Graduate STEM Fellow Profile

Joseph Califano

Project Title: CLIMB: Cornell's Learning Initiative in Medicine and Bioengineering
Thesis: The Role of Matrix Mechanics and Chemistry in Mediating Endothelial Cell Network Formation
College/University: Cornell University
Research Advisor: Cynthia Reinhart-King
Degree Sought: Ph.D., Biomedical Engineering
Department: Biomedical Engineering
Research Focus: To understand how matrix stiffness and composition contribute to endothelial cell network assembly
Teaching Partner(s): Jacaranda (Jackie) Henkel

Description of Research

Extracellular matrix stiffness mediates a variety of cellular behaviors ranging from migration to differentiation. I am interested in how matrix stiffness mediates the process of angiogenesis—the formation of new blood vessels from existing vessels, in endothelial cells. To study the role of matrix stiffness in mediating network formation, I culture cells on polymeric substrates of tunable stiffness. We have shown that compliant, but not stiff, substrates promote the spontaneous self-assembly of endothelial cell networks. Furthermore, these networks require the polymerization of fibronectin, a matrix protein, to stabilize cell-to-cell interactions. Our data suggest that network formation results from a balance between cell-cell and cell-substrate interactions. Understanding the mechanisms governing network formation will allow for better control of angiogenesis. This has applicability for tissue engineering (to promote construct vascularization) and disease states (e.g. tumorigenesis).

Example of how my research is integrated into my GK-12 experience

To learn about the role of chemistry in mediating material stiffness, students will fabricate polymeric gels of variable stiffness and characterize their mechanical properties. We hope students will gain an understanding of how materials can be designed with specific mechanical properties. This concept will be extended to physiology, where the organization of cells and matrix contributes to the mechanical properties of tissues—an important consideration for developing tissue engineering constructs.