title: Phenformin-loaded polymeric micelles for targeting both cancer cells and cancer stem cells in vitro and in vivo.
abstract: Conventional cancer chemotherapy often fails as most anti-cancer drugs are not effective against drug-resistant cancer stem cells. These surviving cancer stem cells lead to relapse and metastasis. In this study, an anti-diabetic drug, phenformin, capable of eliminating cancer stem cells was loaded into micelles via self-assembly using a mixture of a diblock copolymer of poly(ethylene glycol) (PEG) and urea-functionalized polycarbonate and a diblock copolymer of PEG and acid-functionalized polycarbonate through hydrogen bonding. The phenformin-loaded micelles, having an average diameter of 102 nm with narrow size distribution, were stable in serum-containing solution over 48 h and non-cytotoxic towards non-cancerous cells. More than 90% of phenformin was released from the micelles over 96 h. Lung cancer stem cells (side population cells, i.e. SP cells) and non-SP cells were sorted from H460 human lung cancer cell line, and treated with free phenformin and phenformin-loaded micelles. The results showed that the drug-loaded micelles were more effective in inhibiting the growth of both SP and non-SP cells. In vivo studies conducted in an H460 human lung cancer mouse model demonstrated that the drug-loaded micelles had greater anti-tumor efficacy, and reduced the population of SP cells in the tumor tissues more effectively than free phenformin. Liver function analysis was performed following drug treatments, and the results indicated that the drug-loaded micelles did not cause liver damage, a harmful side-effect of phenformin when used clinically. These phenformin-loaded micelles may be used to target both cancer cells and cancer stem cells in chemotherapy for the prevention of relapse and metastasis.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Krishnamurthy
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors.forename: Victor W L
authors.initials: VW
authors.lastname: Ng
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors.forename: Shujun
authors.initials: S
authors.lastname: Gao
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors.forename: Min-Han
authors.initials: MH
authors.lastname: Tan
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore. Electronic address: yyyang@ibn.a-star.edu.sg.
authors.forename: Yi Yan
authors.initials: YY
authors.lastname: Yang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008823:Micelles; D014411:Neoplastic Stem Cells / Q000187:drug effects*; D010629:Phenformin / Q000737:chemistry / Q000494:pharmacology*; D011076:Polycarboxylate Cement / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D008823:Micelles; D011076:Polycarboxylate Cement; C005506:polycarbonate; D011092:Polyethylene Glycols; D010629:Phenformin
keywords: Cancer stem cells; In vivo efficacy; Lung cancer; Phenformin; Polymeric micelles