10.1021/ac403700u.s001
Dong Xu
Dong
Xu
Yan He
Yan
He
Edward S. Yeung
Edward S.
Yeung
Direct Imaging of Transmembrane Dynamics of Single
Nanoparticles with Darkfield Microscopy: Improved Orientation Tracking
at Cell Sidewall
American Chemical Society
2014
internalization processes
orthogonal polarizations
NP endocytosis mechanisms
birefringent prism
NP biosafety
AuNR orientation
gold nanorods
transmembrane process
intensity sum
split AuNR plasmonic
Cell SidewallInvestigation
AuNR azimuth
Darkfield Microscopy
microscope objective
Direct Imaging
intensity difference
orientation probes
cell sidewall
Orientation Tracking
Transmembrane Dynamics
DFM
polarization darkfield microcopy
drug delivery
Single Nanoparticles
monitoring AuNR orientation dynamics
2014-04-01 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Direct_Imaging_of_Transmembrane_Dynamics_of_Single_Nanoparticles_with_Darkfield_Microscopy_Improved_Orientation_Tracking_at_Cell_Sidewall/2310637
Investigation
of the cellular internalization processes of individual
nanoparticles (NPs) is of great scientific interest with implications
to drug delivery and NP biosafety. Herein, by using dual-channel polarization
darkfield microcopy (DFM) and single gold nanorods (AuNRs) as orientation
probes, we developed a method that is capable of monitoring AuNR orientation
dynamics during its transmembrane process. With annular oblique illumination
and a birefringent prism to split AuNR plasmonic scattering into two
channels of orthogonal polarizations, the AuNR azimuth and polar angles
are obtained from their intensity difference and intensity sum. By
placing the focal plane of the microscope objective at the elevated
cell sidewall rather than at the flat cell top, interference from
cellular background is reduced and the signal-to-noise ratio of AuNR
orientation sensing is improved significantly, especially for AuNRs
inserting into the membrane at a large out-of-plane angle. As a result,
we were able to capture the complete membrane-crossing dynamics of
single AuNRs. This powerful method could be utilized to obtain valuable
insights on NP endocytosis mechanisms of various cells.