Close

Search

Search Menu
Photonics Media Photonics Marketplace Photonics Spectra BioPhotonics EuroPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook

Tissue-Integrated Microlasers Measure Beating Heart of Zebra Fish

Facebook Twitter LinkedIn Email Comments
ST. ANDREWS, Scotland, April 13, 2021 — An imaging method developed by researchers at the University of St. Andrews aims to overcome difficulties in analyzing and imaging the beating heart. Researchers integrated tiny lasers into heart muscle cells of live zebra fish to acquire high-resolution measurements of their contractility. The method allowed them to perform the measurements at locations several times deeper than with other light-based techniques.

Obtaining images and analyses of the beating heart is difficult due to the constant motion of living tissue. The dense muscle fibers of the heart tend to strongly scatter and absorb light. While advanced microscopy methods such as multiphoton imaging are able to see up to 1 mm into the brain, the challenging environment of the heart limits functional imaging to about 100 µm.

“In the future, this technique could help to overcome the increasing burden of cardiovascular diseases by guiding the development of artificial cardiac tissue and regenerative cardiac therapies,” said Marcel Schubert, a researcher at the Centre for Biophotonics at the University of St. Andrews.

The new work employs spherical microlasers that are just 15 µm in diameter. Due to their unique emission characteristics, they are well suited to applications requiring high signal strength and short acquisition times, the researchers said. The lasers are specifically able to be internalized by neonatal mouse heart muscle cells.

Once inside the cell, the laser remains in direct contact with myofibrils, the contractile filaments forming the muscle fiber. The cell’s contraction changes the refractive index of the myofibrils touching the laser, creating detectable pulse-shaped perturbations to the lasing wavelength. The changes in refractive index correlate directly with contractility.

The team also injected the microlasers into the outer wall of a zebra fish embryo, and results based on the concentration profiles it obtained showed that the technique isn’t affected by the rapid motion of the heart. The approach also worked, researchers found, in thick sections of heart tissues, which could be used for drug screening or testing regenerative cardiac therapies. In these thicker tissue sections, the microlaser signals and heart contraction could be measured through tissue that was up to 400 µm thick.

“In the future, this approach could be used to study transplanted cells and engineered cardiac tissue,” Schubert said.

The next step will be to reduce the size of the microlasers and to improve their biocompatibility. The researchers intend to switch to multiphoton excitation or infrared-emitting lasers, which could drastically increase light penetration, thereby allowing the sensing of contractions deep inside the beating heart.

The work will be presented at the 2021 Biophotonics Congress: Optics in the Life Sciences on April 14.

Photonics.com
Apr 2021
GLOSSARY
cell
1. A single unit in a device for changing radiant energy to electrical energy or for controlling current flow in a circuit. 2. A single unit in a device whose resistance varies with radiant energy. 3. A single unit of a battery, primary or secondary, for converting chemical energy into electrical energy. 4. A simple unit of storage in a computer. 5. A limited region of space. 6. Part of a lens barrel holding one or more lenses.
Research & TechnologylasersBiophotonicsheartheart tissuezebrafishmicrolaserCellheart cellscontractionsheart contractionscardiaccardiac beat detectionOSA Biophotonics Congress 2021: Optics in the Life SciencespresentationSt. Andrews UniversitySt. AndrewsUniversity of St. AndrewsEuropeScotland

Comments
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2021 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
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.