Bio-ink properties and printability for extrusion printing living cells
Bio-ink properties and printability for extrusion printing living cells
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DOI：
10.1039/c3bm00012e
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发表时间：
2013-01-01
影响因子：
6.6
通讯作者：
Wallace, Gordon G.
中科院分区：
文献类型：
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作者：
Chung, Johnson H. Y.;Naficy, Sina;Wallace, Gordon G.
添加生物制造(3D生物打印)使创建具有精确几何形状的支架成为可能，并可控制孔的互连性和结构，而这是传统技术无法实现的。在墨水中加入细胞以形成“生物墨水”提供了打印3D结构的可能性，这些3D结构可以被植入到受损/患病的组织中，以促进高度受控的基于细胞的再生和修复。油墨的性质由其配方决定，并对所形成的结构的传递和完整性产生重要影响。重要的是，油墨的性能需要符合它们打算支持的细胞系统所必需的生物学要求，而且通常很难找到有利于组织生物工程这一关键方面的打印条件。在这项研究中，海藻酸盐(Alg)被选为用于细胞挤压打印的生物墨水配方的主要成分。将海藻酸盐-明胶(Alg-Gel)共混物与预交联海藻酸盐和海藻酸盐溶液的流变性进行比较，以确定它们的印刷适宜性，同时保持它们支持最佳细胞生长的能力。预交联型海藻酸盐本身在印刷过程中呈液体状。然而，通过控制温度，Alg-Gel配方具有更高的粘度、储存模数和稠度，这有利于更高的打印分辨率/精度。通过压缩和压痕试验，比较了海藻酸盐和Alg-Gel的力学性能。两种类型的凝胶产生相似的结果，随着海藻酸盐浓度的增加，模数增加。随着时间的推移，机械性能的衰退表明Alg-Gel在细胞培养液中缓慢降解，初始弹性系数在7天内下降了60%以上。作为成肌细胞/Alg-Gel生物墨水的原代成肌细胞的活性不受打印过程的影响，表明Alg-Gel基质提供了一种潜在的打印3D构建物的方法，该构建物可能会在肌肉再生应用中得到应用。
Additive biofabrication (3D bioprinting) makes it possible to create scaffolds with precise geometries, control over pore interconnectivity and architectures that are not possible with conventional techniques. Inclusion of cells within the ink to form a "bio-ink" presents the potential to print 3D structures that can be implanted into damaged/diseased tissue to promote highly controlled cell-based regeneration and repair. The properties of an 'ink' are defined by its formulation and critically influence the delivery and integrity of structure formed. Importantly, the ink properties need to conform to biological requirements necessary for the cell system that they are intended to support and it is often challenging to find conditions for printing that facilitate this critical aspect of tissue bioengineering. In this study, alginate (Alg) was selected as the major component of the 'bio-ink' formulations for extrusion printing of cells. The rheological properties of alginate-gelatin (Alg-Gel) blends were compared with pre-crosslinked alginate and alginate solution to establish their printability whilst maintaining their ability to support optimal cell growth. Pre-crosslinked alginate on its own was liquid-like during printing. However, by controlling the temperature, Alg-Gel formulations had higher viscosity, storage modulus and consistency which facilitated higher print resolution/precision. Compression and indentation testing were used to examine the mechanical properties of alginate compared to Alg-Gel. Both types of gels yielded similar results with modulus increasing with alginate concentration. Decay in mechanical properties over time suggests that Alg-Gel slowly degrades in cell culture media with more than 60% decrease in initial modulus over 7 days. The viability of primary myoblasts delivered as a myoblast/Alg-Gel bio-ink was not affected by the printing process, indicating that the Alg-Gel matrix provides a potential means to print 3D constructs that may find application in myoregenerative applications.