کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1426612 986818 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The influence of bile acids on the oral bioavailability of vitamin K encapsulated in polymeric micelles
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد بیومتریال
پیش نمایش صفحه اول مقاله
The influence of bile acids on the oral bioavailability of vitamin K encapsulated in polymeric micelles
چکیده انگلیسی

The purpose of this study was to assess the ability of polymeric micelles to enable gastrointestinal absorption of the extremely hydrophobic compound vitamin K, by comparison of its absorption in bile duct ligated and sham operated rats. Hereto, vitamin K was encapsulated in micelles composed of mPEG5000-b-p(HPMAm-lac2), a thermosensitive block copolymer. Vitamin K plasma levels rose significantly upon gastric administration of 1 mg vitamin K encapsulated in polymeric micelles in sham operated rats, but not after bile duct ligation (AUC 4543 and 1.64 ng/mL/h respectively, p < 0.01). Duodenal administration of polymeric micelles together with bile acids in bile duct ligated rats fully restored absorption. Dynamic light scattering time series showed a significant and dose dependent rise in micellar size in the presence of bile acids in vitro, indicating the gradual formation of mixed micelles during the first 3 h of incubation. The highest bile acid amounts (11 mM deoxycholic acid and 41 mM taurocholic acid) eventually caused aggregation of the loaded micelles after the formation of mixed micelles. These data suggest that the gastrointestinal absorption of encapsulated vitamin K from polymeric micelles is mediated by free bile and that uptake of intact micelles through pinocytosis is insignificant.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Controlled Release - Volume 133, Issue 2, 19 January 2009, Pages 161–168
نویسندگان
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