title: Nanoparticles based on star polymers as theranostic vectors: endosomal-triggered drug release combined with MRI sensitivity.
abstract: Dual-functional star polymers (diameters 15 nm) are synthesized producing nanoparticles with excellent colloidal stability in both water and serum. The nanoparticles are built with aldehyde groups in the core and activated esters in the arms. The different reactivity of the two functional groups to sequentially react with different amino compounds is exploited; doxorubicin (DOX) and 1-(5-amino-3-aza-2-oxypentyl)-4,7,10-tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO3A-tBu-NH2 )-a chelating agent effective for the complexation of Gadolinium ions (Gd). The activated ester group is employed to attach the DO3A chelating agent, while the aldehyde groups are exploited for DOX conjugation, providing a controlled release mechanism for DOX in acidic environments. DOX/Gd-loaded nanoparticles are rapidly taken up by MCF-7 breast cancer cells, subsequently releasing DOX as demonstrated using in vitro fluorescence lifetime imaging microscopy (FLIM). Endosomal, DOX release is observed, using a phasor plot representation of the fluorescence lifetime data, showing an increase of native DOX with time. The MRI properties of the stars are assessed and the relaxivity of Gd loaded in stars is three times higher than conventional organic Gd/DO3A complexes. The DOX/Gd-conjugated nanoparticles yield a similar IC50 to native DOX for breast cancer cell lines, confirming that DOX integrity is conserved during nanoparticle attachment and release.
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, University of New South Wales, Sydney, New South Wales, 2052, Australia; Australian Centre for Nanomedicine, School of Chemical Engineering, University of New South Wales, Sydney, New South Wales, 2052, Australia.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Hien T T
authors.initials: HT
authors.lastname: Duong
authors.forename: Sophie
authors.initials: S
authors.lastname: Laurent
authors.forename: Alexandre
authors.initials: A
authors.lastname: MacMillan
authors.forename: Renee Megan
authors.initials: RM
authors.lastname: Whan
authors.forename: Luce Vander
authors.initials: LV
authors.lastname: Elst
authors.forename: Robert N
authors.initials: RN
authors.lastname: Muller
authors.forename: Jinming
authors.initials: J
authors.lastname: Hu
authors.forename: Andrew
authors.initials: A
authors.lastname: Lowe
authors.forename: Cyrille
authors.initials: C
authors.lastname: Boyer
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Davis
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000378:metabolism; D045744:Cell Line, Tumor; D002614:Chelating Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D004317:Doxorubicin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D011992:Endosomes / Q000378:metabolism; D005260:Female; D005682:Gadolinium / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D008279:Magnetic Resonance Imaging; D053758:Nanoparticles / Q000737:chemistry*; D011859:Radiography
chemical_list: C520644:1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid; D000903:Antibiotics, Antineoplastic; D002614:Chelating Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D006573:Heterocyclic Compounds, 1-Ring; D004317:Doxorubicin; D005682:Gadolinium
keywords: drug delivery; magnetic resonance imaging; pH-responsiveness; polymeric nanoparticles; theranostic