title: Effects of Doxorubicin Delivery Systems and Mild Hyperthermia on Tissue Penetration in 3D Cell Culture Models of Ovarian Cancer Residual Disease.
abstract: Current chemotherapy strategies for second-line treatment of relapsed ovarian cancer are unable to effectively treat residual disease post-cytoreduction. The findings presented herein suggest that tissue penetration of drug is not only an issue for large, unresectable tumors, but also for invisible, microscopic lesions. The present study sought to investigate the potential of a block copolymer micelle (BCM) formulation, which may reduce toxicities of doxorubicin (DOX) in a similar way to pegylated liposomal doxorubicin (PLD, Doxil/Caelyx), while enhancing penetration into tumor tissue and improving intratumoral availability of drug. To achieve this goal, 50 nm-sized BCMs capable of high DOX encapsulation (BCM-DOX) at drug levels ranging from 2 to 7.6 mg/mL were formulated using an ultrafiltration technique. BCM-DOX was evaluated in 2D and 3D cell culture of the human ovarian cancer cell lines HEYA8, OV-90, and SKOV3. Additionally, the current study examines the impact of mild hyperthermia (MHT) on the cytotoxicity of DOX. The BCM-DOX formulation fulfilled the goal of controlling drug release while providing up to 9-fold greater cell monolayer cytotoxicity in comparison to PLD. In 3D cell culture, using multicellular tumor spheroids (MCTS) as a model of residual disease postsurgery, BCM-DOX achieved the benefits of an extended release formulation of DOX and resulted in improvements in drug accumulation over PLD, while yielding drug levels approaching that achievable by exposure to DOX alone. In comparison to PLD, this translated into superior MCTS growth inhibition in the short term and comparable inhibition in the long term. Overall, although MHT appeared to enhance drug accumulation in HEYA8 MCTS treated with BCM-DOX and DOX alone in the short term, improved growth inhibition of MCTS by MHT was not observed after 48 h of drug treatment. Evaluation of BCM-DOX in comparison to PLD as well as the effects of MHT is warranted in vivo.
authors.affiliation: Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College Street, Toronto, Ontario M5S 3M2, Canada.
authors.forename: Sina
authors.initials: S
authors.lastname: Eetezadi
authors.affiliation: Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College Street, Toronto, Ontario M5S 3M2, Canada.
authors.forename: Raquel
authors.initials: R
authors.lastname: De Souza
authors.affiliation: Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College Street, Toronto, Ontario M5S 3M2, Canada.|Division of Pharmaceutical Technology, University of Basel , Basel, Switzerland.
authors.forename: Mirugashini
authors.initials: M
authors.lastname: Vythilingam
authors.affiliation: Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College Street, Toronto, Ontario M5S 3M2, Canada.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Lessa Cataldi
authors.affiliation: Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College Street, Toronto, Ontario M5S 3M2, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Allen
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D004317:Doxorubicin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D008823:Micelles; D018365:Neoplasm, Residual / Q000188:drug therapy* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011092:Polyethylene Glycols / Q000008:administration & dosage; D011108:Polymers / Q000737:chemistry*; D018874:Spheroids, Cellular; D014407:Tumor Cells, Cultured
chemical_list: D000903:Antibiotics, Antineoplastic; D008823:Micelles; D011108:Polymers; C506643:liposomal doxorubicin; D011092:Polyethylene Glycols; D004317:Doxorubicin
keywords: Caelyx; Doxil; block copolymer micelles; doxorubicin; hyperthermia; multicellular tumor spheroids; nanomedicines; ovarian cancer