using Polycaprolactone To Improve Tension Stress

“…This procedure has been called anterior lamellar keratoplasty (ALKP). − Therefore, many researchers have attempted to develop corneal grafts using natural macromolecule materials to replace pathologic corneal tissue via ALKP. , The corneal stroma, which accounts for approximately 90% of the cornea, mainly composes of aligned collagen (Col) I fibrils and quiescent keratocytes. − Bionic corneal structures are the key to the development of successful corneal products. In addition, the cornea repair materials should possess good biocompatibility and nutrition permeability, appropriate optical performance and mechanical strength. − Although many cornea repair materials have been successfully obtained in a variety of ways, ,,− the main problem is that they are difficult to apply in the clinical suture.…”