There is a great demand for blood and stem cells in clinic. It is difficult to achieve high throughput and to increase the cooling rate at the same time during vitrification. In this paper, a micro-droplet spray system with a container collection device was fabricated, and HepG2 cells were sprayed by this system for high-throughput vitrification. First, the container collection device and a cryo-paper were used to receive micro-droplets in the spray vitrification system. The results showed that the cell survival rate and 24h adhesion rate in container collection vitrification group were significantly higher than those in cryo-paper collection group. Second, HepG2 cells were sprayed and vitrified at increased cell density, and it was found that the results of micro-droplet spray vitrification did not change significantly. Finally, micro-droplet spray vitrification is compared with slow freezing. Cell processing capacity in the vitrification group increased, meanwhile, the cell survival rate and 24h adhesion rate in the vitrification group were significantly higher than those in slow freezing group. The results indicated that the micro-droplet spray vitrification system with container collection device designed in this paper can achieve high-throughput cell vitrification, which is of great significance for mass preservation of small cells.
A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (\begin{document}$ \overline {D{I_S}} $\end{document}, \begin{document}$ \overline {D{I_C}} $\end{document}) were used to characterize the deformability of RBCs. A high-throughput detection system was built, and the optimal experimental conditions were obtained through a large number of experiments. Three groups of samples with different deformability were used for statistical verification. The results showed that the smallest cell component \begin{document}$ \overline {D{I_S}} $\end{document} was 9.71%, and the detection flux of 8-channel structure was about 370 cells/min. High-throughput detection and characterization methods can effectively distinguish different deformed RBCs statistically, which provides a solution for high-throughput deformation analysis of other types of samples.
ObjectiveTo explore the influence of enhanced recovery after surgery (ERAS) on intestinal flora in patients with colorectal cancer.MethodsBy convenient sampling method, 60 patients with colorectal cancer were selected from August 2018 to December 2019 in the Department of Gastrointestinal Surgery of West China Hospital of Sichuan University and randomly divided into ERAS group and traditional treatment group (traditional group). Among them, the perioperative clinical management was carried out according to the ERAS management and traditional treatment process in the the ERAS group and in the traditional group, respectively. The fresh fecal samples were collected within 24 h after admission and the first natural defecation after operation. The bacterial 16 Sr DNA V3–V4 region was sequenced by Illumina MiSeq sequencer, and the results were analyzed by bioinformatics.ResultsA total of 60 patients with colorectal cancer were included, 30 cases in the traditional group and 27 cases in the ERAS group (3 people temporarily withdrew from the study). There were no significant differences in the basic informations between the two groups (P>0.05). ① Before or after operation, there were no significant differences in Shannon index and Simpson index between the two groups. The difference between preoperative and postoperative comparison in the same group was also not statistically significant (P>0.05). ② Beta diversity analysis showed that there was no significant difference in community composition between the traditional group and the ERAS group before operation, and there was a clear boundary between the traditional group and the ERAS group after operation. ③ At the phylum level, compared with the preoperative abundance, the postoperative abundance Firmicutes decreased by 26.5% and 5.5% in the traditional and ERAS group, respectively; Bacteroidetes increased by 21.6% and 4.7% in the traditional and ERAS group, respectively; Proteobacteria increased by 7.2% and 2.2% in the traditional and ERAS group, respectively. At the genus level, compared with the preoperative abundance, the postoperative abundance of Bacteroides in the traditional group increased by 17.6% and in the ERAS group decreased by 1.6%; Bifidobacterium decreased by 1.8% and 1.3% in the traditional group and in the ERAS group, respectively.ConclusionsERAS does not affect species diversity of intestinal flora. Although ERAS has some damage to structure of intestinal flora, it is weaker than traditional process, so it is more conducive to reconstruction and restoration of intestinal microecological environment.