Senior Research Fellow, MBI
“Truth in science can be defined as the working hypothesis best suited to open the way to the next better one.” —Konrad Lorentz
Cell migration, tissue dynamics, cell biophysics and biomechanics, bioengineering
My research is focused on the mechanical properties of migratory cells, and the role of physical forces in the regulation of biological systems; especially in physiological, and disease states. To approach these topics from novel perspectives, I enjoy devoting much time and effort to the development of new methods.
Cell migration and biomechanics of cancer cells
Cell migration is a vital process during morphogenesis, tissue repair and wound healing. It is also fundamental to cancer progression, with the activation of cell motility in transformed cells leading to the establishment of population heterogeneity, and drug resistance. In collaboration with the Genome Institute of Singapore (A-Star), and the Cancer Science Institute of Singapore (NUS/NUH), we are characterizing the migration properties of cancer cells with different metastatic potential. Furthermore, we are analysing the dynamics of receptor kinases at the cell cortex in response to ligand binding. Combinatorial analysis of these parameters allows us to determine the invasion potential of cancer cells at a single cell level and to select potentially invasive cells from heterogeneous populations.
Collaborators: Virgile Viasnoff (MBI/CNRS), Jay Goves (MBI/Berkley), Ramanuj DasGupta (GIS, A-Star), Huang Yun Ju Ruby (CSI, NUS/NUH).
Read more: Publication in preparation
During morphogenesis and tissue repair, epithelial cells interact with neighbouring cells, and with the substrate, in order to maintain or restore proper tissue function. In this project, we investigate the effect of tissue geometry, cell-cell interactions, and cell-substrate interactions, on the migration properties of epithelial cells. In collaboration with physicists and mathematicians, we have developed computational models that describe experimental observations in quantitative terms. Using this framework, we are currently studying the molecular organization of cell-cell adhesions by super resolution and FRET microscopy.
Collaborators: Benoit Ladoux (MBI/Institut Jacques Monod), Luis Almeida (Sorbonne Universites), Nir Gov (Weizmann Institute), Cristina Bertocchi (MBI), Pakorn Yony Kanchanawong (MBI), Chwee Teck Lim (MBI).
Read more: Ravasio et al., Nature Communications, 2015; Ravasio et al., Integrative Biology, 2015; Tarle et al., Integrative Biology, 2015; Vedula et al., Physiology, 2013.
Understanding biophysical phenomena often requires approaching our research from novel perspectives. To this end, we continue to design and implement new methodologies, devices and approaches. In recent years, we have introduced micro-pillars made of an index match polymer (MyPoly 134) to measure traction forces, and simultaneously visualize cellular structures at high resolution. We have also introduced a new device (IR-Live) that can obtain chemical maps of living cells by FTIR, at high spatial resolution. Currently, we are using microfabrication techniques to test the effect of substrate geometry, rheology and texture on tissue organization. Finally, we are developing a new device that allows us to measure traction force whilst simultaneously super-resolving cellular structures.
Collaborators: Gianluca Grenci (MBI), Virgile Viasnoff (MBI/CNRS), Benoit Ladoux (MBI/Institut Jacques Monod), Cristina Bertocchi (MBI).
Read more: Ravasio et al., Acta Biomaterialia, 2015; Vedula et al., Methods in Cell Biology, 2014; Braida et al., Lab on a chip, 2016.
Throughout my research career, I have applied highly interdisciplinary approaches aimed at elucidating the interplay between forces and living matter. After my undergraduate studies in biology and physiology at the University of Milan (Italy), I conducted an experiment-based master thesis in Membrane Molecular Physiology (Medical University of Innsbruck, Austria), where I investigated protein-protein and protein-membrane interactions in the context of cell volume regulation using the FRET technique. Thereafter, I pursued a PhD at the Department of Physiology and Biomedical Physics (Medical University of Innsbruck, Austria). During my PhD, I developed and employed a number of pioneering methods to study the physiology of the lung. With my colleagues, we demonstrated for the first time the physiologically important interplay between epithelial cells and the mechanical forces at the alveolar air-liquid interface.
Additionally, I have studied the biophysical properties of lung surfactant during adsorption and interfacial reorganization. Afterwards, I moved to the School of Biological Science at the Nanyang Technological University (NTU, Singapore). During this time at NTU, I studied the molecular events leading up to red blood cell invasion by malaria parasites. Currently, I’m enjoying the stimulating environment of the Mechanobiology Institute (Singapore) where I’m working as senior research fellow in the lab of Virgile Viasnoff, and I closely collaborate with Benoit Ladoux, Jay Groves, Cristina Bertocchi and Gianluca Grenci.
Birarda G, Ravasio A, Suryana M, Maniam S, Holman HN, and Grenci G. IR-Live: fabrication of a low-cost plastic microfluidic device for infrared spectromicroscopy of living cells. Lab Chip 2016; 16(9):1644-51. [PMID: 27040369]
Yu C, Rafiq NBM, Cao F, Zhou Y, Krishnasamy A, Biswas KH, Ravasio A, Chen Z, Wang Y, Kawauchi K, Jones GE, and Sheetz MP. Integrin-beta3 clusters recruit clathrin-mediated endocytic machinery in the absence of traction force. Nat Commun 2015; 6:8672. [PMID: 26507506]
Ravasio A, Le AP, Saw TB, Tarle V, Ong HT, Bertocchi C, Mège R, Lim CT, Gov NS, and Ladoux B. Regulation of epithelial cell organization by tuning cell-substrate adhesion. Integr Biol (Camb) 2015; 7(10):1228-41. [PMID: 26402903]
Ravasio A, Cheddadi I, Chen T, Pereira T, Ong HT, Bertocchi C, Brugues A, Jacinto A, Kabla AJ, Toyama Y, Trepat X, Gov N, Neves de Almeida L, and Ladoux B. Gap geometry dictates epithelial closure efficiency. Nat Commun 2015; 6:7683. [PMID: 26158873]
Ravasio A, Vaishnavi S, Ladoux B, and Viasnoff V. High-resolution imaging of cellular processes across textured surfaces using an indexed-matched elastomer. Acta Biomater 2014; 14:53-60. [PMID: 25462842]
Vedula SRK, Ravasio A, Anon E, Chen T, Peyret G, Ashraf M, and Ladoux B. Microfabricated environments to study collective cell behaviors. Methods Cell Biol. 2014; 120:235-52. [PMID: 24484669]