Blood activation and compatibility on single-molecular-layer biointerfaces

Research on the interactions between living systems and materials is fuelled by diverse biomedical needs, for example, drug encapsulation and stimulated release, stem cell proliferation and differentiation, cell and tissue cultures, as well as artificial organs. Specific single-molecular-layer biointerface design is one of the most important processes to reveal the interactions or biological responses between synthetic biomaterials and living systems. However, until now, there is limited literature on comprehensively revealing biomaterials induced blood component activation and hemocompatibility based on the single-molecular-layer interface approach. In this study, the effects of different groups on blood compatibility are presented using single-molecular-layer silicon (Si) interfaces. Typical hydrophilic groups (hydroxyl, carboxyl, sulfonic, and amino groups) and hydrophobic groups (alkyl, benzene, and fluorinated chains) are introduced onto single-molecular-layer Si interfaces and confirmed by atomic force microscopy, X-ray photoelectron spectroscopy, and water contact angle. The blood activation and compatibility for the prepared biointerfaces are systematically investigated by protein adsorption, clotting time, Factor XII detection, platelet adhesion, contacting activation, and complement activation experiments. The results indicate that the blood activation and hemocompatibility for the biointerfaces are complex and highly related to the chemical groups and hydrophilicity of the surfaces. Our results further indicate the vital importance of carefully designed biointerfaces for specific biomedical applications. The carboxyl group, sulfonic group, and hydroxyl group may be more suitable for the interface designs of antifouling materials. The results also reveal that the sulfonic group and fluorinated surface possess great potential for applications of blood contacting devices due to their low contacting blood activation.