In 2018Newcastle University研究人员成为头条新闻3D生物打印可行的人角膜。Though years from transplantation, the development is a significant step forward for the field, and demonstrates real potential for combating transplant shortage.
现在，同一大学的另一支球队为下一阶段的3D生物打印角膜提供了基础。发表在论文中Advanced Functional Materials这一最新进步描述了自我弯曲“ 4D”角膜的潜力。
折纸角膜
The new research, also from Newcastle University’s遗传学研究所, has been conducted by Martina Miotto, Ricardo M. Gouveia, Ana M. Ionescu, Francisco Figueiredo, Ian W. Hamley, and Che J. Connon.
Rather than a strictly4D生物打印方法，即使用生物生产商，纸张概述了可以合并某些材料以收缩和转换的方式。作为Miottoexplains, “My colleagues and I recently found a way to make gel containing live corneal cells self-assemble into the correct pattern, like a piece of paper that folds itself into an origami design.”
该实验的基本材料是含有角膜细胞的胶原蛋白凝胶。自然地，随着这些细胞的增殖，它们会生长成弯曲的角膜状结构。不过没有指南的形式，结果可能是不规则的。
调谐transformation
通过在胶原蛋白凝胶中添加自然自组装的基于肽的分子，纽卡斯尔大学团队发现该材料的收缩较少。Miotto补充说：“从这个观察结果来看，我们能够设计凝胶混合物以在不同的地方通过不同量的不同位置收缩以采用特定形状。”
The result was “a circular shape divided into two rings, with peptide amphiphiles located either in the outer ring or in the center” as seen in the image below.
在这种安排中，凝胶的一部分比另一部分收缩更多，从而使其弯曲成角膜形状。总体而言，转型大约需要5天才能完成。
The next step for 3D bioprinting?
纽卡斯尔的研究人员希望这种生物材料的4D能力是该方法可以对该领域的未来应用。研究得出的总结说：“在这种情况下，这些构建体可以被视为角膜基质组织的潜在替代方法。”
“For instance, the concept of self-curving design could easily be integrated into current additive manufacturing techniques such as 3D bioprinting […] Such integration would also allow automation, as well as a higher degree of consistency and precision in the spatial localization of the different cellular and matrix components of the composite gels.”
Full results of the recent Newcastle University study are published online in the paper “4D角膜组织工程：通过局部控制细胞执行器来实现时间依赖性组织自我侵蚀。”
世界各地的其他机构都在研究3D生物打印角膜的潜力包括北卡罗来纳州生物技术精确的生物，最近打开了专业眼科设施for this purpose; and a team at theInstituto de Investigación Biomédica del Hospital La Pazin Madrid.
Are Newcastle University’s 3D bioprinted corneas yourMedical Application of the Year？Could these also be contenders for年度研究团队？立即提名2019 3D Printing Industry Awards。
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Featured image shows a macro view of the human eye, iris, pupil, eye lashes, eye lids. Photo via Shutterstock.
