Doxorubicin loaded pH-sensitive micelle: antitumoral efficacy against ovarian A2780/DOXR tumor.
OBJECTIVE
To evaluate pH-sensitive mixed micelles for multidrug resistant (MDR) ovarian tumor targeting and optical imaging of solid tumors.


METHODS
Doxorubicin (DOX) encapsulated pH-sensitive mixed micelles composed of poly(L-histidine)(MW 5K)-b-PEG(MW 2K) and poly(L-lactic acid)(3K)-b-PEG (2K)-folate (PHSM-f) were prepared. Folate receptor-mediated endocytosis, drug uptake, endosomal disruption and cell viability were investigated at the cellular level. For in vivo tumor growth inhibition tests, multidrug resistant ovarian A2780/DOX(R) xenografted nude mice were used. Optical imaging was performed by using a Cy5.5 fluorescence dye-labeled mixed micelle system. Cy5.5 fluorescence intensity at the tumor site was measured in KB epidermoid xenografted nude mice.


RESULTS
In vitro cell viability and drug distribution in the cytoplasm demonstrated the significantly superior efficacy of PHSM-f to free DOX and a control sample of DOX loaded pH-insensitive micelle composed of poly(L-lactic acid)(3K)-b-PEG(2K)/poly(L-lactic acid)(3K)-b-PEG(2K)-folate (80/20 wt/wt%) (PHIM-f). The mechanisms of these results were proved by folate receptor mediated endocytosis of micelle and endosomal disruption function by it. In addition, the optical imaging demonstrated the future application of the diagnositic area. PHSM-f inhibited the growth of multidrug resistant ovarian tumors efficiently in mice, with minimum weight loss.


CONCLUSIONS
The pH-sensitive mixed micelle system demonstrates effective antitumor efficacy against the multidrug resistant ovarian tumor A2780/DOX(R).
Kim
Dongin
D
Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, 421 Wakara Way, Suite 318, Salt Lake City, Utah 84108, USA.
Lee
Eun Seong
ES
Park
Kyeongsoon
K
Kwon
Ick Chan
IC
Bae
You Han
YH
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002626:Chemistry, Pharmaceutical; D004317:Doxorubicin / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004337:Drug Carriers; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004705:Endocytosis; D011992:Endosomes / Q000187:drug effects; D005260:Female; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008823:Micelles; D018613:Microscopy, Confocal; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism; D011506:Proteins / Q000737:chemistry; D011956:Receptors, Cell Surface / Q000378:metabolism; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D023041:Xenograft Model Antitumor Assays
D000903:Antibiotics, Antineoplastic; D002352:Carrier Proteins; D004337:Drug Carriers; D058973:Folate Receptors, GPI-Anchored; D007773:Lactates; D008823:Micelles; D011108:Polymers; D011506:Proteins; D011956:Receptors, Cell Surface; C088513:poly(lactic acid-ethylene glycol); C480317:polyhistidine-block-polyethylene glycol; D011092:Polyethylene Glycols; D004317:Doxorubicin; D005492:Folic Acid