Routes to calcified porous silicon: implications for drug delivery and biosensing

Abstract

This work describes methods for the fabrication of calcium phosphate films on crystalline silicon substrates, with the long-term goal of employing such materials in either drug delivery or sensing applications. The emphasis of this particular account encompasses both film fabrication as well as surface modification strategies relevant to the sensing of bio-molecular species. For the former, a new process for calcium phosphate film formation is described entailing the use of a high energy DC spark onto silicon surfaces in the presence of Ca 10 (PO 4 ) 6 (OH) 2 . For sensing purposes, routes to modification of the calcium phosphate/porous silicon surface have been achieved via the use of bifunctional bisphosphonate derivatives, with proof-of-concept demonstrated by the covalent attachment of fluorescent fluorescein tags.

Stimulated in vitro bone-like apatite formation by a novel laser processing technique

“…Glasses are rich in SiO 2 which yields the formation of surface Si-OH − groups in the SBF, which on their turn ensure active sites for the formation of HA [25]. Further, porous and nanostructured materials (porous Si, polycrystalline Si and CdSe/SiO x nanostructures), obtained by using well-established nanotechnologies were also utilized in our work, since nanosized objects, as well as porous structures are known to promote bone and tissue ingrowth into open pores and they also allow to be easily biodegraded and bioresorbed [24,[26][27][28][29][30][31].…”

Chemical stabilization of porous silicon for enhanced biofunctionalization with immunoglobulin

“…More recently, PSi has been considered for biological and biomedical applications, including biosensing [2], therapeutic delivery [3,4] and as a molecular probe in cellular tracking [5]. PSi has a higher specific surface area (up to 500 m 2 cm −3 ) than that obtainable with planar silicon technology [6], providing a platform for various biomolecular interactions.…”

Chitosan Hydrogel‐Capped Porous SiO2 as a pH Responsive Nano‐Valve for Triggered Release of Insulin

“…Porous Si or SiO 2 host matrices have been used for in vitro release of the steroid dexamethasone (from dodecyl-terminated porous Si), [9] ibuprofen (from templated mesoporous silica particles), [12] and cisplatin (from calcium phosphate-doped porous Si films). [13] In addition, porous Si microparticles have been shown to deliver insulin across Caco-2 monolayers. [14] In most cases, porous Si or SiO 2 acts primarily as a carrier to host the drug, and little data has been presented demonstrating control of the drug release profile.…”