Design of bio-inspired adhesive surface composed of hexanoyl group-modified gelatin and silicon nanowire.

To fabricate a soft-tissue adhesion surface by nanostructural control and functional modification, we prepared bio-inspired adhesive surfaces composed of hexanoyl group-modified gelatin (HxGltn) and silicon nanowire (SiNW). We synthesized the HxGltn with different modification ratios of 27 mol% (27HxGltn), 37 mol% (37HxGltn), and 50 mol% (50HxGltn) and processed two different types of SiNW plates (800 pitch and 1500 pitch) with 1400 nm in height and 400 nm in diameter (800/1400 SiNW and 1500/1400 SiNW, respectively. To enhance the adhesion to the intestine surface, we covalently immobilized HxGltn on the surface of SiNW plates. A significant increase in bonding strength was not observed when Gltn-, 27HxGltn-immobilized 800/1400 SiNW, and Gltn-, 27HxGltn, 37HxGltn, 50HxGltn-immobilized 1500/1400 SiNW were used. Furthermore, 37HxGltn- and 50HxGltn-immobilized 800/1400 SiNW only showed 5-fold higher bonding strength to intestine tissue compared with other samples. These 37HxGltn- and 50HxGltn-immobilized 800/1400 SiNW surfaces had potential for the application of soft tissue adhesion.