Charlie P. Stallard

Modified drug release using atmospheric pressure plasma deposited siloxane coatings

This pilot study evaluates the potential of atmospheric plasma polymerised coatings to modify the rate of drug release from polymeric substrates. The antibiotic rifampicin was deposited in a prototype multi-layer drug delivery system, consisting of a nebulized layer of active drug between a base layer of TEOS deposited on a plastic substrate (polystyrene) and an overlying layer of plasma polymerised PDMS. The polymerised TEOS and PDMS layers were deposited using a helium atmospheric plasma jet system. Elution of rifampicin was measured using UV–VIS spectroscopy, in addition to a antimicrobial well diffusion assay with an established indicator organism. The multi-layered plasma deposited coatings significantly extended the duration of release of the rifampicin from 24 h for the uncoated polymer to 144 h for the coated polymer.

Achieving enhanced material finishing using cold plasma treatments

Abstract Plasma processing treatments are used widely in materials finishing. The plasmas used for these applications can be either ‘hot’ or ‘cold’. Examples of the former include those used in thermal spray and arc discharge machining. Cold plasmas, which are the focus of this review, are used for relatively low temperature surface cleaning and polymer activation. Cold plasmas can also be used for the deposition of coatings including plasma polymerised thin films. These nanometre thick polymer layers exhibit a tailored chemical functionality and can be used, for example, to control surface wetting properties ranging from superhydrophilic to superhydrophobic (SH). These cold plasmas can be operated under both low pressure and atmospheric conditions. Commercial materials finishing applications of ‘cold’ plasma treatments are highlighted.