Dissolution and Swelling Behaviour of Plasma-Polymerized Polyethylene Glycol-Like Hydrogel Films for use as Drug Delivery Reservoirs

• Main Authors: Pathak, Shantanu C., Hess, Dennis W.
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.2831339

Plasma-polymerized polyethylene glycol-like (PEG) thin films were deposited for use as reservoirs in drug delivery applications. Radio frequency power, reactor pressure and deposition temperature were varied in a parallel-plate plasma reactor to obtain two films with different relative crosslink densities, which were established by refractive indices. Variation of crosslink density allowed the tailoring of film swelling and chemical stability in aqueous environments. Film thicknesses and optical properties were measured with variable angle spectroscopic ellipsometry. In-situ ellipsometry dynamically monitored reversible film thickness changes in the presence of water vapor. Highly crosslinked films (deposited at elevated power and temperature and reduced pressure) swelled ~15% and relatively low crosslink density swelled ~70%. Electrophoretic immobilization tested these PEG films as storage materials for drugs. Negatively charged green fluorescent protein (GFP) was used as a model drug and fluorescence marker. Relatively highly crosslinked films showed enhanced incorporation of drifted GFP relative to incorporation by diffusion.