Attacking disease with a laser focus
Tweezers conjure thoughts of removing splinters or plucking eyebrows. But two UT Arlington researchers have found that an optical version of the pincer-like instrument can better deliver medicine for cardiovascular disease, cancer, and other ailments.
Physics Assistant Professor Samarendra Mohanty and bioengineering Associate Professor Kytai Nguyen are part of a collaborative research effort in UT Arlington’s Biophysics and Physiology Lab to use the optical tweezers, or focused laser beams, in cell manipulation.
“A focused laser holds the cell. We then use a force against the cell to measure the single cell’s elasticity,” Dr. Mohanty says. Elasticity measures how much that cell can stretch. “A cancer cell is normally more brittle, so those can be identified. A nanoparticle carrying a drug is then introduced with the optical tweezers.”
The team has tested the process at the microscopic level using human cells. Dr. Nguyen says the research could help investigators design nanoparticles that have more therapeutic benefits while reducing the severe side effects often seen in chemotherapy.
The research encompasses the interaction of nanoparticles with smooth muscle cells and cancer cells for drug delivery. The nanoparticles are embedded with iron and help localize the cancer cells using external magnetic fields. They enhance the optical forces to be trapped, dispersed, or delivered to those desired cells. Additional studies aim to find the best parameters for delivery.
Researchers in the Biophysics and Physiology Lab are concurrently developing patterned optical tweezers to control the interaction of these nanoparticles with cells.
With cardiovascular and many other diseases, it is essential to minimize the number of drug-carrying nanoparticles to be delivered. While making them magnetic would allow doctors to localize them in the desired region, surface functionalization would make them adhere to diseased cells better than normal cells.
Optical tweezers help determine the nanoparticles’ uptake mechanism and optimal size for efficient delivery. They also estimate the binding time (or force) so that the nanoparticles are taken up by cells before being carried away by flow. This enables optimal design of drug-delivery vehicles or other therapeutic nanoparticles.
Nguyen says that how these nanoparticles interact with the cell gives the researchers valuable information. “We can coat them with an antibody or targeting motif that is bound to diseased cells and deliver drugs to only these cells to treat illnesses.”
Mohanty also works in optogenetics, an emerging field using low-power light to stimulate neuronal cells. A micro LED (light-emitting diode) stimulates the specific genetically targeted neurons. He says that using optogenetics to treat retinitis pigmentosa, an eye disease that causes vision loss due to degeneration of photoreceptors in the retina, has been successful.