Reduction of photodynamic damage of blood vessels in the protected region by(–)-epigallocatechin gallate

Photodynamic therapy(PDT)has been increasingly used in the clinical treatment of neoplastic,inflammatory and infectious skin diseases.However,the generation of reactive oxygen species(ROS)may induce undesired side effects in normal tissue surrounding the treatment lesion,which is a big challenge for the clinical application of PDT.To date,(–)-Epigallocatechin gallate(EGCG)has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage.This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether(Hemoporfin)-mediated PDT.The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized 1O2 generation are determined to be 6.8×10^(8)M^(−1)S^(−1),respectively.The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel,suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG.This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and 1O2,and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

Construction of Oriented Structure in Inner Surface of Small-Diameter Artificial Blood Vessels:A Review

There is an urgent need for small-diameter artificial blood vessels in clinic.Physical,chemical and biological factors should be integrated to avoid thrombosis and intimal hyperplasia after implantation and to promote successful fabrication of small-diameter artificial blood vessels.From a physical perspective,the internal oriented structures of natural blood vessels plays an important role in guiding the directional growth of cells,improving the blood flow environment,and promoting the regeneration of vascular tissue.In this review,the effects of the oriented structures on cells,including endothelial cells(ECs),smooth muscle cells(SMCs)and stem cells,as well as the effect of the oriented structures on hemodynamics and vascular tissue remodeling and regeneration are introduced.Various forms of oriented structures(fibers,grooves,channels,etc.)and their construction methods are also reviewed.Conclusions and future perspectives are given.It is expected to give some references to relevant researches.

Endothelial cells and blood vessels are major targets for COVID-19-induced tissue injury and spreading to various organs

The coronavirus disease 2019(COVID-19)infected so far over 250 million people and caused the death of over 5 million worldwide.Aging,diabetes,and cardiovascular diseases,conditions with preexisting impaired endothelial functions predispose to COVID-19.While respiratory epithelium is the main route of virus entry,the endothelial cells(ECs)lining pulmonary blood vessels are also an integral part of lung injury in COVID-19 patients.COVID-19 not only affects the lungs and respiratory system but also gastrointestinal(GI)tract,liver,pancreas,kidneys,heart,brain,and skin.Blood vessels are likely conduits for the virus dissemination to these distant organs.Importantly,ECs are also critical for vascular regeneration during injury/lesions healing and restoration of vascular network.The World Journal of Gastroenterology has published in last two years over 67 outstanding papers on COVID-19 infection with a focus on the GI tract,liver,pancreas,etc.,however,the role of the endothelial and vascular components as major targets for COVID-19-induced tissue injury,spreading to various organs,and injury healing have not been sufficiently emphasized.In the present article,we focus on these subjects and on current treatments including the most recent oral drugs molnupiravir and paxlovid that show a dramatic,significant efficacy in controlling severe COVID-19 infection.

Novel Method Employing Accelerated-Oscillated Wave Saline Solutions to Unblock Blood Vessels—Physics and Fluid Dynamics Perspectives and Simulations

This research assesses the speed of blood flow across blood vessels and more specifically the veins in terms of Reynold’s number (laminar flow vs. turbulence flow) and in terms of overall speed of the blood when being injected with high-speed saline particles. The authors propose a novel technique to generate accelerated-waved particles built from saline solution to enable the unblocking of partially-blocked healthy-walled veins, and to restore normal operations of these veins. The novel technique encompasses a pump that accelerates saline solutions into the blood stream of the vein and these oscillated waves break down the fats or deposits inside the veins in order to help the blood to flow freely without any obstruction. This research simulated the vein with blood stream using characteristics of the vein in terms of vein diameter, blood density, venous blood flow, and the viscosity of the blood at the normal body temperature. The speed of the overall blood flow after the injection of the accelerated saline droplet solution was determined as well as the depth of penetration of the accelerated particles in order to cleanse the inside of the vein. Results are promising in terms of not altering significantly the overall speed of the bloodstream and also in terms of efficacy of the length of the vein which is being cleaned using this accelerated particle method.

BLOOD FLOW AND MACROMOLECULAR TRANSPORT IN CURVED BLOOD VESSELS

A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow.

Reflection-mode photoacoustic microscopy using a hollow focused ultrasound transducer for in vivo imaging of blood vessels

A reflection-mode photoacoustic microscope using a hollow focused ultrasound transducer is developed for highresolution in vivo imaging.A confocal structure of the laser and the ultrasound is used to improve the system resolution.The axial and lateral resolutions of the system are measured to be ～ 32 μm and ～ 58 μm,respectively.Ex vivo and in vivo modes are tested to validate the imaging capability of the photoacoustic microscope.The adjacent vein and artery can be seen clearly from the reconstructed photoacoustic images.The results demonstrate that the reflectionmode photoacoustic microscope can be used for high-resolution imaging of micro-blood vessels,which would be of great benefit for monitoring the neovascularization in tumor angiogenesis.

Design and Development of PHBV/PLA Artificial Blood Vessels

In the research,a β-hydroxybutyrate and β-hydroxyvalerate copolymer(PHBV)/polylactic acid(PLA)artificial blood vessel was designed and developed,and it was also implanted in vivo for a period of time to observe its biocompatibility and degradation performance.The results showed that the developed PHBV/PLA artificial blood vessel could be used to replace the natural blood vessel,but its degradation rate was too fast and the mechanical supporting force was insufficient.Thus,properties of the PHBV/PLA need to be further improved.

Glioma stem cells and the occurrence of tumor blood vessels

Epithelial glioma is the most common brain cancer,accounting for 35.26%-60.69%of intracranial tumors with an average of 44.69%,and it remains the greatest challenge in the field of neurosurgery.The median survival time of patients with advanced glioma is only 12 to 18 months due to the characteristics of high aggression,and the therapeutic effect was poor though surgery,chemotherapy,and targeted drug therapy being treated.Because of the presence of heterogeneity and the differentiation disorder,only a small number of glioma cells are the source of tumor growth and metastasis,which are highly resistant to traditional treatments.They are deemed as the“seed”tumor cells as they could get rid of the effect of the treatment and reconstruct the organization of tumor.They are also termed as brain tumor stem cell(BTSC)or glioma stem cells(GSCs)since neural stem cells share similar features with them.Recent data reveal that they are directly related with invasion,angiogenesis,tolerance,chemotherapy,recurrence of glioma.Based on the research result by the team,the paper elaborates the characteristics of GSCs and the relationship with the tumor angiogenesis.

A Comparative Study Between Tumor Blood Vessels and Dynamic Contrast-enhanced MRI for Identifying Isocitrate Dehydrogenase Gene 1(IDH1)Mutation Status in Glioma

Objective Isocitrate dehydrogenase gene(IDH)mutations are associated with tumor angiogenesis and therefore play an important role in glioma management.This study compared the performance of tumor blood vessels counted from contrast-enhanced 3D brain volume(3D-BRAVO)sequence and dynamic contrast-enhanced(DCE)MRI in differentiating IDH1 status in gliomas.Methods Forty-four glioma patients[16 with IDH1 mutant-type(IDH1-MT),28 with IDH1 wild-type(IDH1-WT)]were retrospectively analyzed.A blood vessel entering a tumor was defined as an intratumoral vessel;a blood vessel adjacent to the edge of a tumor was defined as a peritumoral vessel.Combined vessels were defined as the sum of the intratumoral and peritumoral vessels.DCE-derived metrics of tumor were normalized to the contralateral normal-appearing white matter.Results Intratumoral,peritumoral,and combined tumor blood vessels were all significantly different between IDH1-MT and IDH1-WT gliomas,and the range of area under curves(AUCs)was 0.816–0.855.For DCE-derived parameters,cerebral blood volume,cerebral blood flow,mean transit time,and volume transfer constant were significantly different between IDH1-MT and IDH1-WT gliomas,and the range of AUCs was 0.703–0.756.Combined vessels possessed the best performance for identifying IDH1 mutations in gliomas(AUC:0.855,sensitivity:0.857,specificity:0.812,P<0.001).Conclusion The number of tumor blood vessels has comparable diagnostic performance with DCE-derived parameters for differentiating IDH1 mutations and can serve as a potential imaging biomarker to reflect IDH1 mutations in gliomas.

Bioprinting of Small-Diameter Blood Vessels

There has been an increasing demand for bioengineered blood vessels for utilization in both regenerative medicine and drug screening.However,the availability of a true bioengineered vascular graft remains limited.Three-dimensional(3D)bioprinting presents a potential approach for fabricating blood vessels or vascularized tissue constructs of various architectures and sizes for transplantation and regeneration.In this review,we summarize the basic biology of different blood vessels,as well as 3D bioprinting approaches and bioink designs that have been applied to fabricate vascular and vascularized tissue constructs,with a focus on small-diameter blood vessels.

Fabrication and data harvesting of casting sample of rat liver blood vessels

BACKGROUND: The configuration and course of liver blood vessels (LBVs) are involved in the study of patho-genesis of hepatic diseases including liver cirrhosis, tissue engineering of the liver and surgical treatment of diseases of the liver and gallbladder. In the study of vascularization in tissue engineering of the liver in particular, the work we should do is to get the anatomy data of LBVs for computer-aided reconstruction of digital model of LBVs. In doing so, the casting sample of rat liver blood vessels (RLBVs) is fabricated and the data of each section of the sample is harvested. METHODS: Liquid polymer preparation (8%-10%), which was made of chlorinated poly vinyl chloride ( CPVC) as a solute, acetone as solvent and pigment, was injected into the RLBVs of 40 rats. Once acetone evaporated, the preparation solidified. When the cells and connective tissue were dissolved by hydrochloric acid, a casting sample of RLBV was left. The sample was embedded in paraffin and cut into sections. The data of each section of RLBVs was collected by digital camera. RESULTS: In 36 rats, the casting sample of RLBVs was made successfully by this method. The diameter of the hepatic arteries varied from 0. 8 to 0.2 mm, the portal veins from 2.0 to 0.1 mm, and the hepatic veins from 2.2 to 0.2 mm. In each rat, about 150 photographs of the sections of RLBVs were taken. CONCLUSION: The method described above is feasible for getting experimental data for computer-aided reconstruction of the digital model of RLBVs.

Protocol to study the effects of AMPK-mTOR/PINK-Parkin dual signaling pathways on the formation of coronary heart disease showing blood stasis symptom pattern based on traditional Chinese medicine theory of“heart governing blood and vessels”

In this study,we aim to combine gene transfection techniques with the modeling methods previously employed by the research group to deeply investigate the corresponding theories of traditional Chinese medicine regarding“myocardial energy metabolism”and“aortic thrombosis”.Our goal is to elucidate the biological mechanism underlying the occurrence and development of coronary heart disease with blood stasis syndrome from the perspectives of“heart and vessels”and“Qi(in traditional Chinese medicine,it refers to the most fundamental and subtle substances that constitute the human body and maintain life activities.At the same time,it also has the meaning of physiological function.In terms of traditional Chinese medicine,Qi and different words are used together to express different meanings)and blood”.The research content is divided into four modules as follows:1.establishment of an animal model of coronary heart disease with blood stasis syndrome through fibrinogen overexpression.2.Investigation of the mitochondrial quality control system in coronary heart disease with blood stasis syndrome under fibrinogen overexpression.3.Study of platelet autophagy in coronary heart disease with blood stasis syndrome under fibrinogen overexpression.4.Examination of the relationship between the AMPK-mTOR pathway and metabolism in platelet autophagy of coronary heart disease with blood stasis syndrome under fibrinogen overexpression.Ninety-six Sprague Dawley rats will be randomly assigned to the following groups:control group,model group,fibrinogen group and adeno-associated virus group.All rats will undergo a 14-week model construction process,and modern molecular biology methods will be employed to evaluate the model and examine relevant research indicators.The obtained data will be analyzed according to a predefined statistical analysis plan.

Hemocompatible polyurethane/gelatin-heparin nanofibrous scaffolds formed by a bi-layer electrospinning technique as potential artificial blood vessels

In this paper,a scaffold,which mimics the morphology and mechanical properties of a native blood vessel is reported.The scaffold was prepared by sequential bi-layer electrospinning on a rotating mandrel-type collector.The tubular scaffolds(inner diameter 4 mm,length 3 cm)are composed of a polyurethane(PU)fibrous outer-layer and a gelatin-heparin fibrous inner-layer.They were fabricated by electrospinning technology,which enables control of the composition,structure,and mechanical properties of the scaffolds.The microstructure,fiber morphology and mechanical properties of the scaffolds were examined by means of scanning electron microscopy(SEM)and tensile tests.The PU/gelatinheparin tubular scaffolds have a porous structure.The scaffolds achieved a breaking strength(3.7±0.13 MPa)and an elongation at break(110±8%)that are appropriate for artificial blood vessels.When the scaffolds were immersed in water for 1 h,the breaking strength decreased slightly to 2.2±0.3 MPa,but the elongation at break increased to 145
21%.In platelet adhesion tests the gelatin-heparin fibrous scaffolds showed a significant suppression of platelet adhesion.Heparin was released from the scaffolds at a fairly uniform rate during the period of 2nd day to 9th day.The scaffolds are expected to mimic the complex matrix structure of native arteries,and to have good biocompatibility as an artificial blood vessel owing to the heparin release.

The importance of laminin at the blood-brain barrier

The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.

New Stroke-healing Gel Helped Regrow Neurons and Blood Vessels in Mice with Stroke-damaged Brains, Hinting at What May Someday Be a New Therapy for Stroke in People

In a first-of-its-kind finding,a new stroke-healing gel helped regrow neurons and blood vessels in mice with stroke-damaged brains.The results suggest that such an approach may someday be a new therapy for stroke in people.The study tested this in laboratory mice to determine if it would repair the brain in a model

Tea May Benefit Blood Vessels

读到有关饮茶有益健康的消息,我总是充满了自豪感:茶的故乡毕竟在中国。饮茶对人的心脏有益,这已经不是新闻,但是到底如何起到此类保健作用,多年来一直是一个谜。本文揭开了此谜底: Drinking a cup of tea makes blood vessels work better within 2 hours, dilating(扩张)the arteries(动脉)and improving blood flow. 文章令我感动之处在于那些科研人员的敬业精神。比如茶中含有caffeine(咖啡因),饮茶对心脏有利,此“利”是否源于caffeine呢?试验人员为了弄清这 一点,便让另一组受试人员服用等量的caffeine,结果证实:Caffeine had no response on the blood vessel function.】

Medical application of diffraction enhanced imaging in mouse liver blood vessels

Neovascularization is correlative with many processes of diseases, especially for tumor growth, invasion, and metastasis. What is more, these tumor microvessels are totally different from normal vessels in morphology. Therefore, observation of the morphologic distribution of microvessels is one of the key points for many researchers in the field. Using diffraction enhanced imaging （DEI）, we observed the mirocvessles with diameter of about 40 μm in mouse liver. Moreover, the refraction image obtained from DEI shows higher image contrast and exhibits potential use for medical applications.

COMPUTATIONAL TECHNIQUE FOR FLOW IN BLOODVESSELS WITH POROUS EFFECTS

A finite element solution for the Navier-Stokes equations for steady flow under the porosity effects through a double branched two-dimensional section of a three-dimensional model of a canine aorta was obtained. The numerical solution involves transforming a physical coordinates to a curvilinear boundary fitted coordinate system.The steady flow,branch flow and shear stress under the porous effects were discussed in detail. The shear stress at the wall was calculated for Reynolds number of 1 000 with branch to main aortic flow rate ratio as a parameter. The results are compared with earlier works involving experimental data and it has been observed that our results are very close to the exact solutions.This work is in fact an improvement of the work of Sharma et al. (2001) in the sense that computational technique is economic and (Reynolds) number is large.