Smart wound sealing with nanoparticles and light soldering

For over 5,000 years, the practice of suturing wounds with a needle and thread has remained relatively unchanged. However, depending on the skill of the practitioner and the equipment used, tissue cuts or tears may not be perfectly aligned during the suturing process. In certain situations, sutures can even damage soft tissues, leading to additional injury, or fail to seal wounds on internal organs, posing a grave threat.

Empa and ETH Zurich researchers have now introduced a pioneering method of soldering wounds using lasers, redefining the traditional approach to wound closure.

Soldering typically involves joining materials through the application of heat, using a melting bonding agent. Applying this thermal reaction to biological materials has been challenging, as it requires precise temperature control and non-invasive temperature measurement. The team, led by Oscar Cipolato and Inge Herrmann from Empa's Particles Biology Interactions laboratory in St. Gallen and the Nanoparticle Systems Engineering Laboratory at ETH Zurich, developed a smart wound closure system that enables gentle and efficient laser soldering.

To achieve this, they created a bonding agent containing metallic and ceramic nanoparticles and employed nanothermometry for temperature control. This advanced soldering process relies on the interaction between these two nanoparticle types within the bonding protein-gelatin paste. During laser irradiation, titanium nitride nanoparticles convert light into heat, while specially synthesized bismuth vanadate particles act as microscopic fluorescent nano thermometers. They emit light of a specific wavelength dependent on temperature, allowing for precise real-time temperature regulation.

This method is ideal for minimally invasive surgery, providing accurate temperature control with fine spatial resolution in superficial and deep wounds, eliminating the need for stirring.

Following mathematical modeling and optimization, the researchers achieved fast, stable, and biocompatible wound bonding on organs such as the pancreas and liver in laboratory tests. Additionally, they successfully sealed challenging tissue pieces, such as the urethra, fallopian tube, and intestine, using iSoldering. A patent application has been submitted for the nanoparticle composite material.

The researchers have gone a step further by replacing laser light with gentler infrared (IR) light. This advancement brings the soldering technology closer to practical use in hospitals, as medically approved IR lamps could be used in standard operating rooms without the need for additional laser protection measures.

MEDICA-tradefair.com; Empa