Thomas Group - Biophysics
Our research focus is the application of optical and
fluorescence techniques to study biological and biomaterial systems at the
subcellular level. We are currently working on three projects:
¥ Fluorescence and optical techniques to measure the
ultrasound-driven release of drug mimics from liposomes and lipid-coated
bubbles (Andy Maloney)
¥ Fluorescence correlation spectroscopy, and applications
using local field enhancement (Fang
Huang)
¥ 4-Wave Mixing Microscopy (in collaboration with W.
Rudolph, UNM Physics and Astronomy) (Xuejun Liu)
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The laboratory is
also the UNM host site for a Raydiance Desktop USPTM R&D
laser. The Raydiance is a pulsed (~700 fs, 500 kHz) laser with up to 5 microJoules
of energy per pulse. More information on the laser capabilities may be found
in this PowerPoint
presentation. Researchers in the
UNM community are welcome to use this laser for pilot research projects.
Please contact Dr.
Thomas to discuss your application. |
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Ultrasound-Mediated Release of Entrapped and Adsorbed
Drugs
Using a
Sonic Concepts 1.1 MHz transducer, we are studying whether high-frequency, focusable
ultrasound can effectively release drug mimic compounds from liposomes and
lipid-coated bubbles. Very strong ultra-sound also causes sonoluminescence, through cavitation collapse.
Somewhat paradoxically, in a focused sound field sonoluminescence is not strongest at the focus. The exact
relationship between sonoluminescence and lipid membrane permeabilization has
not been clearly established. |
Fluorescence Ratio System |
US Sonoluminescence / Sample Chamber |
Andy
Maloney |
Fluorescence
Correlation Spectroscopy
Fluorescence
correlation spectroscopy is a well-established technique for determining both
diffusion coefficients and associations of biomolecules in cells. We are using
FCS in a collaboration with Prof. Diane Lidke of the School of Medicine to
measure association of a signal transduction kinase in the cytoplasm. We are
also exploring local field enhancement from metal island arrays to restrict FCS sampled
volumes, and to study correlations in multiphoton signals, such as second
harmonics. |
FCS
Microscope |
Gold
Island Array (Bar= 2mm) Satish
Kasarla, Los Alamos |
Fang
Huang |