title: The endocytic pathway and therapeutic efficiency of doxorubicin conjugated cholesterol-derived polymers.
abstract: Previously synthesized poly(methacrylic acid-co-cholesteryl methacrylate) P(MAA-co-CMA) copolymers were examined as potential drug delivery vehicles. P(MAA-co-CMA) copolymers were fluorescently labelled and imaged in SHEP and HepG2 cells. To understand their cell internalization pathway endocytic inhibition studies were conducted. It was concluded that P(MAA-co-CMA) are taken up by the cells via clathrin-independent endocytosis (CIE) (both caveolae mediated and cholesterol dependent endocytosis) mechanisms. The formation and characterization of P(MAA-co-CMA)-doxorubicin (DOX) nanocomplexes was investigated by fluorescence lifetime imaging microscopy (FLIM), UV-Visible spectroscopy (UV-Vis) and dynamic light scattering (DLS) studies. The toxicity screening between P(MAA-co-CMA)-DOX nanocomplexes (at varying w/w ratios) and free DOX, revealed nanocomplexes to exhibit higher cytotoxicity towards cancer cells in comparison to normal cells. FLIM and confocal microscopy were employed for investigating the time-dependent release of DOX in SHEP cells and the cellular uptake profile of P(MAA-co-CMA)-DOX nanocomplexes in cancer and normal cell lines, respectively. The endocytic pathway of P(MAA-co-CMA)-DOX nanocomplexes were examined in SHEP and HepG2 cells via flow cytometry revealing the complexes to be internalized through both clathrin-dependent (CDE) and CIE mechanisms. The drug delivery profile, reported herein, illuminates the specific endocytic route and therapeutic efficiency of P(MAA-co-CMA)-DOX nanocomplexes strongly suggesting these particles to be promising candidates for in vivo applications.
authors.affiliation: The Centre for Advanced Macromolecular Design (CAMD), The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Sema
authors.initials: S
authors.lastname: Sevimli
authors.forename: Sharon
authors.initials: S
authors.lastname: Sagnella
authors.forename: Alexander
authors.initials: A
authors.lastname: Macmillan
authors.forename: Renee
authors.initials: R
authors.lastname: Whan
authors.forename: Maria
authors.initials: M
authors.lastname: Kavallaris
authors.forename: Volga
authors.initials: V
authors.lastname: Bulmus
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Davis
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000493:pharmacokinetics; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000737:chemistry*; D002788:Cholesterol Esters / Q000737:chemistry* / Q000494:pharmacology; D004317:Doxorubicin / Q000737:chemistry* / Q000494:pharmacology; D016503:Drug Delivery Systems; D004705:Endocytosis / Q000187:drug effects*; D056945:Hep G2 Cells; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000903:Antibiotics, Antineoplastic; D002788:Cholesterol Esters; D011108:Polymers; D011109:Polymethacrylic Acids; C578851:poly(methacrylic acid-co-cholesteryl methacrylate); D004317:Doxorubicin; D002784:Cholesterol