title: Ability of doxorubicin-loaded nanoparticles to overcome multidrug resistance of tumor cells after their capture by macrophages.
abstract: OBJECTIVE
  Investigation of the ability of doxorubicin-loaded nanoparticles (NP/Dox) to overcome multidrug resistance (MDR) when they have first been taken up by macrophages.
  
  
  METHODS
  The growth inhibition of P388 sensitive (P388) and resistant (P388/ADR) tumor cells was evaluated in a coculture system consisting of wells with two compartments. The tumor cells were seeded into the lower compartment, the macrophages were introduced into the upper part in which the drug preparations were also added.
  
  
  RESULTS
  Doxorubicin exerted lower cytotoxicity on tumor cells in coculture compared with direct contact. In P388/ADR, NP/Dox cytotoxicity was far higher than that of free doxorubicin (Dox). Three different formulations of cyclosporin A (either free (CyA), loaded to nanoparticles (NP/CyA) or in a combined formulation with doxorubicin (NP/Dox-CyA)), were added to modulate doxorubicin efficacy. The addition of cyclosporin A to Dox increased drug cytotoxicity. Both CyA added to NP/Dox and NP/Dox-CyA were able to bypass drug resistance.
  
  
  CONCLUSIONS
  Despite the barrier role of macrophages, NP/Dox remained far more cytotoxic than Dox against P388/ADR. Both NP/Dox + CyA and NP/Dox-CyA allowed to overcome MDR, but the last one should present greater advantage in vivo by confining both drugs in the same compartment, hence reducing the adverse effects.
authors.affiliation: Centre d'Etudes Pharmaceutiques, UMR CNRS 8612, Châtenay-Malabry, France.
authors.forename: C E
authors.initials: CE
authors.lastname: Soma
authors.forename: C
authors.initials: C
authors.lastname: Dubernet
authors.forename: G
authors.initials: G
authors.lastname: Barratt
authors.forename: F
authors.initials: F
authors.lastname: Nemati
authors.forename: M
authors.initials: M
authors.lastname: Appel
authors.forename: S
authors.initials: S
authors.lastname: Benita
authors.forename: P
authors.initials: P
authors.lastname: Couvreur
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects*; D002626:Chemistry, Pharmaceutical; D018920:Coculture Techniques; D016572:Cyclosporine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D008264:Macrophages / Q000166:cytology*; D008863:Microspheres; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D004317:Doxorubicin; D016572:Cyclosporine