Data from: Non‐invasive treatment of ischemia/reperfusion injury: Effective transmission of therapeutic near‐infrared light into the human brain through soft skin‐conforming silicone waveguides

Noninvasive delivery of near‐infrared light (IRL) to human tissues has
been researched as a treatment for several acute and chronic disease
conditions. We recently showed that use of specific IRL wavelengths, which
inhibit the mitochondrial enzyme cytochrome c oxidase (COX), leads to
robust neuroprotection in animal models of focal and global brain
ischemia/reperfusion injury. These life‐threatening conditions can be
caused by an ischemic stroke or cardiac arrest, respectively, two leading
causes of death. To translate IRL therapy into the clinic an effective
technology must be developed that allows efficient delivery of IRL to the
brain while addressing potential safety concerns. Here, we introduce IRL
delivery waveguides (IDWs) which meet these demands. We employ a
low‐durometer silicone that comfortably conforms to the shape of the head,
avoiding pressure points. Furthermore, instead of using focal IRL delivery
points via fiberoptic cables, lasers, or light‐emitting diodes, the
distribution of the IRL across the entire area of the IDW allows uniform
IRL delivery through the skin and into the brain, preventing “hot spots”
and thus skin burns. The IRL delivery waveguides have unique design
features, including optimized IRL extraction step numbers and angles, and
a protective housing. The design can be scaled to fit various treatment
areas, providing a novel IRL delivery interface platform. Using fresh
(unfixed) human cadavers and isolated cadaver tissues, we tested
transmission of IRL via IDWs in comparison to laser beam application with
fiberoptic cables. Using the same IRL output energies IDWs performed
superior in comparison to the fiberoptic delivery, leading to an up to 95%
and 81% increased IRL transmission for 750 and 940 nm IRL, respectively,
analyzed at a depth of 4 cm into the human head. We discuss the unique
safety features and potential further improvements of the IDWs for future
clinical implementation.