MCMs formed in 4.2 mM NaHCO3 + 100 mM NaF-containing mSBF reduce cytotoxicity of cationic lipids during transfection of hDFs. (A) Viability comparison between soluble and MCM-mediated delivery using a resazurin reduction viability assay. (B) Representative micrographs 24 hours after hDF transfection. MCM-mediated transfection (bottom) results in spread cell morphology while soluble transfection (top) results in rounded cells. (C) We observed visible lipoplex agglomerates (arrows) 24 hours after addition of soluble lipoplexes (top) which coincided with increased cell debris. No agglomerates were observed with MCM-delivered lipoplexes (bottom) and labeled pDNA was restricted to the MCMs. This absence of agglomerates with MCM-mediated delivery coincided with less cell debris observed relative to the soluble lipoplex delivery method. Scale bars = 100 µm. *2-way ANOVA p-value < 0.0001.