Department of Radiology, Stanford University, Palo Alto, California, 94304.
J Biomed Mater Res A. 2018 Aug;106(8):2213-2228. doi: 10.1002/jbm.a.36428. Epub 2018 Apr 30.
Cryo-hydrogels (cryogels) are polymer hydrogels formed at sub-zero temperatures. Bioscaffolds created from cryogels have interconnected macropores which allow for cell migration, tissue-ingrowth, unhindered diffusion of solutes and mass transport of therapeutics. In this study, we developed collagen based cryogel bioscaffolds and coated them with polydopamine using a simple two-step technique. Cryogel bioscaffolds were synthesized by collagen crosslinking at -20°C and exhibited a macroporous interconnected architecture with 75% ± 3% porosity. Two groups of pore sizes were observed: 300 ± 50 µm and 30 ± 10 µm in diameter. The addition of a polydopamine coating to cryogel bioscaffolds was confirmed using composition analysis. This resulted in a 41% ± 5% decrease in water uptake, 81% ± 10% decrease in swelling rate and 12% ± 3% decrease in their degree of dissolution (p < 0.05), with a 48% ± 2% increase in stiffness and 57% ± 5% increase in compressive strength (p < 0.05). Seeding adipose tissue-derived mesenchymal stem cells (AD-MSCs) into polydopamine coated-cryogel bioscaffolds resulted in cells demonstrating a 52% ± 4% increase in viability and 33% ± 3% increase in proliferation when compared to AD-MSCs seeded into uncoated-cryogel bioscaffolds (p < 0.05). In summary, our novel polydopamine coated-cryogel bioscaffold represents an efficient and low-cost bioscaffold platform to support MSC therapies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2213-2228, 2018.
冷冻水凝胶（cryogel）是在亚低温下形成的聚合物水凝胶。由 cryogel 制成的生物支架具有互连成网的大孔，允许细胞迁移、组织内生长、溶质无阻碍扩散和治疗药物的质量传递。在这项研究中，我们使用简单的两步法开发了基于胶原蛋白的 cryogel 生物支架，并在其上涂覆聚多巴胺。cryogel 生物支架是通过在-20°C 下交联胶原蛋白合成的，表现出具有 75%±3%孔隙率的互连成网的大孔结构。观察到两组孔径：直径 300±50μm 和 30±10μm。聚多巴胺涂层的添加通过组成分析得到证实。这导致吸水率降低 41%±5%，溶胀率降低 81%±10%，溶解度降低 12%±3%（p<0.05），刚性增加 48%±2%，压缩强度增加 57%±5%（p<0.05）。将脂肪组织来源的间充质干细胞（AD-MSCs）接种到聚多巴胺涂覆的 cryogel 生物支架中，与接种到未涂覆的 cryogel 生物支架中的 AD-MSCs 相比，细胞活力增加了 52%±4%，增殖增加了 33%±3%（p<0.05）。总之，我们的新型聚多巴胺涂覆的 cryogel 生物支架代表了一种高效、低成本的生物支架平台，可支持 MSC 治疗。© 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2213-2228, 2018.
