2012年1月1日
Insulin-containing layer-by-layer films deposited on poly(lactic acid) microbeads for pH-controlled release of insulin
Colloids and Surfaces B: Biointerfaces
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- 巻
- 89
- 号
- 1
- 開始ページ
- 242
- 終了ページ
- 247
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1016/j.colsurfb.2011.09.023
- 出版者・発行元
- Elsevier BV
Layer-by-layer (LbL) thin films containing insulin were deposited on the surface of biodegradable poly(lactic acid) (PLA) microbeads and the pH-triggered release of insulin was studied. The LbL films were successfully prepared by the alternate deposition of insulin and poly(vinyl sulfate) (PVS) or dextran sulfate (DS) at pH 4.0 through the electrostatic force of attraction between positively charged insulin and polyanions. The loading of insulin on the microbeads was dependent on the number of insulin layers and the type of polyanions used
higher insulin loading was observed for thicker films and when PVS was used as the polyanion. Insulin was released from the microbeads when they were exposed to neutral solution (pH 7.4) due to a loss of electrostatic attraction between the insulin and polyanions in the films, which in turn was caused by the charge reversal of insulin from positive to negative in the neutral medium. The pH threshold for insulin release was found to be pH 5.0-6.0. The released insulin retained its original secondary structure as evidenced by circular dichroism spectra. The insulin loaded on the microbeads was satisfactorily stable even in the presence of a digestive enzyme (pepsin) at pH 1.5. These results suggest a potential future use for insulin-loaded microbeads in the oral delivery of insulin. © 2011 Elsevier B.V.
higher insulin loading was observed for thicker films and when PVS was used as the polyanion. Insulin was released from the microbeads when they were exposed to neutral solution (pH 7.4) due to a loss of electrostatic attraction between the insulin and polyanions in the films, which in turn was caused by the charge reversal of insulin from positive to negative in the neutral medium. The pH threshold for insulin release was found to be pH 5.0-6.0. The released insulin retained its original secondary structure as evidenced by circular dichroism spectra. The insulin loaded on the microbeads was satisfactorily stable even in the presence of a digestive enzyme (pepsin) at pH 1.5. These results suggest a potential future use for insulin-loaded microbeads in the oral delivery of insulin. © 2011 Elsevier B.V.
- リンク情報
- ID情報
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- DOI : 10.1016/j.colsurfb.2011.09.023
- ISSN : 0927-7765
- ISSN : 1873-4367
- PubMed ID : 21974906
- SCOPUS ID : 80054965965