In recent years, there are tremendous economic and social losses across the world because of virus-related diseases. It is well known that Madin-Darby canine kidney (MDCK) cells are easily handled, quickly amplified and efficiently infected with influenza virus. Therefore, they are considered as one of the most important cell lines for the production of influenza vaccine. In this work, we first developed a serum-free adherent culture process for MDCK cells with an in-house prepared serum-free medium MDCK-SFM. Next, we derived a cell line named ssf-MDCK, which was amenable for single-cell suspension culture in the serum-free medium. We found that during serum-free batch culture of MDCK cells, the peak viable cell density and maximum specific growth rate were 3.81 x 10(6) cells/mL and 0.056 h(-1), respectively; 3.6- and 1.6-fold increase compared with those in serum-containing adherent batch culture. In addition, we compared growth and metabolic characteristics of MDCK cells in serum-containing adherent culture, serum-free adherent culture and serum-free single-cell suspension culture. We found that less metabolic by-products were produced in both serum-free cultures. In serum-free single-cell suspension batch culture, the viable cell density was highest. These results are critical for establishing large-scale suspension culture of MDCK cells as subsequent well as large-scale influenza vaccine production.
Animals ; Batch Cell Culture Techniques ; methods ; Culture Media, Serum-Free ; Dogs ; Influenza Vaccines ; biosynthesis ; Madin Darby Canine Kidney Cells ; Virus Cultivation ; methods

Objective To study the effects of different types of fluid resuscitation on mesenteric microcirculation and inflammatory factors in rabbits with hemorrhagic shock.Methods The model of hemorrhagic shock rabbits was established by reducing the basic mean arterial pressure by 40%through draining the blood from the common carotid artery.Animals were randomly divided into control group,saline group,lactate Ringer group,acetic acid Ringer group,hydroxyethyl starch group and succinyl gelatin group with 8 animals in each group.Mesenteric microcirculation was monitored with microcirculation monitor.Mean arterial pressure(MAP),heart rate(HR),microvascular perfusion ratio(PPV)and microvascular blood flow index(MFI)were recorded before bleeding(T0),at hemorrhagic shock(T1),at the beginning of fluid resuscitation(T2),at the completion of fluid resuscitation(T3),and at the end of the experiment(T4).The contents of tumor necrosis factor-α(TNF-α),interleukin-1(IL-1)and lactic acid(Lac)were measured at T0,T2 and T4.Results Compared with hydroxyethyl starch group,there were statistically significant differences in T3 MAP(P<0.05),except for succinyl gelatin group,hydroxyethyl starch group had higher MAP at T4 than other groups,the difference was statistically significant(P<0.05).The differences in MAP between experimental control group and other groups were statistically significant at T4(P<0.05).PPV and MFI of hydroxyethyl starch group and succinyl gelatin group were higher than those of normal saline group,lactic acid Ringer group and acetic acid Ringer group at T4(P<0.05),and the lactic acid value of hydroxyethyl starch group at T4 was the lowest,compared with lactic acid Ringer group and normal saline group,the difference was statistically significant(P<0.05).There were statistical significances between all groups and experimental control group at T4(P<0.05).There were no significant differences in TNF-αand IL-1 in T0,T2 and T4 among all groups(P<0.05).Conclusion Hydroxyethyl starch solution and succinyl gelatin solution can improve the microcirculation of rabbits with hemorrhagic shock,but can not improve the level of inflammatory factors.