Impact of Modification on the Energy Characteristics of Surfaces and Matrix Properties of the New Effective Polymer Vascular Implants

2021 ◽  
Vol 899 ◽  
pp. 342-354
Author(s):  
Yulia G. Bogdanova ◽  
L.V. Antonova ◽  
V.N. Silnikov ◽  
M.Yu. Khanova ◽  
E.A. Senokosova ◽  
...  
Keyword(s):  
Surface Modification ◽  
Antimicrobial Properties ◽  
Small Diameter ◽  
Water Interface ◽  
Polymer Backbone ◽  
Vascular Prostheses ◽  
Energy Characteristics ◽  
Matrix Properties ◽  
Cell Adhesion And Proliferation

New tissue-engineered vascular prostheses of small diameter (4mm) based on biodegradable polymer backbone – poly (ε-caprolactone) (PCL) and its composition with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV/ PCL) were created. The full cycle of surface modification of the backbone with polyvinylpyrrolidone and drugs permitted to increase significantly the atrombogenic and antimicrobial properties of prostheses and provide its effective matrix properties. Both types of the developed constructs are suitable for testing in vivo. The energy characteristics of the prosthesis surfaces at the different interfaces were determined. It was established that the value of the energy of the "polymer, saturated with octane/water" interface can be used as a parameter for predicting cell adhesion and proliferation in the case when it is difficult to determine or to distinguish the energy characteristics of the surfaces of tissue-engineered materials at the interface with air.

Surface Modification of Silk Fibroin Fabric Using Layer-by-Layer Polyelectrolyte Deposition and Heparin Immobilization for Small-Diameter Vascular Prostheses

Langmuir ◽  
2015 ◽  
Vol 31 (8) ◽  
pp. 2517-2526 ◽  
Author(s):  
M. Fazley Elahi ◽  
Guoping Guan ◽  
Lu Wang ◽  
Xinzhe Zhao ◽  
Fujun Wang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Silk Fibroin ◽  
Small Diameter ◽  
Layer By Layer ◽  
Vascular Prostheses

scholarly journals Biocompatibility of Small-Diameter Vascular Grafts in Different Modes of RGD Modification

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 174 ◽  
Author(s):  
Larisa Antonova ◽  
Vladimir Silnikov ◽  
Victoria Sevostyanova ◽  
Arseniy Yuzhalin ◽  
Lyudmila Koroleva ◽  
...  
Keyword(s):  
Vascular Grafts ◽  
Small Diameter ◽  
Primary Patency ◽  
Rgd Peptides ◽  
Vascular Prostheses ◽  
Sequence Composition ◽  
Rgd Sequence ◽  
Linker Group

Modification with Arg-Gly-Asp (RGD) peptides is a promising approach to improve biocompatibility of small-calibre vascular grafts but it is unknown how different RGD sequence composition impacts graft performance. Here we manufactured 1.5 mm poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) grafts modified by distinct linear or cyclic RGD peptides immobilized by short or long amine linker arms. Modified vascular prostheses were tested in vitro to assess their mechanical properties, hemocompatibility, thrombogenicity and endothelialisation. We also implanted these grafts into rat abdominal aortas with the following histological examination at 1 and 3 months to evaluate their primary patency, cellular composition and detect possible calcification. Our results demonstrated that all modes of RGD modification reduce ultimate tensile strength of the grafts. Modification of prostheses does not cause haemolysis upon the contact with modified grafts, yet all the RGD-treated grafts display a tendency to promote platelet aggregation in comparison with unmodified counterparts. In vivo findings identify that cyclic Arg-Gly-Asp-Phe-Lys peptide in combination with trioxa-1,13-tridecanediamine linker group substantially improve graft biocompatibility. To conclude, here we for the first time compared synthetic small-diameter vascular prostheses with different modes of RGD modification. We suggest our graft modification regimen as enhancing graft performance and thus recommend it for future use in tissue engineering.

Abstract P026: Development of Autologous Tissue Small-Diameter Vascular Grafts (BIOTUBEs)

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Masashi Yamanami ◽  
Taiji Watanabe ◽  
Keiichi Kanda ◽  
Tomonori Oie ◽  
Keiichi Takamizawa ◽  
...  
Keyword(s):  
Healing Process ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Coronary Bypass ◽  
Muscle Layer ◽  
Fiber Formation ◽  
Thin Wall ◽  
Vascular Prostheses ◽  
Pulsatile Pressure

Objectives: There are actually no small-caliber synthetic vascular grafts (< 6 mm) with acceptable patency rate for the use of coronary bypass or peripheral vascular repair below the knee in case the autologous vessels are not available. We developed autologous small-caliber vascular grafts “BIOTUBEs” using simple, safe and economical in vivo tissue engineering. In this study, we summarize the development of BIOTUBEs. Methods: Silicone rod molds (diameter: 1.5∼5 mm, length: 20∼50 mm) were placed into subcutaneous pouches of Wister rats, Japan white rabbits or Beagle dogs. After 1 month, BIOTUBEs formed around the molds were auto-implanted to the aorta (1.5 mm; rats) or the carotid arteries (2 mm; rabbits and 5 mm; dogs) of the respective animals. They were evaluated after determined period of implantation. Results: Irrespective of species, BIOTUBEs had thin wall (ca. 0.1mm) and mainly consisted of autologous fibroblasts and collagen fibers. Rats; After 12-week implantation, other than the oriented endothelial layer and smooth muscle layer, multilayered elastin fiber formation was observed in the grafts. Rabbits; Little thrombus was formed on the luminal surfaces completely covered with endothelial cells within 2 weeks. During 2 year-implantation, neither formation of aneurysms nor rupturing was observed in BIOTUBEs. Dogs; Longest follow up is 3 years under arterial pulsatile pressure condition without any degenerative changes in the grafts. Conclusions: BIOTUBEs could be ideal small caliber vascular prostheses that greatly facilitate healing process and exhibit excellent biocompatibility.

In vivo assessment of anti-CD34 coated ePTFE vascular prostheses

2010 ◽  
Vol 58 (S 01) ◽  
Author(s):  
W Mrowczynski ◽  
A Rungatscher ◽  
F Buchegger ◽  
JC Tille ◽  
D Mugnai ◽  
...  
Keyword(s):  
Vascular Prostheses ◽  
In Vivo Assessment

Platelet Adhesion in Polytetrafluoroethylene (PTFE) Vascular Grafts In Vivo and the Influence of Increased Intramuscular Pressure-An Experimental Model

1983 ◽  
Vol 50 (04) ◽  
pp. 881-884 ◽  
Author(s):  
J T Christenson ◽  
P Qvarfordt ◽  
S-E Strand ◽  
D Arvidsson ◽  
T Sjöberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Graft Failure ◽  
Small Diameter ◽  
Graft Material ◽  
Intramuscular Pressure ◽  
Initial Flow ◽  
Early Graft ◽  
Wick Technique ◽  
Early Graft Failure

SummaryThrombogenicity of graft material is involved in early graft failure in small diameter grafts. The frequently seen postoperative swelling of the leg after distal revascularization may cause an increased intramuscular pressure and early graft failure.Pairs of 4 mm polytetrafluoroethylene (PTFE) grafts were implanted. Autologous platelets were labeled with mIn-oxine. Platelet adhesiveness onto the grafts were analyzed from gamma camera images. Intramuscular pressures were measured with wick technique. Blood flow was measured. One graft served as control the other as test graft. Ninety minutes after declamping the i. m. pressure was increased in the test-leg to 30 mmHg, and later to 60 mmHg.In the control-graft platelet uptake increased to a maximum 60 min after declamping. Blood flow and i.m. pressure remained uneffected. The test-grafts were initially similar but when i.m. pressure was increased to 30 mmHg activity in the grafts increased significantly. Blood flow decreased with 12% of initial flow. When i. m. pressure was raised to 60 mmHg platelet uptake continued to increase.An increased intramuscular pressure of 30 mmHg or more significantly increase the amount of platelets adhering onto PTFE grafts, emphasizing the need for measuring intramuscular pressures after lower limb vascular revascularizations.

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 Antimicrobial Activity of Curcumin in Nanoformulations: A Comprehensive Review

2021 ◽  
Vol 22 (13) ◽  
pp. 7130
Author(s):  
Jeffersson Krishan Trigo-Gutierrez ◽  
Yuliana Vega-Chacón ◽  
Amanda Brandão Soares ◽  
Ewerton Garcia de Oliveira Mima
Keyword(s):  
Polymeric Nanoparticles ◽  
Graphene Quantum Dots ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Clinical Scenarios ◽  
Low Cytotoxicity ◽  
Bacteria And Fungi ◽  
Drug Resistant Strains

Curcumin (CUR) is a natural substance extracted from turmeric that has antimicrobial properties. Due to its ability to absorb light in the blue spectrum, CUR is also used as a photosensitizer (PS) in antimicrobial Photodynamic Therapy (aPDT). However, CUR is hydrophobic, unstable in solutions, and has low bioavailability, which hinders its clinical use. To circumvent these drawbacks, drug delivery systems (DDSs) have been used. In this review, we summarize the DDSs used to carry CUR and their antimicrobial effect against viruses, bacteria, and fungi, including drug-resistant strains and emergent pathogens such as SARS-CoV-2. The reviewed DDSs include colloidal (micelles, liposomes, nanoemulsions, cyclodextrins, chitosan, and other polymeric nanoparticles), metallic, and mesoporous particles, as well as graphene, quantum dots, and hybrid nanosystems such as films and hydrogels. Free (non-encapsulated) CUR and CUR loaded in DDSs have a broad-spectrum antimicrobial action when used alone or as a PS in aPDT. They also show low cytotoxicity, in vivo biocompatibility, and improved wound healing. Although there are several in vitro and some in vivo investigations describing the nanotechnological aspects and the potential antimicrobial application of CUR-loaded DDSs, clinical trials are not reported and further studies should translate this evidence to the clinical scenarios of infections.

scholarly journals Decellularised Human Umbilical Artery as a Vascular Graft Elicits Minimal Pro-Inflammatory Host Response Ex Vivo and In Vivo

2021 ◽  
Vol 22 (15) ◽  
pp. 7981
Author(s):  
Alexander Høgsted Ahlmann ◽  
Shu Fang ◽  
Sussi Bagge Mortensen ◽  
Line Weis Andersen ◽  
Pernille Gejl Pedersen ◽  
...  
Keyword(s):  
Vascular Graft ◽  
Umbilical Artery ◽  
Ex Vivo ◽  
White Blood Cells ◽  
Small Diameter ◽  
M1 Macrophages ◽  
Host Immune Responses ◽  
Cytokine Levels ◽  
Anti Inflammatory Cytokine

Small diameter (<6 mm) vessel grafts still pose a challenge for scientists worldwide. Decellularised umbilical artery (dUA) remains promising as small diameter tissue engineered vascular graft (TEVG), yet their immunogenicity remains unknown. Herein, we evaluated the host immune responses, with a focus on the innate part, towards human dUA implantation in mice, and confirmed our findings in an ex vivo allogeneic human setup. Overall, we did not observe any differences in the number of circulating white blood cells nor the number of monocytes among three groups of mice (1) dUA patch; (2) Sham; and (3) Mock throughout the study (day −7 to 28). Likewise, we found no difference in systemic inflammatory and anti-inflammatory cytokine levels between groups. However, a massive local remodelling response with M2 macrophages were observed in the dUA at day 28, whereas M1 macrophages were less frequent. Moreover, human monocytes from allogeneic individuals were differentiated into macrophages and exposed to lyophilised dUA to maximize an eventual M1 response. Yet, dUA did not elicit any immediate M1 response as determined by the absence of CCR7 and CXCL10. Together this suggests that human dUA elicits a minimal pro-inflammatory response further supporting its use as a TEVG in an allogeneic setup.

scholarly journals Review: Tissue Engineering of Small-Diameter Vascular Grafts and Their In Vivo Evaluation in Large Animals and Humans

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 713
Author(s):  
Shu Fang ◽  
Ditte Gry Ellman ◽  
Ditte Caroline Andersen
Keyword(s):  
Animal Models ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Large Animal ◽  
Large Animal Models ◽  
Graft Outcome ◽  
Limited Success ◽  
Large Animals

To date, a wide range of materials, from synthetic to natural or a mixture of these, has been explored, modified, and examined as small-diameter tissue-engineered vascular grafts (SD-TEVGs) for tissue regeneration either in vitro or in vivo. However, very limited success has been achieved due to mechanical failure, thrombogenicity or intimal hyperplasia, and improvements of the SD-TEVG design are thus required. Here, in vivo studies investigating novel and relative long (10 times of the inner diameter) SD-TEVGs in large animal models and humans are identified and discussed, with emphasis on graft outcome based on model- and graft-related conditions. Only a few types of synthetic polymer-based SD-TEVGs have been evaluated in large-animal models and reflect limited success. However, some polymers, such as polycaprolactone (PCL), show favorable biocompatibility and potential to be further modified and improved in the form of hybrid grafts. Natural polymer- and cell-secreted extracellular matrix (ECM)-based SD-TEVGs tested in large animals still fail due to a weak strength or thrombogenicity. Similarly, native ECM-based SD-TEVGs and in-vitro-developed hybrid SD-TEVGs that contain xenogeneic molecules or matrix seem related to a harmful graft outcome. In contrast, allogeneic native ECM-based SD-TEVGs, in-vitro-developed hybrid SD-TEVGs with allogeneic banked human cells or isolated autologous stem cells, and in-body tissue architecture (IBTA)-based SD-TEVGs seem to be promising for the future, since they are suitable in dimension, mechanical strength, biocompatibility, and availability.

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