Biomechanics Core Facility

The Biomechanics Core works with ITMAT faculty from Penn, ITMAT partner institutions, and members of the ITMAT Program in Translational Biomechanics. Our goal is to lower the experimental barriers to PIs interested in exploring the role of cell and tissue mechanics/stiffness in their research. We currently offer the following services.

  1. Customized ECM-coated polyacrylamide hydrogels
  2. Atomic force microscopy of cells
  3. Pressure myography (NEW service)
  4. Traction force microscopy (NEW service; anticipated start of Jan 1, 2018)

ECM-coated hydrogels represent an advance in cell culture that allows investigators to model the elastic microenvironments that most cell types inhabit in vivo. By culturing cells on ECM-coated hydrogels, investigators can minimize the chance of obtaining the false-negative and false-positive results that may occur when cells are cultured on biologically irrelevant plastic or glass surfaces. Cells cultured on hydrogel substrata are amenable to almost all modern cell and molecular analyses. Continuous cell lines and primary cells are readily accommodated. The elasticity of these substrata can be varied to model changes in microenvironment stiffness that might occur with development, differentiation, or disease.

Atomic Force Microscopy (AFM) is a technique the Core offers to measure cell stiffness. Increased tissue stiffness is a hallmark of fibrosis-associated diseases, and cells tune their intracellular stiffness to match that of their local microenvironment. AFM performed on live cells can be used to monitor changes in intracellular stiffness, most commonly associated with regulators of Rho GTPases.

Pressure myography is most commonly used to model how arteries stiffen in response to changes in luminal pressure. Additionally, the data captured by pressure myography can be used to determine stress-strain relationships in response to ECM remodeling or changes in cell contractility upon exposure to vasodilators/vasoconstrictors. The Core offers pressure myography of fresh or frozen carotid arteries isolated from WT and/or genetically modified mice.  We can also work with PIs to test other biological tubes and species.

Traction force microscopy (TFM) is a method to visualize and measure the spatial distribution of forces within cells, for example in response to a vasodilator/constrictor, changes in ECM stiffness, changes in Rho GTPases or actin organization. TFM is commonly performed will cells cultured on elastomeric microposts or hydrogels:  the Core offers TFM on hydrogels. We will work with PIs so that experiments with hydrogels (e.g. showing how cells respond to changes in ECM stiffness as outlined above) can also provide information on how cells sense that external stiffness and transduce it into intracellular force.

Consultation and initial pilot experiments are free-of-charge to ITMAT faculty from Penn, ITMAT partner institutions, and members of the ITMAT Program in Translational Biomechanics.

Contact Information

Richard K. Assoian, PhD, Director
assoian@upenn.edu

Paola Castagnino, PhD, Technical Director
pcastagn@mail.med.upenn.edu

Ian Roberts, MSE, Core Research Specialist
iroberts@mail.med.upenn.edu