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Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles

[Image: see text] An approach for the preparation of an oxidized porous silicon microparticle drug delivery system that can provide efficient trapping and sustained release of various drugs is reported. The method uses the contraction of porous silicon’s mesopores, which occurs during oxidation of t...

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Autores principales: Fry, Nicole L., Boss, Gerry R., Sailor, Michael J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311935/
https://www.ncbi.nlm.nih.gov/pubmed/25678746
http://dx.doi.org/10.1021/cm500797b
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author Fry, Nicole L.
Boss, Gerry R.
Sailor, Michael J.
author_facet Fry, Nicole L.
Boss, Gerry R.
Sailor, Michael J.
author_sort Fry, Nicole L.
collection PubMed
description [Image: see text] An approach for the preparation of an oxidized porous silicon microparticle drug delivery system that can provide efficient trapping and sustained release of various drugs is reported. The method uses the contraction of porous silicon’s mesopores, which occurs during oxidation of the silicon matrix, to increase the loading and retention of drugs within the particles. First, a porous Si (pSi) film is prepared by electrochemical etching of p-type silicon with a resistivity of >0.65 Ω cm in a 1:1 (v/v) HF/ethanol electrolyte solution. Under these conditions, the pore walls are sufficiently thin to allow for complete oxidation of the silicon skeleton under mild conditions. The pSi film is then soaked in an aqueous solution containing the drug (cobinamide or rhodamine B test molecules were used in this study) and sodium nitrite. Oxidation of the porous host by nitrite results in a shrinking of the pore openings, which physically traps the drug in the porous matrix. The film is subsequently fractured by ultrasonication into microparticles. Upon comparison with commonly used oxidizing agents for pSi such as water, peroxide, and dimethyl sulfoxide, nitrite is kinetically and thermodynamically sufficient to oxidize the pore walls of the pSi matrix, precluding reductive (by Si) or oxidative (by nitrite) degradation of the drug payload. The drug loading efficiency is significantly increased (by up to 10-fold), and the release rate is significantly prolonged (by 20-fold) relative to control samples in which the drug is loaded by infiltration of pSi particles postoxidation. We find that it is important that the silicon skeleton be completely oxidized to ensure the drug is not reduced or degraded by contact with elemental silicon during the particle dissolution–drug release phase.
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spelling pubmed-43119352015-03-20 Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles Fry, Nicole L. Boss, Gerry R. Sailor, Michael J. Chem Mater [Image: see text] An approach for the preparation of an oxidized porous silicon microparticle drug delivery system that can provide efficient trapping and sustained release of various drugs is reported. The method uses the contraction of porous silicon’s mesopores, which occurs during oxidation of the silicon matrix, to increase the loading and retention of drugs within the particles. First, a porous Si (pSi) film is prepared by electrochemical etching of p-type silicon with a resistivity of >0.65 Ω cm in a 1:1 (v/v) HF/ethanol electrolyte solution. Under these conditions, the pore walls are sufficiently thin to allow for complete oxidation of the silicon skeleton under mild conditions. The pSi film is then soaked in an aqueous solution containing the drug (cobinamide or rhodamine B test molecules were used in this study) and sodium nitrite. Oxidation of the porous host by nitrite results in a shrinking of the pore openings, which physically traps the drug in the porous matrix. The film is subsequently fractured by ultrasonication into microparticles. Upon comparison with commonly used oxidizing agents for pSi such as water, peroxide, and dimethyl sulfoxide, nitrite is kinetically and thermodynamically sufficient to oxidize the pore walls of the pSi matrix, precluding reductive (by Si) or oxidative (by nitrite) degradation of the drug payload. The drug loading efficiency is significantly increased (by up to 10-fold), and the release rate is significantly prolonged (by 20-fold) relative to control samples in which the drug is loaded by infiltration of pSi particles postoxidation. We find that it is important that the silicon skeleton be completely oxidized to ensure the drug is not reduced or degraded by contact with elemental silicon during the particle dissolution–drug release phase. American Chemical Society 2014-03-20 2014-04-22 /pmc/articles/PMC4311935/ /pubmed/25678746 http://dx.doi.org/10.1021/cm500797b Text en Copyright © 2014 American Chemical Society Terms of Use (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html)
spellingShingle Fry, Nicole L.
Boss, Gerry R.
Sailor, Michael J.
Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title_full Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title_fullStr Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title_full_unstemmed Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title_short Oxidation-Induced Trapping of Drugs in Porous Silicon Microparticles
title_sort oxidation-induced trapping of drugs in porous silicon microparticles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311935/
https://www.ncbi.nlm.nih.gov/pubmed/25678746
http://dx.doi.org/10.1021/cm500797b
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