Self‐assembly micelles from novel tri‐armed star C₃‐(PS‐b‐PNIPAM) block copolymers for anticancer drug release

Abstract

Novel tri-armed star polystyrene-block-poly(N-isopropylacrylamide) block copolymers with trimesic acid as central molecules were synthesized by successive two-step atom transfer radical polymerization, and confirmed by Fouriertransform infrared spectra, 1 H nuclear magnetic resonance, and laser light scattering gel chromatography system. The copolymers could self-assemble into spherical core-shell micelles in aqueous media independent on drug loading. Physicochemical properties of the blank and drug-loaded micelles were examined by surface tension, fluorescence spectroscopy, UV-vis, transmission electron microscope, and dynamic light scattering measurements. The copolymer micelles exhibited thermo-triggered phase transition, with low critical solution temperature of 33.7 and 34.6 C, varying with copolymer compositions. The critical aggregate concentrations were 11.62 and 47.61 mg L 21 , and hydrodynamic diameters from 200 to 220 nm. Water-insoluble 10-hydroxycamptothecine was encapsulated into the micelle aggregates to investigate the change in the resulting physicochemical parameters, thermo-triggered in vitro drug release, and the applicability as drug targeting release carriers. MTT assays were carried out to uncover cytotoxicity of the newly developed micelle-based drug formulations. V C 2014 American Institute of Chemical Engineers AIChE J, 61: [35][36][37][38][39][40][41][42][43][44][45] 2015

A Three‐Armed Polymer with Tunable Self‐Assembly and Self‐Healing Properties Based on Benzene‐1,3,5‐tricarboxamide and Metal–Ligand Interactions

“…Functionalizing the “B” block of ABA triblock copolymers with BTA groups enhanced the Young's modulus as a result of the BTA assembly . Until now, there are only two types of BTA‐centered three‐armed polymers which were synthesized for drug delivery, and no self‐assembly property of this kind of polymer was studied. Based on the above background and threefold H‐bonding nature of BTA, it is interesting and worthy to investigate the assembly of a three‐armed polymer with BTA in the center and introduce BTA to other fields such as self‐healing to explore the emerged properties.…”

Thermosensitive star polymer pompons with a core–arm structure as thermo-responsive controlled release drug carriers

“… 25 In particular, star polymers can be endowed with a specific environmental responsiveness by adding correspondingly sensitive arms. 26 There are three main approaches for star polymer synthesis: core-first, 27,28 arm-first, 29 and grafting-on. 30 The grafting approach is thought to be beneficial for the structural control of star polymers.…”

Core Cross-linked Star Polymers for Temperature/pH Controlled Delivery of 5-Fluorouracil

“…Furthermore, the release behavior of different drugs from those star polymers was also investigated observing that a star polymer with PNIPAAm-b-PHA arms is more effective in entrapping drugs than a star polymer formed by pure PNIPAAm arms since the PHA block forms a hydrophobic intermediate shell over the core where hydrophobic drugs can be entrapped [12]. Other examples of PNIPAAm-based star polymers have been developed for drug delivery applications [21,[36][37][38][39][40][41][42]. However, most of them have been designed so as to be able to entrap and release the drug due to the ability of PNIPAAm star polymers to self-aggregate [21,[36][37][38][39][40][41], which may have the drawback of early aggregate disruption due to the dilution factor in the bloodstream, resulting in premature drug release.…”

“…Other examples of PNIPAAm-based star polymers have been developed for drug delivery applications [21,[36][37][38][39][40][41][42]. However, most of them have been designed so as to be able to entrap and release the drug due to the ability of PNIPAAm star polymers to self-aggregate [21,[36][37][38][39][40][41], which may have the drawback of early aggregate disruption due to the dilution factor in the bloodstream, resulting in premature drug release. CCS star polymers represent intermediate architecture between branched polymer chains and polymer nanoparticles [43].…”