Please join us for our next Micro-physiological Systems (uPS) seminar in collaboration with the cross-institutional Multi-Cellular Engineered Living Systems (M-CELS) team on the theme of "Student/Postdoc Seminar". This seminar is in collaboration with MIT and UIUC and will feature one speaker from each of the universities.

 

The seminar will be held virtually on February 27th at 1:00 – 2:00 PM Eastern Time

 

Title: Coupled Cardiac and Vascular Responses to Nanoplastic Exposure in a Human Heart-on-a-Chip

Abstract: Engineered in vitro cardiovascular systems offer powerful new ways to study human cardiac physiology and development, model disease, and screen drugs. To realize this promise, however, these models must recapitulate key features of the heart, including its heterocellular composition and dense, functional microvasculature. I will present our work on vascularizing cardiac spheroids within microfluidic devices to create a fully perfusable heart-on-a-chip platform. This integrated system enables measurement of both cardiac contraction and vascular barrier function, while allowing drugs to be delivered through the vasculature in a physiologically-relevant manner. Using this platform, we examine the impact of environmental nanoplastics exposure, revealing deleterious effects on cardiovascular function. These studies highlight the heart-on-a-chip system as a versatile tool for interrogating coupled cardiac and vascular function in contexts relevant to human health, including environmental toxicity.

 

Title: Directional interchromatin trafficking through dynamic multiphase speckle networks

Abstract: Nuclear speckles (NSs) are nuclear bodies that reside in the interchromatin space and concentrate more than a hundred components, including transcription and RNA processing factors as well as various RNAs. NSs play a critical role in spatially and temporally regulation of those functional molecules at speckle-proximal active gene loci, thereby enhancing transcription levels and splicing efficiency. While NS dynamics have primarily been studied in terms of molecular exchange between NSs and their surroundings, little is known about the dynamics of connections and trafficking between NSs, which together may form a nuclear speckle network spanning the nucleus. Using live-cell and super-resolution imaging, we identified connections between specific speckles that are composed of multiple speckle proteins. Through photoactivation experiments, we observed directional transfer of speckle proteins from one speckle to another along these connections. Comparison of the dynamics of multiple speckle proteins within these connections revealed that, despite exhibiting distinct behaviors, they collectively formed stable bridges between adjacent speckles. We found that these multiphase structures depend on ongoing transcription and ATP, with the core proteins transferring along the connections. Together, our findings suggest that multiphase speckle connections facilitate component exchange between specific speckles, contributing to the formation and maintenance of the nuclear speckle network within the interchromatin space.

 

Title: Targeting Endothelial Adhesion Molecules with Glycosaminoglycan-Peptide Conjugates to Reduce Leukocyte Aggregation

Abstract: In sickle cell disease (SCD) patients vaso-occlusion contributes to chronic pain, organ damage, and increased infection rates. In these patients, endothelial activation and the upregulation of adhesion molecules such as E-selectin and VCAM-1 mediate leukocyte recruitment and increase tissue damage. Current therapeutic strategies, including monoclonal antibodies, face limitations such as systemic immunosuppression and high cost. Here, we present the design and in vitro evaluation of glycosaminoglycan (GAG)-peptide conjugates engineered to selectively bind endothelial adhesion molecules and attenuate leukocyte adhesion under flow. Using solid-phase peptide synthesis and carbodiimide-mediated conjugation to dermatan sulfate, we generated constructs targeting key adhesion molecules. Biochemical characterization confirmed conjugation efficiency and binding specificity. Static and flow-based assays showed that the conjugates impacted leukocyte–endothelium interactions. This biomimetic approach offers a localized strategy for modulating vascular inflammation and provides a foundation for future translational studies in SCD treatment.