Welcome to the Hammer Laboratory.

The two main research areas of the Hammer lab are: Cell Adhesion and Motility & Protocell Engineering.

Cell adhesion and motility are critical to many processes in the body including the proper functioning of the immune response. We recreate the homing of T-cells using Adhesive Dynamics, in which we can simulate the rolling, tethering, and firm adhesion of cells in the vasculature. The methods involve integrating signaling cascades into Adhesive Dynamics (so-called Integrated Signaling Adhesive Dynamics) to understand how adhesion is controlled during cell decision making. Our ultimate goal is to reengineer cell signaling to modulate adhesion and homing, using both knockdowns and gene editing.

In motility, we use compliant surfaces to measure the forces exerted during motility for neutrophils, T- lymphocytes, macrophages and dendritic cells. Recently, we have been studying the curious phenomenon where cells can crawl upstream against the direction of flow on surfaces with specific adhesion molecules. Although this was first seen in T-cells, we have now shown that upstream migration can be seen in stem cells and neutrophils. We are interested both in the mechanisms and physiological implications of upstream migration.

In protocell engineering, we have developed biomimetic vesicles into which molecules, enzymes, or organelles can be embedded. These protocells have the potential to serve as drug-delivery vehicles or imagers. For example, by embedding specific molecules within the membrane of a polymersome, we can engineer them to self-destruct. We have recently shown that by harvesting the activity of encapsulated enzymes, we can drive the motility of adhesive protocells on surfaces. Also, using recombinant protein engineering, we have developed a means of making membraneless organelles from coacervating proteins that contain control elements such as protease cleavable or light cleavable domains. We seek to add advanced functionality to our protocells by incorporating enzymatic cascades within their membraneless organelles.