Engineering the chemistry and nanostructure of porous Silicon Fabry-Perot films for loading and release of a steroid
Engineering the chemistry and nanostructure of porous Silicon Fabry-Perot films for loading and release of a steroid
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DOI：
10.1021/la048105t
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发表时间：
2004-12-07
期刊：
影响因子：
3.9
通讯作者：
Sailor, MJ
中科院分区：
文献类型：
--
作者：
Anglin, EJ;Schwartz, MP;Sailor, MJ
描述了一种用于控制疏水药物的装载和释放的目的的在多孔Si膜中的表面化学和孔尺寸的工程方法。类固醇地塞米松的负载通过傅立叶变换红外光谱法确认，并且释放速率通过观察溶液中药物的外观（T-TV-维斯吸收光谱法）和通过测量多孔Si膜的光学反射光谱中的法布里-珀罗条纹来表征。光学反射率的变化提供了一种药物释放速率的测量方法，可用于体内诊断应用。采用电化学腐蚀法制备了多孔硅薄膜，并对其进行了硅氢化改性。十二烯改性的样品在水性环境中更稳健，并且相对于新鲜蚀刻的多孔Si表现出较慢的药物释放速率。而相对较大的地塞米松分子被发现渗透的新鲜蚀刻的样品，它不进入化学改性的膜，因为空间拥挤的十二烷基物种。为了实现这些改性膜的高度负载，在氢化硅烷化之前通过用含有HF和二甲基亚砜的水溶液处理来扩大孔。孔扩大的化学改性样品允许约70%的地塞米松进入未改性（新蚀刻）样品。类固醇从改性的、孔扩大的膜扩散到磷酸盐缓冲盐水溶液中比未改性的样品慢约20倍，与未改性的膜3小时相比，化学改性的膜3天内递送90%的药物。
A method for engineering the surface chemistry and pore dimensions in porous Si films for the purpose of controlling the loading and release of a hydrophobic drug is described. Loading of the steroid dexamethasone is confirmed by Fourier transform infrared spectroscopy, and the release rates are characterized by observation of the appearance of the drug in solution (T-TV-vis absorption spectroscopy) and by measurement of the Fabry-Perot fringes in the optical reflectivity spectrum of the porous Si film. Optical reflectivity changes provide a measure of the release rate of the drug that is amenable to in-vivo diagnostic applications. Fresh porous Si films are prepared by electrochemical etch and subsequently modified by hydrosilylation with 1-dodecene. The dodecene-modified samples are more robust in aqueous environments and exhibit slower release rates of the drug relative to freshly etched porous Si. Whereas the relatively large dexamethasone molecule is found to infiltrate the freshly etched samples, it does not enter the chemically modified films, because of steric crowding from the dodecyl species. To achieve a high degree of loading into these modified films, the pores are enlarged before hydrosilylation by treatment with an aqueous solution containing HF and dimethyl sulfoxide. The pore expanded, chemically modified samples admit approximately 70% of the dexamethasone that can be admitted into an unmodified (freshly etched) sample. Diffusion of the steroid from the modified, pore expanded films into phosphate-buffered saline solution is slower than from the unmodified sample by a factor of similar to20, with 90% of the drug delivered in 3 days for the chemically modified films compared to 3 h for the unmodified films.