Biodegradable star polymers functionalized with beta-cyclodextrin inclusion complexes.
Three-armed biodegradable star polymers made from polystyrene (polySt) and poly (polyethylene glycol) acrylate (polyPEG-A) were synthesized via a "core first" methodology using a trifunctional RAFT agent, created by attaching RAFT agents to a core via their R-groups. The resultant three-armed polymeric structures were well-defined, with polydispersity indices less than 1.2. Upon aminolysis and further reaction with dithiodipyridine (DTDP), these three-armed polymers could be tailored with sulfhydryl and pyridyldisulfide (PDS) end functionalities, available for further reaction with any free-sulfhydryl group containing precursors to form disulfide linkages. Nuclear magnetic resonance (NMR) confirmed that more than 98% of the polymer arms retained integral trithiocarbonate active sites after polymerization. Intradisulfide linkages between the core and the arms conferred biodegradability on the star architectures. Subsequently, the arm-termini were attached to cholesterol also via disulfide linkages. The cholesterol terminated arms were then used to form supramolecular structures via inclusion complex formation with beta-cyclodextrin (beta-CD). The star architectures were found to degrade rapidly on treatment with DL-dithiothereitol (DTT). The star polymers and supramolecular structures were characterized using gel permation chromatography (GPC), static light scattering (SLS), 2D NMR, and fluorescence spectroscopy.
Setijadi
Eki
E
Centre for Advanced Macromolecular Design, School of Chemical Sciences and Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
Tao
Lei
L
Liu
Jingquan
J
Jia
Zhongfan
Z
Boyer
Cyrille
C
Davis
Thomas P
TP
D000179:Acrylates / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D046911:Macromolecular Substances / Q000138:chemical synthesis*; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis*; D011137:Polystyrenes / Q000737:chemistry; D013057:Spectrum Analysis; D047392:beta-Cyclodextrins / Q000737:chemistry*
D000179:Acrylates; D004220:Disulfides; D046911:Macromolecular Substances; D011108:Polymers; D011137:Polystyrenes; D047392:beta-Cyclodextrins; D011092:Polyethylene Glycols; D002784:Cholesterol