Combination of iCVD and porous silicon for the development of a controlled drug delivery system.
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.
School of Chemical and Physical Sciences, Flinders University , Bedford Park, SA 5042 Australia.
Steven J P
SJ
McInnes
Endre J
EJ
Szili
Sameer A
SA
Al-Bataineh
Jingjing
J
Xu
Mahriah E
ME
Alf
Karen K
KK
Gleason
Robert D
RD
Short
Nicolas H
NH
Voelcker
D002166:Camptothecin / Q000008:administration & dosage*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000008:administration & dosage*; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D014835:Volatilization
D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D008689:Methacrylates; D011108:Polymers; C008384:methacrylic acid; C004919:ethylene dimethacrylate; D002166:Camptothecin; D012825:Silicon