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1.
ACS Appl Mater Interfaces ; 16(22): 28134-28146, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38768602

RESUMO

Vessel transplantation is currently considered the "gold standard" treatment for cardiovascular disease. However, ideal artificial vascular grafts should possess good biocompatibility and mechanical strength that match those of native autologous vascular tissue to promote in vivo tissue regeneration. In this study, a series of dynamic cross-linking double-network hydrogels and the resultant hydrogel tubes were prepared. The hydrogels (named PCO), composed of rigid poly(vinyl alcohol) (PVA), flexible carboxymethyl chitosan (CMCS), and a cross-linker of aldehyde-based ß-cyclodextrin (OCD), were formed in a double-network structure with multiple dynamical cross-linking including dynamic imine bonds, hydrogen bonds, and microcrystalline regions. The PCO hydrogels exhibited superior mechanical strength, good network stability, and fatigue resistance. Additionally, it demonstrated excellent cell and blood compatibility. The results showed that the introduction of CMCS/OCD led to a significant increase in the proliferation rate of endothelial cells seeded on the surface of the hydrogel. The hemolysis rate in the test was lower than 0.3%, and both protein adsorption and platelet adhesion were reduced, indicating an excellent anticoagulant function. The plasma recalcification time test results showed that endogenous coagulation was alleviated to some extent. When formed into blood vessels and incubated with blood, no thrombus formation was observed, and there was minimal red blood cell aggregation. Therefore, this novel hydrogel tube, with excellent mechanical properties, exhibits antiadhesive characteristics toward blood cells and proteins, as well as antithrombotic properties, making it hold tremendous potential for applications in the biomedical and engineering fields.


Assuntos
Materiais Biocompatíveis , Quitosana , Hidrogéis , Álcool de Polivinil , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/síntese química , Quitosana/química , Quitosana/análogos & derivados , Quitosana/farmacologia , Humanos , Álcool de Polivinil/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/síntese química , Prótese Vascular , Teste de Materiais , beta-Ciclodextrinas/química , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Animais , Adesividade Plaquetária/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química
2.
Int J Biol Macromol ; 269(Pt 1): 131849, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38670202

RESUMO

Long-term patency and ability for revascularization remain challenges for small-caliber blood vessel grafts to treat cardiovascular diseases clinically. Here, a gelatin/heparin coated bio-inspired polyurethane composite fibers-based artificial blood vessel with continuous release of NO and biopeptides to regulate vascular tissue repair and maintain long-term patency is fabricated. A biodegradable polyurethane elastomer that can catalyze S-nitrosothiols in the blood to release NO is synthesized (NPU). Then, the NPU core-shell structured nanofiber grafts with requisite mechanical properties and biopeptide release for inflammation manipulation are fabricated by electrospinning and lyophilization. Finally, the surface of tubular NPU nanofiber grafts is coated with heparin/gelatin and crosslinked with glutaraldehyde to obtain small-caliber artificial blood vessels (ABVs) with the ability of vascular revascularization. We demonstrate that artificial blood vessel grafts promote the growth of endothelial cells but inhibit the growth of smooth muscle cells by the continuous release of NO; vascular grafts can regulate inflammatory balance for vascular tissue remodel without excessive collagen deposition through the release of biological peptides. Vascular grafts prevent thrombus and vascular stenosis to obtain long-term patency. Hence, our work paves a new way to develop small-caliber artificial blood vessel grafts that can maintain long-term patency in vivo and remodel vascular tissue successfully.


Assuntos
Prótese Vascular , Gelatina , Heparina , Poliuretanos , Poliuretanos/química , Gelatina/química , Heparina/química , Heparina/farmacologia , Humanos , Nanofibras/química , Animais , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Óxido Nítrico/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo
3.
Int J Biol Macromol ; 268(Pt 2): 131685, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38641268

RESUMO

There is an increasing demand for small-diameter blood vessels. Currently, there is no clinically available small-diameter artificial vessel. Bacterial nanocellulose (BNC) has vast potential for applications in artificial blood vessels due to its good biocompatibility. At the same time, medical polyurethane (PU) is a highly elastic polymer material widely used in artificial blood vessels. This study reports a composite small-diameter BNC/PU conduit using a non-solvent-induced phase separation method with the highly hydrophilic BNC tube as the skeleton and the hydrophobic polycarbonate PU as the filling material. The results revealed that the compliance and mechanical matching of BNC/PU tubes were higher than BNC tubes; the axial/radial mechanical strength, burst pressure, and suture strength were significantly improved; the blood compatibility and cell compatibility were also excellent. The molecular and subcutaneous embedding tests showed that the composite tubes had lighter inflammatory reactions. The results of the animal substitution experiments showed that the BNC/PU tubes kept blood flow unobstructed without tissue proliferation after implantation in rats for 9 months. Thus, the BNC/PU small-diameter vascular prosthesis had the potential for long-term patency and acted as an ideal material for small-diameter vessels.


Assuntos
Prótese Vascular , Celulose , Poliuretanos , Poliuretanos/química , Celulose/química , Animais , Ratos , Teste de Materiais , Materiais Biocompatíveis/química , Elasticidade , Humanos , Masculino , Vasos Sanguíneos
4.
J Funct Biomater ; 14(10)2023 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-37888162

RESUMO

Within the human body, the intricate network of blood vessels plays a pivotal role in transporting nutrients and oxygen and maintaining homeostasis. Bioprinting is an innovative technology with the potential to revolutionize this field by constructing complex multicellular structures. This technique offers the advantage of depositing individual cells, growth factors, and biochemical signals, thereby facilitating the growth of functional blood vessels. Despite the challenges in fabricating vascularized constructs, bioprinting has emerged as an advance in organ engineering. The continuous evolution of bioprinting technology and biomaterial knowledge provides an avenue to overcome the hurdles associated with vascularized tissue fabrication. This article provides an overview of the biofabrication process used to create vascular and vascularized constructs. It delves into the various techniques used in vascular engineering, including extrusion-, droplet-, and laser-based bioprinting methods. Integrating these techniques offers the prospect of crafting artificial blood vessels with remarkable precision and functionality. Therefore, the potential impact of bioprinting in vascular engineering is significant. With technological advances, it holds promise in revolutionizing organ transplantation, tissue engineering, and regenerative medicine. By mimicking the natural complexity of blood vessels, bioprinting brings us one step closer to engineering organs with functional vasculature, ushering in a new era of medical advancement.

5.
J Nanobiotechnology ; 21(1): 298, 2023 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-37626396

RESUMO

Myocardial infarction (MI) is a cardiovascular emergency and the leading cause of death worldwide. Inflammatory and immune responses are initiated immediately after MI, leading to myocardial death, scarring, and ventricular remodeling. Current therapeutic approaches emphasize early restoration of ischemic myocardial reperfusion, but there is no effective treatment for the pathological changes of infarction. Biomedical materials development has brought new hope for MI diagnosis and treatment. Biomedical materials, such as cardiac patches, hydrogels, nano biomaterials, and artificial blood vessels, have played an irreplaceable role in MI diagnosis and treatment. They improve the accuracy and efficacy of MI diagnosis and offer further possibilities for reducing inflammation, immunomodulation, inhibiting fibrosis, and cardiac regeneration. This review focuses on the advances in biomedical materials applications in MI diagnosis and treatment. The current studies are outlined in terms of mechanisms of action and effects. It is addressed how biomedical materials application can lessen myocardial damage, encourage angiogenesis, and enhance heart function. Their clinical transformation value and application prospect are discussed.


Assuntos
Infarto do Miocárdio , Humanos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/terapia , Coração , Miocárdio , Materiais Biocompatíveis , Hidrogéis
6.
Colloids Surf B Biointerfaces ; 229: 113449, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37506438

RESUMO

Without differentiated inner and outer biological function, expanded polytetrafluoroethylene (ePTFE) small-diameter (<6 mm) artificial blood vessels would fail in vivo due to foreign body rejection, thrombosis, and hyperplasia. In order to synergistically promote endothelialization, anti-thrombogenicity, and anti-inflammatory function, we modified the inner and outer surface of ePTFE, respectively, by grafting functional biomolecules, such as heparin and epigallocatechin gallate (EGCG), into the inner surface and polyethyleneimine and rapamycin into the outer surface via layer-by-layer self-assembly. Fourier-transform infrared spectroscopy showed the successful incorporation of EGCG, heparin, and rapamycin. The collaborative release profile of heparin and rapamycin lasted for 42 days, respectively. The inner surface promoted human umbilical vein endothelial cells (HUVECs) adhesion and growth and that the outer surface inhibited smooth muscle cells growth and proliferation. The modified ePTFE effectively regulated the differentiation behavior of RAW264.7, inhibited the expression of proinflammatory mediator TNF-α, and up-regulated the expression of anti-inflammatory genes Arg1 and Tgfb-1. The ex vivo circulation results indicated that the occlusions and total thrombus weight of modified ePTFE was much lower than that of the thrombus formed on the ePTFE, presenting good anti-thrombogenic properties. Hence, the straightforward yet efficient synergistic surface functionalization approach presented a potential resolution for the prospective clinical application of small-diameter ePTFE blood vessel grafts.


Assuntos
Prótese Vascular , Trombose , Humanos , Politetrafluoretileno/farmacologia , Politetrafluoretileno/química , Estudos Prospectivos , Heparina/farmacologia , Células Endoteliais da Veia Umbilical Humana , Trombose/tratamento farmacológico , Sirolimo
7.
J Biomater Appl ; 38(2): 194-202, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37408454

RESUMO

Compliance mismatch between the artificial blood vessel and the host vessel leads to abnormal hemodynamics and is a major mechanical trigger of intimal hyperplasia. Efforts have been made to achieve higher compliance of artificial blood vessels. However, the preparation of artificial blood vessels with compliance matching to host vessels has not been realized. A bi-layered artificial blood vessel was successfully prepared by dip-coating and electrospinning composite method using poly(L-Lactide-co-caprolactone) (PLCL) and thermoplastic poly(ether urethane) (TPU). In the case of a certain wall thickness (200 µm), thickness ratios of the PLCL inner layer (dip-coating method) and TPU outer layer (electrospinning method) were controlled at 0:1, 1:9, 3:7, 5:5, 7:3, and 1:0 respectively and the compliance, radial tensile properties, burst pressure, and suture retention strength were investigated. Results showed compliance value of the artificial blood vessel decreased with the increase of the thickness ratio, which suggested the compliance of the bi-layered artificial blood vessel can be regulated by adjusting the ratio of the inner and outer layer thicknesses. In the six different artificial blood vessels, the one with thickness ratio of 1:9 not only had high compliance (8.768 ± 0.393%/100 mmHg) but also can guarantee the other mechanical properties, such as the radial breaking strength (6.333 ± 0.689 N/mm), burst pressure (534.473 ± 20.899 mmHg), and suture retention strength (300.773 ± 9.351 cN). The proposed artificial blood vessel preparation method is expected to achieve compliance matching with the host vessel. It is beneficial for eliminating abnormal hemodynamics and reducing intimal hyperplasia.


Assuntos
Substitutos Sanguíneos , Humanos , Hiperplasia , Complacência (Medida de Distensibilidade) , Prótese Vascular , Poliésteres
8.
Int J Bioprint ; 9(4): 740, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37323481

RESUMO

The coronary artery bypass grafting is a main treatment for restoring the blood supply to the ischemic site by bypassing the narrow part, thereby improving the heart function of the patients. Autologous blood vessels are preferred in coronary artery bypass grafting, but their availability is often limited by due to the underlying disease. Thus, tissue-engineered vascular grafts that are devoid of thrombosis and have mechanical properties comparable to those of natural vessels are urgently required for clinical applications. Most of the commercially available artificial implants are made from polymers, which are prone to thrombosis and restenosis. The biomimetic artificial blood vessel containing vascular tissue cells is the most ideal implant material. Due to its precision control ability, three-dimensional (3D) bioprinting is a promising method to prepare biomimetic system. In the 3D bioprinting process, the bioink is at the core state for building the topological structure and keeping the cell viable. Therefore, in this review, the basic properties and viable materials of the bioink are discussed, and the research of natural polymers in bioink, including decellularized extracellular matrix, hyaluronic acid, and collagen, is emphasized. Besides, the advantages of alginate and Pluronic F127, which are the mainstream sacrificial material during the preparation of artificial vascular graft, are also reviewed. Finally, an overview of the applications in the field of artificial blood vessel is also presented.

9.
ACS Nano ; 17(8): 7296-7310, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37026563

RESUMO

Coronary artery bypass grafting is commonly used to treat cardiovascular diseases by replacing blocked blood vessels with autologous or artificial blood vessels. Nevertheless, the availability of autologous vessels in infants and the elderly and low long-term patency rate of grafts hinder extensive application of autologous vessels in clinical practice. The biological and mechanical properties of the resealable antithrombotic artificial vascular graft (RAAVG) fabricated herein, comprising a bioelectronic conduit based on a tough self-healing polymer (T-SHP) and a lubricious inner coating, match with the functions of autologous blood vessels. The self-healing and elastic properties of the T-SHP confer resistance against mechanical stimuli and promote conformal sealing of suturing regions, thereby preventing leakage (stable fixation under a strain of 50%). The inner layer of the RAAVG presents antibiofouling properties against blood cells and proteins, and antithrombotic properties, owing to its lubricious coating. Moreover, the blood-flow sensor fabricated using the T-SHP and carbon nanotubes is seamlessly integrated into the RAAVG via self-healing and allows highly sensitive monitoring of blood flow at low and high flow rates (10- and 100 mL min-1, respectively). Biocompatibility and feasibility of RAAVG as an artificial graft were demonstrated via ex vivo, and in vivo experiment using a rodent model. The use of RAAVGs to replace blocked blood vessels can improve the long-term patency rate of coronary artery bypass grafts.


Assuntos
Fibrinolíticos , Nanotubos de Carbono , Hemodinâmica
10.
Surg Neurol Int ; 14: 8, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36751444

RESUMO

Background: There are few reports on the treatment of carotid artery stenosis after arterial vessel replacement. We report and discuss an illustrative case of carotid artery stenting (CAS) performed for stenosis after carotid artery replacement. Case Description: A woman in her 20s experienced injury to the right carotid artery during an operation for removal of a carotid body tumor 6 years before presentation. The right common carotid artery and internal carotid artery were replaced with an artificial vessel graft at that time. Intraluminal stenosis in the graft was not identified 3 years after surgery; however, 4 years after surgery, stenosis was recognized at the non-anastomotic site inside the artificial vessel graft. Subsequently, antiplatelet therapy was initiated. The stenosis was noted to progress gradually in follow-up appointments. Therefore, we decided to intervene because of the patient's young age and the risk of long-term hemodynamic stress. Angiography revealed pseudo-occlusion in the artificial vessel. Percutaneous transluminal angioplasty was performed for stenosis with distal protection; subsequently, CAS was performed. The patient was discharged without neurological deficits 4 days after the operation, and no apparent restenosis was observed as of the 1-year follow-up. Conclusion: Stenosis after cervical artery replacement can be safely treated with CAS. Inflation pressure and stent should be selected according to the pathology of the stenosis.

11.
Asian Cardiovasc Thorac Ann ; 31(3): 266-268, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36683326

RESUMO

This is the first report of total arch replacement to repair re-coarctation. A 14-year-old boy with hypoplastic left heart syndrome developed re-coarctation, severe stenosis of neck vessels, and right ventricle dysfunction after a Norwood procedure. We performed total arch replacement; the postoperative course was unremarkable. He was followed up until 18 years of age and did not need re-intervention. Using artificial blood vessels in total arch replacement is rarely indicated but can be safely achieved when required. Mismatch between patient and graft size may be an issue in the future.


Assuntos
Coartação Aórtica , Síndrome do Coração Esquerdo Hipoplásico , Procedimentos de Norwood , Adolescente , Humanos , Masculino , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/cirurgia , Coartação Aórtica/diagnóstico por imagem , Coartação Aórtica/cirurgia , Constrição Patológica , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico por imagem , Síndrome do Coração Esquerdo Hipoplásico/cirurgia , Procedimentos de Norwood/efeitos adversos
12.
Int J Comput Assist Radiol Surg ; 18(3): 433-447, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36477583

RESUMO

PURPOSE: Current steerable catheters (SCs) for endoscopic retrograde cholangiopancreatography (ERCP) have performance limitations caused by an asymmetric multiple-slit tube design with a small maximum bend angle, lesser curvatures, and insufficient durability. We propose a wire-driven SC for balanced bidirectional bending using artificial blood vessel material to overcome these limitations. We assess the SC prototype's steerability using phantom and animal models. METHODS: The SC prototype employed a slit-less and multiple-lumen seamless tube with a polytetrafluoroethylene (PTFE) body with stretch-retractable porous expanded PTFE at the distal end, and loop-formed control wires. We evaluated the wire routing design using a static model. The bending performance was compared with conventional SCs. Feasibility studies were performed, including major duodenal papilla insertions and ductal branch selections in desktop phantoms and a mini-pig model. RESULTS: The proposed design reduced the wire contact force by 48% compared to the single wire configuration. The maximum bend angle was 162°, almost twofold larger than that for conventional SCs. The lateral tip position in the bent shape was maximally 56% smaller. The tip flexibility was comparable to conventional SCs, and the insertion resistance was similar to the passive catheters. Phantom studies showed that the SC prototype could perform the large and protuberant papilla insertions and fine ductal branch selections without breaking; the animal study was completed successfully. CONCLUSION: We propose a wire-driven SC design for ERCP using a multi-lumen seamless tube and two loop-formed control wires, different from the conventional SC design with a multiple-slit tube and single control wire. The SC prototype records balanced bidirectional bending with a maximum bending angle of ± 162° without breakage risk. The phantom and animal studies show that the prototype performance potentially facilitates papilla cannulations and intrahepatic ductal branch seeking.


Assuntos
Substitutos Sanguíneos , Animais , Suínos , Desenho de Equipamento , Porco Miniatura , Catéteres , Colangiopancreatografia Retrógrada Endoscópica
13.
Cureus ; 14(11): e31457, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36523740

RESUMO

Pancreatic cancer is often advanced and invades the major blood vessels around the pancreas. Portal vein (PV) and/or superior mesenteric vein (SMV) resection is performed for radical resection. In such cases, end-to-end anastomosis is best if the remnant vein is sufficiently long. However, when the excision distance is long, reconstruction requires an artificial blood vessel. In contrast, there is no consensus concerning the need for splenic vein (SV) reconstruction. We herein report a case in which portal vein thrombus and congestion of the bowel that occurred after PV-SMV reconstruction were improved by additional anastomosis of the PV-SV.

14.
Int J Mol Sci ; 23(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36232417

RESUMO

Vascular replacement is one of the most effective tools to solve cardiovascular diseases, but due to the limitations of autologous transplantation, size mismatch, etc., the blood vessels for replacement are often in short supply. The emergence of artificial blood vessels with 3D bioprinting has been expected to solve this problem. Blood vessel prosthesis plays an important role in the field of cardiovascular medical materials. However, a small-diameter blood vessel prosthesis (diameter < 6 mm) is still unable to achieve wide clinical application. In this paper, a response surface analysis was firstly utilized to obtain the relationship between the contact angle and the gelatin/sodium alginate mixed hydrogel solution at different temperatures and mass percentages. Then, the self-developed 3D bioprinter was used to obtain the optimal printing spacing under different conditions through row spacing, printing, and verifying the relationship between the contact angle and the printing thickness. Finally, the relationship between the blood vessel wall thickness and the contact angle was obtained by biofabrication with 3D bioprinting, which can also confirm the controllability of the vascular membrane thickness molding. It lays a foundation for the following study of the small caliber blood vessel printing molding experiment.


Assuntos
Bioimpressão , Substitutos Sanguíneos , Alginatos , Prótese Vascular , Gelatina , Hidrogéis/farmacologia , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais
15.
Polymers (Basel) ; 14(20)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36297946

RESUMO

Bacterial nanocellulose (BNC) has received great attention for application as an artificial blood vessel material. However, many results showed that pristine BNC could not perfectly meet all the demands of blood vessels, especially for rapid endothelialization. In order to improve the properties of small-caliber vessels, different concentrations of fish gelatin (Gel) were deposited into the 3D network tubes and their properties were explored. The BNC/Gel composite tubes were treated with glutaraldehyde to crosslink BNC and fish gelatin. Compared with pristine BNC tubes, the BNC/Gel tubes had a certain improvement in mechanical properties. In vitro cell culture demonstrated that the human endothelial cells (HUVECs) and human smooth muscle cells (HSMCs) planted on the internal walls of BNC/Gel tubes showed better adhesion, higher proliferation and differentiation potential, and a better anticoagulation property, as compared to the cells cultured on pristine BNC tubes. Whole-blood coagulation experiments showed that the BNC/Gel tube had better properties than the BNC tube, and the hemolysis rate of all samples was less than 1.0%, satisfying the international standards for medical materials. An increase in the content of fish gelatin also increased the mechanical properties and the biocompatibility of small-caliber vessels. Considering the properties of BNC/Gel tubes, 1.0 wt/v% was selected as the most appropriate concentration of fish gelatin for a composite.

16.
Biomater Transl ; 3(1): 81-98, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35837341

RESUMO

Cardiovascular disease serves as the leading cause of death worldwide, with stenosis, occlusion, or severe dysfunction of blood vessels being its pathophysiological mechanism. Vascular replacement is the preferred surgical option for treating obstructed vascular structures. Due to the limited availability of healthy autologous vessels as well as the incidence of postoperative complications, there is an increasing demand for artificial blood vessels. From synthetic to natural, or a mixture of these components, numerous materials have been used to prepare artificial vascular grafts. Although synthetic grafts are more appropriate for use in medium to large-diameter vessels, they fail when replacing small-diameter vessels. Tissue-engineered vascular grafts are very likely to be an ideal alternative to autologous grafts in small-diameter vessels and are worthy of further investigation. However, a multitude of problems remain that must be resolved before they can be used in biomedical applications. Accordingly, this review attempts to describe these problems and provide a discussion of the generation of artificial blood vessels. In addition, we deliberate on current state-of-the-art technologies for creating artificial blood vessels, including advances in materials, fabrication techniques, various methods of surface modification, as well as preclinical and clinical applications. Furthermore, the evaluation of grafts both in vivo and in vitro, mechanical properties, challenges, and directions for further research are also discussed.

17.
J Biomater Appl ; 36(6): 965-975, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34284662

RESUMO

BACKGROUND: The most common materials of artificial blood vessels are polyethylene terephthalate and polytetrafluoroethylene. But polycarbonate polyurethane (PCU) is an ideal material for vascular prostheses because of their excellent characteristics. As far as we know, our artificial blood vessel is the first type of hybrid PCU/polyester three-layered large-diameter artificial blood vessel in the world. OBJECTIVE: The purpose of this preclinical animal experiment is to evaluate the hemocompatibility, histocompatibility, effectiveness, and safety of the three-layered large-diameter artificial blood vessel in sheep. METHODS: The artificial blood vessels took place of the initial segments of the sheep's thoracic aorta by end-to-end anastomosis. RESULTS: All of the 14 sheep are male, their average body weight (BW) was 30.57 ± 3.95 kg. All 14 artificial blood vessels successfully replaced the thoracic aortas. 5 sheep did not survive to the end of the experiment, while the remaining 9 sheep did. After the surgery, the blood biochemical and blood routine indicators fluctuate slightly within the normal range. The angiography showed that the implanted artificial blood vessels were unobstructed without obvious stenosis or expansion. 24 weeks after surgery, the lumen surfaces of the artificial blood vessels were covered by endothelia in different degrees, and the average endothelialization rate was 69.44% (range: 20% to 100%). CONCLUSIONS: This artificial blood vessel is the first to use PCU in large-diameter artificial vascular grafts. It has excellent blood compatibility, wonderful biocompatibility, high endothelialization rate, and 100% patency.


Assuntos
Substitutos Sanguíneos , Poliuretanos , Animais , Prótese Vascular , Masculino , Cimento de Policarboxilato , Poliésteres , Politetrafluoretileno , Ovinos
18.
Mater Sci Eng C Mater Biol Appl ; 122: 111900, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33641903

RESUMO

In order to prevent thrombosis, reduce intima hyperplasia, and to maintain long-term patency after implantation of an artificial blood vessel, the formation of intact endothelial cells layer on an inner surface of graft is desirable. The present study aimed to improve endothelial cell adhesion by regulating the morphology of the inner surface of artificial blood vessels. Zein fibre membranes with three fibre diameters (small, ~100 nm; medium, ~500 nm; and large, ~1000 nm) were constructed by electrospinning. A flow chamber device was designed to simulate the blood flow environment. The morphology and adhesion of human umbilical vein fusion cells (EA.hy926) on the surface of the fibre membranes were studied under a shear stress of approximately 15 dynes/cm2. The results showed that oriented electrospun zein fibre surfaces with both medium- and large-diameter fibres can regulate the morphology of endothelial cells (EA.hy926), which are aligned by the fibre direction. The three fibre membranes improved the adhesion of endothelial cells significantly compared to that on the flat membrane. When the fibre direction was fixed parallel to the fluid direction, the medium-diameter oriented-fibre membrane could significantly improve the ability endothelial cells to resist shear stress, and there was a significant difference at 1, 2 and 4 h time points compared with the shear stress resistance on the small-diameter and large-diameter oriented-fibre membranes. When the fibre direction was perpendicular to the fluid direction, again the medium-diameter oriented-fibre membrane improved the ability of endothelial cells to resist shear stress significantly at 1 and 2 h time points. It was concluded that by changing the diameter and arrangement of electrospun fibres, cell morphology control and shear stress resistance can be achieved.


Assuntos
Circulação Sanguínea , Nanoestruturas , Zeína , Adesão Celular , Células Endoteliais , Humanos , Estresse Mecânico
19.
Mater Sci Eng C Mater Biol Appl ; 118: 111406, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33255009

RESUMO

An artificial blood vessel with a tubular structure was additively manufactured via fused deposition modeling (FDM) starting from a single strand of polyvinyl alcohol (PVA) filament coated with a specific thickness of biocompatible polydimethylsiloxane (PDMS), followed by removal of the inner core via hydrogen peroxide leaching under sonication. In particular, we examined the relationship between the extruded deposition diameter and the filament migration speed/nozzle control speed (referred to as the filament/nozzle transition ratio), which is almost independent of the extruded deposition flow rate due to the weak die-swelling and memory effects of the extruded PVA arising from its intrinsically low viscoelasticity. The chemical stability of the PDMS during sonication in the hydrogen peroxide solution was then determined by spectroscopic techniques. The PDMS displayed no mechanical degradation in the hydrogen peroxide solution, resulting in similar fracture elongation and yield strength to those of the pristine specimen without the leaching treatment. As a further advantage, the inside surface of the PDMS was smooth regardless of the hydrogen peroxide leaching under sonication. The potential application of the as-developed scaffold in soft tissue engineering (particularly that involving vascular tissue regeneration) was demonstrated by the successful transplantation of the artificial blood vessel in a right-hand surgical replica used in a clinical simulation.


Assuntos
Substitutos Sanguíneos , Álcool de Polivinil , Engenharia Tecidual
20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1006773

RESUMO

【Objective】 To evaluate the performance of the magnetic artificial blood vessel device for fast non-suture anastomosis of caval reconstruction with artificial blood vessel transplantation after resection in canines. 【Methods】 Sixteen adult mongrel dogs of either gender were randomly divided into two groups for vena cava reconstruction with artificial blood vessel transplantation after inferior vena cava (IVC) resection. Group MCA (n=8): magnetic artificial blood vessel device for IVC reconstruction; Group manual sewing (MS) (n=8): hand suturing for IVC reconstruction. Operation time and stoma errhysis were recorded during operation. Patency and stoma stenosis were confirmed via color Doppler ultrasound scanning and X-ray cholangiography at different time points as late as 4 weeks after surgery. 【Results】 The time required to perform the vascular anastomosis was significantly shorter for the magnetic artificial blood vessel device (6.25±2.25)min than for MS (27.32±5.12)min (P<0.001). There were four cases of stoma errhysis in MS group which had to be repaired (P=0.077). Vascular X-ray angiography and color Doppler ultrasound found normal blood flow and no stoma stenosis in MCA group, but three cases of stoma stenosis in MS groups (P=0.200). Compared with MS group, the magnetic ring device stoma was associated with smooth re-endothelialization and depressed infiltration of inflammatory cells at the anastomotic site. 【Conclusion】 The magnetic artificial blood vessel device offers a simple, fast, reliable, and efficacious technique for vena cava reconstruction with artificial blood vessel transplantation.

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