Research Assistant Professor
Ph.D., Physics, University of Colorado at Boulder (2009)
Diplom Physics, University of Stuttgart, Germany (2001)
Volker Schweikhard probes how biological cells communicate to organize and maintain functional tissues and organs, and how these mechanisms fail in disease. Through this basic and applied research, he plans to establish a suite of sensitive biophysical techniques that will increase the amount of molecular and biochemical information that can be gleaned from a single biological sample. His experimental approaches are rooted in a life-long passion to develop cutting-edge instrumentation that addresses challenging problems in science and human health. Examples range from multiplexed super-resolution microscopy of cancer cells undergoing metastatic processes, to real-time recordings of gene transcription by single molecules of RNA polymerase II, to the development of nonlinear optical spectroscopy techniques to study the optical properties of plasmonic metal nanoparticles.
Working in affiliation with Associate Professor Michael Diehl’s Synthetic Biology and Macromolecular Systems Bioengineering Group, Schweikhard is involved in the development and application of a new molecular imaging technique aimed at visualizing the expression levels and sub-cellular localization patterns of dozens of proteins within individual human cells. He also works towards extending such multiplexed imaging techniques to multi-protein complexes . In a collaborative effort with Assistant Professor Amina Qutub’s Systems Biology Laboratory, Schweikhard contributes to the development of quantitative computational analyses for the resulting high-dimensional image data. This combined experimental and computational approach will enable increasingly comprehensive studies of complex biochemical pathways in a spatially defined manner, and allow for improved characterizations of cellular phenotypes and functions. Schweikhard applies these tools to study disease processes such as epithelial-to-mesenchymal transitions, in which cells lose nearest-neighbor contacts and gain migratory and invasive properties that are thought to drive cancer metastasis.
Complementing these molecular imaging techniques, Schweikhard is working towards establishing alternative, label-free platforms to probe cells and tissues with high spatiotemporal resolution and biochemical specificity. Examples include the development of label-free biochemical microscopy approaches (based on coherent Raman microscopy) with applications ranging from probing the influence of deregulated lipid metabolism on cancer invasiveness and radio-sensitivity, to identifying predictive signatures for the progression of premalignant breast lesions to invasive cancer [2, 3]. In addition, he works with materials scientists and neuroscientists to explore the potential of two-dimensional materials (such as graphene) as interfaces for non-invasive electrophysiological studies of large neuronal networks .
Prior to joining Rice University, Schweikhard was awarded a Damon Runyon Postdoctoral Fellowship to develop single-molecule optical trapping assays to study the process of gene transcription by the enzyme RNA polymerase II. This work, in the laboratory of Professor Steven M. Block at Stanford University, resulted in the first direct visualization of the synergistic effects of two important regulatory proteins – the transcription factors TFIIF and TFIIS – on the mechanical robustness and fidelity of gene transcription [5, 6]. In parallel, he developed single-molecule assays to monitor the folding of gene regulatory RNA structures (riboswitches) in real time. This work uncovered a novel mode of post-transcriptional gene regulation, in which cotranscriptionally folded RNA persists in out of equilibrium structures for long enough times to influence gene expression at the translational level .
While earning his doctorate in physics from JILA / University of Colorado at Boulder, Schweikhard worked with physics Nobel laureate Eric A. Cornell in the development of sophisticated optical microscopy and manipulation techniques for ultra-cold quantum gases (see e.g. [8-12]). In working with Professor David Nesbitt, he constructed a femtosecond multi-photon photoemission microscope to investigate the unique optical and electronic properties of individual plasmon-resonant metalnanoparticles with single-electron sensitivity [13-16]. This work established multi-photon photoemission as a sensitive probe of the nanoparticles’ local environment, and demonstrated their potential for novel nanoscale sensing applications.
Research grants and publications
Schweikhard V, Diehl MR. Programmable high-content in situ analyses of multi-protein complexes. NIH Grant Application.
Woodward W, Hittelman WN, Diehl MR, Schweikhard V. Dyslipidemia and Radiation Sensitivity in Breast Cancer. NIH R35 Grant Application, Pending. 2014.
Schweikhard V, Thomann I, Hittelman WN. Label-free, multiplexed molecular analyses of cancer cells by stimulated Raman microscopy. NIH R21 Grant Application. 2014.
Schweikhard V, Arenkiel B, Ajayan P. Unpublished Grant Application. 2014.
Zhou J, Schweikhard V, Block S. Single-molecule studies of RNAPII elongation. Biochimica et Biophysica Acta. 2013;1829:29–38.
Schweikhard V, Meng C, Murakami K, Kaplan CD, Kornberg RD, Block SM. Transcription factors TFIIF and TFIIS promote transcript elongation by RNA polymerase II by synergistic and independent mechanisms. Proceedings of the National Academy of Sciences of the United States of America. 2014;111(18):6642-7. PMCID: 4020062.
Schweikhard V, Frieda K, Garcia-Garcia C, Block SM. to be published. 2015.
Schweikhard V, Coddington I, Engels P, Mogendorff VP, Cornell EA. Rapidly rotating Bose-Einstein condensates in and near the lowest Landau level. Phys Rev Lett. 2004;92(4).
Coddington I, Engels P, Schweikhard V, Cornell EA. Observation of Tkachenko oscillations in rapidly rotating Bose-Einstein condensates. Phys Rev Lett. 2003;91(10).
Schweikhard V, Coddington I, Engels P, Tung S, Cornell EA. Vortex-lattice dynamics in rotating spinor Bose-Einstein condensates. Phys Rev Lett. 2004;93(21).
Schweikhard V, Tung S, Cornell EA. Vortex proliferation in the Berezinskii-Kosterlitz-Thouless regime on a two-dimensional lattice of bose-einstein condensates. Phys Rev Lett. 2007;99(3).
Tung S, Schweikhard V, Cornell EA. Observation of vortex pinning in Bose-Einstein condensates. Phys Rev Lett. 2006;97(24).
Schweikhard V, Grubisic A, Baker TA, Thomann I, Nesbitt DJ. Polarization-Dependent Scanning Photoionization Microscopy: Ultrafast Plasmon-Mediated Electron Ejection Dynamics in Single Au Nanorods. ACS Nano. 2011;5(5):3724-35.
Schweikhard V, Grubisic A, Baker TA, Nesbitt DJ. Multiphoton Scanning Photoionization Imaging Microscopy for Single-Particle Studies of Plasmonic Metal Nanostructures. J Phys Chem C. 2011;115(1):83-91.
Grubisic A, Schweikhard V, Baker TA, Nesbitt DJ. Coherent Multiphoton Photoelectron Emission from Single Au Nanorods: The Critical Role of Plasmonic Electric Near-Field Enhancement. ACS Nano. 2013;7(1):87-99.
Grubisic A, Schweikhard V, Baker TA, Nesbitt DJ. Multiphoton photoelectron emission microscopy of single Au nanorods: combined experimental and theoretical study of rod morphology and dielectric environment on localized surface plasmon resonances. Physical Chemistry Chemical Physics. 2013;15(26):10616-27.