BC/CS复合水凝胶的3D打印工艺研究

3D printing technology research of BC/CS composite hydrogel

以细菌纤维素(BC)和壳聚糖(CS)为基质的水凝胶同时具有细菌纤维素的高生物相容性和壳聚糖的抗菌性能,在伤口敷料、组织工程等领域获得了广泛的应用,但其3D打印仍面临困难。本文利用BC和CS的物理特性和其交联机制,制备出可用于3D打印的BC/CS复合水凝胶油墨,同时使用纳米粘土作为流变改性剂,提升水凝胶的自支撑能力。对于交联方法,不再采用传统的浸泡方式,使用喷雾器将戊二醛溶液均匀喷洒在打印样品表面,既不会破坏样品的结构,也可以达到交联的目的。接着,构建了一种适合BC/CS复合水凝胶打印的3D打印系统,并在此基础上研究分析了喷头挤出压力、移动速度、打印高度对水凝胶精度的影响。本文提出的方法有望实现BC/CS复合水凝胶的墨水直写(DIW)打印提供指导。

Hydrogels based on bacterial cellulose(BC)and chitosan(CS)have both high biocompatibility of BC and the antibacterial properties of CS,and have been widely used in wound dressing,tissue engineering and other fields,but their 3D printing is still facing difficulties.The physical properties and cross-linking mechanism of BC and CS are utilized to prepare BC/CS composite hydrogel ink which can be used for 3D printing.At the same time,nano-clay is used as rheological modifier to improve the self-supporting ability of hydrogel.For the cross-linking method,the traditional soaking method is no longer used,instead,glutaraldehyde solution is evenly sprayed on the surface of the printed sample with a sprayer,which may not damage the structure of the sample and can achieve the purpose of cross-linking.Then,a 3D printing system suitable for BC/CS composite hydrogel printing is constructed,and on this basis,the effects of nozzle extrusion pressure,moving speed and printing height on the precision of hydrogel are studied and analyzed.The proposed method is expected to provide guidance for DIW printing of BC/CS composite hydrogels.