BioPhotonics Preview - May/June 2023

Facebook X LinkedIn Email
Here is your first look at the editorial content for the upcoming May/June issue of BioPhotonics.


Microscopy and Cardiology

Two-photon intravital microscopy enables the visualization of the behavior of cells within living animals. Coupled with novel functional markers, like calcium indicators that light up when cells are activated, it enables us to watch how cells move, neurons fire, and blood flows in animal experiments. We will discuss some of the special challenges that needed to be overcome to adapt this method to the beating heart in live mice. We will then show some examples of unique things that can be visualized with cardiac in vivo two-photon microscopy in mice.

Key Technologies: Two-Photon Microscopy

OCT and Cardiology

Optical coherence tomography (OCT) is capable of cross-sectional and volumetric visualization of biological tissue structures with 15 micron resolution. Advances in micro-optics and miniaturization of percutaneous coronary imaging (PCI) catheters have propelled the utilization of OCT in interventional cardiology, where its adoption is growing, owing to its order-of-magnitude higher resolution than intravascular ultrasound (IVUS). The high resolution of intravascular OCT enables it to be used for coronary plaque characterization (calcified, lipid-rich, or fibrous) based on reflectance and polarization properties. Next-generation multimodal OCT imaging can further allow PCI catheters to obtain complementary structural and chemical/molecular functional information. A new form of OCT capable of about 1 micron resolution has also been developed, termed uOCT, enabling cellular imagine within the coronary arteries. These advancements will provide OCT-based virtual histology during PCI, enabling therapy optimization for existing blockages and guided proactive treatment of coronary plaques at risk for a future coronary event.

Key Technologies: optical coherence tomography

Spectroscopy and Cardiology

Histopathological studies have shown lipid core plaque burden with a coronary artery wall is one of the main compositional characteristics when predicting a coronary event. Gold standard cardiovascular imaging techniques provide useful structural information but cannot distinguish underlying pathological differences within a plaque burden. Intravascular ultrasound-guided near-infrared spectroscopy (IVUS-NIRS) is a novel quasi-instantaneous diagnostic tool which can identify lipid core plaque. IVUS provides the ability to identify voxels of plaque burden within the artery wall. Simultaneously, NIRS utilizes spectral reflectance to differentiate the biological makeup of plaque burden and identify lipid. Intravascular NIRS technology implemented in cardiac catheterization labs today has proven the ability to successfully detect lipid core plaques and predict MACE. The potential of this technology has yet to be exhausted; future work will encompass the lipid core plaque burden and detection of the collagen content within the fibrous cap to establish plaque rupture vulnerability.

Key Technologies: Near-infrared spectroscopy

Light Therapy and Cardiology

Heart disease is the leading cause of death in the developed world. Sudden cardiac death is triggered by the breakdown of a normal periodic heart rhythm known as the sinus rhythm. The emergence of aberrant high-frequency sources of electrical activity is the cause of death due to cardiac arrhythmia and the resulting failure of the heart to pump blood. there are only two effective types of treatment for arrhythmia, which are based on the delivery of electrical energy to the heart to eliminate the sources of arrhythmia: ablation and electrical stimulation or defibrillation. While efficient, these methods are painful and potentially damaging to the healthy myocardium and other tissues. Optogenetics has recently emerged as a potential novel treatment of arrhythmias by light rather than the electrical field. In our recent publications, we have developed several devices which can deliver lifesaving optical stimulation, including optical pacemakers and defibrillators. These miniature devices were implanted into rodents, where they demonstrated their ability to treat various arrhythmias, including bradycardia and tachycardia, by either traditional electrical stimulation or by optical stimulation. This promising platform includes machine learning algorithms to detect life-threatening arrhythmia automatically and to deliver optimal therapies.

Key Technologies: optogenetics, light therapy, LEDs

Lasers and Cardiology

For many years, lasers including excimer and carbon dioxide lasers have been employed to remove blockages, driven largely by a global increase in cardiovascular diseases (CVD-driven deaths were at 17.9 million worldwide in 2019). Lasers were developed at the Oregon Medical Laser Center to destroy plaques and were patented 20 years ago. Companies like RA Medical Systems have capitalized on this need in the present day. However, the use of lasers has grown increasingly sophisticated on both the research and academic side. The Wellman Center for Photomedicine has used laser speckle imaging, which captures a pattern from interference of light scattered from tissue, to identify hardened arteries. And therapeutic lasers are now used to treat varicose veins and other ailments through a gold tip fiber (which can be followed through ultrasound) thanks to technology marketed by AngioDynamics. Lasers can also be used to assist in the grafting between blood vessels. Laser treatments in cardiology are even advancing on the microscopic level, as a sidebar will relate how at the University of Cologne, microscopic whispering gallery mode lasers have been shown to interact and affect specific cardiac cells.

Key Technologies: Therapeutic lasers, laser speckle imaging

See Pricing

Published: February 2023

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.