کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5186628 | 1381109 | 2008 | 6 صفحه PDF | دانلود رایگان |
A series of novel pH- and temperature-sensitive multiblock poly(ester amino urethane)s were synthesized. The copolymers were characterized by 1H NMR, FT-IR and GPC. In the multiblock copolymers, the tertiary amino groups of the poly(amino urethane) segments act as pH-responsive moieties, while the PCL-PEG-PCL blocks act as biodegradable and temperature-sensitive segments. At a relatively high pH (7.0 or above), the multiblock copolymer aqueous solution showed a sol-to-gel-to-aggregation transition with increasing temperature. In contrast, at a lower pH (below 7.0), the polymer solution always existed as a sol state within the experimental temperature range. The gel window covers the physiological conditions. After subcutaneous injection of the 20Â wt% multiblock copolymer solutions into mice, polymeric hydrogels were formed in situ in a short time. The in vitro release of an anticancer drug, paclitaxel, persisted over 1 month under physiological conditions.
Journal: Polymer - Volume 49, Issue 21, 6 October 2008, Pages 4620-4625