Customizable Collagen Vitrigel Membranes and Preliminary Results in Corneal Engineering.

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.

Phytochemical Profile and Antioxidant and Antiproliferative Activity of Sedum dendroideum on Pterygium Fibroblasts.

BACKGROUND: Sedum dendroideum has antioxidant effects that are beneficial for different diseases. We aimed to analyze the antiproliferative activity of S. dendroideum in human pterygium fibroblasts (HPFs). METHODS: HPFs were treated for 24 h with 0-1000 µg/mL of S. dendroideum lyophilized to analyze its effect on cell viability using the CellTiter assay. RNA from HPF treated with 250 µg/mL of S. dendroideum lyophilized was isolated, and the expression of VEGF and CTGF genes was evaluated by qPCR. A dermal fibroblast cell line (HDFa) was used as a healthy control. The total phenolic content, antioxidant activity, and chemical profile of S. dendroideum lyophilized were determined. RESULTS: Viability of HPF decreased after 24 h treatment of S. dendroideum in a dose-dependent manner. The expression of VEGF and CTGF significantly decreased (P < 0.01) in HPF treated with 250 µg/mL of S. dendroideum when compared with untreated HPF. The total phenolic concentration in the S. dendroideum lyophilized was 33.67 mg gallic acid equivalents (GAE)/g. Antioxidant activity was 384.49 mM Trolox equivalents/mL. The main phenolic compounds identified by HPLC analysis were the kaempferol-3-O-glycoside, kaempferol-3-O-rhamnoside, kaempferol-3-O-neohesperidoside-7-O-α-rhamnopyranoside, and kaempferol-3-O-glycoside-7-O-rhamnoside. CONCLUSIONS: S. dendroideum decreases the proliferation of HPF and the expression of VEGF and CTGF. The phenolic compound concentration, antioxidant activity, and phytochemical profile may play a role in these effects.

Arresting proliferation improves the cell identity of corneal endothelial cells in the New Zealand rabbit.

Purpose: Corneal endothelium engineering aims to reduce the tissue shortage for corneal grafts. We investigated the impact of mitogenic and resting culture systems on the identity of corneal endothelial cells (CECs) for tissue engineering purposes. Methods: Rabbit CECs were cultured in growth factor-supplemented media (MitoM) until confluence. At the first passage, the CECs were divided into two populations: P1 remained cultured in MitoM, and P2 was cultured in a basal medium (RestM) for another passage. Morphologic changes in the CECs were analyzed, and RNA was isolated for transcriptome analysis. Quantitative PCR and immunocytochemistry validation of selected differentially expressed markers were performed. Results: The CECs in MitoM showed fibroblastic morphology, whereas the CECs in RestM exhibited polygonal morphology. Circularity analysis showed similar values in human (0.75±0.056), rabbit basal (before cultured; 0.77±0.063), and CECs in RestM (0.73±0.09), while MitoM showed lower circularities (0.41±0.19). Genes related to collagen type IV and the extracellular matrix, along with the adult CEC markers ATP1A1, ATP1B1, COL8A2, GPC4, and TJP1, were highly expressed in RestM. Conversely, the IL-6, F3, and ITGB3 genes and the non-adult CEC markers CD44, CNTN3, and CD166 were more expressed in MitoM. Overall, from the transcriptome, we identified 832 differentially expressed probes. A functional analysis of the 308 human annotated differentially expressed genes revealed around 13 functional clusters related to important biological terms, such as extracellular matrix, collagen type 4, immune responses, cell proliferation, and wound healing. Quantitative PCR and immunocytochemistry confirmed the overexpression of ATP1A1, TJP1, and GPC4 in CECs in RestM. Conclusions: The addition of a stabilization step during CEC culture improves the cells' morphology and molecular identity, which agrees with transcriptome data. This suggests that stabilization is useful for studying the plasticity of the corneal endothelium's morphology, and stabilization is proposed as a necessary step in corneal endothelium engineering.

Primary explant culture and collagen I substrate enhances corneal endothelial cell morphology.

OBJECTIVES: Corneal endothelial cell (CEC) isolation and harvest aim to produce engineered grafts to solve donor corneal tissue shortage. To yield high amounts of CEC maintaining morphological and molecular characteristics, several isolation and culture conditions are reported. Here, we combined direct explant culture, with three different coating conditions and a two-step media approach to compare confluence efficiency, morphology, and specific molecular markers expression. DATA DESCRIPTION: Confluence was reached after 2 weeks in the three coating conditions (Matrigel, collagen I, and in uncoated plates) using a two-step approach (proliferative medium without pituitary extract, followed by stabilizer basal medium). Na/K-ATPase and GPC4 markers were detected by immunocytochemistry while GPC4, CD200, and TJP1 by RT-PCR in the three CEC coating culture conditions. CEC in proliferative medium showed spindle morphology in the three conditions. Polygonal morphology was seen in CEC cultures using basal medium under uncoated and collagen I coated plates. CEC cultured in Matrigel-coated plates remained with spindle morphology in basal medium.