Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran.
School of Engineering, University of British Columbia, Kelowna, BC, V1V 1V7, Canada.
Ann Biomed Eng. 2020 Jul;48(7):1955-1970. doi: 10.1007/s10439-020-02537-6. Epub 2020 Jun 5.
3D bioprinting technology is a promising approach for corneal stromal tissue regeneration. In this study, gelatin methacrylate (GelMA) mixed with corneal stromal cells was used as a bioink. The visible light-based stereolithography (SLA) 3D bioprinting method was utilized to print the anatomically similar dome-shaped structure of the human corneal stroma. Two different concentrations of GelMA macromer (7.5 and 12.5%) were tested for corneal stroma bioprinting. Due to high macromer concentrations, 12.5% GelMA was stiffer than 7.5% GelMA, which made it easier to handle. In terms of water content and optical transmittance of the bioprinted scaffolds, we observed that scaffold with 12.5% GelMA concentration was closer to the native corneal stroma tissue. Subsequently, cell proliferation, gene and protein expression of human corneal stromal cells encapsulated in the bioprinted scaffolds were investigated. Cytocompatibility in 12.5% GelMA scaffolds was observed to be 81.86 and 156.11% at day 1 and 7, respectively, which were significantly higher than those in 7.5% GelMA scaffolds. Elongated corneal stromal cells were observed in 12.5% GelMA samples after 7 days, indicating the cell attachment, growth, and integration within the scaffold. The gene expression of collagen type I, lumican and keratan sulfate increased over time for the cells cultured in 12.5% GelMA scaffolds as compared to those cultured on the plastic tissue culture plate. The expression of collagen type I and lumican were also visualized using immunohistochemistry after 28 days. These findings imply that the SLA 3D bioprinting method with GelMA hydrogel bioinks is a promising approach for corneal stroma tissue biofabrication.
3D 生物打印技术是一种有前途的角膜基质组织再生方法。在本研究中，使用甲基丙烯酰化明胶（GelMA）混合角膜基质细胞作为生物墨水。利用基于可见光的立体光刻（SLA）3D 生物打印方法打印出与人体角膜基质相似的解剖学上相似的穹顶形结构。测试了两种不同浓度的 GelMA 大分子（7.5%和 12.5%）用于角膜基质生物打印。由于大分子浓度较高，12.5% GelMA 比 7.5% GelMA 更硬，因此更容易处理。就生物打印支架的含水量和光透过率而言，我们观察到 12.5% GelMA 浓度的支架更接近天然角膜基质组织。随后，研究了封装在生物打印支架中的人角膜基质细胞的增殖、基因和蛋白质表达。在 12.5% GelMA 支架中观察到细胞相容性在第 1 天和第 7 天分别为 81.86%和 156.11%，明显高于 7.5% GelMA 支架。在第 7 天，在 12.5% GelMA 样本中观察到伸长的角膜基质细胞，表明细胞在支架内附着、生长和整合。与在塑料组织培养板上培养的细胞相比，在 12.5% GelMA 支架中培养的细胞的 I 型胶原、亮氨酸聚糖和硫酸角质素的基因表达随时间增加。在第 28 天还通过免疫组织化学观察到 I 型胶原和亮氨酸聚糖的表达。这些发现表明，使用 GelMA 水凝胶生物墨水的 SLA 3D 生物打印方法是角膜基质组织生物制造的一种有前途的方法。
