Human Vascular System Research Articles

Transcriptomic profiling with vascular tension analyses reveals molecular targets and phenotypes in preeclamptic placental vasculature

IntroductionThe placental vascular system plays an important role in the development of pregnancy hypertension in preeclampsia. The gene profiles of whole placental tissue (containing blood vessels and many other structural components) and pure vascular tissue should be very different. All previous reports using RNA-seq analysis in the placenta have tested its whole tissue or the villous part, and thus the gene profiles in the pure placental blood vessels are unknown.MethodsThis study was the first to address this point with RNA-seq in human placenta at the transcript level. Isolated placental micro-vessels from normal and preeclamptic pregnancies were used for RNA-seq analysis, real-time quantitative polymerase chain reaction (RT-qPCR) verification, and vascular function tests. Furthermore, a vascular function-centric core network was constructed to show the gene-gene interactions and gene-function associations in the placental vessel system.ResultsDifferential expression analysis identified a total of 486 significantly changed transcripts. Bioinformatics analysis further confirmed that multiple genes were highly related to blood vessel and placental phenotypes. Several hub genes, including ELMO1, YWHAE, and IL6ST, were significantly reduced in the placental vessels in preeclampsia. Vascular tension experiments showed that angiotensin II-mediated vasoconstriction and exogenous NO donor sodium nitroprusside-induced vasodilation were decreased, while phenylephrine-mediated vascular responses were unchanged in placental micro-vessels in preeclampsia.DiscussionThe results provide important insights into the pathological process in the placental vasculature in preeclampsia and offer great potential for further investigation of these molecular targets in the human placental vascular system.

Solute Dispersion in Casson Blood Flow through a Stenosed Artery with the Effect of Temperature and Electric Field

This study develops a mathematical model to address solute dispersion in arterial blood flow, particularly considering the effects of temperature and electric fields using the Casson fluid model. Given the physiological importance of drug delivery within the human vascular system, understanding these dynamics is crucial, especially in the presence of cardiovascular diseases (CVD). The Generalized Dispersion Model (GDM) is employed to simulate the dispersion function. Results demonstrate that elevated temperatures and electric fields enhance drug uptake and distribution by increasing blood flow. The model accurately predicts drug behavior in narrowed arteries, optimizing dosage regimens and improving therapeutic outcomes. Visual representations and detailed discussions of these findings are presented in the subsequent sections. The results are validated against a previous study that did not consider the effects of stenosis height, temperature and electric field. The findings suggest a strong agreement between the two studies. Additionally, an increase in mean absorption leads to an increase in velocity. When mean absorption increases, the functions of steady dispersion and overall dispersion decrease, while the function of unsteady dispersion increases. The reverse behavior is observed for the electric field. The study concludes that integrating temperature and electric field effects into drug delivery systems can significantly enhance treatment efficacy and reduce side effects, providing a valuable tool for advanced targeted therapies in CVD and cancer management.

A single Angiofil-latex injection for both radiological and anatomical assessment of arterial territories in the limbs

IntroductionPostmortem evaluation of the human vascular system has a long history, with advancements ranging from dissections to modern imaging techniques like computed tomography (CT scan). This study designs a novel combination of Angiofil, a liquid radiopaque polymer, and latex, a flexible cast material, for cadaveric vascular analysis. Material & methodsThe aim was to synergize the advantages of both components, providing accurate radiological images and optimal dissection conditions. Three arterial territories (lateral circumflex femoral artery, profunda brachii artery, and radial artery) were injected and assessed through CT scans and dissections. ResultsThe Angiofil-latex mixture allowed successful visualization of the vascular networks, offering a simple, reproducible, and non-toxic approach. Quantitative assessments of the three territories, including diameters and lengths, showed comparable results between CT scan and dissection. DiscussionThe technique precision and versatility make it an accessible and valuable tool for anatomical studies, potentially extending its application to MRI analyses. Overall, the Angiofil-latex combination presents a cost-effective solution for researchers, offering enhanced visibility and detailed anatomical insights for various applications, including anatomical variation studies.

ARCHITECTURE OF A DEVICE FOR MONITORING THE HEALTH OF THE HUMAN BODY BASED ON ULTRASONIC MEASUREMENTS

This article explores the development of a device architecture for non-invasive monitoring of the human body's performance based on ultrasound measurements. The implementation of this architecture is carried out using programmable integrated circuits (FPGAs). Ultrasonic sensors are connected to the FPGA to make measurements. The purpose of the study is a detailed description of the architecture of the device under development. The proposed technical device is capable of detecting pathologies in the human vascular system at a precision stage, which in turn, with surgical treatment, can increase the life expectancy of an individual. Methodology. To ensure the correct functionality of the device with high accuracy, it is necessary to ensure sufficient processing speed of the data coming from each sensor and output of the result. To increase the accuracy of the measured parameters, it is necessary to install ultrasonic sensors in the form of a phased array. Since ultrasonic sensors are analog, it is necessary to use high-frequency digital-to-analog and analog-to-digital converters with high bit depth to obtain high-quality data. These transducers are connected to ultrasonic sensors via signal amplifiers. The proposed architecture provides optimal performance and flexible configuration for measuring ultrasonic signals using sensors. The results of the study. A device demonstrating high data processing speed has been developed and experiments have been conducted on its use. The device has a compact size, which allows you to carry it on yourself without restricting movement. The scope of application. The device is designed to study the work of the heart and human cardiac activity, and is used in the field of healthcare.

IMPROVEMENT OF CAPILLAROSCOPY METHOD FOR STUDYING HUMAN MICROCIRCULATION

The human circulatory system has historically captivated researchers in the field of medicine. Modern medicine, however, has moved beyond identifying a single crucial element, such as the heart or venous system, for maintaining blood flow. Instead, it emphasizes a more analytical approach, focusing on the interconnected functioning of all components within the system. The aim of this work is to analyze the existing methods of studying blood microcirculation and to improve the technology of capillaroscopy, technical means of raster microphotography to determine the physiological state and disorders of capillary circulation. To achieve this objective, we address the following tasks: analyzing existing non-invasive methods for studying the human vascular system; enhancing the optical capillaroscopy method through the utilization of modern high-resolution digital cameras, computer, and multimedia equipment, along with appropriate software for analyzing electronic images; developing a technological scheme and equipment design for digital microphotography of capillaries in the periungual region of the upper extremities; providing software solutions for registering and analyzing digital microphotographic images obtained through capillaroscopy; conducting experimental studies to explore the structure and properties of capillaries utilizing the developed technologies and equipment. Magnetic resonance imaging (MRI) enables the comprehensive evaluation of both anatomical and functional aspects of blood flow. Magnetic resonance angiography (MRA) capitalizes on the distinction between the signal emitted by moving tissue (blood) and that of surrounding stationary tissue, facilitating the acquisition of vascular images without the need for radiopaque contrast agents. Ultrasonography integrates Doppler and conventional ultrasound techniques, providing physicians with insights into blood vessel structure and blood flow dynamics. Traditional ultrasound employs sound waves that are imperceptible to the human ear and bounce off blood vessels, while Doppler ultrasound measures the velocity of sound wave reflection from moving elements. Ophthalmoscopy constitutes a fundamental component of standard ophthalmological examinations, serving as a pivotal tool for diagnosing eye conditions and evaluating the condition of blood vessels. Additionally, ophthalmoscopy aids in diagnosing autoimmune disorders. Capillaroscopy enables comprehensive assessments of both systemic and regional microcirculation disorders, facilitating the characterization of tissue metabolism. Dysfunction in capillary function contributes to circulatory impairments, leading to blood stasis, metabolic irregularities, and compromised immunity, thereby exacerbating existing conditions and predisposing individuals to new diseases. Optical computerized capillaroscopy offers a non-invasive means of visualizing, examining, and archiving capillary images, enabling clinicians to make informed assessments regarding blood microcirculation. Experimental validation of the optimized hardware and software capillaroscopy system was conducted using nail bed capillaries of a patient with type II diabetes mellitus undergoing insulin therapy for 10 years. This study underscores the importance of refining and enhancing optical capillaroscopy methodologies by leveraging high-resolution camera sensors and modern computational tools for image processing.

Abstract 6763: A human-relevant vascularized organ-on-a chip platform for anti-tumor drug efficacy and liver injury assessment

Abstract Cancer global burden accounts for 19.3 million new cases and 10 million deaths in 2020. Despite advances on the understanding of disease progression and efforts to find successful therapeutic strategies, most drugs fail in clinical stages. Lack of models with clinical mimicry recapitulating the in vivo pathophysiology and the organ microenvironment where the tumor forms is a key driver reducing the success rate of anti-cancer drugs. Animal models remain the gold standard for preclinical research but fail to recapitulate the complex human tumor microenvironment, a critical component determining tumor development, progression, and response to treatments. Organ-on-a-chip models allow to control the environment and organization of cells in an in vivo-like arrangement by culturing multiple cell types to better replicate human conditions, and by implementing different biochemical and physical stimuli, such as fluid shear stress, chemical/nutrient gradients, and perfusion/flow to recapitulate the human vascular system physiology. We leverage our 3D bioprinting technologies to develop complex vascularized organ-on-a-chip models aimed to recapitulate the tumor and liver niche. Both organ-systems are interconnected by our h-VIOS™ platform, allowing dynamic perfusion for 21 days and enabling the simultaneous assessment of anti-tumor therapeutic efficacy and drug-induced liver injury. Our hydrogels feature a complex perfusable vasculature that interfaces with an interstitial chamber where tissues of interest are grown. The vasculature allows for continued and controlled delivery of nutrients, oxygen, and small molecule drugs. Dextran diffusion studies revealed diffusion coefficients ranging from 43.2 μm2/s (4kDa) to 8 μm2/s (70kDa). Vascular architectures are lined with endothelial cells forming a functional barrier expressing the junctional markers ZO-1 and PECAM-1. Moreover, we can modulate the permeability of our vasculature architecture, allowing the extravasation of immune and cancer cells. PBMC-derived T cells and Jurkat cells undergo transendothelial migration in response to a CXCL12 gradient, highlighting the applicability of our model for immunotherapeutic efficacy studies. The tumor interstitial chamber incorporates co-culture of cancer spheroids or tumoroids, fibroblasts, endothelial and immune cells. Colon carcinoma spheroids effectively integrate into the tumor niche with no growth arrest. The liver model consists of an interstitial chamber with a lobular microstructure supporting the monoculture of primary human hepatocytes, and sustaining their viability and function for 9 days as demonstrated by high albumin production, urea synthesis and CYP activity. Our organ-on-a-chip models are fully customizable and anticipated to contribute to advance personalized medicine and improve clinical translation rates. Citation Format: Juliana Navarro-Yepes, Queeny Dasgupta, Purboja Purkayastha, Kevin Janson, Cassio Mello, Ameya Narkar, Soon Seng Ng, Taci Pereira. A human-relevant vascularized organ-on-a chip platform for anti-tumor drug efficacy and liver injury assessment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6763.

Soft electrodes for simultaneous bio-potential and bio-impedance study of the face

The human body’s vascular system is a finely regulated network: blood vessels can change in shape (i.e. constrict, or dilate), their elastic response may shift and they may undergo temporary and partial blockages due to pressure applied by skeletal muscles in their immediate vicinity. Simultaneous measurement of muscle activation and the corresponding changes in vessel diameter, in particular at anatomical regions such as the face, is challenging, and how muscle activation constricts blood vessels has been experimentally largely overlooked. Here we report on a new electronic skin technology for facial investigations to address this challenge. The technology consists of screen-printed dry carbon electrodes on soft polyurethane substrate. Two dry electrode arrays were placed on the face: One array for bio-potential measurements to capture muscle activity and a second array for bio-impedance. For the bio-potential signals, independent component analysis (ICA) was used to differentiate different muscle activations. Four-contact bio-impedance measurements were used to extract changes (related to artery volume change), as well as beats per minute (BPM). We performed concurrent bio-potential and bio-impedance measurements in the face. From the simultaneous measurements we successfully captured fluctuations in the superficial temporal artery diameter in response to facial muscle activity, which ultimately changes blood flow. The observed changes in the face, following muscle activation, were consistent with measurements in the forearm and were found to be notably more intricate. Both at the arm and the face, a clear increase in the baseline impedance was recorded during muscle activation (artery narrowing), while the impedance changes signifying the pulse had a clear repetitive trend only at the forearm. These results reveal the direct connection between muscle activation and the blood vessels in their vicinity and start to unveil the complex mechanisms through which facial muscles might modulate blood flow and possibly affect human physiology.

A combined experimental and DFT study of metal core/indocyanine green shell hybrid nanoparticles

Indocyanine green (ICG) is the FDA-approved fluorescent dye used for in vivo medical imaging, diagnostics, and photothermal therapy. However, this dye is easily degradable in the human vascular system, and therefore its stabilization is preferable. In this work, ICG molecules were stabilized by their adsorption on the surface of the L-methionine-capped Ag and Au nanoparticles (Ag and Au @LM NPs) in aqueous colloidal dispersions. The result is the formation of hybrid metal core/ICG shell NPs in colloidal dispersions. Additionally, colloidal dispersions were stabilized, indicating a double effect of ICG adsorption. The obtained hybrid NPs were studied experimentally (UV–Vis spectrophotometry, HRTEM, DLS, FTIR) and theoretically (DFT calculations). HRTEM revealed that the interplanar spacing between adjacent planes of NPs decreases after the dye adsorption. The results obtained from the DFT study confirmed the formation of a covalent bond between the oxygen from ICG dye SO3− group and metal NPs. Considering the characteristics of both components of the NPs/ICG hybrid system, the authors assume that this hybrid system can exhibit the synergistic effect that could lead to more successful theranostic treatment of cancer in nanomedicine.

Decellularized plant-derived vasculature-on-a-chip interacting with breast cancer spheroids to evaluate a dual-drug therapy

Breast cancer progression is a complex process involving the primary tumor and its microenvironment supported by a vascular network. Multicellular spheroids closely mimic in vivo-like tumor conditions, paving the way for effective treatments. Although spheroid formation by simulated microgravity emerges as a promising technique for cancer spheroids, the lack of a perfusable vascular network still limits the evaluation of tumor progression. Recently, decellularized plant structures with hierarchically formed vasculatures similar to the human vascular system gained interest as engineered vascular networks. In this study, breast cancer spheroids co-cultured with endothelial cells were grown both under unit-gravity and simulated microgravity conditions, whereas vasculature was formed by the decellularization of spinach leaf. The optimized spheroids and plant-derived vasculature populated with endothelial cells were integrated into a microplatform, where fibroblasts were embedded into the extracellular matrix (ECM) to mimic the tumor microenvironment (TME). The vasculature-on-a-chip was used to assess the response of breast cancer spheroids to a combinatorial dose of Doxorubicin (DOX) and Bevacizumab (BMAB) treatment administered to circulating flow emulating intravenous administration. The developed platform offers a biomimetic model to recapitulate key aspects of breast cancer progression and evaluate the responses of both the tumor and the vasculature to chemotherapeutic drugs.

Cerebral perfusion simulation using realistically generated synthetic trees for healthy and stroke patients

Background and objectiveCerebral vascular diseases are among the most burdensome diseases faced by society. However, investigating the pathophysiology of diseases as well as developing future treatments still relies heavily on expensive in-vivo and in-vitro studies. The generation of realistic, patient-specific models of the cerebrovascular system capable of simulating hemodynamics and perfusion promises the ability to simulate diseased states, therefore accelerating development cycles using in silico studies and opening opportunities for the individual assessment of diseased states, treatment planning, and the prediction of outcomes. By providing a patient-specific, anatomically detailed and validated model of the human cerebral vascular system, we aim to provide the basis for future in silico investigations of the cerebral physiology and pathology. MethodsIn this retrospective study, a processing pipeline for patient-specific quantification of cerebral perfusion was developed and applied to healthy individuals and a stroke patient. Major arteries are segmented from 3T MR angiography data. A synthetic tree generation algorithm titled tissue-growth based optimization (GBO)1 is used to extend vascular trees beyond the imaging resolution. To investigate the anatomical accuracy of the generated trees, morphological parameters are compared against those of 7 T MRI, 9.4 T MRI, and dissection data. Using the generated vessel model, hemodynamics and perfusion are simulated by solving one-dimensional blood flow equations combined with Darcy flow equations. ResultsMorphological data of three healthy individuals (mean age 47 years ± 15.9 [SD], 2 female) was analyzed. Bifurcation and physiological characteristics of the synthetically generated vessels are comparable to those of dissection data. The inability of MRI based segmentation to resolve small branches and the small volume investigated cause a mismatch in the comparison to MRI data. Cerebral perfusion was estimated for healthy individuals and a stroke patient. The simulated perfusion is compared against Arterial-Spin-Labeling MRI perfusion data. Good qualitative agreement is found between simulated and measured cerebral blood flow (CBF)2. Ischemic regions are predicted well, however ischemia severity is overestimated. ConclusionsGBO successfully generates detailed cerebral vascular models with realistic morphological parameters. Simulations based on the resulting networks predict perfusion territories and ischemic regions successfully.

RBC Membrane-coated Nanoparticles: A Comprehensive Review on the Preparation Methods, Characterisations and Applications

Abstract:Natural cells have become an area of interest due to their biocompatibility, nonimmunogenicity, biodegradability, and targeting specificity. The human vascular system retains distinctive physiological features that can be developed for enhanced and effective targeted drug delivery. Red blood cells (RBCs) have unique features and properties that make them potential natural carriers for numerous substances. Recently, the RBC membrane has become a unique biological carrier and it has been extensively studied due to its long-circulating half-life, low toxicity, high stability and the ability to transport various biologically active substances with higher drug release efficiency. Among the benefits of the RBC membrane as a drug delivery carrier in medical and biological fields is the use of this system in anticancer therapy. Antitumor drugs are loaded in gold NP, magnetic NPs, or mesoporous silica NPs. Then, the loaded NP is used as a core and coated with an RBC membrane to protect the NP from immune attack and enhance drug targeting. Moreover, RBCs have been used for encapsulating different enzymes to overcome the undesirable outcomes associated with enzyme replacement therapy. This review highlighted the most recent RBC membrane preparation methods, such as Membrane coating technology and Osmotic Loading Procedures. The recent advances in the design of RBC membrane carriers and discuss the applications of RBCs in different fields such as therapeutic enzymes, immunotherapy and anti-tumour therapy. Given the potential risks and challenges in the development of any treatment protocol, this review elucidated the problematic aspects and prospects, describing new modalities to overcome these problems. RBCs as a drug carriers are among the most interesting topics as a novel drug delivery system as they are convenient, effective, safer, biocompatible and have good properties to deliver and administrate the drug specifically to the target site of action with fewer side effects and interference with therapeutic aspects.

Embryonic exposure to chloroxylenol induces developmental defects and cardiovascular toxicity via oxidative stress, inflammation, and apoptosis in zebrafish

Chloroxylenol is an extensively consumed anti-microbial compound. Since its usage is on the rise due to the coronavirus pandemic and ban on other antimicrobial ingredients, recent studies have suggested the necessity of estimating its potential for ecotoxicity. The detrimental effect of chloroxylenol on zebrafish (Danio rerio) viability has been reported; however, research on the mechanisms underlying its toxicity is quite limited. Therefore, we applied the zebrafish model for elucidating responses against chloroxylenol to predict its toxicity toward human health and ecology. Zebrafish exposed to chloroxylenol (0, 0.5, 1, 2.5, 5, and 10 mg/L) at the embryonic stage (from 6 h post-fertilization (hpf) to 96 hpf) showed impaired viability and hatchability, and pathological phenotypes. To address these abnormalities, cellular responses such as oxidative stress, inflammation, and apoptosis were confirmed via in vivo imaging of a fluorescent dye or measurement of the transcriptional changes related to each response. In particular, developmental defects in the cardiovascular system of zebrafish exposed to 0, 0.5, 1, and 2.5 mg/L of chloroxylenol from 6 to 96 hpf were identified by structural analyses of the system in the flk1:eGFP transgenic line. Additional experiments were conducted using human umbilical vein endothelial cells (HUVECs) to predict the adverse impacts of chloroxylenol on the human vascular system. Chloroxylenol impairs the viability and tube formation ability of HUVECs by modulating ERK signaling. The findings obtained using the zebrafish model provide evidence of the possible risks of chloroxylenol exposure and suggest the importance of more in-depth ecotoxicological studies.

Realizations of vascularized tissues: From in vitro platforms to in vivo grafts.

Vascularization is essential for realizing thick and functional tissue constructs that can be utilized for in vitro study platforms and in vivo grafts. The vasculature enables the transport of nutrients, oxygen, and wastes and is also indispensable to organ functional units such as the nephron filtration unit, the blood-air barrier, and the blood-brain barrier. This review aims to discuss the latest progress of organ-like vascularized constructs with specific functionalities and realizations even though they are not yet ready to be used as organ substitutes. First, the human vascular system is briefly introduced and related design considerations for engineering vascularized tissues are discussed. Second, up-to-date creation technologies for vascularized tissues are summarized and classified into the engineering and cellular self-assembly approaches. Third, recent applications ranging from in vitro tissue models, including generic vessel models, tumor models, and different human organ models such as heart, kidneys, liver, lungs, and brain, to prevascularized in vivo grafts for implantation and anastomosis are discussed in detail. The specific design considerations for the aforementioned applications are summarized and future perspectives regarding future clinical applications and commercialization are provided.

Convolutional neural network for automatic detection and characterization of abdominal aortic aneurysm.

We read with great interest the recent publication of Camara et al. on the development of an artificial intelligence (AI)-derived method to enable an automatic detection of abdominal aortic aneurysm (AAA) (1Camara JR TR, Pop A, Matthew BS, Shedd P, Brandon S, Dobrowski BS, Cole J, Knox BS, Abou-Zamzam A, Sharon C, Kiang Journal of Vascular Surgery Cases and Innovative techniquesGoogle Scholar). Using datasets composed of 200 computed tomography angiography (CTA) from patients with AAA and 200 matched control patients with non-aneurysmal infrarenal aorta, the authors developed a method based on convolutional neural network (CNN) and testing demonstrated a robust accuracy of the model (99.1% with an area under the curve of 0.99). Their results point to the interest of such application for the screening of AAA. The VGG-16 neural network architecture was used to develop the AAA detection system and transfer learning was applied to the neural network. It would be interesting to know what was the accuracy of the CNN before transfer learning to show what was the added value of the transfer learning in the pipeline. The use of CNN to classify aneurysmal from non-pathological aortas has been so far poorly reported (2Mohammadi S. Mohammadi M. Dehlaghi V. Ahmadi A. Automatic Segmentation, Detection, and Diagnosis of Abdominal Aortic Aneurysm (AAA) Using Convolutional Neural Networks and Hough Circles Algorithm.Cardiovasc Eng Technol. 2019; 10: 490-499Crossref PubMed Scopus (27) Google Scholar). Nevertheless, it is to note that several studies have recently demonstrated the interest of CNN to develop a fully automatic segmentation of AAA (3Lareyre F. Adam C. Carrier M. Raffort J. Automated Segmentation of the Human Abdominal Vascular System Using a Hybrid Approach Combining Expert System and Supervised Deep Learning.J Clin Med. 2021; 10Crossref Scopus (9) Google Scholar, 4Caradu C. Spampinato B. Vrancianu A.M. Berard X. Ducasse E. Fully automatic volume segmentation of infrarenal abdominal aortic aneurysm computed tomography images with deep learning approaches versus physician controlled manual segmentation.J Vasc Surg. 2021; 74: 246-256 e6Abstract Full Text Full Text PDF Scopus (20) Google Scholar, 5Adam C. Fabre D. Mougin J. Zins M. Azarine A. Ardon R. et al.Pre-surgical and Post-surgical Aortic Aneurysm Maximum Diameter Measurement: Full Automation by Artificial Intelligence.Eur J Vasc Endovasc Surg. 2021; Abstract Full Text Full Text PDF Scopus (12) Google Scholar). These studies showed a good accuracy of the methods compared to human experts and demonstrated the feasibility to use AI for an automatic measurement of AAA maximal diameter (4Caradu C. Spampinato B. Vrancianu A.M. Berard X. Ducasse E. Fully automatic volume segmentation of infrarenal abdominal aortic aneurysm computed tomography images with deep learning approaches versus physician controlled manual segmentation.J Vasc Surg. 2021; 74: 246-256 e6Abstract Full Text Full Text PDF Scopus (20) Google Scholar, 5Adam C. Fabre D. Mougin J. Zins M. Azarine A. Ardon R. et al.Pre-surgical and Post-surgical Aortic Aneurysm Maximum Diameter Measurement: Full Automation by Artificial Intelligence.Eur J Vasc Endovasc Surg. 2021; Abstract Full Text Full Text PDF Scopus (12) Google Scholar, 6Lareyre F. Chaudhuri A. Flory V. Augene E. Adam C. Carrier M. et al.Automatic measurement of maximal diameter of abdominal aortic aneurysm on computed tomography angiography using artificial intelligence.Ann Vasc Surg. 2021; Google Scholar). Hence, CNN offers perspectives to develop applications oriented toward screening and identification of AAA as well as new tools to facilitate its anatomic characterization, which could improve pre-surgical planning and follow-up. As stated by the authors, in addition to develop advanced imaging analysis, ML has the potential to build predictive models of patients’ outcomes and several studies have underlined its interest to better assess AAA growth, risk of rupture, as well as risks of post-operative complications including mortality or re-interventions (7Raffort J. Adam C. Carrier M. Ballaith A. Coscas R. Jean-Baptiste E. et al.Artificial intelligence in abdominal aortic aneurysm.J Vasc Surg. 2020; Abstract Full Text Full Text PDF Scopus (53) Google Scholar, 8Raffort J. Adam C. Carrier M. Lareyre F. Fundamentals in Artificial Intelligence for Vascular Surgeons.Ann Vasc Surg. 2020; 65: 254-260Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar, 9Lareyre F. Raffort J. Looking for the Optimal Evaluation of Abdominal Aortic Aneurysm Risk of Rupture.J Endovasc Ther. 2020; 27: 345-346Crossref Scopus (0) Google Scholar). AI has the potential to enhance precision medicine and although further studies are required to evaluate the accuracy and external validation, applications for clinical practice can hopefully be expected within the next few years. This work has been supported by the French government, through the 3IA Côte d’Azur Investments in the Future project managed by the National Research Agency (ANR) with the reference number ANR-19-P3IA-0002.

Design of artificial vascular devices: Hemodynamic evaluation of shear-induced thrombogenicity

Blood-circulating devices such as oxygenators have offered life-saving opportunities for advanced cardiovascular and pulmonary failures. However, such systems are limited in the mimicking of the native vascular environment (architecture, mechanical forces, operating flow rates and scaffold compositions). Complications involving thrombosis considerably reduce their implementation time and require intensive anticoagulant treatment. Variations in the hemodynamic forces and fluid-mediated interactions between the different blood components determine the risk of thrombosis and are generally not taken sufficiently into consideration in the design of new blood-circulating devices. In this Review article, we examine the tools and investigations around hemodynamics employed in the development of artificial vascular devices, and especially with advanced microfluidics techniques. Firstly, the architecture of the human vascular system will be discussed, with regards to achieving physiological functions while maintaining antithrombotic conditions for the blood. The aim is to highlight that blood circulation in native vessels is a finely controlled balance between architecture, rheology and mechanical forces, altogether providing valuable biomimetics concepts. Later, we summarize the current numerical and experimental methodologies to assess the risk of thrombogenicity of flow patterns in blood circulating devices. We show that the leveraging of both local hemodynamic analysis and nature-inspired architectures can greatly contribute to the development of predictive models of device thrombogenicity. When integrated in the early phase of the design, such evaluation would pave the way for optimised blood circulating systems with effective thromboresistance performances, long-term implantation prospects and a reduced burden for patients.

A Novel Low-Profile Self-Expanding Biodegradable Percutaneous Heart Valve Frame That Grows with a Child

According to rough estimates, one in every 125 newborns born in the United States has a congenital cardiac abnormality that must be repaired. With the recent development of new biomaterials and innovative treatment methods, percutaneous cardiac valve replacement has been considered as an alternative to surgical procedures. While percutaneous heart valve replacement is a relatively new procedure with a few commercially available devices, the devices are not sufficiently low-profile, and do not grow with the child. To address this issue, a novel low-profile growing percutaneous pediatric heart valve frame made of two types of unique metallic biomaterials (supere lastic nitinol and biodegradable iron) has been developed through this study. The developed pediatric heart valve frame has an innovative mechanism that will expand its diameter by disconnecting biodegradable metals, enabling the growth of the device with the surrounding tissue in the cardiac space. The thermally treated iron wires show stable and gradual degradation characteristics, showing approximately 7.66% for both wires treated under 350 and 450 °C. Polymer-coated wires show a degradation range of 4.96 to 5.55% depending on the type of coating. Degradation test results show the predicted 9–23 months of degradation depending on the type of surface treatment (e.g., thermal treatment, polymer coating), which is a suitable range when compared with the theoretical arterial vessel remodeling process period in the human vascular system. Radial forces calculated by finite element analysis and measured by mechanical testing matched well, showing 5–6 N with a 20% diameter reduction considering the deployed valve frame in the heart. Biocompatibility study results demonstrated superior cell viability in thermally treated iron wires after 3 days of cell culture and showed rarely found platelets on the surface after 3-h blood exposure tests. Prototype devices were successfully fabricated using optimized advanced joining processes for dissimilar metallic materials such as nitinol and iron. This study represents the first demonstration of self-expanding and biodegradable percutaneous heart valve frames for pediatric patients that grow with a child.

Convective Flow of Blood through a Constricted Cylinder and the Effect of Cholesterol Growth Rate on the Motion in the Presence of a Magnetic Field

An inflammatory disease resulting in the pathological constriction of the intima and media of the arterial system, such as the aorta, causes symptoms like stroke, heart attack, or angina; This research investigates the convective flow of blood through a constricted cylinder and the effect of cholesterol growth rate on the motion in the presence of a magnetic field by transforming the problem into a system of time-dependent partial differential equations. The governing partial differential equations (PDEs) were transformed into dimensionless ordinary differential equations (ODEs) and solved using the Laplace method. After obtaining the analytical solution, Wolfram Mathematica was used to perform the numerical computation where the various physical parameters such as Soret number, radiation number, solutal Grashof number, Schmidt number, and Prandtl number were varied to their impact studied. The study discovered that increasing the Soret number causes an increase in blood velocity, whereas decreasing the Solutal Grashof number decreases blood velocity. Furthermore, an increase in radiation parameter increases the blood velocity, but a Soret number increase results in a decrease in the concentration of cholesterol in the fluid, a Schmidt number, and oscillatory frequency increase, causing the temperature to decrease. This research is useful for clinicians and mathematical modellers who are trying to understand the flow of cholesterol saturated fluid in the human vascular system and how best to proffer analytical and numerical solutions in synergy with laboratory investigation.

Evaluation of toxicity of polystyrene microplastics under realistic exposure levels in human vascular endothelial EA.hy926 cells

Microplastics (MPs) have emerged as a global concern, with a recent study being the first to detect them in the bloodstream of healthy people. However, precise information regarding the toxic effects of MPs on the human vascular system is currently lacking. In this study, we used human vascular endothelial EA. hy926 cells to examine the toxic potential of polystyrene MPs (PSMPs) under realistic blood concentrations. Our findings indicated that PSMPs can cause oxidative stress by reducing the expression of antioxidants, thereby leading to apoptotic cytotoxicity in EA. hy926 cells. Furthermore, the protective potential of heat shock proteins can be reduced by PSMPs. PSMP-induced apoptosis might also lower the expression of rho-associated protein kinase-1 and nuclear factor-κB expression, thus dampening LRR- and pyrin domain-containing protein 3 in EA. hy926 cells. Moreover, we observed that PSMPs induce vascular barrier dysfunction via the depletion of zonula occludens-1 protein. However, although protein expression of the nuclear hormone receptor 77 was inhibited, no significant increase in ectin-like oxidized low-density lipoprotein receptor-1 was noted in PSMP-treated EA. hy926 cells. These results demonstrate that exposure to PSMPs may not sufficiently increase the risk of developing atherosclerosis. Overall, our research signifies that exposure to realistic blood concentrations of PSMPs is associated with low atherosclerotic cardiovascular risk in humans.

The Effect of Body Mass Index on the Degree of Renal Interstitial Fibrosis and Tubular Atrophy - A Retrospective Case-Control Study

IntroductionThe degree of interstitial fibrosis and tubular atrophy (IFTA) seen on kidney biopsy has long been used to judge the chronicity of kidney disease to predict renal disease outcomes and prognosis. It is an essential component incorporated in many renal disease prognostic classification systems on the native and renal allograft. The impact of increased body mass index on the body metabolism, and the human vascular system, including the functional unit of the kidney, the nephron, is well-addressed in the literature. In this study, we focus on evaluating the degree of IFTA concerning the patient's body mass index (BMI).MethodAll the specimens of nephrectomies performed in King Abdulaziz University Hospital for adults from January 2010 to February 2021 were evaluated for this study. A total of 125 cases were selected for the study. The glass slides were pulled and assessed for the degree of IFTA. The demographic data, and the patient's BMI, were collected from the hospital records.ResultsSubjects with high BMI showed a 1.62 (OR: 1.62, 95% CI: 0.62, 4.22) and 1.52 (AOR: 1.52, 95% CI: 0.56, 4.13) increased risk of high IFTA score compared with those with normal BMI. This study has proved that only at a BMI of 25 or more will there be a measurable, independent effect on the degree of IFTA.ConclusionAlthough a small number of hospital-based populations limits this study, it could prove the increased severity of IFTA in patients with high BMI. Its result may act as a spark that will drive extensive population-based studies that more precisely delineate the relationship between BMI and the degree of IFTA on different levels.

A1D–0D–3Dcoupled model for simulating blood flow and transport processes in breast tissue

In this work, we present mixed dimensional models for simulating blood flow and transport processes in breast tissue and the vascular tree supplying it. These processes are considered, to start from the aortic inlet to the capillaries and tissue of the breast. Large variations in biophysical properties and flow conditions exist in this system necessitating the use of different flow models for different geometries and flow regimes. In total, we consider four different model types. First, a system of 1D nonlinear hyperbolic partial differential equations (PDEs) is considered to simulate blood flow in larger arteries with highly elastic vessel walls. Second, we assign 1D linearized hyperbolic PDEs to model the smaller arteries with stiffer vessel walls. The third model type consists of ODE systems (0D models). It is used to model the arterioles and peripheral circulation. Finally, homogenized 3D porous media models are considered to simulate flow and transport in capillaries and tissue within the breast volume. Sink terms are used to account for the influence of the venous and lymphatic systems. Combining the four model types, we obtain two different 1D-0D-3D coupled models for simulating blood flow and transport processes: The first model results in a fully coupled 1D-0D-3D model covering the complete path from the aorta to the breast combining a generic arterial network with a patient specific breast network and geometry. The second model is a reduced one based on the separation of the generic and patient specific parts. The information from a calibrated fully coupled model is used as inflow condition for the patient specific sub-model allowing a significant computational cost reduction. Several numerical experiments are conducted to calibrate the generic model parameters and to demonstrate realistic flow simulations compared to existing data on blood flow in the human breast and vascular system. Moreover, we use two different breast vasculature and tissue data sets to illustrate the robustness of our reduced sub-model approach.