Silicone rubber (poly(dimethyl siloxane; PDMS)), is extensively used for
biomedical implants due to its low toxicity, flexible processing techniques, long-term
endurance and good blood compatibility. However, the presence of low molecular weight
organic molecules and catalyst residues that cause host systemic inflammatory reactions.
The hydrophobic nature of PDMS also allows microbial adhesion followed by infection.
Hydrophilic PDMS surfaces would be of great value in inhibiting biofilm formation thus
prolonging the lifetime of the implants. This could be obtained by surface-initiated atom
transfer radical polymerization (ATRP). The robustness and versatility of ATRP allow the
preparation of functional bioactive surfaces, including antifouling, antibacterial, stimuliresponsive,
biomolecule-coupled and micropatterned surfaces.[1-3]
We aim at establishing the experimental conditions allowing the surface-grafting of
polyethylene glycol methacrylate (PEGMA) by surface attaching an initiator (1-
trichlorosilyl-2-(chloromethylphenyl)ethane) onto PDMS (Sylgard ® 184). Here, cooper is
being used as a metal catalyst and 2,2'-Bipyridine as a ligant. Polymerizations are being
assayed in aqueous media.
The native smooth and transparent surface of the PDMS could be preserved following
polymerization (as confirmed by SEM). FTIR-ATR also showed the presence of PEGMA
polymer chains. By contact angle measurement, a change in the surface hydrophobicity
was observed, the values changing from 114º to 60º, following 30h polymerization.
Work is in progress to optimize the modification of PDMS by PEGMA surface-ATRP.
This implies following up the polymer chain growth kinetics, surface characterization by
XPS, FTIR-ATR, SEM and contact angle measurements. Static and dynamic microbial
adhesion, as well as biocompatibility studies are also envisaged
