title: Thermosensitive hydrogel-containing polymersomes for controlled drug delivery.
abstract: PNIPAAm-containing polymersomes (N/Ps) were prepared by injecting a solution of poly(ethylene glycol)-b-poly(D,L-lactide) (mPEG-PDLLA) and poly(N-isopropylacrylamide) (PNIPAAm) in THF into water to incorporate PNIPAAm into polymersomes (Ps). At 37 degrees C, hydrogel-containing Ps (Hs, hydrosomes) with an average diameter of 127 nm as measured with dynamic light scattering (DLS) were obtained which may be used as potential novel carriers for anticancer drugs and proteins. Dual-labeled N/Ps (FITC-N/RB-Ps) were prepared analogously using rhodamine B tagged mPEG-PDLLA (mPEG-PDLLA-RB) and fluorescein isothiocyanate labeled PNIPAAm (FITC-N). The co-localization of RB labeled Ps (RB-Ps) and FITC-N in RB-Ps was shown by dual fluorescence CLSM. Fluorescence correlation spectroscopy (FCS) and fluorescence anisotropy (FA) measurements with these systems gave further evidence for the colocalization of PNIPAAm and Ps. Micron-sized giant Ps with a diameter of 5-10 microm containing FITC-N were prepared using CHCl(3) as the organic phase. The presence of FITC-N in these giant Ps as well as the phase separation of the internal FITC-N solution above the lower critical solution temperature (LCST) was also shown by CLSM. The release of fluorescein isothiocyanate tagged dextran (FD, FITC-dextran, Mw 4000 g/mol) from Hs revealed that in the presence of the hydrogel at 37 degrees C a more sustained release of FD (up to 30 days) with a low initial burst effect was obtained as compared to the release from bare Ps.
authors.affiliation: Department of Polymer Chemistry and Biomaterials, Institute for Biomedical Technology and Technical Medicine, MIRA, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
authors.forename: Jung Seok
authors.initials: JS
authors.lastname: Lee
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Fenghua
authors.initials: F
authors.lastname: Meng
authors.forename: Dianwen
authors.initials: D
authors.lastname: Zhang
authors.forename: Cees
authors.initials: C
authors.lastname: Otto
authors.forename: Jan
authors.initials: J
authors.lastname: Feijen
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D003692:Delayed-Action Preparations / Q000737:chemistry*; D003911:Dextrans / Q000008:administration & dosage; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D007773:Lactates / Q000737:chemistry; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D003911:Dextrans; D007773:Lactates; D011108:Polymers; C088513:poly(lactic acid-ethylene glycol); C052970:poly-N-isopropylacrylamide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols