02/20/2023
By Joanne Gagnon-Ketchen

Physics colloquium, Wednesday, Feb. 22 at 4 p.m. in Olsen 102

Prof. Chiara Ghezzi, Dept. of Biomedical Engineering, UMass Lowell will be giving a talk on "hiPSC cortical tissue model to study the effect of radiation on functional cortical networks."

Abstract:
Exposure to ionizing radiation (IR) causes long-term deleterious health effects. Studies on radiation induced acute radiation syndromes have long been focused on hematopoietic, gastrointestinal, and cardiovascular systems yet little is known about the effects of ionizing radiation on the function of human cerebral cortical tissue. To understand the documented cognitive effects of IR, physiologically relevant models of neuronal tissue are necessary to elucidate IR injury effects at the cellular and tissue levels. In vivo systems have illuminated certain aspects of IR on the brain, but face limitations due to intrinsic differences between human neurons and those of model organisms. Simple in vitro models have been employed, but traditional 2D cultures lack the physiological architecture and connective characteristics exhibited in cortical tissue in vivo. The absence of a reliable 3D human neuronal tissue model leaves a gap in our ability to accurately replicate IR induced injury. We have recently designed and built a 3D neuronal tissue model based on a dense type I collagenous structure populated with human neurons. This platform enables the modulation of physiological properties, including ECM content, scaffold stiffness, cell density, and cell maturity to recapitulate discrete human tissues. Tissue models were treated with ionizing protons and gamma rays at UML Radiation Laboratory facilities to simulate the effects of radiation therapy treatment and mass casualty exposure on healthy tissue. Biological responses to IR injury were assessed via quantitative measurement of cell death, apoptosis, reactive oxygen species content, DNA damage, resulting in significant changes in electrophysiological behavior. Moving forward, this model represents a tool which can be used to understand the cell-level mechanisms by which ionizing radiation affects human cortical tissue and could be used to screen for new radioprotectant compounds and countermeasures.

Bio:
Chiara Ghezzi, Ph.D. is assistant professor and associate chair in the department of biomedical engineering at University of Massachusetts Lowell. She received her undergraduate and master’s degrees in biomedical engineering from Politecnico di Milano, in Italy. During her doctoral studies at McGill University in Materials Science and Engineering, she developed several fabrication strategies based on natural polymers, such as collagen and silk, to design biomimetic airways tissue models and study cell-material interaction in three-dimensional soft materials. Her research interests have been centered in developing biopolymer substrates to mimic physiological native environments towards medical devices and functional tissue models, with particular emphasis on cornea, gingival and cortical tissues.