Rabbit Arteries Research Articles

Assessment of Blood Clot Formation in the Rabbit Artery upon Implantation of Polyurethane Vascular Prosthesis Treated with Nitrogen Plasma

Assessment of Blood Clot Formation in the Rabbit Artery upon Implantation of Polyurethane Vascular Prosthesis Treated with Nitrogen Plasma

A rabbit model for embolic infarct potentials of injectables using ultrasound-guided carotid artery puncture

In order to evaluate the in vivo thrombogenicity of injectable agents, a suitable animal model is needed. We introduce an ultrasound-guided non-selective cerebral artery occlusion model via the common carotid arteries of rabbits. A total of 30 rabbits were assigned to an experimental group (n = 20) and a control group (n = 10). Each group received 2 mL suspension of embolic agent or 2 mL of normal saline, respectively, under ultrasound guidance. The animals were observed for immediate reaction and underwent magnetic resonance imaging (MRI) scan. Follow-up neurologic examination was conducted 24 h following the procedure. In 7 of the 30 rabbits, 2 in the control group and 5 in the experimental group, the administration of either normal saline or the embolic agent failed. Among the successfully injected 15 experimental animals, 14 showed neurologic impairment or deceased, whereas 1 animal did not show significant neurologic deficit. The MRI of 4 experimental animals showed detectable cerebral infarction on diffusion-weighted imaging. None of the 8 control animals showed neurologic abnormality and their brain MRI was normal. Our minimally invasive model is technically feasible and competent to show thrombogenecity of an injectable agent and consequent in vivo neurologic outcome.

Repair effect of the poly (D,L-lactic acid) nanoparticle containing tauroursodeoxycholic acid-eluting stents on endothelial injury after stent implantation.

Chronic endoplasmic reticulum stress (ERS) plays a crucial role in cardiovascular diseases. Thus, it can be considered a therapeutic target for these diseases. In this study, poly (D,L-lactic acid) (PDLLA) nanoparticle-eluting stents loaded with tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, was fabricated to assess their ability to reduce endothelial cell apoptosis and promote re-endothelialization after stent implantation. PDLLA nanoparticles loaded with TUDCA were prepared via the emulsification-solvent evaporation method. The cumulative release rates of TUDCA were measured in vitro via high-performance liquid chromatography. The carotid arteries of rabbits were subsequently implanted with stents in vivo. The rabbits were then sacrificed after 4 weeks for scanning electron microscopy. Meanwhile, TUDCA concentration in the homogenate of the peripheral blood and distal vascular tissue after stent implantation was measured. The effect of TUDCA on ERS, apoptosis, and human umbilical vein endothelial cell (HUVEC) function was investigated in vitro by performing cell migration assay, wound healing assay, cell proliferation assays, endoplasmic reticulum (ER)-specific fluorescence staining, immunofluorescence, and western blotting. TUDCA nanoparticles were released slowly over 28 days. In addition, TUDCA-eluting stents enhanced re-endothelialization and accelerated the recovery of endotheliocytes in vivo. ERS and apoptosis significantly increased in H2O2-treated HUVECs in vitro. Meanwhile, TUDCA reduced apoptosis and improved function by inhibiting ERS in H2O2-treated HUVECs. Decreased rates of apoptosis and ERS were observed after silencing XBP-1s in H2O2-treated HUVECs. TUDCA can inhibit apoptosis and promote re-endothelialization after stent implantation by inhibiting IRE/XBP1s-related ERS. These results indicate the potential therapeutic application of TUDCA as a drug-coated stent.

The inhibiting effect of alpha-based TARE on embolized vessels and neovascularization.

Transarterial embolization (TAE) is a personalized technology that offers precise delivery of chemotherapeutic drugs or selective internal radiation therapy for hepatocellular carcinoma (HCC). Beta-emitting radionuclide embolisms for TAE (β-based TARE) are commonly used in the clinic via inducing biochemical lethality on tumor cells, while alpha-emitting radionuclides-based embolisms for TAE (α-based TARE) are still under study. The feeding artery plays a key role in tumor growth, metastasis, and recurrence. In this research, the auricular central arteries (ACAs) of rabbits were embolized with silk fibroin-based microspheres (SFMs) or SFMs integrated with α (Ra-223) or β (I-131) radionuclides to investigate the influence on vessels. TARE-induced tissue necrosis and the following neovascularization were measured by pathological analysis and 68Ga-DOTA-RGD PET/CT. The results showed that, compared to I-131, Ra-223 enhanced the growth inhibition of human hepatoma cells Huh-7 and induced more DNA double-strand breaks in vascular smooth muscle cells. Unlike β-based TARE, which mainly led to extensive necrosis of surrounding tissues, α-based TARE induced irreversible necrosis of a limited area adjacent to the embolized vessels. RGD PET revealed the inhibition on neovascularization in α-based TARE (SUVmax = 0.053 ± 0.004) when compared with normal group (SUVmax = 0.099 ± 0.036), the SFMs-lipiodol group (SUVmax = 0.240 ± 0.040), and β-based TARE (SUVmax = 0.141 ± 0.026), owing to the avoidance of the embolism-induced neovascularization. In conclusion, α-based TARE provided a promising strategy for HCC treatments via destroying the embolized vessels and inhibiting neovascularization.

Fasudil inhibits hepatic artery spasm by repressing the YAP/ERK/ ETA/ETB signaling pathway via inhibiting ROCK activation.

Objective: To explore the effect of Fasudil on HA spasm and its underlying mechanism.Methods: Rabbits were divided into Sham, Fasudil, and Model groups for experiments. Fasudil was injected into the left medial lobe of the rabbit liver using a 16G lumbar puncture needle through the laparotomic route. The spasm model was established by inserting the catheter sheath into the femoral arteries of rabbits, followed by celiac artery angiography and left HA catheterization with a micro-catheter. Next, the GSE60887 and GSE37924 datasets concerning Fasudil treatment were analyzed. Moreover, immunofluorescence staining was conducted for YAP1 and α-SMA. Finally, Western blotting was performed to examine the expressions of YAP1, ROCK, ERK1/2, ETA, and ETB.Results: Fasudil could relieve HA spasm. The Go and KEGG pathway analyses revealed that the MAPK signaling pathway and the Hippo signaling pathway were enriched in vasospasm. Besides, GSEA revealed that ROCK was functionally enriched in the MAPK and Hippo signaling pathways. Co-expression analysis revealed that MAPK1 was significantly correlated with YAP1 and MYC, and YAP1 was significantly correlated with ETA and ETB. It was manifested in the results of immunofluorescence staining that the YAP1-positive fluorescence area was significantly decreased after Fasudil treatment. Moreover, Western blotting results showed that Fasudil decreased the expressions of YAP1, RhoA, ROCK, ETA, ETB, and p-ERK1/2. In addition, in-vitro Western blotting revealed that Fasudil suppressed the YAP/ERK/ETA/ETB signaling pathway in the case of HA spasm by inhibiting ROCK activation.Conclusions: Fasudil ameliorates HA spasm through suppressing the YAP/ERK/ETA/ETB signaling pathway and the ROCK activation.

Matrix Regeneration Ability In Situ Induced by a Silk Fibroin Small-Caliber Artificial Blood Vessel In Vivo.

The success of a small-caliber artificial vascular graft in the host in order to obtain functional tissue regeneration and remodeling remains a great challenge in clinical application. In our previous work, a silk-based, small-caliber tubular scaffold (SFTS) showed excellent mechanical properties, long-term patency and rapid endothelialization capabilities. On this basis, the aim of the present study was to evaluate the vascular reconstruction process after implantation to replace the common carotid artery in rabbits. The new tissue on both sides of the SFTSs at 1 month was clearly observed. Inside the SFTSs, the extracellular matrix (ECM) was deposited on the pore wall at 1 month and continued to increase during the follow-up period. The self-assembled collagen fibers and elastic fibers were clearly visible in a circumferential arrangement at 6 months and were similar to autologous blood vessels. The positive expression rate of Lysyl oxidase-1 (LOXL-1) was positively correlated with the formation and maturity of collagen fibers and elastic fibers. In summary, the findings of the tissue regeneration processes indicated that the bionic SFTSs induced in situ angiogenesis in defects.

Effects of exogenous hydrogen sulfide on pulmonary hypertension in rabbits with endotoxic shock

Objective: To investigate the effects of exogenous hydrogen sulfide (H2S) on pulmonary vascular reactivity induced by endotoxic shock (ES) in rabbits. Methods: In this experiment, the model of endotoxic shock (ES) was induced by injection of lipopolysaccharides (LPS) to New Zealand big eared white rabbit through jugular vein (8 mg/0.8 ml/kg), the intervention was performed by H2S donor(sodium hydrosulfide, NaHS) which was injected intraperitoneally (28 μmol/kg) 15 min in advance. New Zealand rabbits were randomly divided into 4 groups(n=8):control group, LPS group, LPS+NaHS group and NaHS group. The changes of mean arterial pressure (MAP) and mean pulmonary arterial pressure (MPAP) were detected. The tension of pulmonary artery ring (PARs) was detected byin vitro vascular ring technique. The ultrastructure of pulmonary artery wall and pulmonary artery endothelial cells were observed by light microscope and scanning electron microscope. Results: ①MAP was decreased while MPAP was increased in rabbits after LPS injection, and ES animal model was established successfully. Compared with LPS group, mPAP of rabbit in LPS+NaHS group was decreased significantly (all P＜0.05). ②Compared with normal control group, pulmonary artery of rabbits in LPS group had an increased contractile response to phenylephrine (PE) and a decreased relaxation response to acetylcholine (ACh) (both P＜0.01); Compared with LPS group, pulmonary artery of rabbits in LPS+NaHS group had a decreased contractile response to PE and an increased relaxation response to ACh (both P＜0.05). ③Under light microscope, the structure of vascular endothelial cells was continuous in the normal control group, the elastic fibers were intact in the subcutaneous layer, and the smooth muscle layer was arranged neatly. LPS can shed some of the pulmonary artery endothelial cells, break the subcutaneous elastic fibers, and disorder the smooth muscle layer structure. Compared with LPS group, the injury of pulmonary artery wall in LPS+NaHS group was ameliorated. The morphology of pulmonary artery wall was normal in NaHS group. It is showed that some endothelial cells of pulmonary artery were missing in LPS group by Scanning electron microscopy. The morphology of pulmonary artery endothelial cells in LPS+NaHS group was similar to that in the control group: slightly widened intercellular space was observed, and no cell exfoliation was observed. Conclusion: These results suggest that exogenous H2S can protect pulmonary artery endothelial cells and regulate the reactivity changes of pulmonary artery during ES, which may be one of the mechanisms reducing PAH in ES rabbits.

A preliminary study on perioperative hemostatic effect of spray dried powder of <em>Chromolaena odorata</em> leaf extract

Accidents or surgery often cause internal haemorrhage in liver and arteries which may lead to patient morbidity and mortality. The current hemostatic agents used for treatment like collagen, oxidized cellulose, and chitosan suffer from side effects which include infection, inflammation and even sepsis. In the present study, we studied the spray dried powder (SDP) of the aqueous extract of the leaves of Chromolaena odorata (L.) R.M.King & H.Rob., commonly known as Siam weed or Common floss flower and also Christmas bush, for its hemostatic efficacy in two experimental models of surgery. Firstly, the SDP was screened through standard pharmacognostical parameters, and a part of the liver was lacerated in rats and femoral artery was transected in rabbits to assess the blood loss in pre-weighed gauze with and without treatment. In the liver laceration model, an effective blood loss reduction of 54.30 % was observed with oral administration of SDP 7 days prior to surgery. Similarly, application of SDP at the site of artery transection caused 70.36% reduction in blood loss as compared to the control rabbit artery. The results suggest that oral delivery and/or application of SDP of C. odorata by formulating it in a suitable drug delivery tool could minimize perioperative bleeding in hepatic and arterial tissue and improve recovery.

Blood vessel assessment using computed tomography : Effects of ephedrine on uterine artery.

Background: Ephedrine increased blood pressure due to the contractile properties of resistance vessels. Excessive contraction of the uterine arteries might cause fetal distress. This study was to determine the diameter of the uterine artery of female New Zealand rabbits after the administration of different doses of ephedrine using CT.Methods: Thirty-two rabbits were randomly divided into a control group (Group C), low dosage group (Group L), medium dosage group (Group M) and high dosage group (Group H). Normal saline and doses corresponding to the human dose of 7.5, 15 and 30 mg of ephedrine were injected respectively. The marginal ear and uterine artery diameters were measured 5, 10, 15, 30, and 45 min after injection using CT, and the hemodynamic changes were recorded.Results: The increase in mean arterial pressure in group M (p = 0.009), and H (p = 0.013) was higher than that in group C. Compared with group C, substantial contraction of the marginal ear artery was observed at the three doses of ephedrine. There were no differences in the uterine artery diameter among groups L, M and C, However, in Group H, a significant contraction of the uterine artery compared with the other groups (p < 0.001) was observed.Discussion: CT can be used to evaluate the effects of drugs on organs and blood vessels. Ephedrine can not only constrict the peripheral blood vessels but also do not affect the uterine artery at a dose of 15 mg or less. However, the dose should not exceed 30 mg, which may cause severe uterine artery depression.

3D printed personalized, heparinized and biodegradable coronary artery stents for rabbit abdominal aorta implantation

Biodegradable stents have become the focus of attention in the field of interventional medicine. Compared to non-biodegradable stents, these stents are designed to degrade, leaving behind regenerating healthy arteries. In addition to biodegradability, customizability and anticoagulation are also important for stent treatments. The combination of magnetic resonance angiography (MRA) and 3D printing can customize coronary stents according to different vascular geometries of patients. Therefore, this work focused on the rapid fabrication of stents composed of polycaprolactone (PCL) by 3D printing and then functionalized the stents with heparin via covalent grafting. The 3D printed stents were implanted into the abdominal aorta of rabbits to evaluate the feasibility of implantation and biocompatibility. Mechanical tests showed that 3D printed stents have good mechanical properties. In vitro data demonstrated that the stents had excellent blood compatibility and cytocompatibility. The heparinized PCL(PCL-NH2-Hep) stent can promote the adhesion, spreading and proliferation of human umbilical vein endothelial cells (HUVECs) and inhibit the excessive proliferation of smooth muscle cells (SMCs). Presently, there is insufficient study about 3D printed stent implantation in rabbit arteries. Hence, personalized stents were prepared via MRA and 3D printing, which tailored to the patient's unique anatomy. A 3D printed stent-balloon delivery system was employed to deliver stents to the abdominal aorta. At 3-month follow-up, the PCL-NH2-Hep stent maintained good vascular patency. Moreover, the heparinized stents showed rapid endothelialization and prevention of neointimal restenosis in vivo. This study demonstrated that personalized PCL-NH2-Hep stent may have the potential in the field of biodegradable coronary artery stents.

A Dual-Bioinspired Tissue Adhesive Based on Peptide Dendrimer with Fast and Strong Wet Adhesion.

Although tissue adhesives have potential advantages over traditional sutures, existing ones suffer from several limitations: slow adhesion kinetic, low mechanical strength, and poor interfacial bonding with wet biological tissues. Herein, a cooperative mussel/slug double-bioinspired hydrogel adhesive (DBHA) composed of a robust adhesive interface and a stretchable dissipative matrix is developed. The DBHA is formed by a cationic polysaccharide (chitosan), an anionic polysaccharide (carboxymethyl cellulose), and a barbell-like dendritic lysine grafted with catechol groups (G3KPCA). Compared to various commercial bio-glues and traditional adhesives, the DBHA has significantly stronger tissue adhesion and enhanced toughness both ex vivo and in vivo. Meanwhile, the DBHA exhibits fast, strong, tough, and durable adhesion to diverse ex vivo tissue surfaces with blood. The adhesion energy between the adhesive and porcine skin can reach 200-900 J m-2 . Additionally, in vivo studies prove that DBHA has good hemostasis of rabbit artery trauma and achieves better wound healing of tissue incision than commercial bio-glues. This study provides a novel strategy for fabricating fast and strong wet adhesives, which can be used in many applications, such as soft robots, tissue adhesives and hemostats.

Effects of Cervical Rotatory Manipulation on Hemodynamics and Plaque Stability of Atherosclerotic Internal Carotid Artery in Rabbits

ObjectiveThe purpose of this study was to investigate the effects of cervical rotatory manipulation (CRM) on hemodynamics and plaque stability of atherosclerotic internal carotid artery (ICA) in rabbits. MethodsForty rabbits were randomly divided into 4 groups: (1) internal carotid atherosclerosis (ICAS) rabbits treated with CRM (ICAS-CRM group); (2) ICAS rabbits treated without CRM (ICAS group), (3) Normal-CRM group (normal rabbits treated with CRM), and (4) blank control group. In the ICAS-CRM group and ICAS group, the ICAS model was induced by ICA balloon injury combined with a high-fat diet for 12 weeks. CRM was applied to rabbits in the ICAS-CRM and the Normal-CRM groups. During the study, an ultrasonography examination was performed for detecting plaque and hemodynamics on the ICAs. At the end of the study, all atherosclerotic ICAs were removed for histological and immunohistochemical detection. ResultsThe hemodynamics (especially end-diastolic velocity, resistance index, and pulsatility index) through the ICAs were adversely affected by atherosclerosis while not adversely affected by CRM. Compared with the ICAS group, the micro-vessel density and average integrated optical densities of macrophages in the ICAS-CRM group were significantly increased. Compared to the ICAS group, in the ICAS-CRM group, the atherosclerosis was more serious, and the tunica intima was more unstable. ConclusionsAlthough CRM did not affect the hemodynamic index of ICA, it was observed to decrease the stability of severe ICAS plaques in rabbits, which may increase the plaque vulnerability.

A Senolytic-Eluting Coronary Stent for the Prevention of In-Stent Restenosis.

The vast majority of drug-eluting stents (DES) elute either sirolimus or one of its analogues. While limus drugs stymie vascular smooth muscle cell (VSMC) proliferation to prevent in-stent restenosis, their antiproliferative nature is indiscriminate and limits healing of the endothelium in stented vessels, increasing the risk of late-stent thrombosis. Oxidative stress, which is associated with vascular injury from stent implantation, can induce VSMCs to undergo senescence, and senescent VSMCs can produce pro-inflammatory cytokines capable of inducing proliferation of neighboring nonsenescent VSMCs. We explored the potential of senolytic therapy, which involves the selective elimination of senescent cells, in the form of a senolytic-eluting stent (SES) for interventional cardiology. Oxidative stress was modeled in vitro by exposing VSMCs to H2O2, and H2O2-mediated senescence was evaluated by cytochemical staining of senescence-associated β-galactosidase activity and qRT-PCR. Quiescent VSMCs were then treated with the conditioned medium (CM) of H2O2-treated VSMCs. Proliferative effects of CM were analyzed by staining for proliferating cell nuclear antigen. Senolytic effects of the first-generation senolytic ABT263 were observed in vitro, and the effects of ABT263 on endothelial cells were also investigated through an in vitro re-endothelialization assay. SESs were prepared by dip coating. Iliofemoral arteries of hypercholesteremic rabbits were implanted with SES, everolimus-eluting stents (EESs), or bare-metal stents (BMSs), and the area of stenosis was measured 4 weeks post-implantation using optical coherence tomography. We found that a portion of H2O2-treated VSMCs underwent senescence, and that CM of H2O2-treated senescent VSMCs triggered the proliferation of quiescent VSMCs. ABT263 reverted H2O2-mediated senescence and the proliferative capacity of senescent VSMC CM. Unlike everolimus, ABT263 did not affect endothelial cell migration and/or proliferation. SES, but not EES, significantly reduced stenosis area in vivo compared with bare-metal stents (BMSs). This study shows the potential of SES as an alternative to current forms of DES.

Functionalized Spiral-Rolling Millirobot for Upstream Swimming in Blood Vessel.

Untethered small robots with multiple functions show considerable potential as next‐generation catheter‐free systems for biomedical applications. However, owing to dynamic blood flow, even effective upstream swimming in blood vessels remains a challenge for the robot, let alone performing medical tasks. This paper presents an untethered millirobot with a streamlined shape that integrates the engine, delivery, and biopsy modules. Based on the proposed spiral‐rolling strategy, this robot can move upstream at a record‐breaking speed of ≈14 mm s−1 against a blood phantom flow of 136 mm s−1. Moreover, benefiting from the bioinspired self‐sealing orifice and easy‐open auto‐closed biopsy needle sheath, this robot facilitates several biomedical tasks in blood vessels, such as in vivo drug delivery, tissue and liquid biopsy, and cell transportation in rabbit arteries. This study will benefit the development of wireless millirobots for controllable, minimally invasive, highly integrated, and multifunctional endovascular interventions and will inspire new designs of miniature devices for biomedical applications.

Interaction between bacteria and cholesterol crystals: Implications for endocarditis and atherosclerosis.

BackgroundThe interaction between pathogenic bacteria and cholesterol crystals (CCs) has not been investigated. However, CCs are found extensively in atherosclerotic plaques and sclerotic cardiac valves. Interactions between pathogenic bacteria and CCs could provide insights into destabilization of atherosclerotic plaques and bacterial adhesion to cardiac valves.MethodsStaphylococcus aureus and Pseudomonas aeruginosa were used to assess in vitro bacterial adhesion to CCs and proliferation in the presence of CCs compared to plastic microspheres and glass shards as controls. Ex vivo studies evaluated bacterial adhesion to atherosclerotic rabbit arteries compared to normal arteries and human atherosclerotic carotid plaques compared to normal carotid arteries. Scanning electron microscopy (SEM) was used to visualize bacterial adhesion to CCs and confocal microscopy was used to detect cholesterol binding to bacteria grown in the presence or absence of CCs.ResultsIn vitro, S. aureus and P. aeruginosa displayed significantly greater adhesion, 36% (p<0.0001) and 89% (p<0.0001), respectively, and growth upon exposure to CCs compared to microspheres or glass shards. Rabbit and human atherosclerotic arteries contained significantly greater bacterial burdens compared to controls (4× (p<0.0004); 3× (p<0.019), respectively. SEM demonstrated that bacteria adhered and appeared to degrade CCs. Consistent with this, confocal microscopy indicated increased cholesterol bound to the bacterial cells.ConclusionsThis study is the first to demonstrate an interaction between bacteria and CCs showing that bacteria dissolve and bind to CCs. This interaction helps to elucidate adhesion of bacteria to sclerotic valves and atherosclerotic plaques that may contribute to endocarditis and plaque destabilization.

Improve endothelialization of metallic cardiovascular stent via femtosecond laser induced micro/nanostructure dependent cells proliferation and drug delivery control

Regarding restenosis occurrence risk after metallic stent deployment in artery, stents with vascular smooth muscle cells antiproliferative agents sustained released from poly(lactic-co-glycolic acid) (PLGA) coating and endothelial cells proliferation favored surface textures were both attempted for endothelialization enhancement. In order to explore the interaction between the surface texture and performance of drug loaded PLGA coating, femtosecond laser surface treatment was used to change the surface characteristics of 316L stainless steel. Two different surface patterns in form of stripe (FSL100) and isolated island-like structure (FSL800) were firstly generated by femtosecond laser processing with 100 and 800 mW energy, then Rapamycin loaded PLGA coating was further deposited to polished and femtosecond laser processed 316L surfaces via a dip-coating method. The subsequent drug loading capacity and release profile studies confirmed the roles of surface texture. Morphological transition characteristics of the PLGA coating on the FLS100 sample indicate that the coating has integrity during degradation compared to the polished one. Finally, rapamycin eluting FLS100 stent was deployed to iliac arteries of New Zealand White rabbits with vascular plaques to demonstrate its endothelialization potential and resistance to restenosis.

Fabrication and Hemocompatibility Evaluation of a Robust Honeycomb Nanostructure on Medical Pure Titanium Surface.

Thrombosis induced by blood-contacting medical devices is still a major clinical problem, resulting in some serious complications such as infarction, irreversible tissue damage, and even death. Therefore, seeking an effective and safe surface modification approach to improve the hemocompatibility of the material is still urgent. In this research, a novel and facile approach was proposed to fabricate a robust honeycomb nanostructure on medical pure titanium surface by two-step anodic oxidation, which effectively enhanced the physicochemical performance and hemocompatibility of the material. Especially, the honeycomb nanostructure that underwent annealing treatment at 500 °C (HN-Ti-500 °C) presented significant performance to suppress the coagulation cascade in the in vitro tests, the reason mainly ascribed to an overall repulsive interaction between the protein molecule related to thrombosis and material surface based on an extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory analysis. Furthermore, a vessel stent fabricated by HN-Ti-500 °C was implanted into the left carotid artery of rabbits for 1 month. The antithrombotic mechanism and biocompatibility of the modified surface were further verified. The results presented that no thrombus generated and adhered onto the inner surface of the modified stent, and no obvious disorder hyperplasia and inflammation were observed in the intima tissue of the vessel at the implantation site, which indicated that the modified surface could effectively decrease the risk of in-stent restenosis and thrombosis. This work offers a promising strategy for surface modification of blood-contacting medical titanium material to address the clinical complications associated with restenosis and thrombosis.

9. The Effect Of L-Arginine On Decreasing Foam Cell Development Post Surgical Embolectomy With Fogarty Balloon Catheter On Iliac Arteries Of Rabbit

9. The Effect Of L-Arginine On Decreasing Foam Cell Development Post Surgical Embolectomy With Fogarty Balloon Catheter On Iliac Arteries Of Rabbit

An evaluation of the effects of ascorbic acid on the endothelium of coronary and aorta arteries in lead-intoxicated rabbits.

Objectives:Lead exposure has destructive effects on some organs. It may produce a variety of toxic effects on endothelial cells of the vascular system. Any changes or damages to endothelial cells may lead to cardiovascular diseases, particularly the formation of atherosclerotic plaques. The aim of this study was to determine the ameliorative effects of ascorbic acid on the endothelium of coronary and aorta arteries in lead-exposed rabbits.Methods:In this study, 30 white male rabbits of New Zealand race (weighing about 1.6–2 kg and 5 months old) were used and divided randomly into three groups: Group 1 (N = 10) that served as the control and received water and normal diet, Group 2 (N = 10) was exposed to lead acetate 547 ppm (5 mg/L) daily for 40 days, and Group 3 (N = 10) received vitamin C (500 mg/kg) and underwent the same duration of lead exposure (5 mg/L) daily for 40 days. The levels of cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein were measured using spectrophotometry, and the level of blood lead was calculated using a lead analyzer (Magellan Diagnostics, USA). The animals were anesthetized by pentobarbital (50 mg/kg). Subsequently, they were sacrificed, and their thoracic aortas and coronary arteries were removed. Then fixation, tissue processing, histological sectioning, and H & E staining were carried out. Finally, the sections were studied using light microscopy. The results were analyzed using the Mann–Whitney test.Results:The results indicated that ascorbic acid could reduce the destructive effects of lead on vascular endothelial cells and prevent the formation of atherosclerotic plaques in coronary and aorta arteries.Conclusion:The results of this study confirm the beneficial effects of ascorbic acid against the destructive effects of lead on vascular endothelial cells. Hence, it could be proposed as a potential prophylactic treatment for the amelioration of lead toxicity, prevention of atherosclerosis, and improvement of endothelial cells dysfunction.

Vascular Response on a Novel Fibrin-Based Coated Flow Diverter

PurposeDue to thromboembolic complications and in-stent-stenosis after flow diverter (FD) treatment, the long-term use of dual antiplatelet treatment (DAPT) is mandatory. The tested nano-coating has been shown to reduce material thrombogenicity and promote endothelial cell proliferation in vitro. We compared the biocompatibility of coated (Derivo Heal) and non-coated (Derivo bare) FDs with DAPT in an animal model.MethodsDerivo® bare (n = 10) and Derivo® Heal (n = 10) FD were implanted in the common carotid arteries (CCAs) of New Zealand white rabbits. One additional FD, alternately a Derivo bare (n = 5) or Derivo Heal (n = 5), was implanted in the abdominal aorta (AA) for assessment of the patency of branch arteries. Histopathological examinations were performed after 28 days. Angiography was performed before and after FD implantation and at follow-up.ResultsStatistical analysis of the included specimens showed complete endothelialization of all FDs with no significant differences in neointima thickness between Derivo® bare and Derivo® Heal (CCA: p = 0.91; AA: p = 0.59). A significantly reduced number of macrophages in the vessel wall of the Derivo Heal was observed for the CCA (p = 0.02), and significantly reduced fibrin and platelet deposition on the surface of the Derivo Heal was observed for the AA. All branch arteries of the stented aorta remained patent.ConclusionIn this animal model, the novel fibrin-based coated FD showed a similar blood and tissue compatibility as the non-coated FD.