Silicon–Polymer Hybrid Materials for Drug Delivery

Abstract

Silicon and its oxides are widely used in biomaterials research, tissue engineering and drug delivery. These materials are highly biocompatible, easily surface functionalized, degrade into nontoxic silicic acid and can be processed into various forms such as micro- and nano-particles, monoliths, membranes and micromachined structures. The large surface area of porous forms of silicon and silica (up to 1200 m2/g) permits high drug loadings. The degradation kinetics of silicon- and silica-based materials can be tailored by coating or grafting with polymers. Incorporation of polymers also improves control over drug-release kinetics. The use of stimuli-responsive polymers has enabled environmental stimuli-triggered drug release. Simultaneously, silicon microfabrication techniques have facilitated the development of sophisticated implantable drug-delivery microdevices. This paper reviews the synthesis, novel properties and biomedical applications of silicon-polymer hybrid materials with particular emphasis on drug delivery. The biocompatible and bioresorptive properties of mesoporous silica and porous silicon make these materials attractive candidates for use in biomedical applications. The combination of polymers with silicon-based materials has generated a large range of novel hybrid materials tailored to applications in localized and systemic drug delivery.

Functionalized silica nanoparticles as a carrier for Betamethasone Sodium Phosphate: Drug release study and statistical optimization of drug loading by response surface method

“…According to the Higuchi model [42], Eq. (6) may be used to fit the drug release rates for a planar system with a porous matrix, where M is the overall amount of drug released after time t and k H is the Higuchi dissolution constant [4].…”

“…The second advantage is a smaller amount of drugs would be used, and so the synthesis and preparation of drugs would be less expensive. Finally, the efficiency of treatment could be improved by controlling the conditions and minimizing the side effects [4,5]. Biocompatibility and capacity of drug loading are important characteristics of drug carriers.…”

Fabrication and Characterization of a Porous Silicon Drug Delivery System with an Initiated Chemical Vapor Deposition Temperature-Responsive Coating

“…pSi is a versatile drug delivery platform: it is nontoxic and biodegradable, 15 it is a biocompatible implantable material, 16 and it can be combined with biosensing and be tailored for specific controlled or sustained drug delivery applications. 17 To improve the release or degradation kinetics of the pSi drug delivery vehicle, its surface can be coated with a polymer that acts as a capping layer, protects the payload from the surrounding environment, and enables sustained release. 14,18 In particular, this polymer can display stimulus-responsive properties for controlled release of the drug under specific biological conditions.…”

Targeted drug delivery using genetically engineered diatom biosilica

“…The most intensively investigated silica materials for drug delivery are mesoporous silica and oxidized porous silicon 3 . Both feature high surface area, thermal stability, tunable pore size, chemical inertness, excellent biocompatibility and (at least in the case of porous silicon) biodegradability 4 . A significant drawback for the use of these materials is that their synthesis requires toxic chemicals (in particular silanes and hydrofluoric acid) and is timeconsuming and costly.…”