Nanoparticle solutions as adhesives for gels and biological tissues

• Published in: Nature (London) 2014-01, Vol.505 (7483), p.382-385
• Main Authors: Rose, Séverine, Prevoteau, Alexandre, Elzière, Paul, Hourdet, Dominique, Marcellan, Alba, Leibler, Ludwik
• Format: Article
• Language: English
• Subjects: 639/301/357; 639/301/923; Adhesion; Adhesives; Adhesives - chemistry; Adsorption; Animals; Aqueous solutions; Atoms & subatomic particles; Bond strength; Carbon; Cattle; Cellulose; Cellulose - chemistry; Chains (polymeric); Chemical properties; Chemical reactions; Chemical Sciences; Contact; Dissipation; Droplets; Free radicals; Gels; Humanities and Social Sciences; Hydrogels; Hydrogels - chemistry; Irradiation; letter; Liver; multidisciplinary; Nanocrystals; Nanoparticles; Nanoparticles - chemistry; Nanotechnology; Nanotubes, Carbon - chemistry; Polymers; Polymers - chemistry; Properties; Science; Shear Strength; Silica; Silicon Dioxide - chemistry; Solutions; Surface chemistry; Surface Properties; Water - chemistry
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature12806

Strong, rapid adhesion between two hydrogels and even slices of animal tissue can be achieved at room temperature by using a silica nanoparticle solution as a ‘glue’. Nanoparticle glue makes gels stick Hydrogels are invaluable materials for many emerging technological and biomedical applications. But making assemblies of these gels has been difficult because typical adhesives don't stick hydrogels together. Historically, gluing gels required complex and aggressive treatments such as heating or chemical reactions. But now Ludwik Leibler and colleagues show that highly swollen gels can be efficiently and rapidly glued together simply by spreading a nanoparticle solution onto a gel's surface and then pressing another gel onto it. The method relies on the nanoparticles' ability to bind to polymer chains in the gels, and to act as connectors between chains from the two different gels. This approach also works for some biological tissues, as the authors demonstrate by joining two pieces of calf's liver. Adhesives are made of polymers 1 because, unlike other materials, polymers ensure good contact between surfaces by covering asperities, and retard the fracture of adhesive joints by dissipating energy under stress 2 , 3 . But using polymers to ‘glue’ together polymer gels is difficult, requiring chemical reactions, heating, pH changes, ultraviolet irradiation or an electric field 4 , 5 , 6 , 7 . Here we show that strong, rapid adhesion between two hydrogels can be achieved at room temperature by spreading a droplet of a nanoparticle solution on one gel’s surface and then bringing the other gel into contact with it. The method relies on the nanoparticles’ ability to adsorb onto polymer gels and to act as connectors between polymer chains, and on the ability of polymer chains to reorganize and dissipate energy under stress when adsorbed onto nanoparticles. We demonstrate this approach by pressing together pieces of hydrogels, for approximately 30 seconds, that have the same or different chemical properties or rigidities, using various solutions of silica nanoparticles, to achieve a strong bond. Furthermore, we show that carbon nanotubes and cellulose nanocrystals that do not bond hydrogels together become adhesive when their surface chemistry is modified. To illustrate the promise of the method for biological tissues, we also glued together two cut pieces of calf’s liver using a solution of silica nanoparticles. As a rapid, simple and efficient way to assemble gels