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1. Perfusion–mechanics coupling of the hippocampus

   https://doi.org/10.1098/rsfs.2024.0051  

   Neher, Caitlin Maria; Triolo, Em; RezayAraghi, Fargol; Khegai, Oleksandr; Balchandani, Priti; McGarry, Matthew; Kurt, Mehmet (April 2025, Interface Focus)

   The hippocampus is a highly scrutinized brain structure due to its entanglement in multiple neuropathologies and vulnerability to metabolic insults. This study aims to non-invasively assess the perfusion–mechanics relationship of the hippocampus in the healthy brain across magnetic resonance imaging sequences and magnetic field strengths. In total, 17 subjects (aged 22–35, 7 males/10 females) were scanned with magnetic resonance elastography and arterial spin labelling acquisitions at 3T and 7T in a baseline physiological state. No significant differences in perfusion or stiffness were observed across magnetic field strengths or acquisitions. The hippocampus had the highest vascularity within the deep grey matter, followed closely by the caudate nucleus and putamen. We discovered a positive perfusion–mechanics correlation in the hippocampus across both 3T and 7T groups, with a highly significant correlation overall (R= 0.71,p= 0.0019), which was not observed in the caudate nucleus, a similarly vascular region. Furthermore, we supported our hypothesis that increased perfusion in the hippocampus would lead to greater pulsatile displacement in a small cohort (n= 10). Given that the hippocampus is an exceptionally vulnerable structure, with perfusion deficits often seen in diseases related to learning and memory, our results suggest a unique mechanistic link between metabolic health and stiffness biomarkers in this key region for the first time. 

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2. Role of Machine Perfusion in Liver Transplantation

   https://doi.org/10.1016/j.suc.2023.07.001  

   Longchamp, Alban; Nakamura, Tsukasa; Uygun, Korkut; Markmann, James F (February 2024, Surgical Clinics of North America)
3. Safe Model-Based Multivariable Control of Peritoneal Perfusion

   https://doi.org/10.1016/j.ifacol.2023.12.041  

   Moon, Yejin; KadkhodaeiElyaderani, Behzad; Leibowitz, Joshua; Rezaei, Parham; Abdelazim, Eman M.; Awad, Morcos; Stachnik, Stephen; Stewart, Shelby; Friedberg, Joseph S.; Hahn, Jin-Oh; et al (January 2023, IFAC-PapersOnLine)
4. Anionic polymers amplify electrokinetic perfusion through extracellular matrices

   https://doi.org/10.3389/fbioe.2022.983317  

   Walker, Joseph C.; Jorgensen, Ashley M.; Sarkar, Anyesha; Gent, Stephen P.; Messerli, Mark A. (September 2022, Frontiers in Bioengineering and Biotechnology)

   Electrical stimulation (ES) promotes healing of chronic epidermal wounds and delays degeneration of articular cartilage. Despite electrotherapeutic treatment of these non-excitable tissues, the mechanisms by which ES promotes repair are unknown. We hypothesize that a beneficial role of ES is dependent on electrokinetic perfusion in the extracellular space and that it mimics the effects of interstitial flow. In vivo , the extracellular space contains mixtures of extracellular proteins and negatively charged glycosaminoglycans and proteoglycans surrounding cells. While these anionic macromolecules promote water retention and increase mechanical support under compression, in the presence of ES they should also enhance electro-osmotic flow (EOF) to a greater extent than proteins alone. To test this hypothesis, we compare EOF rates between artificial matrices of gelatin (denatured collagen) with matrices of gelatin mixed with anionic polymers to mimic endogenous charged macromolecules. We report that addition of anionic polymers amplifies EOF and that a matrix comprised of 0.5% polyacrylate and 1.5% gelatin generates EOF with similar rates to those reported in cartilage. The enhanced EOF reduces mortality of cells at lower applied voltage compared to gelatin matrices alone. We also use modeling to describe the range of thermal changes that occur during these electrokinetic experiments and during electrokinetic perfusion of soft tissues. We conclude that the negative charge density of native extracellular matrices promotes electrokinetic perfusion during electrical therapies in soft tissues and may promote survival of artificial tissues and organs prior to vascularization and during transplantation. 

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5. DETECTING PULMONARY EDEMA THROUGHOUT EX VIVO LUNG PERFUSION

   https://doi.org/10.1115/dmd2023-4133  

   Nadybal, Ryan; Wang, Andrew; Iaizzo, Paul A. (April 2023, American Society of Mechanical Engineers)

   Abstract Ex Vivo Lung Perfusion (EVLP) is now a powerful clinical technique that has facilitated the increase in successful human lung transplantation procedures. By having the abilities to assess marginal lungs, extend preservation times, and expand geographical distances for donations, EVLP has effectively both expanded the human lung transplantation donor pool and shortened times on the transplant waitlist. While clinical usage has expanded, preclinical research on EVLP has not. EVLP can be utilized as a preclinical research model, i.e., to investigate pharmacological responses (e.g., post-conditioning agents), organ preservation, device testing and/or methodology development. To facilitate the use of EVLP as a research tool, we have developed a low-cost testing system with ever increasing capabilities e.g., the use of a novel continuous weight sensor to evaluate lung edema. Real time tracking of edema allows us to hone in on potential causes of lung damage, and investigate techniques to rehabilitate and mitigate damage on a short time scale (<8 hours). This system enhances our abilities to accurately test medical devices, lung physiology, and potential treatment impacts on lungs. 

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