Universal surface modification using dopamine-hyaluronic acid conjugates for anti-biofouling.

Various materials are used to make implantable devices such as pumps, catheters, and stimulators. However, such implants inevitably undergo biofouling, which is associated with non-specific proteins and cell adhesion on the material surfaces. Severe biofouling often leads to adverse tissue reactions, such as foreign body responses, and thick scar tissue formation around the implantation, which in turn hampers the function and performance of the implants. Herein, a simple and effective surface modification method using dopamine-hyaluronic acid conjugate (DA-HA) is demonstrated to implement anti-biofouling in various biomaterials. DA-HA was synthesized and utilized as a coating material and five commonly used implantable substrates (i.e., polyimide (PI), gold (Au), poly(methyl methacrylate) (PMMA), polytetrafluoroethylene (PTFE), and polyurethane (PU)) were tested for modification with DA-HA. Highly hydrophilic HA chains were immobilized on the substrate surfaces through self-polymerization of DA-HA at an alkaline pH. The DA-HA-modified substrates displayed significant resistance to both non-specific protein adsorption and cell adhesion on the surfaces. In addition, a reduction in scar tissue formation was observed in the DA-HA-coated substrates compared to the unmodified bare substrates after a 4-week subcutaneous implantation. This universal surface coating can be further implemented in various biomedical applications in which severe biofouling is highly undesirable.