A new modified silicone was obtained by the physical entrapment of a hydrophobic lipid, isopropyl myristate (IPM), to improve the encapsulation properties and corrosion resistance of medical electronic implants. Differences between the water transport for films in contact with water vapor versus those in contact with liquid water were identified; they showed increased permeability to water vapor, which was possibly the result of differences in the water organization at the hydrophobic film interface. Improvements, including enhanced scratch resistance and adhesion, in the mechanical properties of the modified material was also achieved. The incorporation of IPM further resulted in a significant improvement in the cell biocompatibility compared with the unmodified polymer; this suggested that the IPM combination could be a viable basis for implant device packaging. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2917-2924, 2011