气动阀控式微米按需液滴喷射过程对细胞活性的影响

摘要

为了提高气动阀控式微液滴产生装置打印过程中的细胞活性,利用自建气动阀控式微米按需液滴( drop-on-demand,DOD)产生装置,在10~70 Hz微液滴产生频率下对2种人体活细胞做喷射实验. 2种细胞分别是人外周血单个核细胞(hPBMCs,直径10~15 μm)和人支气管上皮细胞(hBECs,直径50~70 μm). 该喷射装置的喷嘴直径为100 μm,微液滴直径180~200 μm. 实验中,将未经喷射细胞悬液记为对照组,每种频率下向加有磷酸盐缓冲液的样品管中喷射大约6 000滴细胞液. 随后以7-AAD试剂进行荧光抗体染色,并用流式细胞仪进行细胞活性检测. 结果显示, hPBMCs和hBECs喷射后的细胞相对成活率分别为0. 991 ± 0. 009和0. 996 ± 0. 014. 经分析,喷射频率对细胞活性无显著影响. 气动阀控式打印后的细胞活性较高,归因于打印的细胞悬液黏度较低,细胞喷射过程中产生的剪切应力较小. 气动阀控微液滴产生技术有望应用在生物细胞打印领域,并为实现体外构建组织器官提供参考.%To study the impact of printing process on the cell viability, two types of human living cells, human peripheral blood mononuclear cells ( hPBMCs, 10 -15 μm in diameter) and human bronchial epithelial cells ( hBECs, 50-70 μm in diameter) , were printed at several jetting frequencies from 10 Hz to 70 Hz. The printing device was a home-made pneumatic drop-on-demand generator with a diameter nozzle, and producing micro-droplet with size of 180-200 μm. Non-ejected cell suspension was taken as control group, while in experimental groups about 6 000 drops of cell suspension were delivered to sample tube containing phosphate buffered saline ( PBS ) for each jetting frequency. Then 7-AAD dye and cytometry methodwere utilized to evaluate the cell viability. The relative viabilities of hPBMCs and hBECs are 0. 991 ± 0. 009 and 0. 996 ± 0. 014, respectively. The experimental analysis shows that the jetting frequency has no significant effect on cell viability,and the pneumatic printing device can reach high cell viability that may result from the low viscosity of printing cell-load suspension and low shear stress during the cell printing process. The pneumatic printing can be successfully applied in the fields of bioprinting.