Biocompatible nanostructured solid adhesives for biological soft tissues.

Over the past few years, the development of novel adhesives for biological soft tissue adhesion has gained significant interest. Such adhesives should be non-toxic and biocompatible. In this study, we synthesized a novel solid adhesive using nanostructured hydroxyapatite (HAp) and evaluated its physical adhesion properties through in vitro testing with synthetic hydrogels and mouse soft tissues. The results revealed that HAp-nanoparticle dispersions and HAp-nanoparticle-assembled nanoporous plates showed efficient adhesion to hydrogels. Interestingly, the HAp plates showed different adhesive properties depending upon the shape of their nanoparticles. The HAp plate made up of 17nm-sized nanoparticles showed an adhesive strength 2.2times higher than that of the conventional fibrin glue for mouse skin tissues. STATEMENT OF SIGNIFICANCE: The present study indicates a new application of inorganic biomaterials (bioceramics) as a soft tissue adhesive. Organic adhesives such as fibrin glues or cyanoacrylate derivatives have been commonly used clinically. However, their limited biocompatibility and/or low adhesion strength are some drawbacks that impair their clinical application. In this study, we synthesized a novel solid adhesive with biocompatible and biodegradable HAp nanoparticles without the aid of organic molecules, and showed a rapid and strong adhesion of mouse soft tissues compared to conventional fibrin glues. Given the importance of wet adhesion in biomedicine and biotechnology applications, our results will help not only in developing an efficient approach to close incised soft tissues, but also in finding novel ways to integrate soft tissues with synthetic hydrogels (such as drug reservoirs).