By using the size distribution of cell aggregates, viable cell density, cell viability, specific consumption rate of glucose qglc), specific production rate of lactate (qlac), and yield of lactate from glucose (Ylac/glc) as the evaluation indexes, the effects of hydrodynamics on aggregates formation, growth and metabolism of HEK 293 cells in suspension culture were examined in 250 mL spinner flasks by setting the agitation rates at 25, 50, 75, and 100 r/min, respectively. It was found that agitation plays an important role in HEK 293 cell aggregates formation and cell aggregates size distribution. After 7 days of cultivation in spinner flasks operated at 50 r/min and 75 r/min, the average diameter of HEK 293 cell aggregates was 201 μm and 175 μm, respectively, with the fraction of aggregates larger than or equivalent to 225 μm less than 10 %. The cell viability was kept above 90 % with the metabolic indexes, including qglc, qlac, and Ylac/glc kept constant. These results demonstrated that hydrodynamics derived from the proper agitation of the impeller play a decisive role in controlling the formation and size distribution of HEK 293 cell aggregates, and provided sufficient mass transfer to support the normal growth and metabolism of HEK 293 cells in suspended aggregates.

By using the cell density, cell viability, size distribution of cell aggregates,specific consumption rate of glucose (q_ glc ), specific production rate of lactate (q_ lac ), lactate transform rate (Y_ lac/glc ) and amino acids utilization as the evaluation indexes, the growth and metabolism of HEK293 cells under carrier-free immobilization culture mode were examined and compared with those of HEK293 cells cultured in static tissue flasks. It was found that HEK293 cells grown as suspended cell aggregates in spinner flasks maintained the basic growth and metabolism characteristics of HEK293 cells in stationary anchored culture, and HEK293 cells under carrier-free immobilization culture mode as suspended aggregates in stirred bioreactor facilitate perfusion performance and increase unit productivity. Cultivation of HEK293 cells in carrier-free immobilization culture mode has potential for further improving mammalian cells culture technique.

利用HEK293细胞在悬浮培养中具有聚集成团的体外培养特性,在250ml的Bellco的搅拌培养体系中,以细胞团粒径、细胞粒径、细胞数、细胞活力、葡萄糖比消耗速率 (qglc)、乳酸比生产速率 (qlac) 和乳酸对葡萄糖得率 (Ylac/glc) 为观察指标,考察了HEK293细胞在Ca2+浓度设置为0μmol/L、250μmol/L、500μmol/L、750μmol/L和1000μmol/L的搅拌培养体系中的细胞团形成、细胞生长和代谢.实验发现:培养基中的Ca2+浓度决定着HEK293细胞在悬浮培养中能否形成细胞团并影响着细胞团的粒径分布和细胞团内细胞相互连接的紧密程度;在250～1000μmol/L的Ca2+浓度范围内,HEK293细胞团的平均粒径与培养基中的Ca2+浓度成正比;Ca2+浓度对以细胞团的形式悬浮培养的HEK293细胞的生长和代谢无明显的影响.实验结果提示,Ca2+浓度是调节HEK293细胞团粒径分布、维持悬浮细胞团中HEK293细胞正常生长和代谢的有效控制参数.