Combination of iCVD and Porous Silicon for the Development of a Controlled Drug Delivery System

Abstract

We describe a pH responsive drug delivery system which was fabricated using a novel approach to functionalize biodegradeable porous silicon (pSi) by initiated chemical vapor deposition (iCVD). The assembly involved first loading a model drug (camptothecin, CPT) into the pores of the pSi matrix followed by capping the pores with a thin pH responsive copolymer film of poly(methacrylic acid-co-ethylene dimethacrylate) (p(MAA-co-EDMA)) via iCVD. Release of CPT from uncoated pSi was identical in two buffers at pH 1.8 and pH 7.4. In contrast, the linear release rate of CPT from the pSi matrix with the p(MAA-co-EDMA) coating was dependent on the pH; release of CPT was more than four times faster at pH 7.4 (13.1 nmol/(cm(2) h)) than at pH 1.8 (3.0 nmol/(cm(2) h)). The key advantage of this drug delivery approach over existing ones based on pSi is that the iCVD coating can be applied to the pSi matrix after drug loading without degradation of the drug because the process does not expose the drug to harmful solvents or high temperatures and is independent of the surface chemistry and pore size of the nanoporous matrix.

Hybrid organic–inorganic porous semiconductor transducer for multi-parameters sensing

“…In the past, dry technologies have been scarcely used: few attempts have been made in PSi surface modification using evaporation or plasma deposition [20], as it is not straightforward obtaining uniform coverage of a complex surface such as disordered microporous silicon. Recently, chemical vapour deposition and plasma deposition of polymers in mesoporous silicon matrices have been successfully reported [21,22]: this is a new route, really attractive from the technological point of view, for adding new sensing features to optical transducers. Following this direction, PDIF-CN 2 modified PSi and PDIF-CN 2 modified oxidized PSi were used for optical and electrical tests; PSi and oxidized PSi devices have been used in same condition in order to highlight differences and improvements.…”

“…The stable and compact organic film deposited by OBMD is able to penetrate the PSi matrix of microcavity and protects the samples against corrosion on exposure to diluted HF (1% v/v) and NaOH 2 mol l 21 . Moreover, the current signal, in the case of PDIF-CN 2 modified PSi is five orders of magnitude higher than bare PSi.…”

Drug Delivery with Porous Silicon

“…However, in certain case, simple capping of PSi may lead to desired functionality. This approach has been used to obtain pH-triggered delivery systems, in which pH-sensitive protein or polymer is used to trigger the release of loaded drug (Perelman et al 2008;McInnes et al 2012). Another approach to the triggered drug release is to use thermoresponsive polymers.…”

Silicon-Based Nanoagents for Cancer Therapy

“…In 2012, Voelcker et al developed a kind of biodegradable pSi-based pH responsive drug delivery system [38]. In comparison to standard CPT (the cytotoxic topoisomerase inhibitor) release behavior of uncoated pSi at different pH values, the linear release rate of CPT from the p(MAA-co-EDMA)-coated pSi matrix was largely dependent on pH values.…”