Acellular porcine corneal matrix as a carrier scaffold for cultivating human corneal epithelial cells and fibroblasts in vitro

AIM：To investigate the feasibility of corneal anterior lamellar reconstruction with human corneal epithelial cells and fibroblasts,and an acellular porcine cornea matrix（APCM） in vitro.·METHODS：The scaffold was prepared from fresh porcine corneas which were treated with 0.5%sodium dodecyl sulfate（SDS）solution and the complete removal of corneal cells was confirmed by hematoxylin-eosin（HE）staining and 4’,6-diamidino-2-phenylindole（DAPI）staining.Human corneal fibroblasts and epithelial cells were cultured with leaching liquid extracted from APCM,and then cell proliferative ability was evaluated by MTT assay.To construct a human corneal anterior lamellar replacement,corneal fibroblasts were injected into the APCM and cultured for 3d,followed by culturing corneal epithelial cells on the stroma construction surface for another 10d.The corneal replacement was analyzed by HE staining,and immunofluorescence staining.·R ESULTS：Histological examination indicated that there were no cells in the APCM by HE staining,and DAPI staining did not detect any residual DNA.The leaching liquid from APCM had little influence on the proliferation ability of human corneal fibroblasts and epithelial cells.At 10d,a continuous 3 to 5 layers of human corneal epithelial cells covering the surface of the APCM was observed,and the injected corneal fibroblasts distributed within the scaffold.The phenotype of the construction was similar to normal human corneas,with high expression of cytokeratin 12 in the epithelial cell layer and high expression of Vimentin in the stroma.·CONCLUSION：Corneal anterior lamellar replacement can be reconstructed in vitro by cultivating human corneal epithelial cells and fibroblasts with an acellular porcine cornea matrix.This laid the foundation for the further transplantation in vitro.

A cellular and proteomic approach to assess proteins extracted from cryopreserved human amnion in the cultivation of corneal stromal keratocytes for stromal cell therapy

Background:Human corneal stromal keratocytes propagated in culture media supplemented with human amnion extract(AME)can correct early corneal haze in an animal model.Clinical application of cultivated keratocytes is limited by infectious disease screening before amnion products can be used in humans.It remains unclear if AME from cryopreserved versus fresh human amnion can support human keratocyte propagation,and which components of the extract promote keratocyte growth.Methods:Three placentas were collected for the preparation of fresh and cryopreserved amnion tissues followed by homogenization and protein extraction.AME protein profiles were studied using isobaric tagging for relative and absolute quantitation(iTRAQ)proteomics.Enriched gene ontology(GO)terms and functional classes were identified.Primary human keratocytes from 4 donor corneas were cultured in media supplemented with fresh AME(F-AME)or cryopreserved AME(C-AME).Cell viability,proliferation and keratocyte marker expression were examined by confocal immunofluorescence and flow cytometry.Results:AME proteomics revealed 1385 proteins with similar expression levels(between 0.5-and 2-fold)between Fand C-AME,while 286 proteins were reduced(less than 0.5-fold)in C-AME.Enriched GO term and biological pathway analysis showed that those proteins with comparable expression between F-AME and C-AME were involved in cell metabolism,epithelial-mesenchymal transition,focal adhesion,cell-extracellular matrix interaction,cell stress regulation and complement cascades.Human corneal stromal keratocytes cultured with F-AME or C-AME showed similar morphology and viability,while cell proliferation was mildly suppressed with C-AME(P>0.05).Expression of aldehyde dehydrogenase 3A1(ALDH3A1)and CD34 was similar in both cultures.Conclusion:AME from cryopreserved amnion had limited influence on keratocyte culture.It is feasible to use protein extract from cryopreserved amnion to propagate human keratocytes for potential translational applications.