Mechanisms of Controlled Release from Silk Fibroin Films
Mechanisms of Controlled Release from Silk Fibroin Films
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DOI：
10.1021/bm101421r
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发表时间：
2011-03-01
影响因子：
6.2
通讯作者：
Kaplan, David L.
中科院分区：
文献类型：
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作者：
Hines, Daniel J.;Kaplan, David L.
模拟了异硫氰酸荧光素（FITC）标记的葡聚糖从甲醇处理和未处理的丝素膜中的控释，以表征其释放动力学和机制。丝膜用各种分子量（4、10、20、40 kDa）的FITC-葡聚糖制备。甲醇处理用于促进结晶。释放数据进行了评估与两种不同的模型，经验指数方程通常适合释放数据和基于机制的半经验模型来自Fickian扩散通过多孔膜。作为分子量的函数，评估了FITC-葡聚糖释放动力学，并比较了未处理和甲醇处理的薄膜。对于经验模型，模型参数的估计值随着分析物的分子量而降低，并且未处理的和甲醇处理的膜之间没有显着差异。对于基于扩散的模型，估计的扩散系数是小于甲醇处理的膜比未处理的膜。此外，观察到扩散系数随分析物分子量的增加而线性降低。的百分比的FITC-葡聚糖负载截留和不释放的甲醇处理的薄膜比未处理的薄膜和线性增加的分子量。线性回归拟合分子量和包埋的FITC-葡聚糖颗粒的百分比之间的关系。使用这些定义的线性关系，我们提出了一个更新版本的扩散模型模拟释放的FITC-葡聚糖的不同分子量的甲醇处理和未处理的丝膜。
The controlled release of fluorescein-iso-thio-cyanate (FITC)-labeled dextrans from methanol-treated and untreated silk fibroin films was modeled to characterize the release kinetics and mechanisms. Silk films were prepared with FITC-dextrans of various molecular weights (4, 10, 20, 40 kDa). Methanol treatment was used to promote crystallinity. The release data were assessed with two different models, an empirical exponential equation commonly fit to release data and a mechanism-based semiempirical model derived from Fickian diffusion through a porous film. The FITC-dextran release kinetics were evaluated as a function of molecular weight and compared between the untreated- and methanol-treated films. For the empirical model, the estimated values of the model parameters decreased with the molecular weight of the analyte and showed no significant difference between untreated- and methanol-treated films. For the diffusion-based model, the estimated diffusion coefficient was smaller for the methanol-treated films than for the untreated films. Also, the diffusion coefficient was observed to decrease linearly with increasing molecular weight of the analyte. The percent of FITC-dextran loading entrapped and not released was less for the methanol-treated films than for untreated films and linearly increased with molecular weight. A linear regression was fit to the relationship between molecular weight and the percent of entrapped FITC-dextran particles. Using these defined linear relationships, we present an updated version of the diffusion model for simulating release of FITC-dextran of varied molecular weights from methanol-treated and untreated silk films.