title: Doxorubicin and paclitaxel-loaded lipid-based nanoparticles overcome multidrug resistance by inhibiting P-glycoprotein and depleting ATP.
abstract: To test the ability of nanoparticle formulations to overcome P-glycoprotein (P-gp)-mediated multidrug resistance, several different doxorubicin and paclitaxel-loaded lipid nanoparticles were prepared. Doxorubicin nanoparticles showed 6- to 8-fold lower IC(50) values in P-gp-overexpressing human cancer cells than those of free doxorubicin. The IC(50) value of paclitaxel nanoparticles was over 9-fold lower than that of Taxol in P-gp-overexpressing cells. A series of in vitro cell assays were used including quantitative studies on uptake and efflux, inhibition of calcein acetoxymethylester efflux, alteration of ATP levels, membrane integrity, mitochondrial membrane potential, apoptosis, and cytotoxicity. Enhanced uptake and prolonged retention of doxorubicin were observed with nanoparticle-based formulations in P-gp-overexpressing cells. Calcein acetoxymethylester and ATP assays confirmed that blank nanoparticles inhibited P-gp and transiently depleted ATP. I.v. injection of pegylated paclitaxel nanoparticles showed marked anticancer efficacy in nude mice bearing resistant NCI/ADR-RES tumors versus all control groups. Nanoparticles may be used to target both drug and biological mechanisms to overcome multidrug resistance via P-gp inhibition and ATP depletion.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky, USA.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Dong
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Mattingly
authors.forename: Michael T
authors.initials: MT
authors.lastname: Tseng
authors.forename: Moo J
authors.initials: MJ
authors.lastname: Cho
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Val R
authors.initials: VR
authors.lastname: Adams
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Mumper
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D005260:Female; D005452:Fluoresceins / Q000737:chemistry; D006801:Humans; D008545:Melanoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D017239:Paclitaxel / Q000008:administration & dosage* / Q000737:chemistry; D023041:Xenograft Model Antitumor Assays
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005452:Fluoresceins; C085925:calcein AM; D004317:Doxorubicin; D000255:Adenosine Triphosphate; D017239:Paclitaxel