The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive lipos...The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.展开更多
Drug resistance of anthracycline in the invasive cancer is associated with the lowered cellular drug uptake and diminished co-localization of drug with nuclei. In the present study, we aimed to construct the folate-co...Drug resistance of anthracycline in the invasive cancer is associated with the lowered cellular drug uptake and diminished co-localization of drug with nuclei. In the present study, we aimed to construct the folate-conjugated epirubicin liposomes by incorporating a synthesized folate-lipid derivative; and to assess the effects on cellular drug uptake, co-localization of drug with nuclei and efficacy in treatment of invasive breast cancer cells. The studies were performed on invasive human breast cancer cells. The folate-PEG2ooo-DSPE conjugate was synthesized, and the constructed folate-conjugated epirubicin liposomes were approximately 1 O0 nm in size. The in vitro studies demonstrated that the folate-conjugated epirubicin liposomes had the strongest cellular drug uptake and co-localization with nuclei of the invasive breast cancer cells. Besides, the liposomes displayed the most significant efficacy in killing the invasive cancer cells, in preventing their invasive potential, and in penetrating ability into breast cancer spheroid as well. In conclusion, the constructed folate-conjugated epirubicin liposomes were able to enhance the efficacy in treatment of invasive breast cancer by improving the cellular drug uptake and increasing the co-localization with nuclei, hence offering a new strategy for potentially eradicating the invasive breast cancer cells.展开更多
基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120001110012)the National Basic Research Program of China(973 Program,Grant No.2013CB932501)National Natural Science Foundation of China(Grant No.81172992)
文摘The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.
基金The National Natural Science Foundation of China(Grant No.81373343 and 81673367)
文摘Drug resistance of anthracycline in the invasive cancer is associated with the lowered cellular drug uptake and diminished co-localization of drug with nuclei. In the present study, we aimed to construct the folate-conjugated epirubicin liposomes by incorporating a synthesized folate-lipid derivative; and to assess the effects on cellular drug uptake, co-localization of drug with nuclei and efficacy in treatment of invasive breast cancer cells. The studies were performed on invasive human breast cancer cells. The folate-PEG2ooo-DSPE conjugate was synthesized, and the constructed folate-conjugated epirubicin liposomes were approximately 1 O0 nm in size. The in vitro studies demonstrated that the folate-conjugated epirubicin liposomes had the strongest cellular drug uptake and co-localization with nuclei of the invasive breast cancer cells. Besides, the liposomes displayed the most significant efficacy in killing the invasive cancer cells, in preventing their invasive potential, and in penetrating ability into breast cancer spheroid as well. In conclusion, the constructed folate-conjugated epirubicin liposomes were able to enhance the efficacy in treatment of invasive breast cancer by improving the cellular drug uptake and increasing the co-localization with nuclei, hence offering a new strategy for potentially eradicating the invasive breast cancer cells.
