CISMM

The nanoManipulator System integrates haptic force feedback control of a nanoscale probe tip with imaging in a fluorescence optical microscope. It has been used for virus, chromosome, cell and clot manipulation experiments. Beyond developments in instrumentation and software, CISMM develops methodologies for force measurements. Through our work with our Thrombosis collaborators on fibrin fiber mechanics, we have developed methods of fabricating “structured surfaces” (SS). These engineered surfaces enable stretching experiments in which biological fiber samples are suspended across channels and there for free of the confounding mechanical influence underlying surfaces. We will be developing integrated in-plane uniaxial and biaxial strain capabilities that will greatly expand the host of mechanical interrogations our collaborators can perform.

At right is (A) side view of experimental set up. Inverted optical microscope objective images the fibrin manipulation through the coverslip with structured channel-ridge surface. Suspended fibrin fibers are labeled with fluorescent beads and then stretched with the afm tip. Perspective view (b,d) of afm tip, and fibrin fiber suspended across channel. Fluorescence images of suspended fiber before being stretched (c) after and stretched to ~200% strain by the afm tip (e).

1.    Hudson, N.E., J.R. Houser, E.T. O’Brien, 3rd, R.M. Taylor, 2nd, R. Superfine, S.T. Lord, and M.R. Falvo, Stiffening of individual fibrin fibers equitably distributes strain and strengthens networks. Biophys J, 2010. 98(8): p. 1632-40.

2.    Houser, J.R., N.E. Hudson, L. Ping, E.T. O’Brien, 3rd, R. Superfine, S.T. Lord, and M.R. Falvo, Evidence that alphaC region is origin of low modulus, high extensibility, and strain stiffening in fibrin fibers. Biophys J, 2010. 99(9): p. 3038-47.

3.    Falvo, M.R., O.V. Gorkun, and S.T. Lord, The molecular origins of the mechanical properties of fibrin. Biophys Chem, 2010. 152(1-3): p. 15-20.

4.    O’Brien, E.T., 3rd, M.R. Falvo, D. Millard, B. Eastwood, R.M. Taylor, 2nd, and R. Superfine, Ultrathin self-assembled fibrin sheets. Proc Natl Acad Sci U S A, 2008. 105(49): p. 19438-43.

5.    Falvo, M.R., D. Millard, E.T. O’Brien, 3rd, R. Superfine, and S.T. Lord, Length of tandem repeats in fibrin’s alphaC region correlates with fiber extensibility. J Thromb Haemost, 2008. 6(11): p. 1991-3.

6.    Guthold, M., W. Liu, E.A. Sparks, L.M. Jawerth, L. Peng, M. Falvo, R. Superfine, R.R. Hantgan, and S.T. Lord, A comparison of the mechanical and structural properties of fibrin fibers with other protein fibers. Cell Biochem Biophys, 2007. 49(3): p. 165-81.

7.    Falvo, M.R., E.T. O’Brien, L. Ping, L.A. Hartle, S.T. Lord, and R. Superfine, Mechanical evaluation of individual fibrin fibers with Atomic Force Microscopy. Biophysical Journal, 2007: p. 523a-523a.

8.    Liu, W., L.M. Jawerth, E.A. Sparks, M.R. Falvo, R.R. Hantgan, R. Superfine, S.T. Lord, and M. Guthold, Fibrin fibers have extraordinary extensibility and elasticity. Science, 2006. 313(5787): p. 634.

9.    Guthold, M., W. Liu, B. Stephens, S.T. Lord, R.R. Hantgan, D.A. Erie, R.M. Taylor, Jr., and R. Superfine, Visualization and mechanical manipulations of individual fibrin fibers suggest that fiber cross section has fractal dimension 1.3. Biophys J, 2004. 87(6): p. 4226-36.

10.  Falvo, M.R., R.M. Taylor II, A. Helser, V. Chi, F.P. Brooks Jr. , S. Washburn, and R. Superfine, Nanometre-scale rolling and sliding of carbon nanotubes. Nature, 1999. 397(21 January): p. 236-238.

11.  Taylor, R., G. Matthews, A. Negishi, M. Guthold, M. Falvo, R. Superfine, S. Washburn, and F. Brooks, Molecular structure investigation and modification using the nanoManipulator. Journal of Molecular Graphics & Modelling, 1998. 16(4-6): p. 291-292.

12.  Falvo, M.R., S. Washburn, R. Superfine, M. Finch, F.P. Brooks, V. Chi, and R.M. Taylor, Manipulation of individual viruses: Friction and mechanical properties. Biophysical Journal, 1997. 72(3): p. 1396-1403.

13.  Falvo, M.R., G.J. Clary, R.M. Taylor, V. Chi, F.P. Brooks, S. Washburn, and R. Superfine, Bending and buckling of carbon nanotubes under large strain. Nature, 1997. 389(6651): p. 582-584.