Silicon Micro‐ and Nanofabrication for Medicine

Abstract

This manuscript constitutes a review of several innovative biomedical technologies fabricated using the precision and accuracy of silicon micro- and nanofabrication. The technologies to be reviewed are subcutaneous nanochannel drug delivery implants for the continuous tunable zero-order release of therapeutics, multi-stage logic embedded vectors for the targeted systemic distribution of both therapeutic and imaging contrast agents, silicon and porous silicon nanowires for investigating cellular interactions and processes as well as for molecular and drug delivery applications, porous silicon (pSi) as inclusions into biocomposites for tissue engineering, especially as it applies to bone repair and regrowth, and porous silica chips for proteomic profiling. In the case of the biocomposites, the specifically designed pSi inclusions not only add to the structural robustness, but can also promote tissue and bone regrowth, fight infection, and reduce pain by releasing stimulating factors and other therapeutic agents stored within their porous network. The common material thread throughout all of these constructs, silicon and its associated dielectrics (silicon dioxide, silicon nitride, etc.), can be precisely and accurately machined using the same scalable micro- and nanofabrication protocols that are ubiquitous within the semiconductor industry. These techniques lend themselves to the high throughput production of exquisitely defined and monodispersed nanoscale features that should eliminate architectural randomness as a source of experimental variation thereby potentially leading to more rapid clinical translation.

Controlling Protein Adsorption through Nanostructured Polymeric Surfaces

“…[52] The latter development of micro-and nanofabrication techniques led to an increase in experimental setups using micro-and nanopatterns for in vitro studies. [53][54][55] The cellular response to the surface nanotopography and its correlation to the surface-bound proteins have been highlighted by Lim et al who showed that cell adhesion was unaffected by surface nanotopography if performed in the absence of serum. [56] This was a very important finding which allowed speculations that implant surfaces should be designed not for cells but more prominently for proteins as primary targets.…”

General Strategy To Make an On-Demand Library of Structurally and Functionally Diverse SERS Substrates

“…29,61 Ultrathin, nanofabricated membrane filters, such as nanoporous silicon and silicon nitride, offer significant advantages over conventional polymer ultrafiltration membranes. 54,[62][63][64][65][66][67][68][69][70] Mechanically robust, unsupported ultrathin filters allow for high hydraulic and diffusive permeabilities. The material properties and ultrathin dimensions allow for the straightforward fabrication of smooth pores in controllable, welldefined sizes with narrow size distributions, and with high areal densities.…”

An Environmentally-Conscious Approach to the Synthesis and Separation of Ultrasmall Si Nanoparticles

“…8 Copyright: American Scientific Publishers approaches are limited in that a polydisperse blend is often generated. [9][10][11] Further compounding the issue, traditional methods for separating populations of nanoparticles with little variation in size [12][13][14] are unlikely to be applicable to SiNPs due to their small size (<5 nm in diameter) and light density (∼1400 g/cm 3 . 15 Specifically, while centrifugation provides the most direct approach to obtain the desired products, the size and density of SiNPs does not allow for the efficient isolation of different NP subpopulations.…”