French scientists have devised an adhesive from silica nanoparticles that can glue together gel-like materials and resist deformation. Credit: © CNRS Photothèque/ESPCI/MMC – GRACIA Marie.

Polymers make great adhesives, but they just can’t stick it when it comes to gluing together gel-like materials.

French researchers at ESPCI ParisTech and CNRS may have devised a superior adhesive—silica nanoparticles. The researchers recently reported in Nature a simple and inexpensive method of using commercial silica nanoparticles as an adhesive for gels and even biological tissues.

The scientists simply applied a solution containing silica nanoparticles to the surface of poly(dimethylacrylamide) (PDMA) gel, and briefly pressed another piece of PDMA on top—voilà, adhesion!

The glued PDMA could withstand significant deformation without breakage, and the nanoparticle glue was water-resistant and self-repairing. With hopes of biological applications, they showed that it was also possible to glue together two cut pieces of calf liver tissue (pictured below).

si glue liver lo res

French scientists also used silica nanoparticles to glue together calf liver tissue pieces. Credit: © CNRS Photothèque/ESPCI/MMC – KAUFFMANN Mathieu.

The trick, the authors found, was to match the size of the nanoparticles to the gel network mesh size. The polymer chains within the gel pieces adsorb on the surfaces of the nanoparticles, providing a strong bond between two cut pieces. Because so many chains adsorb onto the nanoparticle surface, the material can support deformation through energy dissipation, rather than chain breakage, when the pieces are stretched apart.

Because the size of the nanoparticles and their interaction with the gel network influence adhesion, silica nanoparticles could be tuned to specific applications and materials just by adjusting the particle size and surface chemistry.

The French team’s findings pave new avenues for adhesives. As stated in the press release, “This discovery opens up new applications and areas of research, particularly in the medical and veterinary fields and especially in surgery and regenerative medicine. It may, for example, be possible to use this method to glue together skin or organs having undergone an incision or a deep lesion. This method could moreover be of interest to the food processing and cosmetics industries, as well as to manufacturers of prostheses and medical devices (bandages, patches, hydrogels, etc.).”

The paper is “Nanoparticle solutions as adhesives for gels and biological tissues” (DOI: 10.1038/nature12806).

Also check out the News & Views article on the paper in the latest issue of Nature Materials.

Feature image credit: © CNRS Photothèque/ESPCI/MMC – MARCELLAN Alba.