From Molecular to Micro: Engineering the Biomaterials Interface for Guiding Cell Fate Decisions

Friday, May 24, 2013 - 2:00pm
Fung Auditorium | Powell-Focht Bioengineering Hall
Kristopher A. Kilian, Ph.D.

Assistant Professor of Materials Science and Engineering

University of Illinois at Urbana-Champaign

From Molecular to Micro: Engineering the Biomaterials Interface for Guiding Cell Fate Decisions

The architecture of the stem cell microenvironment provides various physical and biochemical cues to guide cell fate and orchestrate tissue form and function. Cell culture materials that are engineered at the molecular, nano and micro scale can be designed to more closely recapitulate the cellular microenvironment for studying cell fate determination. In this seminar I will present our efforts in modifying both “hard” and “soft” biomaterials with patterned biomolecules to study stem cell fate decisions. First I will demonstrate how soft lithography can be used to pattern single stem cells on self-assembled monolayers for exploring the influence of shape on signaling in adherent mesenchymal stem cells. MSCs cultured in small islands become quiescent and express elevated levels of multipotency markers. In contrast, MSCs that are allowed to spread express higher levels of myogenesis and osteogenesis markers. Next I will show how the degree of cell spreading—and associated lineage specification—can be modulated by changing the affinity of the adhesive microenvironment through the use of short peptide ligands that are presented at different densities. Using a microarraying approach, we have identified unique combinations of adhesion and signaling peptides that influence MSC signaling. Micropatterning these different peptide ligands in defined geometries enables the exploration of how geometric and biochemical cues operate independently and together to regulate cell fate. Finally, I will discuss how this model system can serve to identify optimal cell shapes and ligand presentations for translation to hydrogel substrates that more closely emulate the mechanics of tissue. These studies reveal how a well-defined presentation of signaling ligands at the cell-biomaterial interface is critical for studying and ultimately controlling cell fate decisions.

Professor Kristopher Kilian received B.S. and M.S. degrees in Chemistry from the University of Washington in 1999 and 2003 respectively. He worked at Rosetta Inpharmatics/Merck & Co. in the Methods Development group from 2000-2004 before travelling to Sydney, Australia to do his PhD at the University of New South Wales. In 2007, he joined the laboratory of Milan Mrksich at the University of Chicago as a NIH postdoctoral fellow to investigate materials based approaches for directing the differentiation of stem cells. Kris joined the faculty of the University of Illinois at Urbana-Champaign as Assistant Professor of Materials Science and Engineering in 2011. He is an allied faculty member in the Department of Chemistry, and affiliate faculty in the Micro and Nanotechnology Laboratory, the Institute for Genomic Biology and the Department of Bioengineering.