目的 探讨利用生物打印系统一次性同步快速构建复层管状结构的可行性.方法 将不同浓度的海藻酸盐和GelMA配比,进行生物力学检测,确定复合水凝胶打印的可行性;将水凝胶分别混合示踪剂及标记细胞,打印具有双层结构空腔管状结构,进行细胞活力检测并验证可灌注性.结果 复合水凝胶杨氏模量为（8.78±1.73）×10^-3 MPa,较单纯GelMA的（2.38±0.69）×10^-3 MPa和单纯海藻酸盐的（0.83±0.24）×10^-3 MPa有明显统计学差异;同轴打印内外复层结构的壁厚分别为（62.06±0.45）μm和（93.78±10.25）μm;内、外管的管径分别为（663.66±51.74）μm和（976.84±63.44）μm;外管（红色微珠颗粒标识）和内管（绿色微珠颗粒标识）具有明显的分层差异;3T3细胞分别在内、外层同时打印后,体外培养1周,第1、3、7天细胞活力可以维持在（88.50％±5.8％）、（85.57％±6.22％）和（96.29％±2.64％）;复层管状结构橙色溶液灌注,复层管壁完整性良好,未见明显液体渗出.结论 本实验利用复合水凝胶构建复层空腔组织,打印后空腔组织内细胞能够长期存活,并具有一定的灌注功能.
Objective To investigate the feasibility of building complex hollow tissue in one-step by using the technique of 3D bioprinting. Methods New blends were combined GelMA with Alginate on different concentration, and tested by mechanical examination to explore the feasibility of printable. After bioprinting of hollow tissue with double-layer loading with cells, cell viability assay and perfusion test of printed tissue with microbeads were used. Results Compared with pure group of GelMA （2.38±0.69）×10^-3 MPa and alginate （0.83 ±0.24）×10^-3 MPa, the Young]s mold of combined bioink was （8.78±1.73）×10^-3 MPa.There were significant statistical differences. Based on the combined hydrogel, double-layerd hollow fiber could be printed with the thickness of （62.06 ±0.45）μm of inner wall and （93.78 ±10.25）μm of outer wall. Diameter of inner and outer was （663.66 ±51.74）μm and （976.84±63.44）μm relatively. There were significant differences between inner and outer layer tracked by microbeads with different color. After loading with 3T3 mouse fibroblast cells in inner layer and outer layer in process of bioprinting, live-dead test showed the viability of cells in hollow fibers on day 1 （88.50%±5.8%）,day 3 （85.57%±6.22%） and day 7 （96.29%±2.64%）. Perfused with orange microbeads in 3T3 printed hollow tissue showed good integrity of the wall, and no obvious liquid exudation was observed. Conclusion Using such combined bioinks could fabricate complex hollow tissue with certain perfusion function, in which cells can survive.