title: Unloading of cryoprotectants from cryoprotectant-loaded cells on a microfluidic platform.
abstract: In this paper, a multistep dilution-filtration microdevice (MDFD) is developed for unloading cryoprotectants from cryoprotectant-loaded cells. The MDFD contained a diluent producing region, a dilution-filtration execution region, and a filtrate collection region. It was made of two patterned PMMA stamps with four pieces of sandwiched PVDF membranes. Firstly, the performances of the mixers that were used in the diluent producing region and the dilution-filtration execution region were assessed using fluorescence experiments. Then, the effect of the MDFD structure on the loss of cells was investigated by applying the MDFD to unload glycerin from glycerin-loaded porcine red blood cells. Finally, the effects of the cell density, glycerin concentration, and membrane pore size on the clearance efficiency of glycerin (CG), the survival rate of cells (SC) and the recovery rate of cells (RC) have been studied. Under the designed conditions, CGachieved ~80% and SCreached ~90%. However, RCwas only ~40%, mainly resulting from the cells detained on the membrane surface and squeezed through the membrane pores into the filtrate. Increasing the membrane pore size caused high CGand SC, but low RC. For a low glycerin concentration, CG, SC, and RCwere all high. For a high cell density, CGwas high, but both SCand RCwere low. This work is of significance to develop a microfluidic chip for unloading cryoprotectants from a small amount of cryopreserved cell samples.
authors.affiliation: Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, 230027, China.|Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, 230027, China.|Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zou
authors.affiliation: Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, 230027, China.|Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027, China.
authors.forename: Bensheng
authors.initials: B
authors.lastname: Qiu
authors.affiliation: Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, 230027, China.|Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Sijie
authors.initials: S
authors.lastname: Sun
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Dayong
authors.initials: D
authors.lastname: Gao
authors.affiliation: Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, 230027, China. wpdings@ustc.edu.cn.|Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui, 230027, China. wpdings@ustc.edu.cn.
authors.forename: Weiping
authors.initials: W
authors.lastname: Ding
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000166:cytology; D003451:Cryoprotective Agents / Q000302:isolation & purification*; D004867:Equipment Design; D005990:Glycerol / Q000302:isolation & purification; D056656:Lab-On-A-Chip Devices; D013552:Swine
chemical_list: D003451:Cryoprotective Agents; D005990:Glycerol
keywords: Cryoprotectant; Deglycerolization; Dilution; Filtration; Microfluidic