Viruses, drug delivery vectors, and other external particles exhibit a variety of complex behaviors on and in the cell membrane that are reflective of their physical and chemical properties, including size, shape, charge and the availability of membrane receptors, before they trigger internalization pathways to enter the cell. Understanding the dynamics of these cellular membrane processes is essential for many important human health related problems, such as the rational design of nanoparticle-based drug delivery systems and the prevention and control of infectious pathogens. The past efforts provided excellent visualization of cellular membrane processes, but primarily for translational dynamics. This proposal focuses on utilizing the recently-developed single particle orientation and rotational tracking (SPORT) technique to elucidate the characteristic live-cell rotational dynamics. SPORT affords high spatial, angular, and temporal resolutions simultaneously, for visualizing the rotational dynamics of anisotropic plasmonic gold nanorods in live cells in differential interference contrast (DIC) microscopy. By using SPORT, the proposed research will acquire new fundamental knowledge about the detailed rotational dynamics of cellular membrane processes, such as adhesion, transport, and endocytosis of functionalized nanoparticles, as may be relevant to drug delivery and viral entry. The rotational patterns on cell membranes for functionalized gold nanorods will be identified and correlated with their lateral movements and the presence of relevant functional biomolecules tagged with fluorescent proteins. The characteristic rotational motions of cargos during different internalization pathways will also be visualized directly, leading to new opportunities for understanding the timing, signaling and chemical and mechanical functions of protein modules involved in different pathways. Computer simulations will be developed to understand the effects of nanoparticle shapes, sizes and surface modifiers. The simulations will aid the project by providing suggestions for further informative experiments. Finally, SPORT will be utilized to study the uptake mechanism of aptamer-loaded gold nanostars in cancer cells. The proposed research may initiate a shift in the current research paradigm on membrane structure and function by demonstrating the importance of rotational dynamics at the single molecule and nanoparticle level. A thorough understanding of the fundamental motions in evidence will inform about the details of the molecular mechanisms involved in the diffusion of membrane proteins and parallel internalization pathways that will be critical for the better design of antiviral drugs, as well asthe development of targeted delivery vehicles and anti-cancer medicines.

Public Health Relevance

Advances in imaging technologies have greatly improved medical diagnostics and our ability to perform research on the cellular processes that lead to disease, ultimately resulting in new and more effective treatments. The proposed research will apply novel live-cell imaging tools to visualize and understand nanoparticle-cell membrane interactions. The knowledge acquired from live-cell studies will provide new insights for better design of nanoparticle drug carriers for targeted and triggered delivery of therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM115763-05
Application #
9732556
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Sammak, Paul J
Project Start
2015-09-22
Project End
2021-06-30
Budget Start
2019-07-01
Budget End
2021-06-30
Support Year
5
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Georgia State University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
837322494
City
Atlanta
State
GA
Country
United States
Zip Code
30302
Augspurger, Ashley E; Sun, Xiaoxing; Trewyn, Brian G et al. (2018) Monitoring the Stimulated Uncapping Process of Gold-Capped Mesoporous Silica Nanoparticles. Anal Chem 90:3183-3188
Wu, Yue; Ali, Moustafa R K; Dong, Bin et al. (2018) Gold Nanorod Photothermal Therapy Alters Cell Junctions and Actin Network in Inhibiting Cancer Cell Collective Migration. ACS Nano 12:9279-9290
Culver, Kayla S B; Liu, Tingting; Hryn, Alexander J et al. (2018) In Situ Identification of Nanoparticle Structural Information Using Optical Microscopy. J Phys Chem Lett 9:2886-2892
Chen, Kuangcai; Gu, Yan; Sun, Wei et al. (2017) Characteristic rotational behaviors of rod-shaped cargo revealed by automated five-dimensional single particle tracking. Nat Commun 8:887
Zhao, Fei; Chen, Kuangcai; Dong, Bin et al. (2017) Localization accuracy of gold nanoparticles in single particle orientation and rotational tracking. Opt Express 25:9860-9871
Ali, Moustafa R K; Wu, Yue; Ghosh, Deepraj et al. (2017) Nuclear Membrane-Targeted Gold Nanoparticles Inhibit Cancer Cell Migration and Invasion. ACS Nano 11:3716-3726
Ali, Moustafa R K; Wu, Yue; Tang, Yan et al. (2017) Targeting cancer cell integrins using gold nanorods in photothermal therapy inhibits migration through affecting cytoskeletal proteins. Proc Natl Acad Sci U S A 114:E5655-E5663
Zhang, Peng; Kim, Kyungsoo; Lee, Seungah et al. (2016) Augmented 3D super-resolution of fluorescence-free nanoparticles using enhanced dark-field illumination based on wavelength-modulation and a least-cubic algorithm. Sci Rep 6:32863