Fig. 9: Mitigating the non-specific uptake of immunomagnetic microparticles (IMPs) by adipose tissue-derived stromal/stem cells (ASCs) facilitates the enrichment of human adipose tissue-derived microvascular endothelial cells (HAMVECs).

a Schematic depicting the magnet-assisted cell sorting (MACS) procedure used to acquire HAMVECs from enzymatically digested fat, as well as the different combinations of IMPs tested for the isolation and enrichment of HAMVECs using an in vitro model of their contaminated primary cultures. Specifically, HAMVECs and ASCs were seeded in a 9:1 proportion with or without IMPs to recapitulate their potential exclusion from primary cultures, made possible by enzymatically cleaving the deoxyribonucleic acid linkers coupling the antibodies to the superparamagnetic microparticles (i.e. cleavable (c)IMPs). Their enrichment was performed after 4 days, and their purities (% CD31⁺) were evaluated after a total of 7 days. Created with BioRender.com b Effects of alternative target antigens (CD31 vs. CD93), sizes (4.4 µm IMPs vs. 4.8 µm cIMPs), and exposures (introduced vs. excluded from cultures) of IMPs on the enrichment efficacy of the MACS procedure. Values represent mean. c Effect of the target antigen on the enrichment efficacy of the MACS procedure. ‘None’ depicts the distribution of purities of co-cultures that were not subjected to MACS after 4 days; ‘CD31’, those that were enriched using anti-CD31 IMPs or anti-CD31 cIMPs; and, ‘CD93’, those that were enriched using anti-CD93 cIMPs. d Effect of introducing IMPs into primary cultures on the efficacy of their sequential enrichment. ‘None’ depicts the distribution of purities of enriched co-cultures that were free of IMPs and cIMPs at the time of MACS; ‘4.4 µm IMPs’, those that were laden with the smaller anti-CD31 IMPs; and, ‘4.8 µm cIMPs’, those that were laden with the larger anti-CD31 cIMPs or anti-CD93 cIMPs. *p < 0.05; ns represents not statistically significant. Dashed lines in the violin plots represent median; dotted lines, quartiles; and, horizontal solid lines, range. The experiment was performed in biological triplicate, using cells derived from three different donors (n = 3 biologically independent samples).