Dr. Chachisvilis investigates molecular mechanisms of mechano-chemical signal transduction in live cells. Particular emphasis is placed on the role of plasma membrane in mediating mechano-chemical response. Picosecond time-resolved fluorescence spectroscopy and imaging are used to study conformational dynamics of membrane proteins (GPCRs) in model bilayer systems and endothelial cells in real time. Fluorescence correlation spectroscopy is employed to investigate how mechanical deformation of lipid bilayer membrane affects lateral diffusion of membrane proteins in plasma membrane. The ultimate goal of this research is to show how mechanically induced changes in physical properties of the lipid-bilayer membrane modulate signal transduction processes in endothelial cells. 

PUBLICATIONS:  

1. M. Chachisvilis, Y.-L. Zhang, J.A. Frangos, G Protein-coupled Receptors Sense Fluid Shear Stress in Endothelial Cells, Proc. Natl. Acad. Sci. USA, 103 (2006) 15463-15468. [Full Text]  (See also highlights by J. Pickett, Even Receptors get stressed, Nature Reviews Molecular and Cell Biology, 7 (2006) 880 [Full Text]; and by R.P. Kruger, Stress Prods a GPCR in Action, Cell 127 (2006) 655). [Full Text] 

2. Y-L. Zhang, J.A. Frangos, and M. Chachisvilis, Laurdan Fluorescence Senses Mechanical Strain in the Lipid Bilayer Membrane, Biochem.  Biophys. Res. Commun. 347 (2006) 838-841.  [Full Text]

3. B. Shao, J.S. Jaffe, M. Chachisvilis and S.C. Esener, Angular resolved light scattering for discriminating among marine picoplankton: modeling and experimental measurements, Optics Express 14 (2006) 12473.  [Full Text]

4. R.A. Flynn, B. Shao, M. Chachisvilis, M. Ozkan, S.C. Esener, Counter-propagating optical trapping system for size and refractive index measurement of microparticles, Biosensors & Bioelectronics 21 (2006) 1029-1036.  [Full Text]

5. R.A. Flynn, B. Shao, M. Chachisvilis, M. Ozkan, S.C. Esener, Two-beam optical traps: Refractive index and size measurements of microscale objects, Biomedical Microdevices 7 (2005) 93-97.[Full Text]

6. D. Watson, N.D. Hagen, J. Diver, P. Marchand, and M. Chachisvilis, Elastic light scattering from single cells: orientational dynamics in optical trap, Biophysical Journal  87 (2004) 1 [Full Text]

7. A. H. Forster, M. M. Wang, W. F. Butler, M. Chachisvilis, T. D.Y. Chung, Sadik C. Esener, J. M. Hall, O. Kibar, K. Lykstad, P. J. Marchand, E. M. Mercer, L. M. Pestana, S. Sur, E. Tu, R. Yang, H. Zhang, and I. Kariv, Use of moving optical gradient fields for analysis of apoptotic cellular responses in a chronic myeloid leukemia cell model, Analytical Biochemistry 327 (2004) 14 [Full Text]

8. H. Zhang, E. Tu, N. D. Hagen, C. A. Schnabel, M. J. Paliotti, W. S. Hoo, P. M. Nguyen, J. R. Kohrumel, W. F. Butler, M. Chachisvilis, and P. J. Marchand, Time-of-Flight Optophoresis Analysis of Live Whole Cells in Microfluidic Channels, Biomedical Microdevices, 6 (2004) 11.   [Full Text]

9. M. M.-L. Grage, Y. Zaushitsyn, A. Yartsev, M. Chachisvilis, V. Sundström, and T. Pullerits, Ultrafast excitation energy transfer and trapping in a thin polymer film, Phys. Review. B 67 (2003) 205207 [Full Text]

10. M. M. Wang, C.A. Schnabel, M. Chachisvilis, R. Yang, M. J. Palioti, L. A. Simons, L. McMullin, N. Hagen, K. Lykstad, E. Tu, L. M. Pestana, S. Sur, H. Zhang, W. F. Butler, I. Kariv, and P. J. Marchand, Optical forces for noninvasive cellular analysis, Applied Optics, 42 (2003) 5765  [Full Text]

11. M. Chachisvilis, A.H. Zewail, Femtosecond dynamics of pyridine in the condensed phase: valence isomerization by conical intersections, J. Phys. Chem. A 103 (1999) 7408. [Full Text]

12. T. Fiebig, M. Chachisvilis, M.M. Manger, A. Douhal, I. Garcia-Ochoa, A. de La Hoz Ayuzo, A.H. Zewail, Femtosecond dynamics of double proton transfer in a model DNA base pair: 7-Azaindole dimers in the condensed phase, J. Phys. Chem. A 103 (1999) 7419. [Full Text]

13. A. Douhal, T. Fiebig, M. Chachisvilis, A.H. Zewail, Femtochemistry in nanocavities: Reactions in cyclodextrins, J. Phys. Chem. A 102 (1998) 1657. [Full Text]

14. M. Chachisvilis, I. Garcia-Ochoa, A. Douhal, A.H. Zewail, Femtochemistry in nanocavities: dissociation, recombination and vibrational cooling of iodine in cyclodextrin, Chem. Phys. Lett. 293 (1998) 153. [Full Text]

15. M. Chachisvilis, T. Fiebig, A. Douhal, A.H. Zewail, Femtosecond dynamics of a hydrogen-bonded model base pair in the condensed phase: Double proton transfer in 7-azaindole, J. Phys. Chem. A 102 (1998) 669.  [Full Text]

16. J.S. Baskin, M. Chachisvilis, M. Gupta, A.H. Zewail, Femtosecond dynamics of solvation: Microscopic friction and coherent motion in dense fluids, J. Phys. Chem. A 102 (1998) 4158.  [Full Text]

17. S. Jursenas, A. Gruodis, G. Kodis, M. Chachisvilis, V. Gulbinas, E.A. Silinsh, Free and self-trapped charge-transfer excitons in crystals of dipolar molecules of  N,N-dimethylaminobenzylidene 1,3-indandione, J. Phys. Chem. B 102 (1998) 1086. [Full Text]

18. J.S. Baskin, M. Gupta, M. Chachisvilis, A.H. Zewail, Femtosecond dynamics of microscopic friction: nature of coherent versus diffusive motion from gas to liquid density, Chem. Phys. Lett. 275 (1997) 437.  [Full Text]

19. M. Chachisvilis, O. Kuhn, T. Pullerits, V. Sundström, Excitons in photosynthetic purple bacteria: Wavelike motion or incoherent hopping? J. Phys. Chem. B 101 (1997) 7275. [Full Text]

20. M. Chachisvilis and V. Sundström, Femtosecond vibrational dynamics and relaxation in the core light‑harvesting complex of photosynthetic purple bacteria, Chem. Phys. Lett. 261 (1996) 165.  [Full Text]

21. M. Chachisvilis, V. Chervony, A. Shulga, B. Källebring, S. Larsson and V. Sundström, Spectral and Photophysical Properties of Ethylene-Bridged Side-to-Side Porphyrin Dimers. I. Ground State Absorption and Fluorescence Study and Calculation of Electronic Structure of tbis=OEP [trans-1,2-bis(meso-octaethylporphyrinyl)ethene], J. Phys. Chem. 100 (1996) 13857.  [Full Text]

22. M. Chachisvilis, V. Chervony, A. Shulga, B. Källebring, S. Larsson and V. Sundström, Spectral and Photophysical Properties of Ethylene-Bridged Side-to-Side Porphyrin Dimers. II. Femtosecond Transient Absorption and Picosecond Fluorescence Study of tbis=OEP {trans-1,2-bis(meso-octaethylporphyrinyl)ethene}, J. Phys. Chem. 100 (1996) 13867.  [Full Text]

23. T. Pullerits, M. Chachisvilis, and V. Sundström, Exciton delocalization length in the B850 antenna of Rhodobacter Sphaeroides, J. Phys. Chem. 100 (1996) 10787.  [Full Text]

24. M. Chachisvilis and V. Sundström,  The tunneling contributions to optical coherence in femtosecond pump-probe spectroscopy of a three level system. J. Chem. Phys. 104, (1996) 5734.  

25. V. Gulbinas, M. Chachisvilis, L. Valkunas and V. Sundström, Excited state dynamics of phthalocyanine films.  J. Phys. Chem. 100 (1996) 2213.  [Full Text]

26. S. Hess, M. Chachisvilis, K. Timpmann, M.R. Jones, G.J. Fowler, C.N. Hunter and V. Sundström,  Temporally and spectrally resolved subpicosecond energy transfer within the peripheral antenna complex (LH2) and from LH2 to the core antenna complex in photosynthetic purple bacteria.  Proc. Natl. Acad. Sci. USA, 92 (1995) 12333.  [Full Text]

27. M. Chachisvilis, H. Fidder, T. Pullerits, and V. Sundström,  Coherent nuclear motions in light-harvesting pigments and dye molecules, probed by ultrafast spectroscopy. J. of Raman Spectroscopy,  26 (1995) 513.  [Full Text]

28. M. Chachisvilis, H. Fidder and V. Sundström,   Electronic coherence in pseudo two-colour pump-probe spectroscopy,  Chem. Phys. Lett.  234 (1995) 141. [Full Text]

29. T. Pullerits, M. Chachisvilis, I. Fedchenia, M.R. Jones, C.N. Hunter, S. Larsson and V. Sundström, Coherent versus incoherent energy transfer in the light harvesting complexes of photosynthetic bactria, Lithuanian J. of Physics, 34 (1994) 329.

30. V. Gulbinas, M. Chachisvilis, A. Persson, S. Svanberg and V. Sundström, Ultrafast excitation relaxation in colloidal particles of chloroaluminum phthalocyanine: one-dimensional exciton-exciton anihilation. J. Phys. Chem. 98 (1994) 8118. [Full Text]

31. T. Pullerits, M. Chachisvilis, M.R. Jones, C.N. Hunter, and V. Sundström, Exciton dynamics in the light-harvesting complexes of Rhodobacter sphaeroides. Chem. Phys. Lett. 224 (1994) 355.  [Full Text]

32. M. Chachisvilis, T. Pullerits, M.R. Jones, C.N. Hunter, and V. Sundström,  Vibrational dynamics in the light-harvesting complexes of the photosynthetic bacterium Rhodobacter sphaeroides. Chem. Phys. Lett. 224  (1994) 345.  [Full Text]

33. V. Kopp, I. Mochalov, A. Mikhailov and M. Chachisvilis, Interference of two-photon and Raman resonances in KGd (WO4)2 Nd3+ crystals. Sov. Optics and Spectroscopy, 5 (1991) 950.

34. V. Ivaska, M. Zilinskas and M. Chachisvilis, Investigation of magnetic field   distribution in the transition: superconductor-ferromagnetic. Lithuanian J. of Phys.  3 (1989) 310.

CONFERENCE PAPERS:

1. S. Hess, M. Chachisvilis, T. Pullerits, M.R. Jones, G.J.C. Fowler, C.N. Hunter and  V.Sundström, Localized and delocalized excitations in photosynthetic antenna, Femtochemistry: Ultrafast Chemical and Physical Processes in Molecular Systems, Lausanne, 1995 (World Scientific, Singapore, 1996).

2. T. Pullerits, M. Chachisvilis, and V. Sundström,  Exciton dynamics and delocalization length in B850 molecules of LH2 of Rhodobacter Sphaeroides. in Photosynthesis: from Light to Biosphere, Proccedings of the Xth Inter, Photosynthesis Congress, Montpeler 1995.  Vol. 1 (1995), 107-114.

3. S. Hess, M. Chachisvilis, T. Pullerits, M.R. Jones, G.J.C. Fowler, C.N. Hunter and V. Sundström, Localized excitations in photsynthesis. LH2 - a testing ground of energy transfer. in Photysthesis: from Light to Biosphere, Proccedings of the Xth Inter, Photosynthesis Congress, Montpeler 1995.  Vol. 1 (1995) 119-122.

4. M. Chachisvilis and V. Sundström, The tunneling contributions in the pump-probe spectroscopy of the three level system, Femtochemistry: Ultrafast Chemical and Physical Processes in Molecular Systems, Lausanne, 1995 (World Scientific, Singapore, 1996).

5. M. Chachisvilis, T. Pullerits, M.R. Jones, C.N. Hunter and V .Sundström,  Coherent nuclear motions and exciton state dynamics photosynthetic light-harvesting pigments. In Ultrafast Phenomena, 1994.

6. P.J. Marchand, M.M. Wang, A.H. Forster, W.F.Butler, M.Chachisvilis, J.M. Hall, and I. Kariv, "Drug response measurements using optical forces," Proc. OSA Optics in Computing OC'2003, Washington, DC, June 2003.

7. P. J. Marchand, M. Wang, C. Schnabel, M. Chachisvillis, H. Zhang, R. Yang, L. McMullin, N. Hagen, O. Kibar, S. Esener, G. Tu, S. Sur, L. Pestana, K. Haden, K. Truong, W. Seto, K. Lykstad, L. Simons, M. Paliotti, I. Kariv, J. Hall, and W. Butler, "Cellular analysis based on moving infrared optical gradient fields," SPIE's International Symposium on Optical & Opto-Electronic Applied Science and Engineering, San Diego, August 2003.

8. M. Chachisvilis, J.A. Frangos, Y. Zhang, "G Protein-coupled respond to sense fluid shear stress in endothelial cells", The 20th Symposium of the Protein Society, San Diego, CA, 2006.

9. M. Chachisvilis, J.A. Frangos, Y. Zhang, "G Protein-coupled respond to mechanical perturbation of plasma membrane", 2006 Annual Fall Meeting of the Biomedical Engineering Society, Chicago, Illinois, October 2006.

PATENTS:

1. 2002 - US 20040067167,  Methods and apparatus for optophoretic diagnosis of cells and particles. 

2. 2005 - US 20050207940, Methods and apparatus for sorting cells using an optical switch in a microfluidic channel network.

3. 2 pending applications for US patents.

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