Hamid Omar A, Eltaher Hoda M, Sottile Virginie, Yang Jing
Pharmaceutics Division, College of Pharmacy, University of Mosul, 41002 Mosul, Iraq; Regenerative Medicine and Cellular Therapies Division, Faculty of Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
Regenerative Medicine and Cellular Therapies Division, Faculty of Science, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, 21521, Egypt.
Mater Sci Eng C Mater Biol Appl. 2021 Jan;120:111707. doi: 10.1016/j.msec.2020.111707. Epub 2020 Nov 6.
Development of a biomimetic tubular scaffold capable of recreating developmental neurogenesis using pluripotent stem cells offers a novel strategy for the repair of spinal cord tissues. Recent advances in 3D printing technology have facilitated biofabrication of complex biomimetic environments by precisely controlling the 3D arrangement of various acellular and cellular components (biomaterials, cells and growth factors). Here, we present a 3D printing method to fabricate a complex, patterned and embryoid body (EB)-laden tubular scaffold composed of polycaprolactone (PCL) and hydrogel (alginate or gelatine methacrylate (GelMA)). Our results revealed 3D printing of a strong, macro-porous PCL/hydrogel tubular scaffold with a high capacity to control the porosity of the PCL scaffold, wherein the maximum porosity in the PCL wall was 15%. The method was equally employed to create spatiotemporal protein concentration within the scaffold, demonstrating its ability to generate linear and opposite gradients of model molecules (fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) and rhodamine). 3D bioprinting of EBs-laden GelMA was introduced as a novel 3D printing strategy to incorporate EBs in a hydrogel matrix. Cell viability and proliferation were measured post-printing. Following the bioprinting of EBs-laden 5% GelMA hydrogel, neural differentiation of EBs was induced using 1 μM retinoic acid (RA). The differentiated EBs contained βIII-tubulin positive neurons displaying axonal extensions and cells migration. Finally, 3D bioprinting of EBs-laden PCL/GelMA tubular scaffold successfully supported EBs neural differentiation and patterning in response to co-printing with 1 μM RA. 3D printing of a complex heterogeneous tubular scaffold that can encapsulate EBs, spatially controlled protein concentration and promote neuronal patterning will help in developing more biomimetic scaffolds capable of replicating the neural patterning which occurs during neural tube development.
开发一种能够利用多能干细胞重现发育性神经发生的仿生管状支架，为脊髓组织修复提供了一种新策略。3D打印技术的最新进展通过精确控制各种无细胞和细胞成分（生物材料、细胞和生长因子）的三维排列，促进了复杂仿生环境的生物制造。在此，我们提出一种3D打印方法，以制造由聚己内酯（PCL）和水凝胶（海藻酸盐或甲基丙烯酸明胶（GelMA））组成的复杂、有图案且载有胚状体（EB）的管状支架。我们的结果显示，3D打印出了一种坚固的、大孔PCL/水凝胶管状支架，其具有高度控制PCL支架孔隙率的能力，其中PCL壁中的最大孔隙率为15%。该方法同样用于在支架内创建时空蛋白质浓度，证明了其生成模型分子（异硫氰酸荧光素偶联牛血清白蛋白（FITC-BSA）和罗丹明）线性和相反梯度的能力。载有EBs的GelMA的3D生物打印被引入作为一种新的3D打印策略，将EBs纳入水凝胶基质中。打印后测量细胞活力和增殖情况。在载有EBs的5%GelMA水凝胶进行生物打印后，使用1μM视黄酸（RA）诱导EBs的神经分化。分化后的EBs包含显示轴突延伸和细胞迁移的βIII-微管蛋白阳性神经元。最后，载有EBs的PCL/GelMA管状支架的3D生物打印成功支持了EBs的神经分化和图案形成，这是对与1μM RA共打印的响应。3D打印一种能够封装EBs、空间控制蛋白质浓度并促进神经元图案形成的复杂异质管状支架，将有助于开发更多能够复制神经管发育过程中发生的神经图案形成的仿生支架。
