Liu Qiongqiong, Li Qingtao, Xu Sheng, Zheng Qiujian, Cao Xiaodong
School of Medicine, South China University of Technology, 382 Outer Ring Rd, Guangzhou 510006, China.
National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, 382 Outer Ring Rd, Guangzhou 510006, China.
Polymers (Basel). 2018 Jun 14;10(6):664. doi: 10.3390/polym10060664.
Three-dimensional (3D) printing holds great potential for preparing sophisticated scaffolds for tissue engineering. As a result of the shear thinning properties of an alginate solution, it is often used as 3D printing ink. However, it is difficult to prepare scaffolds with complexity structure and high fidelity, because the alginate solution has a low viscosity and alginate hydrogels prepared with Ca crosslinking are mechanically weak. In this work, chitosan powders were dispersed and swelled in an alginate solution, which could effectively improve the viscosity of an alginate solution by 1.5⁻4 times. With the increase of chitosan content, the shape fidelity of the 3D printed alginate⁻chitosan polyion complex (AlCh PIC) hydrogels were improved. Scanning electron microscope (SEM) photographs showed that the lateral pore structure of 3D printed hydrogels was becoming more obvious. As a result of the increased reaction ion pairs in comparison to the alginate hydrogels that were prepared with Ca crosslinking, AlCh PIC hydrogels were mechanically strong, and the compression stress of hydrogels at a 90% strain could achieve 1.4 MPa without breaking. In addition, human adipose derived stem cells (hASCs) adhered to the 3D printed AlCh PIC hydrogels and proliferated with time, which indicated that the obtained hydrogels were biocompatible and could potentially be used as scaffolds for tissue engineering.
三维（3D）打印在制备用于组织工程的精密支架方面具有巨大潜力。由于藻酸盐溶液的剪切变稀特性，它常被用作3D打印墨水。然而，由于藻酸盐溶液粘度低，且用钙交联制备的藻酸盐水凝胶机械性能较弱，因此难以制备具有复杂结构和高保真度的支架。在这项工作中，壳聚糖粉末分散并溶胀于藻酸盐溶液中，这可有效将藻酸盐溶液的粘度提高1.5至4倍。随着壳聚糖含量的增加，3D打印的藻酸盐 - 壳聚糖聚离子复合物（AlCh PIC）水凝胶的形状保真度得到改善。扫描电子显微镜（SEM）照片显示，3D打印水凝胶的横向孔隙结构变得更加明显。与用钙交联制备的藻酸盐水凝胶相比，由于反应离子对增加，AlCh PIC水凝胶机械性能较强，在90％应变下，水凝胶的压缩应力可达到1.4 MPa而不破裂。此外，人脂肪来源干细胞（hASCs）附着于3D打印的AlCh PIC水凝胶并随时间增殖，这表明所获得的水凝胶具有生物相容性，并有可能用作组织工程支架。
