Gold Nanoparticle-Coated Surgical Meshes for Photothermal Infection Control

Researchers at the Institute of Photonic Sciences (ICFO) in Catalonia have developed a new technique to decontaminate surgical meshes once they are implanted in the body. The technique involves gold nanoparticle-coated meshes that heat up when they are exposed to near infrared light, destroying bacterial biofilms on the mesh surface. The researchers hope that this technique could be used to treat serious bacterial infections that can occur following the implantation of such meshes.

Surgical meshes are used in a variety of surgical procedures, with one of the most common being hernia repair. However, the meshes can become contaminated with bacteria during implantation, and such bacteria can easily form a biofilm over the mesh. This thick bacterial layer makes it difficult for antibiotics to penetrate, meaning that such infections are often very difficult to treat.

In the case of antibiotic-resistant bacteria, it is even more challenging to control or eradicate the infection, and patients may need additional surgery to address the problem. A total of 20 million hernia repair surgeries are performed globally every year, so new solutions are urgently required.

Scanning electron microscope micrographs of the S. aureus biofilm formed on the surgical mesh surface. (Image credit: ICFO)

To combat such infections, these ICFO researchers have combined nanotechnology with light therapy to burn bacterial biofilms off surgical meshes. The technique involves creating a homogeneous coating of millions of gold nanoparticles on surgical meshes, before they are implanted in a patient. The nanoparticles have a useful property – they heat up significantly when exposed to near infrared light.

By exploiting this phenomenon, the researchers aimed to kill cultured S. Aureus bacterial biofilms on surgical meshes. They subjected the biofilm-covered meshes to short intense pulses of near-infrared light, and saw that a significant proportion of the bacteria were killed outright. The remaining bacteria were weakened, and likely became more susceptible to antibiotic therapy or the body’s immune response.

The technique could be useful in treating infected meshes in the body, as the range of near-infrared light required is likely to cause minimal damage to nearby tissues. Options for administering the light inside the body include a minimally invasive catheter or perhaps a remotely controlled light source that is co-implanted with the mesh during the initial surgical procedure.

Study in Nano Letters: Plasmon-Based Biofilm Inhibition on Surgical Implants