The Kaufman group supports a diverse and continually evolving program of research in frontier areas at the intersection of chemistry, physics, and biology. Thematically, our core interests are in the study of unusual dynamics of crowded and complex systems, and technically our research is driven by high resolution imaging and its integration with complementary approaches. Recent work is centered in two long-standing research thrusts in the laboratory as well as in a developing area of interest. In particular, we (1) use single molecule imaging to detail the characteristics and origin of atypical relaxations in molecular and polymeric supercooled liquids, (2) apply super-resolution and other single particle techniques to elucidate structure-function relationships in conjugated polymers, paving the way to fine control of their photophysics, and (3) exploit tools for biopolymer gel design and characterization developed in our laboratory to investigate modes of cancer cell motility that are relevant in vivo.
S. Motte and L.J. Kaufman. Strain stiffening in collagen I networks, Biopolymers, 99, 35-46 (2013).
L.M. Leone and L.J. Kaufman. Single molecule probe reports of dynamic heterogeneity in supercooled ortho-terphenyl, J. Chem. Phys, 138, 12A524 (2013).
L.J. Kaufman. Heterogeneity in single molecule observables in the study of supercooled liquids, Ann. Rev. Phys. Chem, 64, 177-200 (2013).
J. Zhu and L.J. Kaufman. Collagen I self-assembly: Revealing the developing structures that generate turbidity, Biophys. J, 106, 1822-1831 (2014).
A. Guzman, M.J. Ziperstein, and L.J. Kaufman. The effect of fibrillar matrix architecture on tumor cell invasion of physically challenging environments, Biomaterials, 35, 6954-6963 (2014).
D.T. Hoang, K. Paeng, H. Park, L.M. Leone, and L.J. Kaufman. Extraction of rotational correlation times from noisy single molecule fluorescence trajectories, Anal. Chem, 86, 9322–9329 (2014).
K. Stokely, A.S. Manz, and L.J. Kaufman. Revealing and resolving degeneracies in stretching exponents in temporally heterogeneous environments, J. Chem. Phys. 142, 114504 (2015).
H. Park, D.T. Hoang, K. Paeng, L.J. Kaufman. Localizing exciton recombination sites in conformationally distinct single conjugated polymers by super-resolution fluorescence imaging, ACS Nano. 9, 3151-3158 (2015).
K. Paeng, H. Park, D.T. Hoang, and L.J. Kaufman. Ideal probe single-molecule experiments reveal the intrinsic dynamic heterogeneity of a supercooled liquid, Proc. Nat. Acad. Sci. USA. 112, 4952-4957 (2015).
M.J. Ziperstein, A. Guzman, and L.J. Kaufman. Breast cancer cell line aggregate morphology does not predict invasive capacity, PLoS ONE, 10, e0139523 (2015).
H. Park, D.T. Hoang, K. Paeng, J.Yang, and L.J. Kaufman. “Conformation-dependent photostability among and within single conjugated polymers,” Nano. Lett. 15, 7604-7609 (2015).
K. Paeng and L.J. Kaufman. “Single molecule experiments reveal the dynamic heterogeneity and exchange time scales of polystyrene near the glass transition,” Macromolecules. 49, 2876-2885 (2016).
K.E. Yoh, K. Regunath, A. Guzman, S.-M. Lee, N.T. Pfister, O.Akanni, L.J. Kaufman, C.L. Prives, and R. Prwyes. “Repression of p63 and induction of EMT by mutant Ras in mammary epithelial cells,” Proc. Nat. Acad. Sci. USA. 113, E6107–E6116 (2016).
A. Guzman, V. Sanchez Alemany, Y. Nguyen, C.R. Zhang, and L.J. Kaufman. “A novel 3D in vitro metastasis model elucidates differential invasive strategies during and after breaching basement membrane,” Biomaterials. 115, 19-29 (2017).
Hu, E.U. Azeloglu, A. Ron, K.-H. Tran-Ba, R.C. Calizo, S. Bhattacharya, G. Jayaraman, Y. Chen, I. Tavassoly, R. Iyengar, J.C. He, J.C. Hone, and L.J. Kaufman. “A crosslinked gelatin platform induces a differentiated podocyte phenotype through stiffness sensing,” Sci. Reports. 7, 43934 (2017).
Yang, H. Park, and L.J. Kaufman. “Highly anisotropic conjugated polymer aggregates: preparation and quantification of physical and optical anisotropy,” J. Phys. Chem. C. 121, 13854–13862 (2017).
K.-H. Tran-Ba, D.J. Lee, J. Zhu, K. Paeng, and L.J. Kaufman. “Confocal Rheology Probes Structure and Mechanics of Collagen through the Sol-Gel Transition,” Biophys. J. 113, 1882-1892 (2017).
J. Yang, H. Park, and L.J. Kaufman. “In-situ optical imaging of the growth of conjugated polymer aggregates,” Angew. Chem. Int. Ed. 57, 1826–1830 (2018).
A.S. Manz, K. Paeng, and L.J. Kaufman. “Single molecule studies reveal temperature independence of lifetime of dynamic heterogeneity in polystyrene,” J. Chem. Phys. 148, 204508 (2018).
K. Paeng and L.J. Kaufman. “Which probes can report intrinsic dynamic heterogeneity of a glass forming liquid?” J. Chem. Phys. 149, 164501 (2018).
H. Kaur, S.D. Verma, K. Paeng, L.J. Kaufman, and M.A. Berg, “Biphasic rate exchange in supercooled o-terphenyl from an ensemble analysis of single-molecule data,” Phys. Rev. E. 98, 040603 (2018).