scholarly journals Surface Modification With Gelatin For Polyurethane Vascular Grafts: A Review

2020 ◽  
Vol 8 (2) ◽  
pp. 100-117
Author(s):  
Iman Adipurnama ◽  
Ming Chien Yang ◽  
Tomasz Ciach ◽  
Beata Butruk Raszeja
Keyword(s):  
Surface Modification ◽  
Thrombus Formation ◽  
Vascular Grafts ◽  
Synthetic Polymers ◽  
The Other ◽  
Natural Polymers ◽  
Promising Candidate ◽  
Potential Development ◽  
Limited Supply ◽  
Promote Cell Adhesion

The means for developing synthetic vascular grafts to replace blood vessels is increasing extensively because of the limited supply of autologous vessels. Synthetic polymers as the alternatives still suffer from restenosis and thrombus formation. Natural polymers, on the other hand, are commonly biocompatible and biodegradable, compliment the synthetic ones. Blending, grafting and coating of natural polymers have been proposed to improve surface properties of synthetic polymers. Gelatin is a promising candidate to help improving synthetic vascular grafts surface owing to its ability to promote cell adhesion without promoting platelet aggregation at its surface. In this review, several techniques to incorporate gelatin onto synthetic polymers, mainly polyurethane, for vascular grafts application are summarized, together with the recent updates and potential development in the future.

Surface Modification by Nanobiomaterials for Vascular Tissue Engineering Applications

2020 ◽  
Vol 27 (10) ◽  
pp. 1634-1646 ◽  
Author(s):  
Huey-Shan Hung ◽  
Shan-hui Hsu
Keyword(s):  
Tissue Engineering ◽  
Vascular Tissue ◽  
Thrombus Formation ◽  
Vascular Grafts ◽  
Vascular Tissue Engineering ◽  
Great Success ◽  
Natural Polymers ◽  
Vascular Biomaterials

Treatment of cardiovascular disease has achieved great success using artificial implants, particularly synthetic-polymer made grafts. However, thrombus formation and restenosis are the current clinical problems need to be conquered. New biomaterials, modifying the surface of synthetic vascular grafts, have been created to improve long-term patency for the better hemocompatibility. The vascular biomaterials can be fabricated from synthetic or natural polymers for vascular tissue engineering. Stem cells can be seeded by different techniques into tissue-engineered vascular grafts in vitro and implanted in vivo to repair the vascular tissues. To overcome the thrombogenesis and promote the endothelialization effect, vascular biomaterials employing nanotopography are more bio-mimic to the native tissue made and have been engineered by various approaches such as prepared as a simple surface coating on the vascular biomaterials. It has now become an important and interesting field to find novel approaches to better endothelization of vascular biomaterials. In this article, we focus to review the techniques with better potential improving endothelization and summarize for vascular biomaterial application. This review article will enable the development of biomaterials with a high degree of originality, innovative research on novel techniques for surface fabrication for vascular biomaterials application.

Platelet Suruival and Function in Rats with Enhanced Thrombotic Tendency

1985 ◽  
Vol 54 (04) ◽  
pp. 739-743 ◽  
Author(s):  
Federica Delaini ◽  
Elisabetta Dejana ◽  
Ine Reyers ◽  
Elisa Vicenzi ◽  
Germana De Bellis Vitti ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Nephrotic Syndrome ◽  
Platelet Function ◽  
Laboratory Tests ◽  
Thrombus Formation ◽  
The Other ◽  
Mean Survival Time ◽  
The Mean ◽  
And Function ◽  
Thrombotic Tendency

SummaryWe have investigated the relevance of some laboratory tests of platelet function in predicting conditions of thrombotic tendency. For this purpose, we studied platelet survival, platelet aggregation in response to different stimuli, TxB2 and 6-keto-PGFlα production in serum of rats bearing a nephrotic syndrome induced by adriamycin. These animals show a heavy predisposition to the development of both arterial and venous thrombosis. The mean survival time was normal in nephrotic rats in comparison to controls. As to aggregation tests, a lower aggregating response was found in ADR-treated rats using ADP or collagen as stimulating agents. With arachidonic acid (AA) we observed similar aggregating responses at lower A A concentrations, whereas at higher AA concentrations a significantly lower response was found in nephrotic rats, despite their higher TxB2 production. Also TxB2 and 6-keto-PGFlα levels in serum of nephrotic rats were significantly higher than in controls. No consistent differences were found in PGI2-activity generated by vessels of control or nephrotic rats.These data show that platelet function may appear normal or even impaired in rats with a markedly increased thrombotic tendency. On the other hand, the significance of high TxB2 levels in connection with mechanisms leading to thrombus formation remains a controversial issue.

Studies of Suloctidil in Experimental Thrombosis in Baboons

1985 ◽  
Vol 53 (03) ◽  
pp. 423-427 ◽  
Author(s):  
Stephen R Hanson ◽  
Laurence A Harker
Keyword(s):  
Oral Administration ◽  
Thrombus Formation ◽  
Vascular Grafts ◽  
Scintillation Camera ◽  
Control Data ◽  
Experimental Thrombosis ◽  
Arteriovenous Shunts ◽  
Platelet Deposition ◽  
Heparin Anticoagulation ◽  
Antithrombotic Efficacy

SummarySuloctidil has been evaluated in the baboon for its antithrombotic efficacy using models of both acute and chronic arterial thrombogenesis. Acute thrombus formation was initiated by Dacron vascular grafts inserted as extension segments into chronic arteriovenous shunts. 111In-platelet deposition was measured by scintillation camera imaging for one hour. The results after oral administration of suloctidil (100 mg/kg/d in two divided doses) were not different from control studies. Moreover, concurrent heparin anticoagulation did not affect 111In-platelet deposition compared with control data. In contrast, ticlopidine (20 mg/ kg/d) significantly decreased platelet deposition that was reduced further by the addition of heparin.Chronic arterial-thromboembolism was initiated by segments of polyurethane (Biomer) cannula introduced into chronic arteriovenous shunts. Thrombus formation by the polyurethane cannula was measured as 111In-platelet turnover (corrected for removal of senescent platelets). Cannula platelet consumption was unaffected by suloctidil (20 mg/kg/d given in two divided doses for two days preceding and throughout the period of platelet survival measurement). In contrast, dipyridamole (10 mg/ kg/d) and sulfinpyrazone (100 mg/kg/d) completely interrupted cannula platelet consumption.We conclude that suloctidil probably has little or no effect on platelet-dependent thrombus formation.

scholarly journals Topographical and Biomechanical Guidance of Electrospun Fibers for Biomedical Applications

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2896
Author(s):  
Sara Ferraris ◽  
Silvia Spriano ◽  
Alessandro Calogero Scalia ◽  
Andrea Cochis ◽  
Lia Rimondini ◽  
...  
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Electrospun Fibers ◽  
Natural Polymers ◽  
Polymeric Fibers ◽  
Biological Phenomena ◽  
Proper Design ◽  
Synthetic And Natural Polymers ◽  
Selection Of

Electrospinning is gaining increasing interest in the biomedical field as an eco-friendly and economic technique for production of random and oriented polymeric fibers. The aim of this review was to give an overview of electrospinning potentialities in the production of fibers for biomedical applications with a focus on the possibility to combine biomechanical and topographical stimuli. In fact, selection of the polymer and the eventual surface modification of the fibers allow selection of the proper chemical/biological signal to be administered to the cells. Moreover, a proper design of fiber orientation, dimension, and topography can give the opportunity to drive cell growth also from a spatial standpoint. At this purpose, the review contains a first introduction on potentialities of electrospinning for the obtainment of random and oriented fibers both with synthetic and natural polymers. The biological phenomena which can be guided and promoted by fibers composition and topography are in depth investigated and discussed in the second section of the paper. Finally, the recent strategies developed in the scientific community for the realization of electrospun fibers and for their surface modification for biomedical application are presented and discussed in the last section.

Natural Polymers in Fast Dissolving Tablets

2021 ◽  
pp. 2859-2866
Author(s):  
Ratnaparkhi M.P. ◽  
Karnawat G.R. ◽  
Andhale R.S.
Keyword(s):  
Geriatric Patients ◽  
Nutritional Supplement ◽  
Synthetic Polymers ◽  
Oral Route ◽  
Water Soluble ◽  
Natural Polymers ◽  
Disintegration Time ◽  
Water Soluble Drug ◽  
Poorly Water Soluble ◽  
Poorly Water Soluble Drug

Oral route is most preferable route of administration for various drugs, because it is convenient, economical, safest route. Fast dissolving tablets are popular nowadays, as they disintegrated in mouth within a few seconds without using water for swallow. Problems like Dysphagia in pediatric and geriatric patients have been overcome by formulating Fast dissolving tablet. Natural polymers are preferable because they are chemically inert, nontoxic, less expensive, biodegradable, and available easily than synthetic polymers. Natural polymers are obtained from the natural origin so they are devoid of any side effect. It is proved from the previous studies that Natural polymers are more-safe and effective than the synthetic polymers. Natural polymers improve the properties of tablet and they are used as binder, diluent, superdisintegrant, they also enhance the solubility of poorly water-soluble drug, decrease the disintegration time and provide nutritional supplement. The aim of the present article is to study various natural polymers used in fast dissolving tablets.

scholarly journals Layer-by-layer coating of stainless steel plates mediated by surface priming treatment to improve antithrombogenic properties

2016 ◽  
Author(s):  
Irene Carmagnola ◽  
Tiziana Nardo ◽  
Francesca Boccafoschi ◽  
Valeria Chiono
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Platelet Activation ◽  
Colorimetric Assay ◽  
Thrombus Formation ◽  
Human Platelets ◽  
Steel Plates ◽  
Blue Dye ◽  
Layer By Layer

The stainless steel (SS) stents have been used in clinics since 1994. However, typical drawbacks are restenosis and thrombus formation due to limited endothelialisation and hemocompatibility. Surface modification is a smart strategy to enhance antithrombogenicity by promoting endothelialisation. In this work, the layer-by-layer (LbL) technique was applied for coating SS model substrates, after surface priming by functionalisation with 3-aminopropyl triethoxysilane (APTES). A LbL coating made of 14 layers of poly(styrene sulfonate)/poly(diallyldimethylammonium chloride) and heparin as last layer was deposited. FTIR-ATR analysis and contact angle measurements showed that LbL was an effective method to prepare nanostructured coatings. XPS analysis and colorimetric assay employing 1,9-dimethylmethylene blue dye to detect -COOH groups confirmed the successful polyelectrolyte deposition on the coated samples. Preliminary in vitro cell tests, using whole blood and human platelets, were performed to evaluate how surface modification affects platelet activation. Results showed that SS and SS-APTES surfaces induced platelet activation, as indicated by platelet spreading and filopodia formation. After surface modification by LbL coating, the platelets assumed a round shape and no fibrin nets were detected. Data demonstrated that LbL coating is a promising technique to fabricate antithrombogenic surface.

scholarly journals Surface modification of decellularized bovine carotid arteries with human vascular cells significantly reduces their thrombogenicity

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Eriselda Keshi ◽  
Peter Tang ◽  
Marie Weinhart ◽  
Hannah Everwien ◽  
Simon Moosburner ◽  
...  
Keyword(s):  
Surface Modification ◽  
Whole Blood ◽  
Carotid Arteries ◽  
Complete Blood Count ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Blood Perfusion ◽  
Vascular Cells ◽  
Perfusion System ◽  
Human Whole Blood

Abstract Background Since autologous veins are unavailable when needed in more than 20% of cases in vascular surgery, the production of personalized biological vascular grafts for implantation has become crucial. Surface modification of decellularized xenogeneic grafts with vascular cells to achieve physiological luminal coverage and eventually thromboresistance is an important prerequisite for implantation. However, ex vivo thrombogenicity testing remains a neglected area in the field of tissue engineering of vascular grafts due to a multifold of reasons. Methods After seeding decellularized bovine carotid arteries with human endothelial progenitor cells and umbilical cord-derived mesenchymal stem cells, luminal endothelial cell coverage (LECC) was correlated with glucose and lactate levels on the cell supernatant. Then a closed loop whole blood perfusion system was designed. Recellularized grafts with a LECC > 50% and decellularized vascular grafts were perfused with human whole blood for 2 h. Hemolysis and complete blood count evaluation was performed on an hourly basis, followed by histological and immunohistochemical analysis. Results While whole blood perfusion of decellularized grafts significantly reduced platelet counts, platelet depletion from blood resulting from binding to re-endothelialized grafts was insignificant (p = 0.7284). Moreover, macroscopic evaluation revealed thrombus formation only in the lumen of unseeded grafts and histological characterization revealed lack of CD41 positive platelets in recellularized grafts, thus confirming their thromboresistance. Conclusion In the present study we were able to demonstrate the effect of surface modification of vascular grafts in their thromboresistance in an ex vivo whole blood perfusion system. To our knowledge, this is the first study to expose engineered vascular grafts to human whole blood, recirculating at high flow rates, immediately after seeding.

scholarly journals Biomaterials in ophthalmology: human cornea bioengineering

2019 ◽  
Vol 1 (1) ◽  
pp. 012-018
Keyword(s):  
Materials Science ◽  
Medical Engineering ◽  
Optical Power ◽  
Synthetic Polymers ◽  
The Body ◽  
Human Cornea ◽  
Natural Polymers ◽  
Innovative Method ◽  
High Elasticity ◽  
Healthcare Practice

Medical engineering, as an auspicious conjunction between healthcare practice, biotechnology and materials science, has emerged over time with the aim to improve human’s health. Cornea, an essential part of the eye responsible for most of its optical power, suffers every day due to accidents or various diseases. To avoid complications and overcome limitations of conventional transplantation and other surgical procedures, biomaterials and bioprinting proved beneficial can be used to design optimal devices for corneal implantation. During medical evolution, biopolymers have been used especially in tissue engineering applications, due to their high elasticity and flexibility, adaptable optical properties and tunable microstructure. Natural polymers are well accepted by the body, their offer support for tissue regeneration and, in most cases, they are easy to obtain. Beside natural-derived biopolymers, synthetic polymers can be used in bioprinting to develop performance-enhanced platforms for corneal bioengineering. Bioprinting represents an innovative method to obtain a corneal implant and has the advantage to enable the facile control over some specific properties, such as thickness, color, elasticity or shape.

scholarly journals Modification of PLA-Based Films by Grafting or Coating

2020 ◽  
Vol 11 (2) ◽  
pp. 30 ◽  
Author(s):  
Aleksandra Miletić ◽  
Ivan Ristić ◽  
Maria-Beatrice Coltelli ◽  
Branka Pilić
Keyword(s):  
Surface Modification ◽  
Active Component ◽  
Mechanical Characterization ◽  
Natural Polymer ◽  
Natural Polymers ◽  
Hydrophilic Surfaces ◽  
Nanostructured Systems ◽  
Grafting From ◽  
Specific Challenge

Recently, the demand for the use of natural polymers in the cosmetic, biomedical, and sanitary sectors has been increasing. In order to meet specific functional properties of the products, usually, the incorporation of the active component is required. One of the main problems is enabling compatibility between hydrophobic and hydrophilic surfaces. Therefore, surface modification is necessary. Poly(lactide) (PLA) is a natural polymer that has attracted a lot ofattention in recent years. It is bio-based, can be produced from carbohydrate sources like corn, and it is biodegradable. The main goal of this work was the functionalization of PLA, inserting antiseptic and anti-inflammatory nanostructured systems based on chitin nanofibrils–nanolignin complexes ready to be used in the biomedical, cosmetics, and sanitary sectors. The specific challenge of this investigation was to increase the interaction between the hydrophobic PLA matrix with hydrophilic chitin–lignin nanoparticle complexes. First, chemical modification via the “grafting from” method using lactide oligomers was performed. Then, active coatings with modified and unmodified chitin–lignin nanoparticle complexes were prepared and applied on extruded PLA-based sheets. The chemical, thermal, and mechanical characterization of prepared samples was carried out and the obtained results were discussed.

scholarly journals Vascular Tissue Engineering: Recent Advances in Small Diameter Blood Vessel Regeneration

2014 ◽  
Vol 2014 ◽  
pp. 1-27 ◽  
Author(s):  
Valentina Catto ◽  
Silvia Farè ◽  
Giuliano Freddi ◽  
Maria Cristina Tanzi
Keyword(s):  
Tissue Engineering ◽  
Cardiovascular Diseases ◽  
Blood Vessel ◽  
Polyethylene Terephthalate ◽  
Vascular Tissue ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Synthetic Polymers ◽  
Vascular Tissue Engineering ◽  
Vessel Regeneration

Cardiovascular diseases are the leading cause of mortality around the globe. The development of a functional and appropriate substitute for small diameter blood vessel replacement is still a challenge to overcome the main drawbacks of autografts and the inadequate performances of synthetic prostheses made of polyethylene terephthalate (PET, Dacron) and expanded polytetrafluoroethylene (ePTFE, Goretex). Therefore, vascular tissue engineering has become a promising approach for small diameter blood vessel regeneration as demonstrated by the increasing interest dedicated to this field. This review is focused on the most relevant and recent studies concerning vascular tissue engineering for small diameter blood vessel applications. Specifically, the present work reviews research on the development of tissue-engineered vascular grafts made of decellularized matrices and natural and/or biodegradable synthetic polymers and their realization without scaffold.

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