Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, 33302 Taiwan, Republic of China.
J Mater Sci Mater Med. 2013 Sep;24(9):2201-10. doi: 10.1007/s10856-013-4961-y. Epub 2013 May 16.
Gelatin is a protein molecule that displays bioaffinity and provides a template to guide retinal pigment epithelial (RPE) cell organization and growth. We have recently demonstrated that the carbodiimide cross-linked gelatin membranes can be used as retinal sheet carriers. The purpose of this work was to further determine the role of solvent composition in the tissue delivery performance of chemically modified biopolymer matrices. The gelatin molecules were treated with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in the presence of binary ethanol/water mixtures with varying ethanol concentrations (70-95 vol%) to obtain the carriers with different cross-linking efficiencies and mechanical properties. Results of melting point measurements and in vitro degradation tests showed that when the cross-linking index reached a high level of around 45 %, the EDC cross-linked gelatin materials have sufficient thermal stability and resistance to enzymatic degradation, indicating their suitability for the development of carriers for retinal sheet delivery. Irrespective of the solvent composition, the chemically modified gelatin samples are compatible toward human RPE cells without causing toxicity and inflammation. In particular, the membrane carriers prepared by the cross-linking in the presence of solvent mixtures containing 80-90 vol% of ethanol have no impact on the proliferative capacity of ARPE-19 cultures and possess good efficiency in transferring and encapsulating the retinal tissues. It is concluded that, except for cell viability and pro-inflammatory cytokine expression, the retinal sheet delivery performance strongly depends on the solvent composition for EDC cross-linking of gelatin molecules.
明胶是一种具有生物亲和力的蛋白质分子，可为视网膜色素上皮 (RPE) 细胞的组织和生长提供模板。我们最近已经证明，碳化二亚胺交联的明胶膜可用作视网膜片载体。这项工作的目的是进一步确定溶剂组成在化学改性生物聚合物基质的组织传递性能中的作用。通过在二元乙醇/水混合物中用 1-乙基-3-(3-二甲基氨基丙基)碳化二亚胺 (EDC) 处理明胶分子，得到具有不同交联效率和机械性能的载体，乙醇浓度（70-95 vol%）不同。熔点测量和体外降解试验的结果表明，当交联指数达到约 45%的高水平时，EDC 交联的明胶材料具有足够的热稳定性和抗酶降解性，表明它们适合用于开发用于视网膜片递送的载体。无论溶剂组成如何，化学改性的明胶样品都与人 RPE 细胞相容，不会引起毒性和炎症。特别是，在含有 80-90 vol%乙醇的溶剂混合物存在下交联制备的膜载体对 ARPE-19 培养物的增殖能力没有影响，并且在传递和封装视网膜组织方面具有良好的效率。结论是，除细胞活力和促炎细胞因子表达外，视网膜片的传递性能强烈取决于 EDC 交联明胶分子的溶剂组成。
