Jad Hamze

While traditional 2D in vitro models have been widely used for drug screening, 3D tissue culture systems are gaining traction due to their superior ability to replicate in vivo tumor microenvironments. In this study, we utilize Microtissues™, a validated, scaffold-free, high-throughput 3D tissue culture platform, as the basis for a microscale tissue-engineered model to study drug absorption and transport dynamics. Despite their physiological relevance, such 3D constructs pose analytical challenges, particularly in quantifying trace drug levels within the microenvironment. We developed and validated an integrated experimental workflow combining optimized liquid–liquid extraction and protein precipitation with LC-MS/MS analysis to accurately quantify paclitaxel absorption in Microtissues™ molds using small sample volumes. The assay achieved a validated lower limit of quantification of 0.03 μM, with robust linearity across analytical runs (R² ≥ 0.90; best-run performance > 0.99) and precision (CV ≤ 10%) across both MRMs. This microengineered in vitro system allows for precise characterization of drug–tissue interactions in MCF7 breast cancer Microtissues™, enabling in vitro-to-in vivo extrapolation (IVIVE) relevant to therapeutic optimization. The platform’s scalability and modularity support its application in precision medicine, where patient-derived microtissues can guide individualized treatment decisions.

Despite significant improvements in revascularization strategies and medical management, ischemic heart disease (IHD) remains the top cause of mortality and disability worldwide. The myocardium lacks regenerative capacity and consequently, recovery depends on re-establishing microvascular integrity and sustaining angiogenesis to preserve viable myocardium. Emerging and novel bioengineering approaches, such as stem cells, extracellular vesicles (EVs), and matrix-based strategies, seek to address this unmet need by promoting neovascularization and structural restoration. However, clinical translation remains limited by poor engraftment, product variability, and arrhythmogenic risk. Large animal models provide a clinically relevant platform to thoroughly investigate these interventions and ideally enhance their translational potential. This review discusses cellular approaches leveraging stem and progenitor cells and acellular modalities using extracellular vesicles, growth factors, or extracellular matrix-based scaffolds with an emphasis on large animal translational models and clinical trials.

Ischemic heart disease (IHD) is the leading cause of mortality worldwide, underscoring the urgent need for innovative therapeutic strategies. The cardiac extracellular matrix (ECM) undergoes extreme transformations during IHD, adversely influencing the heart’s structure, mechanics, and cellular signaling. Researchers investigating the regenerative capacity of the diseased heart have turned their attention to exploring the modulation of ECM to improve therapeutic outcomes. In this review, we thoroughly examine the current state of knowledge regarding the cardiac ECM and its therapeutic potential in the ischemic myocardium. We begin by providing an overview of the fundamentals of cardiac ECM, focusing on the structural, functional, and regulatory mechanisms that drive its modulation. Subsequently, we examine the ECM’s interactions within both chronically ischemic and acutely infarcted myocardium, emphasizing key ECM components and their roles in modulating angiogenesis. Finally, we discuss recent ECM-based approaches in biomedical engineering, focusing on different types of scaffolds as delivery tools and their compositions, and conclude with future directions for therapeutic research. By harnessing the potential of these emerging ECM-based therapies, we aim to contribute to the development of novel therapeutic modalities for IHD.

Cardioplegic arrest and cardiopulmonary bypass (CP/CPB) are known to engender microvascular dysfunction in patients undergoing cardiac surgery. These effects are significantly varied by patient comorbidities including diabetes and hypertension. Both diabetes and hypertension are associated with worse outcomes after cardiac surgery, partly related to increased microvascular complications. In this review, we examine several key facets of microvascular dysfunction after CP/CPB: microvascular endothelial and vasomotor dysfunction, altered gene and protein expression, endothelial adherens junction dysfunction, and programmed cell death as they relate to diabetes and hypertension. This review examines both classical techniques, including microvessel reactivity assays, and modern multiomic approaches to characterizing these microvascular changes.