The ability to accurately and efficiently isolate specific cells from cell mixtures has enabled researchers to advance the fields of experimental cell biology and translational medicine. Traditionally, fluorescence activated cell sorting (FACS), magnetic micro/nanoparticle-based cell sorting and other methods were utilized to fulfill cell isolation. However, FACS equipment is usually expensive and nonportable, and magnetic interaction between microparticles and targeted cell populations is known to have a negative impact on cell viability, phenotypic identity, and cell function. To develop a kind of reliable method of cell isolation, the following issues need to be achieved. The isolated cells should have high viability and the phenotype of the cells should be well-preserved for downstream studies. And the method must achieve both high efficiency of cell recovery and cell purity.
Recently, Ziye Dong and colleagues reported a novel approach which was simple and effective for cell isolation and recovery. In their work, self-floating hollow glass microspheres (HGMS) were coated with enzymatically degradable nanolayered polymer films and then conjugated with specific antibodies to allow both fast capture and release of targeted cells from cell mixture. Then microspheres could float to the top of the hosting liquid, thereby isolating targeted cells. To minimize nonspecific adhesion of untargeted cells and to enhance the purity of the isolated cells, an antifouling PEG polymer layer was grafted onto the nanolayered films. With the cancer cell line PC-3 in blood as a model system, their approach had achieved 80% recovery of targeted cells with 81% cell viability, as well as 70% purity of PC-3 cells in collected cell mixture. The entire process of cell isolation and recovery takes less than 1 h and requires no formal lab equipment or electrical, magnetic, or optical sources.