Precursor and PGG Concentration Affects the Tropoelastin Coacervation Peak Absorbance

This project investigates the effects of the precursor and PGG concentration on the coacervation kinetics for three different types of polypeptides: Elastin ES12, Alpha-Elastin AE17, and Elastin-Opcein E154. The objects of this set of experiments are 1) to compare the coacervation kinetics for different concentrations of tropoelastin proteins; 2) to compare the coacervation kinetics with the PGG addition in different concentrations

Advancements in Panoramic-DIC System for Vascular Imaging

Digital Image Correlation (DIC) has become an important imaging technique in biomechanics, known for its non-invasive, optical assessment capabilities. However, traditional DIC systems have several limitations in biomechanical applications such as restricted observational fields and challenges to maintain the sample integrity. Advancements in the DIC technique have led to the development of panoramic-DIC (pDIC) systems. The pDIC system addresses the need for more comprehensive imaging of quasi-cylindrical samples by utilizing a sophisticated array of cameras and mirrors. It employs a concave conical mirror, transforming a conventional binocular stereo-DIC setup into an almost infinite-view system, through the use of multiple cameras that cover the full 360-degree surface of cylindrical samples. The objective of this research project is to further develop the hardware of the pDIC system for vascular imaging, arrange the software for image processing, and formulate the accessible steps to use this system. The ultimate goal is to enhance the utility of pDIC in vascular biomechanics, contributing to a better understanding of vascular diseases and their treatments

Micro-Tug Device Fabrication as Platform for 3D Tissue Dynamical Construction and Magnetic Actuation

This study presents the development of a micro-tug tissue platform aimed at improving the study of tissue morphogenesis. The research focused on fabricating high-throughput devices for tissue construction and integrating magnetically responsive particles to control stress and manipulate tissue morphogenesis. The devices enable the simulation of various mechanical environments, such as hypertension in cardiomyocytes. We successfully fabricated Polydimethylsiloxane (PDMS) micro-tug devices and their iron-containing variants, along with a magnetic field-generating device to apply variable mechanical stresses. The fabrication process transitioned from a time-consuming hydrogel casting method to a more efficient system using 3D print models and surface chemistry on PDMS replicas. Through imaging and analysis, we quantified tissue parameters, gaining insights into tissue compaction, growth factor effects, and micro-pillar deflection. We also studied the role of transforming growth factor-beta (TGF-β) in enhancing tissue contractility and focal adhesion. The study underscores the potential of this platform in advancing our understanding of tissue morphogenesis and the mechanical forces that modulate it, opening avenues for future engineering improvements and more comprehensive research

Non-invasive imaging of atherosclerotic plaque macrophage in a rabbit model with F-18 FDG PET: a histopathological correlation

BACKGROUND: Coronary atherosclerosis and its thrombotic complications are the major cause of mortality and morbidity throughout the industrialized world. Thrombosis on disrupted atherosclerotic plaques plays a key role in the onset of acute coronary syndromes. Macrophages density is one of the most critical compositions of plaque in both plaque vulnerability and thrombogenicity upon rupture. It has been shown that macrophages have a high uptake of (18)F-FDG (FDG). We studied the correlation of FDG uptake with histopathological macrophage accumulation in atherosclerotic plaques in a rabbit model. METHODS: Atherosclerosis was induced in rabbits (n = 6) by a combination of atherogenic diet and balloon denudation of the aorta. PET imaging was performed at baseline and 2 months after atherogenic diet and coregistered with magnetic resonance (MR) imaging. Normal (n = 3) rabbits served as controls. FDG uptake by the thoracic aorta was expressed as concentration (μCi/ml) and the ratio of aortic uptake-to-blood radioactivity. FDG uptake and RAM-11 antibody positive areas were analyzed in descending aorta. RESULTS: Atherosclerotic aortas showed significantly higher uptake of FDG than normal aortas. The correlation of aortic FDG uptake with macrophage areas assessed by histopathology was statistically significant although it was not high (r = 0.48, p < 0.0001). When uptake was expressed as the ratio of aortic uptake-to-blood activity, it correlated better (r = 0.80, p < 0.0001) with the macrophage areas, due to the correction for residual blood FDG activity. CONCLUSION: PET FDG activity correlated with macrophage content within aortic atherosclerosis. This imaging approach might serve as a useful non-invasive imaging technique and potentially permit monitoring of relative changes in inflammation within the atherosclerotic lesion