title: Endocytic uptake of a large array of HPMA copolymers: Elucidation into the dependence on the physicochemical characteristics.
abstract: Endocytic uptake and subcellular trafficking of a large array of HPMA (N-(2-hydroxypropyl)methacrylamide) based copolymers possessing positively or negatively charged residues, or hydrophobic groups were evaluated by flow cytometry and living cell confocal microscopy in cultured prostate cancer cells. The degrees of cellular uptake of various copolymer fractions with narrow polydispersities were quantified. The copolymer charge was the predominant physicochemical feature in terms of cellular uptake. Fast and efficient uptake occurred in positively charged copolymers due to non-specific adsorptive endocytosis, whereas slow uptake of negatively charged copolymers was observed. The uptake of copolymers was also molecular weight dependent. The copolymers were internalized into the cells through multiple endocytic pathways: positively charged copolymers robustly engaged clathrin-mediated endocytosis, macropinocytosis and dynamin-dependent endocytosis, while weakly negatively charged copolymers weakly employed these pathways; strongly negatively charged copolymers only mobilized macropinocytosis. HPMA copolymer possessing 4 mol% of moderately hydrophobic functional groups did not show preferential uptake. All copolymers ultimately localized in late endosomes/lysosomes via early endosomes; with varying kinetics among the copolymers. This study indicates that cell entry and subsequent intracellular trafficking of polymeric drug carriers are strongly dependent on the physicochemical characteristics of the nanocarrier, such as charge and molecular weight.
authors.affiliation: Department of Pharmaceutics and Pharmaceutical Chemistry/CCCD, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Jihua
authors.initials: J
authors.lastname: Liu
authors.forename: Hillevi
authors.initials: H
authors.lastname: Bauer
authors.forename: Jon
authors.initials: J
authors.lastname: Callahan
authors.forename: Pavla
authors.initials: P
authors.lastname: Kopecková
authors.forename: Huaizhong
authors.initials: H
authors.lastname: Pan
authors.forename: Jindrich
authors.initials: J
authors.lastname: Kopecek
mesh_terms: D000178:Acrylamides / Q000737:chemistry / Q000378:metabolism*; D001692:Biological Transport; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical; D002850:Chromatography, Gel; D002966:Clathrin / Q000378:metabolism; D004337:Drug Carriers; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008297:Male; D018613:Microscopy, Confocal; D015394:Molecular Structure; D008970:Molecular Weight; D010873:Pinocytosis; D011471:Prostatic Neoplasms / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013678:Technology, Pharmaceutical / Q000379:methods; D014162:Transfection; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000178:Acrylamides; D002966:Clathrin; D004337:Drug Carriers; D020691:rab GTP-Binding Proteins; C032976:N-(2-hydroxypropyl)methacrylamide