Credit: © 2009 Elsevier

Surgical wounds can be sealed by either laser soldering, which uses protein or polymer pastes that coagulate on heating, or laser welding, which relies on irradiating a chromophore with a laser to trigger local thermal-reorganization of the collagenous tissues. However, organic chromophores have limited efficiency, poor stability and diffuse rapidly in the biological environment, making it difficult to induce any thermal reorganization accurately. Researchers in Italy and India now show that gold nanorods can generate sufficient heat to fuse tissues locally.

Roberto Pini and co-workers1 excised lens capsules from the eyes of pigs and assembled two lenses in a sandwich configuration — similar to transplantation of a donor lens to a recipient. Gold nanorods with an aspect ratio of four were applied on the internal side of the donor lens, and the side of the sandwich was irradiated with a laser tip. This procedure produced sufficient heat to denature the collagenous tissue and seal the two lenses together. The welded lenses were resistant to traction and did not show any signs of misalignment. Furthermore, the thermal damage was confined within a 150 μm radius from the centre of the irradiated area, beyond which the tissues remained intact.

This preliminary study shows that gold nanorods could potentially be used in laser welding operations, but more in vivo research is required to understand the recovery and metabolism dynamics of the particles.