Enhanced Cytocompatibility and Reduced Genotoxicity of Polydimethylsiloxane Modified by Plasma Immersion Ion Implantation

Polydimethylsiloxane (PDMS) which is flexible, thermo-tolerant, resistant to oxidation, and tunable in hardness is very promising in microelectronics encapsulation. [1,2] In the biomedical field, PDMS is particularly suitable as contact lenses and implants [3,4] on account of its transparency, high gas permeability, and long-term durability in aqueous solutions. Nevertheless, PDMS with the basic structure of (-OSi(CH3)2-)n has many methyl groups (-CH3) and the surface free energy of PDMS is quite small (22–25 mJ/m2). [5] The inherent hydrophobicity and concomitant biocompatibility inadequacy have hitherto restricted the application of PDMS in biomedical engineering. Plasma immersion ion implantation (PIII), a non-line-of-sight plasma- and ion-beam-based surface treatment technique, is particularly suitable for biomedical devices with an irregular shape. [6,7] By using different plasma gases, PIII can create different chemical groups on the surface of different types of samples including PDMS to enhance the biological performances.