In a newly reported study, the development of a super-resolution imaging platform technology to enhance the knowledge of how nanoparticles interact within cells has been explained.
Stefan Wilhelm, Ph.D., assistant professor in the Stephenson School of Biomedical Engineering. Image Credit: University of Oklahoma
The study was headed by Stefan Wilhelm, Ph.D., Assistant Professor in the Stephenson School of Biomedical Engineering at the University of Oklahoma, a research group from the Gallogly College of Engineering at OU, OU Health Sciences Center, and Yale University recently reported an article in the journal ACS Nano.
Since technology-driven capabilities in engineering and healthcare are on a continuous increase, scientists and engineers are coming up with new technologies to progress the future of health. Nanomedicine is one such area that explores the use of nanoparticles for drug delivery in the body to combat infectious diseases or cancer.
The evaluation of such nanomedicines in cells, tissues, and organs is frequently executed by optical imaging, which could have a restricted quality of imaging resolution. It is necessary to add new imaging technologies to view nanoparticles in their 3D ultrastructural context inside biological tissues.
To see nanomedicines in biological samples, researchers either use electron microscopy, which provides excellent spatial resolution but lacks 3-D imaging capabilities, or optical microscopy, which achieves excellent 3-D imaging, but exhibits relatively low spatial resolution.
Stefan Wilhelm, Ph.D., Assistant Professor, Stephenson School of Biomedical Engineering, the University of Oklahoma
Wilhelm added, “We demonstrate that we can perform 3-D imaging of biological samples with electron microscopy-like resolution. This technique, called super-resolution imaging, allows us to see nanomedicines inside individual cells.”
“Using this new super-resolution imaging method, we can now start to track and monitor nanoparticles inside cells, which is a prerequisite for designing nanomedicines that are safer and more efficient in reaching certain areas within cells,” continued Wilhelm.
A 3D super-resolution imaging technique called expansion microscopy was applied by scientists, which involves fixing cells within swellable hydrogels. Similar to water-absorbing materials utilized in diapers, the hydrogel materials tend to physically expand up to 20-fold their original size while getting into contact with water.
This expansion enables the imaging of cells with a lateral resolution of approximately 10 nanometers using a conventional optical microscope. We combined this method with an approach to image metallic nanoparticles within cells.
Stefan Wilhelm, Ph.D., Assistant Professor, Stephenson School of Biomedical Engineering, the University of Oklahoma
“Our approach exploits the inherent ability of metallic nanoparticles to scatter light. We used the scattered light to image and quantify nanoparticles inside cells without the need for any additional nanoparticle labels,” added Wilhelm.
The authors indicate that their super-resolution imaging platform technology can be utilized to enhance the engineering of secure and highly effective nanomedicines to progress the shift of such technologies into the clinic.
Wilhelm, the corresponding author of the study, is an affiliate faculty at the OU Health Stephenson Cancer Center and a faculty fellow for the OU Office of the Vice President for Research and Partnerships. The study’s first author is Vinit Sheth, a doctoral student at the Stephenson School of Biomedical Engineering.
Journal Reference
Sheth, V., et al. (2023) Quantifying Intracellular Nanoparticle Distributions with Three-Dimensional Super-Resolution Microscopy. ACS Nano. doi.org/10.1021/acsnano.2c12808.