Phototherapy technique uses IR laser to release drugs

This discovery represents a major innovation, said Adah Almutairi, PhD, associate professor and director of the joint UC San Diego-KACST Center of Excellence in Nanomedicine. Up to now, she said, only a handful of strategies using light-triggered release from nanoparticles have been reported.

The mechanism, developed in collaboration with materials scientists, engineers and neurobiologists and described in ACS Nano, employs near-infrared (NIR) light from a low-power laser to heat pockets of water trapped within non-photo-responsive polymeric nanoparticles infused with drugs.

The water pockets absorb the light energy as heat, which softens the encapsulating polymer and allows the drug to be released into the surrounding tissue. The process can be repeated multiple times, with precise control of the amount and dispersal of the drug.

‘A key advantage of this mechanism is that it should be compatible with almost any polymer, even those that are commercially available,’ said Mathieu Viger, a post-doctoral fellow in Almutairi’s laboratory and co-lead author of the study. ‘We’ve observed trapping of water within particles composed of all the biodegradable polymers we’ve so far tested.’