ABSTRACT
OBJECTIVE: To illustrate and evaluate the properties of folate-targeted liposomes loaded with quantum dots (folate- QDs-liposomes) nanoprobes in vitro and in vivo, such as cytotoxicity, the targeting of folate-QDs-liposomes nanoprobes for tumor cells mediated by the folate-folate receptor pathway, their toxicity in vivo and so on. METHODS: Firstly, the inhibitory effects of folate- QDs-liposomes on cell growth and apoptosis were investigated by MTT and flow cytometry. Secondly, the targeting of folate-QDs-liposomes for folate receptor-positive tumor cells was verified by fluorescence staining. Finally, the epidermal infiltration method was adopted to examine the toxicity and distribution in vivo. RESULTS: Under the same concentration, folate-QDs-liposomes and QDs-liposomes had similar cytotoxicity, and QDs had the most obvious cytotoxicity, which verified that the cytotoxicity of QDs was significantly reduced after liposome coating. In the fluorescence experiment, it was observed that folate-QDs-liposomes targeted at Hela cells, but did not target at A549 cells. Free folic acid could block the specific binding of folate-QDs-liposomes to folate receptors on tumor cells. It was proved that folate-QDs-liposomes could enter tumor cells positively expressing folate receptors through the path of folic acid and folate receptors. In vivo, folate-QDs-liposomes nanoprobes could spread throughout the zebrafish body through the blood circulation system. They were distributed from head and excreted from the tails. CONCLUSION: Folate-QDs-liposomes have potential biomedical application prospects, and can be expected to play an important role in the early detection and diagnosis of tumors.