In vitro evaluation of cationic liposomes cytotoxicity on J774 macrophage cell line. Confluent cell populations were incubated with: naked hsp65 or vector; liposome entrapped (ENTR) hsp65 or vector; liposome complexed (COMP) hsp65 or vector. Macrophages were cultured in RPMI medium as the control. The vaccine agents or controls were added to the culture in concentrations ranging from 10–200 μg/mL of DNA, the equivalent of 20–400 μL/mL of liposome, for 24 hours. After treatment, MTT reagent was added to the culture medium and after 4 h of incubation, medium was removed and 100 μL of isopropanol containing HCl 0.1 mol/L was added to the wells to dissolve formazan crystals. Values are the mean ± SD of percent of viable cells compared to the control. The data represent one of three separate experiments performed in quadruplicate. *p < 0.01 were considered significant when compared to naked hsp65 group.
Rosada et al. BMC Immunology 2008 9:38 doi:10.1186/1471-2172-9-38