Hacettepe University, Bioengineering Department 06800, Beytepe, Ankara, Turkey.
Biofabrication. 2017 Jul 13;9(3):035003. doi: 10.1088/1758-5090/aa7b1d.
Bioprinting can be defined as 3D patterning of living cells and other biologics by filling and assembling them using a computer-aided layer-by-layer deposition approach to fabricate living tissue and organ analogs for tissue engineering. The presence of cells within the ink to use a 'bio-ink' presents the potential to print 3D structures that can be implanted or printed into damaged/diseased bone tissue to promote highly controlled cell-based regeneration and remineralization of bone. In this study, it was shown for the first time that chitosan solution and its composite with nanostructured bone-like hydroxyapatite (HA) can be mixed with cells and printed successfully. MC3T3-E1 pre-osteoblast cell laden chitosan and chitosan-HA hydrogels, which were printed with the use of an extruder-based bioprinter, were characterized by comparing these hydrogels to alginate and alginate-HA hydrogels. Rheological analysis showed that all groups had viscoelastic properties. It was also shown that under simulated physiological conditions, chitosan and chitosan-HA hydrogels were stable. Also, the viscosity values of the bio-solutions were in an applicable range to be used in 3D bio-printers. Cell viability and proliferation analyses documented that after printing with bio-solutions, cells continued to be viable in all groups. It was observed that cells printed within chitosan-HA composite hydrogel had peak expression levels for early and late stages osteogenic markers. It was concluded that cells within chitosan and chitosan-HA hydrogels had mineralized and differentiated osteogenically after 21 days of culture. It was also discovered that chitosan is superior to alginate, which is the most widely used solution preferred in bioprinting systems, in terms of cell proliferation and differentiation. Thus, applicability and printability of chitosan as a bio-printing solution were clearly demonstrated. Furthermore, it was proven that the presence of bone-like nanostructured HA in alginate and chitosan hydrogels improved cell viability, proliferation and osteogenic differentiation.
生物打印可以被定义为通过使用计算机辅助的逐层沉积方法填充和组装活细胞和其他生物材料来对其进行 3D 图案化，从而制造用于组织工程的活组织和器官类似物。在油墨中存在细胞，即使用“生物油墨”，有可能打印出可以植入或打印到受损/患病骨组织中的 3D 结构，以促进高度受控的基于细胞的再生和骨矿化。在这项研究中，首次表明壳聚糖溶液及其与纳米结构类似骨的羟基磷灰石（HA）的复合材料可以与细胞混合并成功打印。用挤出机式生物打印机打印负载有 MC3T3-E1 成骨前体细胞的壳聚糖和壳聚糖-HA 水凝胶，通过将这些水凝胶与藻酸盐和藻酸盐-HA 水凝胶进行比较来表征。流变分析表明，所有组都具有粘弹性。还表明，在模拟生理条件下，壳聚糖和壳聚糖-HA 水凝胶是稳定的。此外，生物溶液的粘度值在可用于 3D 生物打印机的范围内。细胞活力和增殖分析记录表明，在用生物溶液打印后，所有组中的细胞都保持活力。观察到细胞在壳聚糖-HA 复合水凝胶中打印时具有早期和晚期成骨标志物的峰值表达水平。得出的结论是，在培养 21 天后，壳聚糖和壳聚糖-HA 水凝胶中的细胞矿化并向成骨分化。还发现壳聚糖在细胞增殖和分化方面优于藻酸盐，藻酸盐是生物打印系统中最广泛使用的溶液。因此，壳聚糖作为生物打印解决方案的适用性和可打印性得到了明确证明。此外，证明了在藻酸盐和壳聚糖水凝胶中存在类似骨的纳米结构 HA 可以提高细胞活力、增殖和成骨分化。
