title: Synthesis of a new pH-sensitive folate-doxorubicin conjugate and its antitumor activity in vitro.
abstract: Folate-aminocaproic acid-doxorubicin (FA-AMA-DOX) was synthesized and characterized by H NMR spectroscopy and mass spectrometry. Cytotoxicity and cellular uptake experiments were performed in KB and HepG2 cells, which express folic acid receptor, and the cell line A549, which does not express folic acid receptor. Cytotoxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cellular uptake was monitored using fluorescence microscopy. The amount of DOX released from FA-AMA-DOX was much greater at pH 5.0 than that at pH 6.5 or 7.4. The cytotoxicity of FA-AMA-DOX toward KB and HepG2 cells was greater than that of DOX or AMA-DOX at the same concentrations, and cytotoxicity could be attenuated by FA in a dose-dependent manner. On the contrary, the cytotoxicity of FA-AMA-DOX and AMA-DOX toward A549 cells was lower than that of DOX at the same concentration, and cytotoxicity could not be reduced by FA. Compared with FA-AMA, FA-AMA-DOX increased the intracellular accumulation of DOX in KB cells. These results suggested that FA-AMA-DOX have suitable attributes for the active targeting of folate-receptor-positive tumor cells and for releasing the chemotherapeutic agent, DOX, in situ; it therefore has potential as a novel cancer therapeutic.
authors.affiliation: Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Wei-Liang
authors.initials: WL
authors.lastname: Ye
authors.forename: Zeng-Hui
authors.initials: ZH
authors.lastname: Teng
authors.forename: Dao-Zhou
authors.initials: DZ
authors.lastname: Liu
authors.forename: Han
authors.initials: H
authors.lastname: Cui
authors.forename: Miao
authors.initials: M
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Cheng
authors.forename: Tie-Hong
authors.initials: TH
authors.lastname: Yang
authors.forename: Qi-Bing
authors.initials: QB
authors.lastname: Mei
authors.forename: Si-Yuan
authors.initials: SY
authors.lastname: Zhou
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D004317:Doxorubicin / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D005492:Folic Acid / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration
chemical_list: D000970:Antineoplastic Agents; D004337:Drug Carriers; D004317:Doxorubicin; D005492:Folic Acid