Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2018-2019)

Optical tweezers is a powerful tool for manipulating nanoparticles, biological cells and macromolecules. The research on optical forces and trapping has been honored by 4 Nobel Prizes in physics in the recent years.

Optomechanics of the optical tweezers studies the light scattering of the nanoparticle in the tightly focused laser beam and its mechanical effect for a variety of applications. This is a multidisciplinary research facing many new challenges. First, the stable trap of the particles in the size range from tens to hundreds nanometers represents a challenge, as the smaller the nanoparticle size, the smaller the radiation force, and the larger the Brownian movement. Second, the cell mechanics and cell optomechanics are still in its infancy lacking the established common paradigms from physics and biochemistry communities.

Supported by the NSERC Discovery and Research Tool grants we have made significant contributions (16 papers, 300 citations) to advance the fundamental knowledge on the opto-mechanics of various optical tweezers, as optical stretcher, dual trap tweezers, time-sharing tweezers and viscoelastic testing tweezers for trapping nanorod, single cells and adherent cells.

The long term objective of the proposed research program is to develop new applications of optical trapping in the areas of cell mechanics and biomedical engineering. In the medium term, we focus on the targeted drug delivery application, with the objective to explore and push toward to the limit of the optical trap capacity, and use other optical means, to develop innovative physical tools for accelerating the cellular uptake and enhancing penetration of the drug nano-particles through the cell membrane and nuclear envelop in controllable manners in order to study the mechanism of the nano-carrier drug delivery process and the drug therapeutic efficacy in the in vitro condition.

We will try to “drill” additional holes by penetrating the laser trapped nano-probes through cell membrane and the nuclear pore complex. The challenge is that the force needed to dissect the cell membrane is 1-2 orders of magnitude higher than the radiation force in optical tweezers. We plan to test with the irregular shaped particles of sharp edges and the metal nanoparticles. We will use femtosecond laser pulses to inject metal nanoparticles into the cell and nucleus. The third approach will be optoporating the membranes directly with laser pulses. To perform this research, we maintain national and international collaborations with expertise in nano-drug delivery, cell and protein biology, super-resolution imaging, nanoparticles and femtosecond laser nonlinear optics.

This exploratory research at the frontiers of multiple subfields in physics, cell mechanics and biomedicine will deliver original contributions to the optomechanics of optical tweezers, and innovative approaches for the targeted drug delivery.