Vascular System Research Articles

Evaluation of microstructural brain changes in post-coronavirus disease 2019 (COVID-19) patients with neurological symptoms: a cross-sectional study.

Changes in both the vascular system and brain tissues can occur after a prior episode of coronavirus disease 2019 (COVID-19), detectable through modifications in diffusion parameters using magnetic resonance imaging (MRI) techniques. These changes in diffusion parameters may be particularly prominent in highly organized structures such as the corpus callosum (CC), including its major components, which have not been adequately studied following COVID-19 infection. Therefore, the study aimed to evaluate microstructural changes in whole-brain (WB) diffusion, with a specific focus on the CC. A total of 101 probands (age range from 18 to 69 years) participated in this retrospective study, consisting of 55 volunteers and 46 post-COVID-19 patients experiencing neurological symptoms. The participants were recruited from April 2022 to September 2023 at the Institute for Clinical and Experimental Medicine in Prague, Czech Republic. All participants underwent MRI examinations on a 3T MR scanner with a diffusion protocol, complemented by additional MRI techniques. Two volunteers and five patients were excluded from the study due to motion artefacts, severe hypoperfusion or the presence of lesions. Participants were selected by a neurologist based on clinical examination and a serological test for COVID-19 antibodies. They were then divided into three groups: a control group of healthy volunteers (n=28), an asymptomatic group (n=25) with a history of infection but no symptoms, and a symptomatic group (n=41) with a history of COVID-19 and neurological symptoms. Symptomatic patients did not exhibit neurological symptoms before contracting COVID-19. Diffusion data underwent eddy current and susceptibility distortion corrections, and fiber tracking was performed using default parameters in DSI studio. Subsequently, various diffusion metrics, were computed within the reconstructed tracts of the WB and CC. To assess the impact of COVID-19 and its associated symptoms on diffusion indices within the white matter of the WB and CC regions, while considering age, we employed a statistical analysis using a linear mixed-effects model within the R framework. Statistical analysis revealed a significant difference in mean diffusivity (MD) between the symptomatic and control groups in the forceps minor (P=0.001) and CC body (P=0.003). In addition to changes in diffusion, alterations in brain perfusion were observed in two post-COVID-19 patients who experienced a severe course. Furthermore, hyperintense lesions were identified in subcortical and deep white matter areas in the vast majority of symptomatic patients. The main finding of our study was that post-COVID-19 patients exhibit increased MD in the forceps minor and body of the CC. This finding suggests a potential association between microstructural brain changes in post-COVID-19 patients and reported neurological symptoms, with significant implications for research and clinical applications.

Preeclampsia: Short- and Long-Term Effects.

Does our time inside the womb predict our future? Evidence suggests that the environment in the womb plays a powerful role in predicting specific adult diseases. The fetus is constantly responding and adapting to the intrauterine environment by a process called programming. Toxic exposures, such as nutritional deficits and hypoxia, can affect fetal development and increase the risk for specific diseases that manifest later in our adult life. Preeclampsia (PE) is one disorder that results in a less-than-optimal environment for the growing fetus. It is pregnancy-specific and defined as new-onset hypertension after 20 weeks' gestation in the presence of maternal multiorgan dysfunction. To the best of our understanding, the pathogenesis is multifactorial and involves dysfunction of the placenta and the vascular, renal, and immunological systems. Treatment options are limited and may result in adverse outcomes for the fetus and newborn. Preeclampsia is a major contributor to perinatal and maternal morbidity and mortality worldwide, thus generating a significant healthcare burden. Research continues to demonstrate that mothers and infants affected by PE are at increased susceptibility to chronic conditions such as cardiovascular, renal, metabolic, and neurological diseases. More efforts are needed to further understand this disease. Efforts to increase awareness will help improve clinical outcomes for both mothers and infants.

In vivo imaging of microvasculature in human finger skin using SV-OCT

Abstract Speckle variance optical coherence tomography (SV-OCT) enables non-invasive visualization of the three-dimensional vascular information within the microcirculatory tissue bed by utilizing flowing red blood cells as intrinsic contrast agents, without the need for dye injection. This study evaluated the feasibility of using the SV-OCT device for monitoring the microvascular system in human finger skin. An adaptive wavelet Fourier transform filtering algorithm was applied to remove stripe noise from the images of finger vasculature. The results demonstrate that SV-OCT systems can be used to extract the vascular system of finger skin. By employing an adaptive wavelet Fourier transform filtering (AWFTF)algorithm to process the vascular data, stripe noise can be effectively removed, thereby enhancing the imaging quality of the blood vessels.

Optimization of Vascularized Intestinal Organoid Model.

Vasculature is crucial for maintaining organ homeostasis and metabolism. Although 3D organoids can mimic organ structures and patterns, they still lack vascular systems, limiting the recapitulation ofphysiological complexities. Although vascularization of organoids has been demonstrated by mixing Matrigel in fibrin, how the mixed gel niche affects endothelial cells (ECs) and organoids remains unclear. Existing protocols rely on fibroblasts to promote vascular network formation. This study explores how varying the ratio of Matrigel in fibrin-Matrigel co-gel affects vascular network formation and intestinal organoid growth.A fine-tuned hydrogel is developed by adding aprotinin and 15% Matrigel in fibrin. Medium for co-culturing ECs and organoids is modified with basic fibroblast growth factor (bFGF) and heparin. In combination with fine-tuned hydrogel and modified medium, vascular network formation and organoid vascularization are successfully generated in the absence of fibroblast. Furthermore, structural cues and pore architectures are critical for angiogenesis and vascularization. By incorporating engineered thick collagen fiber bundles into the system, vascular network formation is guided by bundle architectures, enhancing interactions between vascular networks and organoids. The results demonstrate an optimized system that advances tissue and organoid vascularization by combining fiber bundles with fine-tuned hydrogel and modified medium.

Cardiovascular effects of long-duration space flight.

Early studies exploring the physiological effects of space travel have indicated the body's capacity for reversible adaptation. However, the impact of long-duration spaceflight, exceeding 6 months, presents more intricate challenges. Extended exposure to microgravity and radiation profoundly affects the CV system. Notable phenomena include fluid shifts toward the head and modified arterial pressure. These changes disrupt blood pressure regulation and elevate cardiac output. Additionally, the loss of venous compression leads to a reduction in central venous pressure. The displacement of fluid from the vascular system to the interstitium, driven by baroreceptor stimulation, results in a 10%-15% decline in plasma volume. Intriguingly, despite potential increases in cardiac workload, cardiac muscle atrophy and perplexing variations in hematocrit levels have been observed. The mechanism underlying atrophy appears to involve a shift in protein synthesis from the endoplasmic reticulum to the mitochondria via mortalin-mediated mechanisms. Instances of arrhythmias have been recurrently documented, although generally nonlethal, in both Russian and American space missions. Long-duration spaceflight has been associated with the prolongation of the QT interval, particularly in extended missions. Exposure of the heart to the proton and heavy ion radiation pervasive in deep space contributes to coronary artery degeneration, augmented aortic stiffness, and carotid intima thickening through collagen-mediated processes. Moreover, it accelerates the onset of atherosclerosis and triggers proinflammatory responses. Upon reentry, astronauts frequently experience orthostatic intolerance and altered sympathetic responses, which bear potential hazards in scenarios requiring rapid mobilization or evacuation. Consequently, careful monitoring of these cardiac risks is imperative for forthcoming missions. While early studies illuminate the adaptability of the body to space travel's challenges, the intricacies of long-duration missions and their effects on the CV system necessitate continued investigation and vigilance to ensure astronaut health and mission success.

High fibrinogen content in pregnant women – pathology or overdiagnosis?

An increased fibrinogen (FG) concentration during pregnancy is considered a protective mechanism against bleeding during childbirth. An enlarged amount of FG increases the aggregation of erythrocytes, blood plasma viscosity, microvascular resistance – permanent elements of the pathogenesis of arterial hypertension, stroke, coronary heart disease. It is also associated with an increased likelihood of development of preeclampsia and stroke with subsequent neurological disorders.In addition to its undeniable importance for hemostasis, FG is directly related to several physiological and pathophysiological conditions, such as infection, wound healing, tumorigenesis, and the severity of atherosclerosis. It also has a decisive role in the development of pregnancy. Maternal FG is necessary for the progress of pregnancy, as it stabilizes the utero-placental connection at the fibrinoid layer of the fetal-maternal junction. No reports on the study of pathological forms of FG in Ukraine were found.The objective: to compare the indicators of FG concentration and related elements of the blood coagulation system of pregnant and parturient women in different gestational periods and after childbirth.Materials and methods. Blood components from the ulnar vein of 30 women in labor at a gestation period of 22–27 weeks (extremely preterm birth (EPB) – I group), 37 women in labor at a term of 28–34 weeks (early preterm birth (PB) – II group) and 40 women with gestational period 37–41 weeks (control group (CG) – III group) was studied. In the collected samples the content of FG, D-dimer (Dd), prothrombin index (PI), activated partial thromboplastin time (APTT), as well as the levels of hemoglobin (Hb), hematocrit (Ht) and total protein (TP) of the blood plasma were determined.All women in labor were hospitalized in the active phase of the I labor period and did not receive infusion therapy. In terms of gestation, corresponding to EPB, early PB and CG, 10 pregnant women who were on outpatient registration at the Perinatal Center were examined for comparison of the studied indicators outside of labor.Indicators of the biochemical coagulogram were studied on a Helena C-2 semi-automatic coagulometer (Helena Biosciences, Great Britain).Results. The FG concentration increased from 4.2±0.56 g/l in the term 22–27 weeks to 4.4±0.57 g/l before delivery with a diapason of 3.5 to 5.0 g/l. In all parturients, the FG concentration was lower than 4.5 g/l, respectively by group: 4.5±0.81; 4.1±0.74 and 4.1±0.65 g/l (р<0.05). In 24 hours after delivery the FG concentration increased in CG to 5.0±0.82 g/l, and after 48 hours – to 5.3±1.19 g/l, which exceeded the indicators of parturients of the EPB and early PB groups and pregnant women of these same terms, in which the highest indicator was 4.5±0.81 g/l in the EPB group (p<0.05).An increase in the Dd index with growing gestational age was observed in all pregnant women (from 274±133.3 to 501±174.7 μg/l). It continued during the first postpartum day – up to 685±157.5 μg/l, decreased on the second day – 429±198.9 μg/l (p<0.05), approaching the indicators of the EPB and early PB groups (487±267.0 and 397±202.3 μg/l; p>0.05) and pregnant women of the same term.Hb decreased to 106±8.9 g/l, and Ht – to 35±6.1% with the progression of pregnancy. In parturients of the PB group, they were probably higher than the indicators of pregnant women of the corresponding terms, increasing on the second day after delivery – 110±6.7 g/l and 41±3.1%.There was no significant blood loss in the clinical groups. In all pregnant and parturient women the APTT and PI indicators varied from 27.0±3.51 s to 35.4±3.43 s and from 88±4.8% to 101±5.2%, respectively.Conclusions. 1. A gradual increase in the fibrinogen (FG) concentration with increasing gestational age from 4.2±0.56 g/l in 22–27 weeks to 4.4±0.57 g/l by the time of delivery indicates an increase in the level of FG in healthy pregnant women as an adaptive response of the body to the formation of an additional vascular system.2. An excessive FG increase is a consequence of hemoconcentration, not absolute hyperfibrinogenemia, and may be a sign of pathological processes underlying hypovolemia. In case of extremely preterm birth (EPB), the concentration of FG in the parturient was 4.5±0.81 g/l. Higher values of FG, hemoglobin, and hematocrit in parturients with EPB than in pregnant women at the same term are evidence of insufficient hemodilution, which can be considered as one of the pathogenetic mechanisms of premature labor.3. Laboratory indicators of the blood coagulation system – APTT, PI – in the absence of bleeding have no diagnostic value.

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.

Protective Effect of DHQ-11 against Hypoxia-induced Vasorelaxation

Hypoxia, or the lack of oxygen, has multiple impacts on the vascular system. The major molecular sensors for hypoxia at the cellular level are hypoxia inducible factor and heme oxygenase. Hypoxia also acts on the vasculature directly conveying its damaging effects through disruption of the control of vascular tone, particularly in the coronary circulation, enhancement of inflammatory responses and activation of coagulation pathways. These effects could be particularly detrimental under pathological conditions such as obstructive sleep apnea and other breathing disorders. Introduction: The effect of conjugate 2-(3,4-Dihydroxyphenyl)-6-{[1-(2’-bromo-3’,4’-dimethoxyphenyl)-6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H )-yl]methyl}-3,5,7-trihydroxychroman-4-one (DHQ-11) on hypoxia-induced vasorelaxation was investigated in rat aortic rings using standard organ bath techniques. Materials and methods: Hypoxia was stimulated by a superfusion of aortic rings with a glucose-free Krebs solution bubbled with 95 % N2/5 % CO2. The effect of conjugate DHQ-11 was assessed after a 60- min period of hypoxia on aortic rings precontracted with 50 mm KCl or 1µM phenylephrine (PE). The conjugate DHQ-11 significantly attenuated hypoxia-induced vasorelaxation in the endothelium-intact aortic rings precontracted with KCl or PE in a concentration-dependent manner. Results and discussion: This effect of conjugate DHQ-11 was more potent in aortic rings precontracted with PE than those with KCl where it maximally reduced hypoxia-induced vasorelaxation from 44.7 ± 3.7 to 5.4 ± 3.7 and 33.9 ± 3.4 to 10.8 ± 4.2 %, respectively. The removal of the endothelium attenuated the effect of conjugate DHQ-11 on hypoxia-induced vasorelaxation. Similarly, pretreatment of endothelium-intact aortic rings with L-NAME and methylene blue also attenuated the effect of conjugate DHQ-11 on hypoxia-induced vasorelaxation. Furthermore, the blockade of the ATP-sensitive KATP channel with glibenclamide and the calcium-activated large conductance BKCa channel with TEA also significantly attenuated the effect of conjugate DHQ-11 on hypoxia-induced vasorelaxation. Collectively, these results indicated that conjugate DHQ-11 attenuated the hypoxia-induced vasorelaxation suggesting that it alleviated the oxidative damage of vasculature. Conclusions: This effect of conjugate DHQ-11 possible is mediated through several mechanisms including the blockage of the extracellular Ca2+ entry via the voltage-dependent and receptor-operative Ca2+ channels, as well as inhibition of sarcoplasmic reticulum Ca2+ release via the inositol triphosphate pathway. In addition, endothelium and NO/sGC/cGMP/PKG pathway, as well as KATP and BKCa channels most likely participate in protection by conjugate DHQ-11 against hypoxia-induced vasorelaxation.

THE ROLE OF FOLATE, VITAMIN B12 AND B6 IN HYPERHOMOCYSTEINEMIA AS THE RISK FACTOR OF CARDIOVASCULAR DISEASE: NARRATIVE REVIEW

Cardiovascular disease (CVD), encompassing ailments affecting the heart and vascular system, is estimated to contribute to one-third of global mortality, and its prevalence is continuously rising. The etiology of this condition is multifactorial, making it challenging to identify a singular causative factor. Homocysteine, a factor identified in the 1990s, is known to contribute to the development of atherosclerotic vascular disease and hypercoagulability. Although there is a definite connection, the assessment and management of this condition are still a subject of debate due to inconsistent research findings on its impact in lowering the risk of cardiovascular disease. B vitamins are a collection of chemical compounds that play a crucial role in physiological function. However, the body does not produce them naturally and they need to be obtained from dietary intake. Vitamins B6, B9, and B12 are crucial in the metabolism of homocysteine. The cause of hyperhomocysteinemia is believed to be a deficiency of certain vitamins, particularly folate, B12, and B6, which are important for effectively recycling homocysteine in the methionine cycle. Vitamin B is intricately linked to both the homocysteine and cardiovascular disease (CVD) pathways.

Patterns, outcomes, and preventability of clinically manifest drug-drug interactions in older outpatients: a subgroup analysis from a 6-year-long observational study in North India.

Older adults are vulnerable to adverse drug reactions (ADRs) and drug-drug interactions (DDIs). Evidence on clinically manifest DDIs in older outpatients is scanty. The present study aims to report clinically manifest DDIs, their risk factors, and preventive measures. A subgroup analysis of a 6-year (2015-2021) long prospective study was conducted in a tertiary hospital in North India. Older outpatients with ADRs constituted the study participants. Among 933 ADRs reported in 10,400 patient registrations, clinically manifest DDIs were involved in 199 (21.3%). DDIs accounted for 29.9%, 26.5%, and 21.3% of drug-related metabolic, vascular, and nervous system disorders, respectively. Movement disorders (n = 18), hypotension (n = 16), and hypoglycemia (n = 15) were the most common manifestations. Eighty-six percent of DDIs were of the pharmacodynamic type, and 13.1% were immune-mediated. Around 35% of DDIs resulted in hospitalization, with hyponatremia, movement disorder, and renal impairment as the common reasons. Older adults with Parkinsonism, infection, coronary artery disease, neuropsychiatric disease, and diabetes mellitus, respectively, had 3.28, 2.85, 1.97, 1.76, and 1.80 times higher odds of DDIs. Those receiving ≥ 10 drugs had 5.31 times higher odds of DDIs compared to individuals receiving 1-4 drugs. "Avoiding the causative drug," "optimal monitoring of the patient," and "start-low and go-slow" policy together could prevent 85% of DDIs. In conclusion,every fifth case of ADRs and nearly one third of ADR-related hospitalizations in older adults are related to DDIs. Movement disorder, hypotension, and hypoglycemia are the common manifestations. A holistic approach with drug omission, optimal patient monitoring, and slow titration of therapy can prevent significant DDIs in older adults.

Relapsing Polychondritis Masquerading as Auricular Pseudolymphoma: Case Report and Literature Review

Relapsing Polychondritis (RP) is a rare autoimmune disease associated with recurring inflammatory episodes predominantly affecting cartilage and other tissues throughout the body, including proteoglycan-rich structures. It is characterized by gradual deformation of tissue that leads to impairment of normal function. Areas involved include, but are not limited to, the respiratory tract, eyes, nose, joints, and vascular system. The inflammation targets cartilage, most commonly causing auricular and nasal chondritis but can involve cartilage throughout the body. Diagnosis of RP is often hindered by the vast variety of symptoms associated with this systemic disease and subtle symptomatology. In this paper, we demonstrate a case of relapsing polychondritis masquerading as pseudolymphoma and review recent literature relating to pathogenesis, diagnosis and treatment.

Systemic aging fuels heart failure: Molecular mechanisms and therapeutic avenues.

Systemic aging influences various physiological processes and contributes to structural and functional decline in cardiac tissue. These alterations include an increased incidence of left ventricular hypertrophy, a decline in left ventricular diastolic function, left atrial dilation, atrial fibrillation, myocardial fibrosis and cardiac amyloidosis, elevating susceptibility to chronic heart failure (HF) in the elderly. Age-related cardiac dysfunction stems from prolonged exposure to genomic, epigenetic, oxidative, autophagic, inflammatory and regenerative stresses, along with the accumulation of senescent cells. Concurrently, age-related structural and functional changes in the vascular system, attributed to endothelial dysfunction, arterial stiffness, impaired angiogenesis, oxidative stress and inflammation, impose additional strain on the heart. Dysregulated mechanosignalling and impaired nitric oxide signalling play critical roles in the age-related vascular dysfunction associated with HF. Metabolic aging drives intricate shifts in glucose and lipid metabolism, leading to insulin resistance, mitochondrial dysfunction and lipid accumulation within cardiomyocytes. These alterations contribute to cardiac hypertrophy, fibrosis and impaired contractility, ultimately propelling HF. Systemic low-grade chronic inflammation, in conjunction with the senescence-associated secretory phenotype, aggravates cardiac dysfunction with age by promoting immune cell infiltration into the myocardium, fostering HF. This is further exacerbated by age-related comorbidities like coronary artery disease (CAD), atherosclerosis, hypertension, obesity, diabetes and chronic kidney disease (CKD). CAD and atherosclerosis induce myocardial ischaemia and adverse remodelling, while hypertension contributes to cardiac hypertrophy and fibrosis. Obesity-associated insulin resistance, inflammation and dyslipidaemia create a profibrotic cardiac environment, whereas diabetes-related metabolic disturbances further impair cardiac function. CKD-related fluid overload, electrolyte imbalances and uraemic toxins exacerbate HF through systemic inflammation and neurohormonal renin-angiotensin-aldosterone system (RAAS) activation. Recognizing aging as a modifiable process has opened avenues to target systemic aging in HF through both lifestyle interventions and therapeutics. Exercise, known for its antioxidant effects, can partly reverse pathological cardiac remodelling in the elderly by countering processes linked to age-related chronic HF, such as mitochondrial dysfunction, inflammation, senescence and declining cardiomyocyte regeneration. Dietary interventions such as plant-based and ketogenic diets, caloric restriction and macronutrient supplementation are instrumental in maintaining energy balance, reducing adiposity and addressing micronutrient and macronutrient imbalances associated with age-related HF. Therapeutic advancements targeting systemic aging in HF are underway. Key approaches include senomorphics and senolytics to limit senescence, antioxidants targeting mitochondrial stress, anti-inflammatory drugs like interleukin (IL)-1β inhibitors, metabolic rejuvenators such as nicotinamide riboside, resveratrol and sirtuin (SIRT) activators and autophagy enhancers like metformin and sodium-glucose cotransporter 2 (SGLT2) inhibitors, all of which offer potential for preserving cardiac function and alleviating the age-related HF burden.

Involvement of the choroid plexus in Alzheimer’s disease pathophysiology: findings from mouse and human proteomic studies

BackgroundStructural and functional changes of the choroid plexus (ChP) have been reported in Alzheimer’s disease (AD). Nonetheless, the role of the ChP in the pathogenesis of AD remains largely unknown. We aim to unravel the relation between ChP functioning and core AD pathogenesis using a unique proteomic approach in mice and humans.MethodsWe used an APP knock-in mouse model, APPNL-G-F, exhibiting amyloid pathology, to study the association between AD brain pathology and protein changes in mouse ChP tissue and CSF using liquid chromatography mass spectrometry. Mouse proteomes were investigated at the age of 7 weeks (n = 5) and 40 weeks (n = 5). Results were compared with previously published human AD CSF proteomic data (n = 496) to identify key proteins and pathways associated with ChP changes in AD.ResultsChP tissue proteome was dysregulated in APPNL-G-F mice relative to wild-type mice at both 7 and 40 weeks. At both ages, ChP tissue proteomic changes were associated with epithelial cells, mitochondria, protein modification, extracellular matrix and lipids. Nonetheless, some ChP tissue proteomic changes were different across the disease trajectory; pathways related to lysosomal function, endocytosis, protein formation, actin and complement were uniquely dysregulated at 7 weeks, while pathways associated with nervous system, immune system, protein degradation and vascular system were uniquely dysregulated at 40 weeks. CSF proteomics in both mice and humans showed similar ChP-related dysregulated pathways.ConclusionsTogether, our findings support the hypothesis of ChP dysfunction in AD. These ChP changes were related to amyloid pathology. Therefore, the ChP could become a novel promising therapeutic target for AD.

Chemotactic recruitment of genetically engineered cell membrane-camouflaged metal−organic framework nanoparticles for ischemic osteonecrosis treatment

Ischemic osteonecrosis, particularly glucocorticoid-induced osteonecrosis of the femoral head (GIONFH), is primarily due to the dysfunction of osteogenesis and angiogenesis. miRNA, as a therapeutic system with immense potential, plays a vital role in the treatment of various diseases. However, due to the unique microenvironmental structure of bone tissue, especially in the case of GIONFH, where there is a deficiency in the vascular system, it is challenging to effectively target and deliver to the ischemic osteonecrosis area. A drug delivery system assisted by genetically engineered cell membranes holds promise in addressing the challenge of targeted miRNA delivery. Herein, we leverage the potential of miR-21 in modulating osteogenesis and angiogenesis to design an innovative biomimetic nanoplatform system. First, we employed metal-organic frameworks (MOFs) as the core structure to load miR-21-m (miR-21-m@MOF). The nanoparticles were further coated with the membrane of bone marrow mesenchymal stem cells overexpressing CXCR4 (CM-miR-21-m@MOF), enhancing their ability to target ischemic bone areas via the CXCR4-SDF1 axis. These biomimetic nanocomposites possess both bone-targeting and ischemia-guiding capabilities, actively targeting GIONFH lesions to release miR-21-m into target cells, thereby silencing PTEN gene and activating the PI3K-AKT signaling pathway to regulate osteogenesis and angiogenesis. This innovative miRNA delivery system provides a promising therapeutic avenue for GIONFH and potentially other related ischemic bone diseases. Statement of significance1.CXCR4-Engineered Membranes Enhance Targeting for Ischemic Osteonecrosis.2.miR-21-Based Gene Therapy for Regulating Osteogenesis and Angiogenesis.3.Expanding the Use of Membrane-Cloaked MOF Nanoparticles.

Peripheral sensory nerve regeneration: Novel target in bone tissue engineering

AbstractSynthetic biomaterials are emerging candidate solutions for treating large bone defects. However, the clinical performances of most synthetic materials are not satisfactory, with the need for improvement in design and synthesis. Although bone is highly innervated, the central role during healing of the peripheral nervous system, and in particular sensory nerves (SNs), has only recently been acknowledged. SNs can improve osteogenic differentiation of bone marrow stem/stromal cells through neurotransmitters and peptides; the interplay between SNs and the vascular system also facilitates vascular network reconstruction, indirectly facilitating bone healing. These factors suggest the importance of SNs in bone healing, a vital point that has been overlooked in bone biomaterial design until very recently. SN regeneration represents a novel direction in the development of biomaterials for bone regeneration. The current perspective paper summarizes the cellular and molecular mechanisms under the regulatory influence of SNs in the bone healing process and outlines the recent advances in biomaterials for innervated bone tissue regeneration. This establishes potential future directions for bone engineering biomaterial design.

Numerical simulation of endovascular treatment options for cerebral aneurysms

AbstractPredicting the long‐term success of endovascular interventions in the clinical management of cerebral aneurysms requires detailed insight into the patient‐specific physiological conditions. In this work, we not only propose numerical representations of endovascular medical devices such as coils, flow diverters or Woven EndoBridge but also outline numerical models for the prediction of blood flow patterns in the aneurysm cavity right after a surgical intervention. Detailed knowledge about the postsurgical state then lays the basis to assess the chances of a stable occlusion of the aneurysm required for a long‐term treatment success. To this end, we propose mathematical and mechanical models of endovascular medical devices made out of thin metal wires. These can then be used for fully resolved flow simulations of the postsurgical blood flow, which in this work will be performed by means of a Lattice Boltzmann method applied to the incompressible Navier–Stokes equations and patient‐specific geometries. To probe the suitability of homogenized models, we also investigate poro‐elastic models to represent such medical devices. In particular, we examine the validity of this modeling approach for flow diverter placement across the opening of the aneurysm cavity. For both approaches, physiologically meaningful boundary conditions are provided from reduced‐order models of the vascular system. The present study demonstrates our capabilities to predict the postsurgical state and lays a solid foundation to tackle the prediction of thrombus formation and, thus, the aneurysm occlusion in a next step.

Fructooligosaccharides reverses hepatic vascular dysfunction and dysbiosis in rats with liver cirrhosis and portal hypertension.

Portal hypertension leads to lethal complications in liver cirrhosis. Oxidative stress induced hepatic vascular dysfunction, which exaggerated vasoconstriction and increases hepatic vascular resistance (HVR). Gut dysbiosis further exacerbates portal hypertension. Fructooligosaccharides are prebiotics with potent antioxidant effect. This study aimed to evaluate the roles of fructooligosaccharides in portal hypertension-related vascular dysregulation and gut microbiome. Sprague-Dawley rats received bile duct ligation to induce cirrhosis or sham operation as controls. The rats then randomly received fructooligosaccharides or vehicle for 4 weeks. Experiments were performed on the 29th day after operations. Fructooligosaccharides did not affect portal pressure. Interestingly, fructooligosaccharides significantly attenuated HVR (p = .03). Malondialdehyde, an oxidative stress marker, reduced significantly in the liver in fructooligosaccharides-treated group. In addition, superoxide dismutase and trolox equivalent antioxidant capacity increased in the treatment group. On the other hand, vasodilatation-related protein expressions, GTPCH and phospho-eNOS, enhanced significantly. Fructooligosaccharides had no adverse vasodilatation effects on splanchnic vascular system or porto-systemic collateral systems. Locomotor function was not affected by fructooligosaccharides. Faecal microbiota analysis showed that Negativicutes, Selenomonadales and Lactobacillus salivarius reduced in the fructooligosaccharides-treated group. In conclusion, fructooligosaccharides attenuate hepatic vascular dysfunction in cirrhotic rats via at least partly, ameliorate of dysbiosis and oxidative stress.

Cu-Doping Layered Double Hydroxides Nanozyme Integrated with Nitric Oxide Donor for Enhanced Antioxidant Therapy in Retinopathy.

The prevalence of retinal neovascular diseases necessitates novel treatments beyond current therapies like laser surgery or anti-VEGF treatments, which often carry significant side effects. A novel therapeutic approach is introduced using copper-containing layered double hydroxides (Cu-LDH) nanozymes integrated with nitric oxide-releasing molecules (GSHNO), forming Cu-LDH@GSHNO aimed at combating oxidative stress within the retinal vascular system. Combination of synthetic chemistry and biological testing, Cu-LDH@GSHNO are synthesized, characterized, and assessed for curative effect in HUVECs and an oxygen-induced retinopathy (OIR) mouse model. The results indicate that Cu-LDH@GSHNO demonstrates SOD-CAT cascade catalytic ability, accompanied with GSH and nitric oxide-releasing capabilities, which significantly reduces oxidative cell damage and restores vascular function, presenting a dual-function strategy that enhances treatment efficacy and safety for retinal vascular diseases. The findings encourage further development and clinical exploration of nanozyme-based therapies, promising a new horizon in therapeutic approaches for managing retinal diseases driven by oxidative stress.

Fibroblast growth factor 23 inhibition attenuates steroid-induced osteonecrosis of the femoral head through pyroptosis

Steroid-induced osteonecrosis of the femoral head (SONFH) is the predominant cause of non-traumatic osteonecrosis of the femoral head (ONFH). Impaired blood supply and reduced osteogenic activity of the femoral head are the key pathogenic mechanisms of SONFH. Fibroblast growth factor 23 (FGF23) levels are not only a biomarker for early vascular lesions caused by abnormal mineral metabolism, but can also act directly on the peripheral vascular system, leading to vascular pathology. The aim of this study was to observe the role of FGF23 on bone microarchitecture and vascular endothelium, and to investigate activation of pyroptosis in SONFH. Lipopolysaccharide (LPS) combined with methylprednisolone (MPS) was applied for SONFH mouse models, and adenovirus was used to increase or decrease the level of FGF23. Micro-CT and histopathological staining were used to observe the structure of the femoral head, and immunohistochemical staining was used to observe the vascular density. The cells were further cultured in vitro and placed in a hypoxic environment for 12 h to simulate the microenvironment of vascular injury during SONFH. The effect of FGF23 on osteogenic differentiation was evaluated using alkaline phosphatase staining, alizarin red S staining and expression of bone formation-related proteins. Matrigel tube formation assay in vitro and immunofluorescence were used to detect the ability of FGF23 to affect endothelial cell angiogenesis. Steroids activated the pyroptosis signaling pathway, promoted the secretion of inflammatory factors in SONFH models, led to vascular endothelial dysfunction and damaged the femoral head structure. In addition, FGF23 inhibited the HUVECs angiogenesis and BMSCs osteogenic differentiation. FGF23 silencing attenuated steroid-induced osteonecrosis of the femoral head by inhibiting the pyroptosis signaling pathway, and promoting osteogenic differentiation of BMSCs and angiogenesis of HUVECs in vitro.

Atrial fibrillation and prediabetes: A liaison that merits attention!

Atrial fibrillation (AF) and prediabetes share common pathophysiological mechanisms with endothelial dysfunction and inflammation playing a key role. The resultant vicious cycle which sets in culminates in a higher atherogenicity and thermogenicity of the vascular system resulting in increased major adverse cardiac or cerebrovascular event (MACCE) events. However, the same has not convincingly been verified in real-world settings. In the recent retrospective study by Desai et al amongst AF patients being admitted to hospitals following MACCE, prediabetes emerged as an independent risk factor for MACCE after adjusting for all confounding variables. However, certain questions like the role of metformin, quantifying the risk for MACCE amongst prediabetes compared to diabetes, the positive impact of reversion to normoglycemia remain unanswered. We provide our insights and give future directions for dedicated research in this area to clarify the exact relationship between the two.