کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2502107 1557376 2013 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis and micellization of a pH-sensitive diblock copolymer for drug delivery
موضوعات مرتبط
علوم پزشکی و سلامت داروسازی، سم شناسی و علوم دارویی علوم دارویی
پیش نمایش صفحه اول مقاله
Synthesis and micellization of a pH-sensitive diblock copolymer for drug delivery
چکیده انگلیسی

A diblock copolymer constituting of a poly(ethylene glycol) (PEG) and a polycaprolactone (PCL) segment, linked with a pH-sensitive hydrazone bond (Hyd), was synthesized. Micelles formed from this copolymer, offer the advantage of encapsulating hydrophobic drugs without the need for conjugation sites. All synthesized polymers were characterized using gel permeation chromatography, infrared and proton nuclear spectroscopies. PEG-Hyd-PCL micelles were prepared using the solvent-displacement method and α-tocopherol was used as a model drug due to its high hydrophobicity. The micelle size and drug loading efficiency were studied with regards to the hydrophilic ratio, f, molecular weight, and the polymer/drug ratio. Dynamic light scattering and transmission electron microscopy showed that the PEG-Hyd-PCL micelles had sizes ranging from 50 to 200 nm. Aqueous micellar dispersions exhibited significantly higher values of turbidity in mildy acidic pH than in neutral, indicating pH-sensitivity for the PEG-Hyd-PCL micelles. The zeta potential of the micellar solutions decreased and the molecular weight distribution became bimodal at mildly acidic pH also supporting the pH sensitive properties of the copolymer. The critical micelle concentration was calculated using fluorescence spectroscopy.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Pharmaceutics - Volume 455, Issues 1–2, 15 October 2013, Pages 5–13
نویسندگان
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