scholarly journals The application of tissue-engineered fish swim bladder vascular graft

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Hualong Bai ◽  
Peng Sun ◽  
Haoliang Wu ◽  
Shunbo Wei ◽  
Boao Xie ◽  
...  
Keyword(s):  
Carassius Auratus ◽  
Inferior Vena ◽  
Vascular Grafts ◽  
Vena Cava ◽  
Small Diameter ◽  
Swim Bladder ◽  
Neointimal Thickness ◽  
Patch Angioplasty

AbstractSmall diameter (< 6 mm) prosthetic vascular grafts continue to show very low long-term patency, but bioengineered vascular grafts show promising results in preclinical experiments. To assess a new scaffold source, we tested the use of decellularized fish swim bladder as a vascular patch and tube in rats. Fresh goldfish (Carassius auratus) swim bladder was decellularized, coated with rapamycin and then formed into patches or tubes for implantation in vivo. The rapamycin-coated patches showed decreased neointimal thickness in both the aorta and inferior vena cava patch angioplasty models. Rapamycin-coated decellularized swim bladder tubes implanted into the aorta showed decreased neointimal thickness compared to uncoated tubes, as well as fewer macrophages. These data show that the fish swim bladder can be used as a scaffold source for tissue-engineering vascular patches or vessels.

scholarly journals BIODEGRADABLE VASCULAR GRAFT REINFORCED WITH A BIODEGRADABLE SHEATH

2019 ◽  
Vol 8 (2) ◽  
pp. 87-97
Author(s):  
L. V. Antonova ◽  
E. O. Krivkina ◽  
M. A. Rezvova ◽  
V. V. Sevost'yanova ◽  
A. V. Mironov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Growth Factor ◽  
Carotid Artery ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Fold Increase ◽  
Layer By Layer ◽  
Layer Coating

Background. Tissue-engineered vascular grafts can be reinforced by a biostable or biodegradable polymer sheath. A combination of electrospinning, routinely used for fabrication of biodegradable tubular grafts, and the layer-by-layer coating allows forming a polymeric sheath ensuring long-term integrity and high biocompatibility of the vascular grafts after the implantation. Aim To evaluate mechanical properties and in vivo performance of biodegradable small-diameter vascular grafts with a reinforcing sheath.Methods. Tubular grafts (4 mm diameter) were fabricated from poly(3-hydroxybutyrate-co3-hydroxyvalerate) and poly(ε-caprolactone) by emulsion electrospinning with the incorporation of vascular endothelial growth factor (VEGF) into the inner third of the graft and basic fibroblast growth factor (bFGF) along with stromal cell-derived factor-1α (SDF-1α) into the outer two thirds of the graft wall. Poly(ε-caprolactone) sheath was formed by the layer-by-layer coating. Upon graft fabrication, scanning electron microscopy was performed to assess the grafts’ surface, tensile testing allowed evaluating mechanical properties. The samples were implanted into the ovine carotid artery (n = 5 animals) for 12 months with the subsequent histological examination.Results. Sintering temperature of 160°C during the extrusion allowed effective and delicate merging of poly(ε-caprolactone) coating with the outer surface of the poly(3hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) tubular graft. The thickness of poly(ε-caprolactone) fiber was 380–400 μm, the increment of the reinforcing filament was 1 mm. The reinforcing sheath led to a 3-fold increase in durability and elastic modulus of the vascular grafts. At the 12-months follow-up, the grafts reported retained integrity. No signs of inflammation or calcification were found.Conclusion. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(ε-caprolactone) vascular grafts with hierarchically incorporated growth factors and the reinforced poly(ε-caprolactone) spiral sheath demonstrated improved mechanical properties while retaining integrity and high biocompatibility after the long-term implantation into the ovine carotid artery.

scholarly journals Acellular Small-Diameter Tissue-Engineered Vascular Grafts

2019 ◽  
Vol 9 (14) ◽  
pp. 2864 ◽  
Author(s):  
Zhen Li ◽  
Xinda Li ◽  
Tao Xu ◽  
Lei Zhang
Keyword(s):  
Effective Means ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Test Results ◽  
In Vivo Test ◽  
Current State

Tissue-engineered vascular grafts (TEVGs) are considered one of the most effective means of fabricating vascular grafts. However, for small-diameter TEVGs, there are ongoing issues regarding long-term patency and limitations related to long-term in vitro culture and immune reactions. The use of acellular TEVG is a more convincing method, which can achieve in situ blood vessel regeneration and better meet clinical needs. This review focuses on the current state of acellular TEVGs based on scaffolds and gives a summary of the methodologies and in vitro/in vivo test results related to acellular TEVGs obtained in recent years. Various strategies for improving the properties of acellular TEVGs are also discussed.

scholarly journals Nitrate-Functionalized poly(ε-Caprolactone) Small-Diameter Vascular Grafts Enhance Vascular Regeneration via Sustained Release of Nitric Oxide

2021 ◽  
Vol 9 ◽  
Author(s):  
Sen Yang ◽  
Xueni Zheng ◽  
Meng Qian ◽  
He Wang ◽  
Fei Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Tissue ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Post Transplantation ◽  
Vascular Regeneration ◽  
Vascular Progenitor Cells ◽  
Small Diameter Vascular Grafts

Artificial small-diameter vascular grafts (SDVG) fabricated from synthetic biodegradable polymers, such as poly(ε-caprolactone) (PCL), exhibit beneficial mechanical properties but are often faced with issues impacting their long-term graft success. Nitric oxide (NO) is an important physiological gasotransmitter with multiple roles in orchestrating vascular tissue function and regeneration. We fabricated a functional vascular graft by electrospinning of nitrate-functionalized poly(ε-caprolactone) that could release NO in a sustained manner via stepwise biotransformation in vivo. Nitrate-functionalized SDVG (PCL/NO) maintained patency following abdominal arterial replacement in rats. PCL/NO promoted cell infiltration at 3-months post-transplantation. In contrast, unmodified PCL SDVG showed slow cell in-growth and increased incidence of neointima formation. PCL/NO demonstrated improved endothelial cell (EC) alignment and luminal coverage, and more defined vascular smooth muscle cell (VSMC) layer, compared to unmodified PCL SDVG. In addition, release of NO stimulated Sca-1+ vascular progenitor cells (VPCs) to differentiate and contribute to rapid luminal endothelialization. Furthermore, PCL/NO inhibited the differentiation of VPCs into osteopontin-positive cells, thereby preventing vascular calcification. Overall, PCL/NO demonstrated enhanced cell ingrowth, EC monolayer formation and VSMC layer regeneration; whilst inhibiting calcified plaque formation. Our results suggested that PCL/NO could serve as promising candidates for improved and long-term success of SDVG implants.

scholarly journals 5-HT does not lower blood pressure in the 5-HT7 knockout rat

2019 ◽  
Vol 51 (7) ◽  
pp. 302-310 ◽  
Author(s):  
Bridget M. Seitz ◽  
Elena Y. Demireva ◽  
Huirong Xie ◽  
Gregory D. Fink ◽  
Teresa Krieger-Burke ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Pressor Response ◽  
Vena Cava ◽  
Cardiovascular Effects ◽  
Vessel Diameter ◽  
Lower Blood ◽  
Work Supports

The fall in mean arterial pressure (MAP) after 24 h of 5-HT infusion is associated with a dilation of the portal vein (PV) and abdominal inferior vena cava (Ab IVC); all events were blocked by the selective 5-HT7 receptor antagonist SB269970. Few studies have investigated the contribution of the 5-HT7 receptor in long-term cardiovascular control, and this requires an understanding of the chronic activation of the receptor. Using the newly created 5-HT7 receptor knockout (KO) rat, we presently test the hypothesis that continuous activation of the 5-HT7 receptor by 5-HT is necessary for the chronic (1 wk) depressor response and splanchnic venodilation. We also address if the 5-HT7 receptor contributes to endogenous cardiovascular regulation. Conscious MAP (radiotelemeter), splanchnic vessel diameter (ultrasound), and cardiac function (echocardiogram) were measured in ambulatory rats during multiday 5-HT infusion (25 μg·kg−1·min−1 via minipump) and after pump removal. 5-HT infusion reduced MAP and caused splanchnic venodilation of wild-type (WT) but not KO rats at any time point. The efficacy of 5-HT-induced contraction was elevated in the isolated abdominal inferior vena cava from the KO compared with WT rats, supporting loss of a relaxant receptor. Similarly, the efficacy of 5-HT causing an acute pressor response to higher doses of 5-HT in vivo was also increased in the KO vs. WT rat. Our work supports a novel mechanism for the cardiovascular effects of 5-HT, activation of 5-HT7 receptors mediating venodilation in the splanchnic circulation, which could prove useful in the treatment of cardiovascular disease.

scholarly journals Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3678
Author(s):  
Vera Chernonosova ◽  
Alexandr Gostev ◽  
Ivan Murashov ◽  
Boris Chelobanov ◽  
Andrey Karpenko ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Wistar Rat ◽  
Graft Occlusion ◽  
Suitable Candidate ◽  
Large Animals ◽  
Cell Adhesion And Proliferation

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

scholarly journals Role of Inferior Vena Cava Filter Retrieval in Patients on Chronic Anticoagulation Therapy

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Savannah Fletcher ◽  
Adam Plotnik ◽  
Ravi N. Srinivasa ◽  
Jeffrey Forris Beecham Chick ◽  
John M. Moriarty
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena Cava Filter ◽  
Inferior Vena ◽  
Treatment Options ◽  
Anticoagulation Therapy ◽  
Vena Cava ◽  
Vena Cava Filter ◽  
Venous Thromboembolic

Abstract Purpose of review Describe the role of inferior vena cava filter (IVCF) retrieval in patients on chronic anticoagulation given the overlap of these treatment options in the management of patients with venous thromboembolic disease. Recent findings Despite the increase in IVCF retrievals since the Food and Drug Administration safety communications in 2010 and 2014, retrieval rates remain low. Previous studies have shown that longer filter dwell times are associated with greater risk for filter complications and more difficulty with filter retrievals. Recent findings suggest that complications are more frequent in the first 30 days after placement. Summary The decision to retrieve an optional IVCF is individualized and requires diligent follow-up with consistent re-evaluation of the need for the indwelling IVCF, particularly in those on long-term anticoagulation therapy.

Retrieval of Bard Simon Nitinol inferior vena cava filters: Approaches, technical successes, complications, and clinical outcomes

2021 ◽  
pp. 026835552092598
Author(s):  
Jacob J Bundy ◽  
Jeffrey Forris Beecham Chick ◽  
Ravi N Srinivasa ◽  
Kyle J Cooper ◽  
Joseph J Gemmete ◽  
...  
Keyword(s):  
Inferior Vena Cava ◽  
Inferior Vena ◽  
Vena Cava ◽  
Inferior Vena Cava Filters ◽  
Vena Cava Filters ◽  
Venous Thromboembolic Events ◽  
Venous Thromboembolic ◽  
Vena Cava Thrombosis ◽  
Inferior Vena Cava Thrombosis

Objective The Simon Nitinol filter is a bi-level filtration device designed for permanent implantation that is no longer commercially available, but may result in similar complications to current commercially available long term indwelling temporary or permanent filters. Complications related to indwelling inferior vena cava filters include inferior vena cava thrombosis, inferior vena cava penetration, filter migration, and filter fracture. There is a paucity of reports describing the technical aspects related to retrieval of Simon Nitinol filters. Materials and methods This study consisted of five patients with Simon Nitinol filters and describes the indication for retrieval, the retrieval techniques used to remove the filters, technical success, complications, and clinical course. Results The indications for retrieval included: abdominal pain ( n = 2; 40%), iliocaval thrombosis ( n = 1; 20%), identification of an intracardiac filter fragment ( n = 1; 20%), and recurrent venous thromboembolic events ( n = 1; 20%). Retrieval techniques included: biopsy forceps ( n = 3; 60%), excimer laser extraction sheaths ( n = 3; 60%), hangman modified loop snares ( n = 3; 60%), rigid endobronchial forceps ( n = 2; 40%), and balloon deflection ( n = 2; 40%). All filters were successfully retrieved. One patient developed a post-procedural intramuscular hematoma near the site of right internal jugular sheath placement. Conclusions Simon Nitinol filters may be retrieved safely and effectively using advanced inferior vena cava filter retrieval techniques.

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