Polydimethylsiloxane Substrates with Surfaces Decorated by Immobilized Hyaluronic Acids of Different Molecular Weight for Biomedical Applications

Polydimethylsiloxane elastomers are a promising class of materials for biomedical applications. However, the surface hydrophobicity of the elastomer causes non-specific adsorption of proteins from the surrounding biological environment, which is undesirable in any biomaterial application. Therefore, this study aims to develop non-degradable and stable hydrophilic surface to minimize protein adsorption and enhance cell interaction. A polydimethylsiloxane surface was prepared from Sylgard 184 PDMS pre-polymer using a crosslinking catalyst, which was then modified by the incorporation of a Si–H bond, followed by the incorporation of amine, to prepare amino functionally modified silicon elastomers. Following the introduction of amino groups, hyaluronic acid was incorporated into the PDMS surfaces. ATR-FTIR and water contact angle measurements confirmed that HA was grafted to the PDMS surfaces. Atomic force microscopy suggested that the PDMS surface was covered by HA. All modified surfaces exhibited very low water contact angles, suggesting that the HA-modified surfaces had increased the hydrophilicity under aqueous conditions relative to the PDMS control. The surface stability, protein-resistant properties and biocompatibility of the different molecular weight of HA-modified PDMS surfaces were explored. All the HA-modified surfaces are found to be very stable and durable. HA 3-modified PDMS surfaces markedly decrease the fibrinogen and albumin adsorption as much as 98% from a buffer. The biocompatibility of the HA 3-modified PDMS surface to the RPE cells was evaluated. These highly protein-resistant hydrophilic transparent surfaces, particularly the HA 3-modified PDMS surface, can potentially be used as an extraordinary biomaterial for biomedical applications.