Inkjet Bioprinting of 3D Silk Fibroin Cellular Constructs Using Sacrificial Alginate
Inkjet Bioprinting of 3D Silk Fibroin Cellular Constructs Using Sacrificial Alginate
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DOI：
10.1021/acsbiomaterials.6b00432
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发表时间：
2017-08-01
影响因子：
5.8
通讯作者：
Huang, Yong
中科院分区：
文献类型：
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作者：
Compaan, Ashley M.;Christensen, Kyle;Huang, Yong
丝素蛋白是一种天然蛋白质，其在组织工程中显示出巨大的前景，但由于缓慢的凝胶化或苛刻的凝胶化条件（其不是细胞友好的）而不可打印。在这项研究中，提出了一个两步凝胶化过程中的丝素蛋白的印刷，利用海藻酸作为牺牲水凝胶在喷墨过程中。藻酸盐与丝素蛋白的细胞负载共混物用于在打印期间通过藻酸钙形成实现快速凝胶化;随后在打印后在酪氨酸残基处进行辣根过氧化物酶（HRP）催化的丝素蛋白共价交联。这种两步凝胶化过程成功地实现了适合长期培养的明确的载有细胞的丝素蛋白结构的3D生物打印。构建体在钙螯合以覆盖藻酸盐组分后保持完整，表明丝素蛋白水凝胶的形成。NIH 3 T3成纤维细胞在打印后增殖并扩散通过水凝胶。打印后5周观察到代谢活性增加，组织学显示培养的构建体中细胞群密集。所提出的两步凝胶化技术有望使3D丝素蛋白打印用于各种应用。
Silk fibroin is a natural protein which has shown great promise for tissue engineering but is not printable due to slow gelation or harsh gelation conditions which are not cell friendly. In this study, a two-step gelation process is proposed for the printing of silk fibroin, which utilizes alginate as a sacrificial hydrogel during an inkjetting-based process. A cell laden blend of alginate with silk fibroin is utilized to achieve rapid gelation by calcium alginate formation during printing; it is followed by horseradish peroxidase (HRP) catalyzed covalent cross-linking of the fibroin protein at tyrosine residues after printing. This two-step gelation process successfully enables 3D bioprinting of well-defined cell-laden silk fibroin constructs suitable for long-term culture. The constructs remain intact after calcium chelation to liquefy the alginate component, demonstrating the formation of silk fibroin hydrogel. NIH 3T3 fibroblasts proliferate and spread through the hydrogel after printing. Increasing metabolic activity is observed for 5 weeks after printing, and histology shows dense cell populations in cultured constructs. The proposed two-step gelation technique is expected to enable 3D silk fibroin printing for various applications.