Sharon Gerecht, PhD - Johns Hopkins University

Regulating the Formation of Vascular Networks

The generation of functional vascular networks has the potential to improve treatment for vascular diseases and to facilitate successful wound healing and transplantation of tissue-engineered organs. Progenitor cells are recruited from a bone marrow niche to the site of vascularization, where low oxygen concentration (hypoxia) and cues from the extracellular matrix (ECM) instigate vascular morphogenesis.We demonstrate how dissolved oxygen levels during 2D and 3D culture of endothelial progenitors and cells vary and affect cellular responses including tube formation. We thus develop microbioreactor for long-term cell culture studies with the capability to accurately control and continuously monitor the dissolved oxygen level in the cell microenvironment.

Polymeric hydrogels are similar to the native ECM of many tissues due to their three- dimensional structural and mechanical properties. We show how synthetic, tunable polysaccharide hydrogels can be utilized to determine physical and biological parameters that enable efficient formation of functional vascular networks. One type of hydrogel enables vascular network formation from human progenitor cells in vitro, and further supportes the integration of the human vascular networks with the host’s circulation and blood flow into the hydrogel following transplantation. Another type of customized hydrogel, applied alone onto deep burn wounds in the absence of growth factors, cytokines, or cells, promotes remarkable neovascularization and complete skin regeneration.

Sharon Gerecht, PhD, is an Assistant Professor, Department of Chemical and Biomolecular Engineering, Whiting School of Engineering. Gerecht is a bioengineer whose research focuses on employing engineering fundamentals to study basic questions in stem cell biology and how to apply them for blood vessel regeneration and repair and the limitation of cancer progression. She joined the Johns Hopkins faculty in the summer of 2007, and is also a lead investigator at the NCI funded Johns Hopkins Engineering in Oncology Center and a member of the Institute for NanoBioTechnology at Johns Hopkins. Gerecht is the recipient of the 2008 Allan C. Davis Medal from the Maryland Academy of Sciences, the North America Vascular Biology Organization Junior Investigator Award (2009), the Basil O’Connor Starter Scholar Research Award from the March of Dimes Foundation (2009-2011), the National Scientist Development Award from American Heart Association (2008-2012), and recently the NSF CAREER award (2011-2016). She is the author of more than 55 papers and 14 book chapters in her field, and edited the recent book, Biophysical Regulation of Vascular Differentiation and Assembly. She also serves as an Editorial Board member in PLoS ONE, and as a member in the Unified Peer Review Steering Committee of American Heart Association.

Every semester, the SCEC welcomes a keynote speaker to the Georgia Tech stem cell research community to speak on behalf of their university, institution, industry, or research lab in regards to stem cell engineering. This experience is meant to broaden the stem cell research alliance between local researchers and worldwide experts for the purposes of communicating stem cell advancements across the globe while developing future collaborative opportunities.