ABSTRACT
Objective To investigate the feasibility of macrophages as cell carriers to deliver floate modified oxygen loaded ultrasound contrast agent . Methods The phagocytic activity of macrophages was analyzed by ink phagocytose test , and the expression of folate recepters ( FRs ) on macrophages cell membrane surface was tested by immunofluofluorescence assay . Oxygen/paclitaxel loaded lipid microbubbles( OPLMB) and folate‐targeted OPLMB ( TOPLMB) were synthesized by mechanical shock method and incubated with macrophages in vitro . According to different treatment conditions ,the cells were divided into three groups:group A ( OPLMB) ,group B ( free folic acid + TOPLMB) and group C ( TOPLMB) , the fluorescence intensity of the cells were observed under fluorescence microscope ,and the phagocytic percentage and the phagocytic index of macrophages uptake OPLMB and TOPLMB were observed by bright field microscope . Results The phagocytic percentage of macrophages phagocytose ink was (99 .3 ± 1 .0)% ,FRs was highly expressed on macrophages cultured in vitro . After incubation for 30 minutes ,the fluorescence intensity of group C was significantly higher than those of A and B ,the phagocytic percentage in three groups were (19 .5 ± 0 .2)% ,(21 .0 ± 0 .2)% and (81 .2 ± 10 .0)% respetively . The phagocytic percentage of group C were significantly higher than those in group A and group B ( P <0 .05) . Conclusions Macrophages cultured in vitro possess highly phagocytic activity and these cells highly express FRs ,and can be used as cell carriers to deliver floate modified oxygen loaded multimodality ultrasound contrast agent .