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Rolińska K, Bakhshi H, Balk M, Parzuchowski P, Mazurek-Budzyńska M. Influence of the hard segments content on the properties of electrospun aliphatic poly(carbonate-urethane-urea)s. RSC Adv 2024; 14:15766-15775. [PMID: 38752158 PMCID: PMC11094699 DOI: 10.1039/d4ra01726a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 05/02/2024] [Indexed: 05/18/2024] Open
Abstract
The study investigated the impact of hard segments (HS) content on the morphology and thermomechanical properties of electrospun aliphatic poly(carbonate-urea-urethane)s (PCUUs). The obtained nonwovens exhibited surface porosity ranging from 50% to 57%, and fiber diameters between 0.59 and 0.71 μm. Notably, the PCUUs nonwovens with the highest HS content (18%) displayed superior mechanical properties compared to those with lower HS contents. This study highlights the ability to customize the properties of polymeric nonwovens based on their chemical compositions, offering tailored solutions for specific application needs.
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Affiliation(s)
- Karolina Rolińska
- Faculty of Chemistry, Warsaw University of Technology Noakowskiego 3 00-664 Warsaw Poland
- Faculty of Chemistry, University of Warsaw Pasteura 1 02-093 Warsaw Poland
- Łukasiewicz Research Network - Industrial Chemistry Institute Rydygiera 8 01-793 Warsaw Poland
| | - Hadi Bakhshi
- Department of Life Science and Bioprocesses, Fraunhofer Institute for Applied Polymer Research IAP Geiselbergstraße 69 14476 Potsdam Germany
| | - Maria Balk
- Institute of Active Polymers, Helmholtz-Zentrum Hereon Kantstraße 55 14513 Teltow Germany
| | - Paweł Parzuchowski
- Faculty of Chemistry, Warsaw University of Technology Noakowskiego 3 00-664 Warsaw Poland
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2
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Rolińska K, Bakhshi H, Balk M, Blocki A, Panwar A, Puchalski M, Wojasiński M, Mazurek-Budzyńska M. Electrospun Poly(carbonate-urea-urethane)s Nonwovens with Shape-Memory Properties as a Potential Biomaterial. ACS Biomater Sci Eng 2023; 9:6683-6697. [PMID: 38032398 PMCID: PMC10716822 DOI: 10.1021/acsbiomaterials.3c01214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 12/01/2023]
Abstract
Poly(carbonate-urea-urethane) (PCUU)-based scaffolds exhibit various desirable properties for tissue engineering applications. This study thus aimed to investigate the suitability of PCUU as polymers for the manufacturing of nonwoven mats by electrospinning, able to closely mimic the fibrous structure of the extracellular matrix. PCUU nonwovens of fiber diameters ranging from 0.28 ± 0.07 to 0.82 ± 0.12 μm were obtained with an average surface porosity of around 50-60%. Depending on the collector type and solution concentration, a broad range of tensile strengths (in the range of 0.3-9.6 MPa), elongation at break (90-290%), and Young's modulus (5.7-26.7 MPa) at room temperature of the nonwovens could be obtained. Furthermore, samples collected on the plate collector showed a shape-memory effect with a shape-recovery ratio (Rr) of around 99% and a shape-fixity ratio (Rf) of around 96%. Biological evaluation validated the inertness, stability, and lack of cytotoxicity of PCUU nonwovens obtained on the plate collector. The ability of mesenchymal stem cells (MSCs) and endothelial cells (HUVECs) to attach, elongate, and grow on the surface of the nonwovens suggests that the manufactured nonwovens are suitable scaffolds for tissue engineering applications.
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Affiliation(s)
- Karolina Rolińska
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Hadi Bakhshi
- Department
of Life Science and Bioprocesses, Fraunhofer
Institute for Applied Polymer Research IAP, Geiselbergstraße 69, 14476 Potsdam, Germany
| | - Maria Balk
- Institute
of Active Polymers, Helmholtz-Zentrum Hereon, Kantstraße 55, 14513 Teltow, Germany
| | - Anna Blocki
- Institute
for Tissue Engineering and Regenerative Medicine, The Chinese University
of Hong Kong, Shatin, New Territories 999077, Hong Kong
- School of
Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories 999077, Hong Kong
- Center
for Neuromusculoskeletal Restorative Medicine, The Chinese University of Hong Kong, Shatin, New Territories 999077, Hong Kong
| | - Amit Panwar
- Institute
for Tissue Engineering and Regenerative Medicine, The Chinese University
of Hong Kong, Shatin, New Territories 999077, Hong Kong
- School of
Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories 999077, Hong Kong
- Center
for Neuromusculoskeletal Restorative Medicine, The Chinese University of Hong Kong, Shatin, New Territories 999077, Hong Kong
| | - Michał Puchalski
- Institute
of Material Science of Textiles and Polymer Composites, Faculty of
Material Technologies and Textile Design, Lodz University of Technology, ul. Żeromskiego 116, 90-924 Łódź, Poland
| | - Michał Wojasiński
- Faculty
of Chemical and Process Engineering, Department of Biotechnology and
Bioprocess Engineering, Laboratory of Biomedical Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw, Poland
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Al Kayal T, Losi P, Asaro M, Volpi S, Bonani W, Bonini M, Soldani G. Analysis of oxidative degradation and calcification behavior of a silicone polycarbonate polyurethane‐polydimethylsiloxane material. J Biomed Mater Res A 2022; 110:1109-1120. [DOI: 10.1002/jbm.a.37357] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 10/22/2021] [Accepted: 12/20/2021] [Indexed: 11/12/2022]
Affiliation(s)
- Tamer Al Kayal
- Institute of Clinical Physiology, National Research Council Massa Italy
| | - Paola Losi
- Institute of Clinical Physiology, National Research Council Massa Italy
| | - Marianna Asaro
- Institute of Clinical Physiology, National Research Council Massa Italy
| | - Silvia Volpi
- Institute of Clinical Physiology, National Research Council Massa Italy
| | - Walter Bonani
- European Commission, Joint Research Centre Karlsruhe Germany
| | - Massimo Bonini
- Department of Chemistry “Ugo Schiff” and CSGI University of Florence Sesto Fiorentino Italy
| | - Giorgio Soldani
- Institute of Clinical Physiology, National Research Council Massa Italy
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Datta P, Barui A, Wu Y, Ozbolat V, Moncal KK, Ozbolat IT. Essential steps in bioprinting: From pre- to post-bioprinting. Biotechnol Adv 2018; 36:1481-1504. [PMID: 29909085 DOI: 10.1016/j.biotechadv.2018.06.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 05/15/2018] [Accepted: 06/10/2018] [Indexed: 12/17/2022]
Abstract
An increasing demand for directed assembly of biomaterials has inspired the development of bioprinting, which facilitates the assembling of both cellular and acellular inks into well-arranged three-dimensional (3D) structures for tissue fabrication. Although great advances have been achieved in the recent decade, there still exist issues to be addressed. Herein, a review has been systematically performed to discuss the considerations in the entire procedure of bioprinting. Though bioprinting is advancing at a rapid pace, it is seen that the whole process of obtaining tissue constructs from this technique involves multiple-stages, cutting across various technology domains. These stages can be divided into three broad categories: pre-bioprinting, bioprinting and post-bioprinting. Each stage can influence others and has a bearing on the performance of fabricated constructs. For example, in pre-bioprinting, tissue biopsy and cell expansion techniques are essential to ensure a large number of cells are available for mass organ production. Similarly, medical imaging is needed to provide high resolution designs, which can be faithfully bioprinted. In the bioprinting stage, compatibility of biomaterials is needed to be matched with solidification kinetics to ensure constructs with high cell viability and fidelity are obtained. On the other hand, there is a need to develop bioprinters, which have high degrees of freedom of movement, perform without failure concerns for several hours and are compact, and affordable. Finally, maturation of bioprinted cells are governed by conditions provided during the post-bioprinting process. This review, for the first time, puts all the bioprinting stages in perspective of the whole process of bioprinting, and analyzes their current state-of-the art. It is concluded that bioprinting community will recognize the relative importance and optimize the parameter of each stage to obtain the desired outcomes.
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Affiliation(s)
- Pallab Datta
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology Shibpur, Howrah 711103, West Bengal, India
| | - Ananya Barui
- Centre for Healthcare Science and Technology, Indian Institute of Engineering Science and Technology Shibpur, Howrah 711103, West Bengal, India
| | - Yang Wu
- Engineering Science and Mechanics Department, Penn State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA
| | - Veli Ozbolat
- Engineering Science and Mechanics Department, Penn State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA; Ceyhan Engineering Faculty, Cukurova University, Adana 01950, Turkey
| | - Kazim K Moncal
- Engineering Science and Mechanics Department, Penn State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA
| | - Ibrahim T Ozbolat
- Engineering Science and Mechanics Department, Penn State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, Penn State University, University Park, PA 16802, USA; Biomedical Engineering Department, Penn State University, University Park, PA 16802, USA; Materials Research Institute, Penn State University, University Park, PA 16802, USA.
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Mattioli-Belmonte M, Giavaresi G, Biagini G, Virgili L, Giacomini M, Fini M, Giantomassi F, Natali D, Torricelli P, Giardino R. Tailoring Biomaterial Compatibility: In Vivo Tissue Response versus in Vitro Cell Behavior. Int J Artif Organs 2018; 26:1077-85. [PMID: 14738191 DOI: 10.1177/039139880302601205] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Biocompatibility relies essentially on surface phenomena, represented by cell-cell, cell-material and material (polymer)-protein interactions. An in vivo and in vitro experimental investigation was carried out on the biomaterials of two different classes with a good potential for in situ utilisation. Non-resorbable (Polypyrrole, Polyaniline, Polyimide) and resorbable (PLLA-PDXO-PLLA) materials for tissue engineering were studied for their overall tissue tolerance and cellular interactions. These non-resorbable polymers conceived for biosensor applications and implantable drug-delivery systems are intrinsically conductive. The PLLA-PDXO-PLLA triblock copolymer showed interesting tensile properties for bone and cartilage tissue engineering due to the presence of 1,5-dioxepan-2-one. In vitro and in vivo parallel studies showed an interesting correspondence: a) the cells in contact with the resorbable material that appeared to be capable of migratory-regenerative aspects in vitro exhibited good compatibility in vivo; whereas b) the non-resorbable materials, which are designed to remain in situ in vivo, were seen to have the potential to represent an adverse factor (inflammation, fibrotic reactions) that correlated with some aspects of cell behaviour in vitro.
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Affiliation(s)
- M Mattioli-Belmonte
- Institute of Normal Human Morphology, Polytechnic University of Marche, Ancona, Italy.
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Liu R, Dai H, Zhou Q, Zhang Q, Zhang P. Synthesis and characterization of shape-memory poly carbonate urethane microspheres for future vascular embolization. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2016; 27:1248-61. [PMID: 27193120 DOI: 10.1080/09205063.2016.1189379] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Two types of shape memory poly carbonate urethanes (PCUs) microspheres were synthesized by pre-polymerization and suspension polymerization, based on Polycarbonate diol (PCDL) as the soft segment, Isophorone diisocyanate (IPDI) and 1,6-hexamethylene diisocyanate (HDI) as the hard segments and 1,4-butanediol (BDO) as the chain expanding agent. The structure, crystallinity, and thermal property of the two synthesized PCUs were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Differential scanning calorimetery (DSC), respectively. The results showed that the two types of PCUs exhibited high thermal stability with phase separation and semi-crystallinity. Also, the results of the compression test displayed that the shape fixity and the shape recovery of two PCUs were more than 90% compared to the originals, indicating their similar bio-applicability and shape-memory properties. The tensile strength, elongation at break was enhanced by introducing and increasing content of HDI. The water contact angles of PCUs decreased and their surface tension increased by surface modified with Bovine serum albumin (BSA). Furthermore, the biological study results of two types of PCUs from the platelet adhesion test and the cell proliferation inhibition test indicated they had some biocompatibilites. Hence, the PCU microspheres might represent a smart and shape-memory embolic agent for vascular embolization.
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Affiliation(s)
- Rongrong Liu
- a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , China
| | - Honglian Dai
- a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , China.,b Biomedical Materials and Engineering Research Center of Hubei Province , Wuhan , China
| | - Qian Zhou
- a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , China
| | - Qian Zhang
- a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , China
| | - Ping Zhang
- a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , China
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Fernández-d’Arlas B, Alonso-Varona A, Palomares T, Corcuera MA, Eceiza A. Studies on the morphology, properties and biocompatibility of aliphatic diisocyanate-polycarbonate polyurethanes. Polym Degrad Stab 2015. [DOI: 10.1016/j.polymdegradstab.2015.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Oh SY, Kang MS, Knowles JC, Gong MS. Synthesis of bio-based thermoplastic polyurethane elastomers containing isosorbide and polycarbonate diol and their biocompatible properties. J Biomater Appl 2015; 30:327-37. [DOI: 10.1177/0885328215590054] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new family of highly elastic polyurethanes (PUs) partially based on renewable isosorbide were prepared by reacting hexamethylene diisocyanate with a various ratios of isosorbide and polycarbonate diol 2000 (PCD) via a one-step bulk condensation polymerization without catalyst. The influence of the isorsorbide/PCD ratio on the properties of the PU was evaluated. The successful synthesis of the PUs was confirmed by Fourier transform-infrared spectroscopy and 1H nuclear magnetic resonance. The resulting PUs showed high number-average molecular weights ranging from 56,320 to 126,000 g mol−1 and tunable Tg values from −34 to −38℃. The thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis. The PU films were flexible with breaking strains from 955% to 1795% at from 13.5 to 54.2 MPa tensile stress. All the PUs had 0.9–2.8% weight lost over 4 weeks and continual slow weight loss of 1.1–3.6% was observed within 8 weeks. Although the cells showed a slight lower rate of proliferation than that of the tissue culture polystyrene as a control, the PU films were considered to be cytocompatible and nontoxic. These thermoplastic PUs were soft, flexible and biocompatible polymers, which open up a range of opportunities for soft tissue augmentation and regeneration.
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Affiliation(s)
- So-Yeon Oh
- Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center, Dankook University Graduate School, Chungnam, South Korea
| | - Min-Sil Kang
- Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center, Dankook University Graduate School, Chungnam, South Korea
| | - Jonathan C Knowles
- Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center, Dankook University Graduate School, Chungnam, South Korea
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK
| | - Myoung-Seon Gong
- Department of Nanobiomedical Science and BK21 PLUS NBM Global Research Center, Dankook University Graduate School, Chungnam, South Korea
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10
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Abstract
Frequent and frequently deliberate release of plastics leads to accumulation of plastic waste in the environment which is an ever increasing ecological threat.
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Affiliation(s)
- Neha Mahajan
- Department of Biotechnology
- Govt Degree College Kathua
- Higher Education Department
- India 184104
| | - Pankaj Gupta
- Department of Chemistry
- Govt Degree College Kathua
- Higher Education Department
- India 184104
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11
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Dempsey DK, Nezarati RM, Mackey CE, Cosgriff-Hernandez EM. High compliance vascular grafts based on semi-interpenetrating networks. MACROMOLECULAR MATERIALS AND ENGINEERING 2014; 299:1455-1464. [PMID: 25601822 PMCID: PMC4296902 DOI: 10.1002/mame.201400101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Current synthetic vascular grafts have poor patency rates in small diameter applications (<6 mm) due to intimal hyperplasia arising from a compliance mismatch between the graft and native vasculature. Enormous efforts have focused on improving biomechanical properties; however, polymeric grafts are often constrained by an inverse relationship between burst pressure and compliance. We have developed a new, semi-interpenetrating network (semi-IPN) approach to improve compliance without sacrificing burst pressure. The effects of heat treatment on graft morphology, fiber architecture, and resultant biomechanical properties are presented. In addition, biomechanical properties after equilibration at physiological temperature were investigated in relation to polyurethane microstructure to better predict in vivo performance. Compliance values as high as 9.2 ± 2.7 %/mmHg x 10-4 were observed for the semi-IPN graft while also maintaining high burst pressure, 1780 ± 230 mm Hg. The high compliance of these heat-treated poly(carbonate urethane) (PCU) and semi-IPN grafts is expected to improve long-term patency rates beyond even saphenous vein autografts by preventing intimal hyperplasia. The fundamental structure-property relationships gained from this work may also be utilized to advance biomedical device designs based on thermoplastic polyurethanes.
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Affiliation(s)
- David K. Dempsey
- Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77840-3120, USA
| | - Roya M. Nezarati
- Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77840-3120, USA
| | - Calvin E. Mackey
- Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77840-3120, USA
| | - Elizabeth M. Cosgriff-Hernandez
- Department of Biomedical Engineering, Texas A&M University, 5033 Emerging Technologies Building, 3120 TAMU, College Station, TX 77840-3120, Phone: (979) 845-1771, Fax: (979) 845-4450
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12
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Dempsey DK, Robinson JL, Iyer AV, Parakka JP, Bezwada RS, Cosgriff-Hernandez EM. Characterization of a resorbable poly(ester urethane) with biodegradable hard segments. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2014; 25:535-54. [DOI: 10.1080/09205063.2014.880247] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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In vitro Endothelialization and Platelet Adhesion on Titaniferous Upgraded Polyether and Polycarbonate Polyurethanes. MATERIALS 2014; 7:623-636. [PMID: 28788479 PMCID: PMC5453079 DOI: 10.3390/ma7020623] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 01/16/2014] [Accepted: 01/19/2014] [Indexed: 01/26/2023]
Abstract
Polycarbonateurethanes (PCU) and polyetherurethanes (PEU) are used for medical devices, however their bio- and haemocompatibility is limited. In this study, the effect of titaniferous upgrading of different polyurethanes on the bio- and haemocompatibility was investigated by endothelial cell (EC) adhesion/proliferation and platelet adhesion (scanning electron microscopy), respectively. There was no EC adhesion/proliferation and only minor platelet adhesion on upgraded and pure PCU (Desmopan). PEUs (Texin 985, Tecothane 1085, Elastollan 1180A) differed in their cyto- and haemocompatibility. While EC adhesion depended on the type of PEU, any proliferative activity was inhibited. Additional titaniferous upgrading of PEU induced EC proliferation and increased metabolic activity. However, adherent ECs were significantly activated. While Texin was highly thrombotic, only small amounts of platelets adhered onto Tecothane and Elastollan. Additional titaniferous upgrading reduced thrombogenicity of Texin, preserved haemocompatibility of Elastollan, and increased platelet activation/aggregation on Tecothane. In conclusion, none of the PUs was cytocompatible; only titaniferous upgrading allowed EC proliferation and metabolism on PEUs. Haemocompatibility depended on the type of PU.
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Bordenave L, Menu P, Baquey C. Developments towards tissue-engineered, small-diameter arterial substitutes. Expert Rev Med Devices 2014; 5:337-47. [DOI: 10.1586/17434440.5.3.337] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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15
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Dempsey DK, Carranza C, Chawla CP, Gray P, Eoh JH, Cereceres S, Cosgriff-Hernandez EM. Comparative analysis of in vitro oxidative degradation of poly(carbonate urethanes) for biostability screening. J Biomed Mater Res A 2013; 102:3649-65. [PMID: 24265203 DOI: 10.1002/jbm.a.35037] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/06/2013] [Accepted: 11/07/2013] [Indexed: 11/08/2022]
Abstract
The resistance to oxidation and environmental stress cracking of poly(carbonate urethanes) (PCUs) has generated significant interest as potential replacements of poly(ether urethanes) in medical devices. Several in vitro models have been developed to screen segmented polyurethanes for oxidative stability. High concentrations of reactive oxygen intermediates produced by combining hydrogen peroxide and dissolved cobalt ions has frequently been used to predict long-term oxidative degradation with short-term testing. Alternatively, a 3% H₂O₂ concentration without metal ions is suggested within the ISO 10993-13 standard to simulate physiological degradation rates. A comparative analysis which evaluates the predictive capabilities of each test method has yet to be completed. To this end, we have utilized both systems to test three commercially available PCUs with low and high soft segment content: Bionate PCU and Bionate II PCUs, two materials with different soft segment chemistries, and CarboSil TSPCU, a thermoplastic silicone PCU. Bulk properties of all PCUs were retained with minor changes in molecular weight and tensile properties indicating surface oxidative degradation in the accelerated system after 36 days. Soft segment loss and surface damage were comparable to previous in vivo data. The 3% H₂O₂ method exhibited virtually no changes on the surface or in bulk properties after 12 months of treatment despite previous in vivo results. These results indicate the accelerated test method more effectively characterized the oxidative degradation profiles than the 3% H₂O₂ treatment system. The lack of bulk degradation in the 12-month study also supports the hydrolytic stability of these PCUs.
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Affiliation(s)
- David K Dempsey
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, 77843-3120
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16
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Arjun GN, Menon G, Ramesh P. Plasma surface modification of fibroporous polycarbonate urethane membrane by polydimethyl siloxane: Structural characterization, mechanical properties, and in vitro
cytocompatibility evaluation. J Biomed Mater Res A 2013; 102:947-57. [DOI: 10.1002/jbm.a.34781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/17/2013] [Accepted: 04/26/2013] [Indexed: 01/05/2023]
Affiliation(s)
- G. N. Arjun
- Biomedical Technology Wing; Sree Chitra Tirunal Institute for Medical Sciences and Technology; Poojappura, Thiruvananthapuram 695012 India
| | - Girish Menon
- Department of Neurosurgery; Sree Chitra Tirunal Institute for Medical Sciences and Technology; Thiruvananthapuram 695011 India
| | - P. Ramesh
- Biomedical Technology Wing; Sree Chitra Tirunal Institute for Medical Sciences and Technology; Poojappura, Thiruvananthapuram 695012 India
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17
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Yang J, Gao Y, Li J, Ding M, Chen F, Tan H, Fu Q. Synthesis and microphase separated structures of polydimethylsiloxane/polycarbonate-based polyurethanes. RSC Adv 2013. [DOI: 10.1039/c3ra40515j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Abstract
BACKGROUND Heart valve disease is currently a growing problem, and demand for heart valve replacement is predicted to increase significantly in the future. Existing "gold standard" mechanical and biological prosthesis offers survival at a cost of significantly increased risks of complications. Mechanical valves may cause hemorrhage and thromboembolism, whereas biologic valves are prone to fibrosis, calcification, degeneration, and immunogenic complications. METHODS A literature search was performed to identify all relevant studies relating to tissue-engineered heart valve in life sciences using the PubMed and ISI Web of Knowledge databases. DISCUSSION Tissue engineering is a new, emerging alternative, which is reviewed in this paper. To produce a fully functional heart valve using tissue engineering, an appropriate scaffold needs to be seeded using carefully selected cells and proliferated under conditions that resemble the environment of a natural human heart valve. Bioscaffold, synthetic materials, and preseeded composites are three common approaches of scaffold formation. All available evidence suggests that synthetic scaffolds are the most suitable material for valve scaffold formation. Different cell sources of stem cells were used with variable results. Mesenchymal stem cells, fibroblasts, myofibroblasts, and umbilical blood stem cells are used in vitro tissue engineering of heart valve. Alternatively scaffold may be implanted and then autoseeded in vivo by circulating endothelial progenitor cells or primitive circulating cells from patient's blood. For that purpose, synthetic heart valves were developed. CONCLUSIONS Tissue engineering is currently the only technology in the field with the potential for the creation of tissues analogous to a native human heart valve, with longer sustainability, and fever side effects. Although there is still a long way to go, tissue-engineered heart valves have the capability to revolutionize cardiac surgery of the future.
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Affiliation(s)
- Radoslaw A Rippel
- UCL Centre for Nanotechnology & Regenerative Medicine, Division of Surgery and Interventional Science, University College London, London, UK.
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19
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Boccafoschi F, Mosca C, Cannas M. Cardiovascular biomaterials: when the inflammatory response helps to efficiently restore tissue functionality? J Tissue Eng Regen Med 2012; 8:253-67. [DOI: 10.1002/term.1526] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 01/30/2012] [Accepted: 04/03/2012] [Indexed: 01/25/2023]
Affiliation(s)
- F. Boccafoschi
- Department of Health Sciences; University of Piemonte Orientale; “A. Avogadro” 28100 Novara Italy
| | - C. Mosca
- Department of Health Sciences; University of Piemonte Orientale; “A. Avogadro” 28100 Novara Italy
| | - M. Cannas
- Department of Health Sciences; University of Piemonte Orientale; “A. Avogadro” 28100 Novara Italy
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Arjun GN, Ramesh P. Structural characterization, mechanical properties, and in vitro cytocompatibility evaluation of fibrous polycarbonate urethane membranes for biomedical applications. J Biomed Mater Res A 2012; 100:3042-50. [PMID: 22707288 DOI: 10.1002/jbm.a.34255] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 04/10/2012] [Accepted: 05/07/2012] [Indexed: 02/01/2023]
Abstract
This paper reports the electrospinning of a series of oxidatively stable polycarbonate urethanes (PCU) [carbothane (ECT), bionate (EBN), and chronoflex (ECF)] using N,N-dimethyl formamide and tetrahydrofuran as the mixed solvent. The nonwoven membranes were characterized for their structure, performance, and compatibility with cells. Scanning electron microscope was utilized to study the structural morphology and fiber diameter. Microcomputed tomography (micro-CT) was used to characterize the 3D architecture, pore size distribution, and percentage porosity. All the membranes displayed a porous architecture with average fiber diameter in the range of 1.5-2 μm. Static mechanical tests on the membranes revealed that the tensile strength was greater than 7 MPa and the dynamic mechanical tests showed that the average storage modulus (E(i) ) is 2 MPa at 37°C. PCU membranes were subjected to accelerated in vitro degradation for 90 days in 20% hydrogen peroxide/0.1M cobalt chloride solution. Mechanical characterization of the membranes postdegradation confirmed a 64% reduction in tensile strength for EBN at the end of 90 days where as ECF and ECT did not show any significant mechanical property deterioration in the oxidative medium. Cytotoxicity of the membranes was evaluated using L929 fibroblast cells and the results indicated that all the PCU membranes were cytocompatible and showed good adherence to L929 cells. Accordingly, these results highlight the potential of these fibrous PCU membranes for biomedical applications but further in vivo correlation studies are required for better understanding of the biodegradation and biological efficacy.
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Affiliation(s)
- G N Arjun
- Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram 695012, India
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21
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Lu J, Feng Y, Gao B, Guo J. Grafting of a novel phosphorylcholine-containing vinyl monomer onto poly-carbonateurethane surfaces by ultraviolet radiation grafting polymerization. Macromol Res 2012. [DOI: 10.1007/s13233-012-0104-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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22
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Rahmani B, Tzamtzis S, Ghanbari H, Burriesci G, Seifalian AM. Manufacturing and hydrodynamic assessment of a novel aortic valve made of a new nanocomposite polymer. J Biomech 2012; 45:1205-11. [DOI: 10.1016/j.jbiomech.2012.01.046] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 12/14/2011] [Accepted: 01/29/2012] [Indexed: 11/27/2022]
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Kultys A, Rogulska M, Pikus S. New thermoplastic segmented polyurethanes with hard segments derived from 4,4′-diphenylmethane diisocyanate and methylenebis(1,4-phenylenemethylenethio)dialcanols. J Appl Polym Sci 2011. [DOI: 10.1002/app.34102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gu X, Wu J, Mather PT. Polyhedral Oligomeric Silsesquioxane (POSS) Suppresses Enzymatic Degradation of PCL-Based Polyurethanes. Biomacromolecules 2011; 12:3066-77. [DOI: 10.1021/bm2006938] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xinzhu Gu
- Syracuse Biomaterials Institute, Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Jian Wu
- Syracuse Biomaterials Institute, Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
| | - Patrick T. Mather
- Syracuse Biomaterials Institute, Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York 13244, United States
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Bakhshi R, Darbyshire A, Evans JE, You Z, Lu J, Seifalian AM. Polymeric coating of surface modified nitinol stent with POSS-nanocomposite polymer. Colloids Surf B Biointerfaces 2011; 86:93-105. [PMID: 21515031 DOI: 10.1016/j.colsurfb.2011.03.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 03/14/2011] [Accepted: 03/18/2011] [Indexed: 11/19/2022]
Abstract
Stent angioplasty is a successful treatment for arterial occlusion, particularly in coronary artery disease. The clinical communities were enthusiastic about the use of drug-eluting stents; however, these stents have a tendency to be a contributory factor towards late stage thrombosis, leading to mortality in a significant number of patients per year. This work presents an innovative approach in self-expanding coronary stents preparation. We developed a new nanocomposite polymer based on polyhedral oligomeric silsesquioxanes (POSS) and poly(carbonate-urea)urethane (PCU), which is an antithrombogenic and a non-biodegradable polymer with in situ endothelialization properties. The aim of this work is to coat a NiTi stent alloy with POSS-PCU. In prolonged applications in the human body, the corrosion of the NiTi alloy can result in the release of deleterious ions which leads to unwanted biological reactions. Coating the nitinol (NiTi) surface with POSS-PCU can enhance surface resistance and improve biocompatibility. Electrohydrodynamic spraying was used as the polymer deposition process and thus a few experiments were carried out to compare this process with casting. Prior to deposition the NiTi has been surface modified. The peel strength of the deposit was studied before and after degradation of the coating. It is shown that the surface modification enhances the peel strength by 300%. It is also indicated how the adhesion strength of the POSS-PCU coating changes post-exposure to physiological solutions comprised of hydrolytic, oxidative, peroxidative and biological media. This part of the study shows that the modified NiTi presents far greater resistance to decay in peel strength compared to the non-modified NiTi.
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Affiliation(s)
- Raheleh Bakhshi
- University College London, Centre for Nanotechnology and Regenerative Medicine, London, UK
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Kozakiewicz J, Rokicki G, Przybylski J, Sylwestrzak K, Parzuchowski PG, Tomczyk KM. Studies of the hydrolytic stability of poly(urethane–urea) elastomers synthesized from oligocarbonate diols. Polym Degrad Stab 2010. [DOI: 10.1016/j.polymdegradstab.2010.08.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ravari H, Kazemzade GH, Modaghegh MHS, Khashayar P. Patency rate and complications of polytetrafluoroethylene grafts compared with polyurethane grafts for hemodialysis access. Ups J Med Sci 2010; 115:245-8. [PMID: 20218943 PMCID: PMC2971481 DOI: 10.3109/03009731003678562] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The survival of hemodialysis patients requiring dialysis depends on the long-term functioning and patency of the vascular access. Prosthetic vascular grafts are inevitably used for patients whose vessels are unsuitable for an autogenous arteriovenous (AV) fistula. The purpose of this study was to compare the patency rate and associated complications using different types of grafts. METHODS This prospective study was conducted on patients who did not have an appropriate vein for arteriovenous fistula from January 2004 through July 2006. They were divided into two groups, sex, age, and basic data matched. Polytetrafluoroethylene (PTFE) and polyurethane (PVAG) were the two types of grafts used in this study. The functionality of the graft was assessed immediately 1 day and 2 weeks after operation. The clinical follow-up was performed each 3 months until 24 months. RESULTS One-year patency rate was reported to be 64% and 52% in the PTFE and PVAG groups, respectively. There was no significant difference in 1-year (64% versus 52%) and 2-year (49% versus 41%) patency rate of the PTFE and PVAG grafts used as vascular access. There was also no difference between the numbers of complications reported in the two groups. CONCLUSION It could be concluded that either PTFE or PVAG grafts can be used with the same expected outcomes.
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Affiliation(s)
- Hassan Ravari
- Sina Hospital, Tehran University of Medical Sciences, Iran
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Cozzens D, Ojha U, Kulkarni P, Faust R, Desai S. Long term in vitro biostability of segmented polyisobutylene-based thermoplastic polyurethanes. J Biomed Mater Res A 2010; 95:774-82. [DOI: 10.1002/jbm.a.32897] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Raghunath J, Georgiou G, Armitage D, Nazhat SN, Sales KM, Butler PE, Seifalian AM. Degradation studies on biodegradable nanocomposite based on polycaprolactone/polycarbonate (80:20%) polyhedral oligomeric silsesquioxane. J Biomed Mater Res A 2009; 91:834-44. [DOI: 10.1002/jbm.a.32335] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kidane AG, Burriesci G, Edirisinghe M, Ghanbari H, Bonhoeffer P, Seifalian AM. A novel nanocomposite polymer for development of synthetic heart valve leaflets. Acta Biomater 2009; 5:2409-17. [PMID: 19497802 DOI: 10.1016/j.actbio.2009.02.025] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 01/28/2009] [Accepted: 02/10/2009] [Indexed: 10/21/2022]
Abstract
A novel nanocomposite polymer with a polycarbonate soft segment (PCU) and polyhedral oligomeric silsesquioxanes (POSS) nanoparticle (POSS-PCU) has been selected for a synthetic heart valve due to its superior biocompatibility and in vivo biostability. However, the development of synthetic heart valves from polymeric materials requires an understanding of the basic mechanical and surface properties of the polymer. In this study, the mechanical properties of POSS-PCU, including tensile strength, tear strength and hardness, were tested and compared to control (PCU). The surface property was analyzed using contact angle measurement and the resistance to platelet adhesion was also investigated. POSS-PCU (hardness 84+/-0.8 Shore A) demonstrated significantly higher tensile strength 53.6+/-3.4 and 55.9+/-3.9Nmm(-2) at 25 and 37 degrees C, respectively) than PCU (33.8+/-2.1 and 28.8+/-3.4Nmm(-2) at 25 and 37 degrees C, respectively). Tensile strength and elongation at break of POSS-PCU was significantly higher than PCU at both 25 and 37 degrees C (P<0.001). POSS-PCU showed a relatively low Young's modulus (25.9+/-1.9 and 26.2+/-2.0Nmm(-2)) which was significantly greater in comparison with control PCU (9.1+/-0.9 and 8.4+/-0.5Nmm(-2)) at 25 and 37 degrees C, respectively, with 100mum thickness. There was no significant difference (P>0.05) in tear strength between POSS-PCU and PCU at 25 degrees C. However, tear strength increased significantly (P<0.001) (at 37 degrees C) as the thickness increased from 100microm (51.0+/-3.3Nmm(-1)) to 200microm (63+/-1.5Nmm(-1)). The surface of POSS-PCU was significantly less hydrophilic than that of PCU.
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31
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Jiang G, Tuo X, Wang D, Li Q. Preparation, characterization, and properties of fluorinated polyurethanes. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23386] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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32
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Wang ZQ, Zhou YM, Ye XY, Chen J, Sun YQ. Synthesis and characterization of novel optically active poly(urethane urea)s: Effect of left/right rotation conformation. J Appl Polym Sci 2009. [DOI: 10.1002/app.29220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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33
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Rashid ST, Fuller B, Hamilton G, Seifalian AM. Tissue engineering of a hybrid bypass graft for coronary and lower limb bypass surgery. FASEB J 2008; 22:2084-9. [DOI: 10.1096/fj.07-096586] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- S. T. Rashid
- Biomaterial and Tissue Engineering Centre (BTEC)Royal Free and University College Medical SchoolUniversity College LondonLondonUK
| | - B. Fuller
- Biomaterial and Tissue Engineering Centre (BTEC)Royal Free and University College Medical SchoolUniversity College LondonLondonUK
| | - G. Hamilton
- Vascular UnitRoyal Free Hampstead National Health Service TrustLondonUK
| | - A. M. Seifalian
- Biomaterial and Tissue Engineering Centre (BTEC)Royal Free and University College Medical SchoolUniversity College LondonLondonUK
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34
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Olbrich M, Punshon G, Frischauf I, Salacinski HJ, Rebollar E, Romanin C, Seifalian AM, Heitz J. UV surface modification of a new nanocomposite polymer to improve cytocompatibility. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2007; 18:453-68. [PMID: 17540119 DOI: 10.1163/156856207780425059] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A novel modified nanocomposite was studied for the adhesion and proliferation of the human umbilical vein endothelial cell (HUVEC) line EA.hy926. The nanocomposite under investigation was poly(carbonate-urea)urethane with silsesquioxane nano-cages, here in the form of a mixture of two polyhedral oligomeric silsesquioxanes. The nanocomposite surfaces were exposed to ultraviolet (UV) light of a Xe(*)(2)-excimer lamp at a wavelength of 172 nm in an ammonia atmosphere. The effects of the irradiation were characterized by atomic force and scanning electron microscopy (AFM, SEM), X-ray photo-electron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR) using an attenuated total reflection (ATR) device and measurements of advancing water contact angle (CA). The irradiation resulted in the introduction of new hydrophilic N- and O-containing groups into the surface, which was initially amphiphilic, while surface morphology remained mainly unchanged. Slight chemical changes were also observed for the silsesquioxane nano-cages at the surface. Onto the untreated and irradiated samples HUVECs were seeded and grown for various durations in culture. Standard tissue-culture polystyrene (PS) was employed as a positive control to check the efficiency of the cell-culture methods. Viability and proliferation of the cells were then assessed using a non-radioactive assay. Compared to the untreated nanocomposite polymer, irradiation times of at least 5 min resulted in a significantly increased cell proliferation between 3 and 8 days after seeding with the HUVEC line EA.hy926.
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Affiliation(s)
- Michael Olbrich
- Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz, Austria
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35
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Christenson EM, Anderson JM, Hiltner A. Antioxidant inhibition of poly(carbonate urethane) in vivo biodegradation. J Biomed Mater Res A 2006; 76:480-90. [PMID: 16278858 DOI: 10.1002/jbm.a.30506] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study compared the effect of an antioxidant on the in vivo biodegradation of a poly(carbonate urethane) (PCU) and a poly(ether urethane) (PEU). Unstrained PEU and PCU films with and without Santowhite were implanted subcutaneously into 3-month-old Sprague-Dawley rats for 3, 6, and 12 months. Characterization of unstabilized PEU and PCU with ATR-FTIR and SEM showed soft-segment and hard-segment degradation consistent with previous studies. In particular, evidence of chain scission and crosslinking of the surface was present in the ATR-FTIR spectra of explanted specimens. Addition of 2.2 wt % antioxidant inhibited the in vivo degradation of both PCU and PEU. Although the antioxidant probably improved polyurethane biostability by decreasing the susceptibility of the polymer to degradation, modulation of the cellular response to prevent the release of degradative agents was also possible. To differentiate the effects, the foreign-body response was investigated with the use of a standard cage implant protocol. Polyurethane films were implanted in wire mesh cages subcutaneously in rats for 4, 7, and 21 days. There were no statistical differences among materials in the inflammatory exudate cell counts, adherent cell densities, or percent fusion of macrophages into foreign-body giant cells (FBGCs). Therefore, it was concluded that the antioxidant inhibited degradation by capturing oxygen radicals that would otherwise cause polyurethane chain scission and crosslinking.
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Affiliation(s)
- Elizabeth M Christenson
- Center for Applied Polymer Research, Case Western Reserve University, Cleveland, Ohio 44106, USA
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36
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Kannan RY, Salacinski HJ, De Groot J, Clatworthy I, Bozec L, Horton M, Butler PE, Seifalian AM. The antithrombogenic potential of a polyhedral oligomeric silsesquioxane (POSS) nanocomposite. Biomacromolecules 2006; 7:215-23. [PMID: 16398518 DOI: 10.1021/bm050590z] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have developed a nanocomposite using a silica nanocomposite polyhedral oligomeric silsesquioxane (POSS) and poly(carbonate-urea)urethane (PCU) for potential use in cardiovascular bypass grafts and the microvascular component of artificial capillary beds. In this study, we sought to compare its antithrombogenicity to that of conventional polymers used in vascular bypass grafts so as to improve upon current patency rates, particularly in the microvascular setting. Using atomic force microscopy (AFM) and transmission electron microscopy (TEM), surface topography and composition were studied, respectively. The ability of the nanocomposite surface to repel both proteins and platelets in vitro was assessed using thromboelastography (TEG), fibrinogen ELISA assays, antifactor Xa assays, scanning electron microscopy (SEM), and platelet adsorption tests. TEG analysis showed a significant decrease in clot strength (one-way ANOVA, p < 0.001) and increase in clot lysis (one-way ANOVA, p < 0.0001) on the nanocomposite when compared to both poly(tetrafluoroethylene) (PTFE) and PCU. ELISA assays indicate lower adsorption of fibrinogen to the nanocomposite compared to PTFE (one-way ANOVA, p < 0.01). Interestingly, increasing the concentration of POSS nanocages within these polymers was shown to proportionately inhibit factor X activity. Platelet adsorption at 120 min was also lower compared to PTFE and PCU (two-way ANOVA, p < 0.05). SEM images showed a "speckled" morphologic pattern with Cooper grades I platelet adsorption morphology on the nanocomposite compared to PTFE with grade IV morphology. On the basis of these results, we concluded that POSS nanocomposites possess greater thromboresistance than PTFE and PCU, making it an ideal material for the construction of both bypass grafts and microvessels.
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Affiliation(s)
- Ruben Y Kannan
- Biomaterials & Tissue Engineering Centre (BTEC), Academic Division of Surgical and Interventional Sciences, University College London, Rowland Hill, Hampstead, London NW3 2PF, U.K
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Kannan RY, Salacinski HJ, Odlyha M, Butler PE, Seifalian AM. The degradative resistance of polyhedral oligomeric silsesquioxane nanocore integrated polyurethanes: An in vitro study. Biomaterials 2006; 27:1971-9. [PMID: 16253324 DOI: 10.1016/j.biomaterials.2005.10.006] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Accepted: 10/03/2005] [Indexed: 12/29/2022]
Abstract
Polymer biostability is one of the critical parameters by which these materials are selected for use as biomedical devices. This is the major rationale for the use of polymers which are highly crystalline and stiff namely expanded polytetrafluoroethylene (ePTFE) and Dacron in particular, as arterial bypass grafts. While this is immaterial in high-flow states, it becomes critically important at lower flows with a greater need for more compliant vessels. Polyurethanes being one of the most compliant polymers known are as such, the natural choice to build such constructs. However, concerns regarding their resistance to degradation have limited their use as vascular prostheses and in order to augment their strength, herein a novel polyhedral oligomeric silsesquioxane integrated poly(carbonate-urea)urethane (POSS-PCU) nanocomposite was synthesised by our group. In the following series of experiments, the POSS-PCU nanocomposite samples were exposed to accelerated degradative solutions, in an 'in-house' established model in vitro for up to 70 days before being subjected to infra-red spectroscopy, scanning electron microscopy, stress-strain studies and differential scanning calorimetry. Our results demonstrate that these silsesquioxane nanocores shield the soft segment(s) of the polyurethane, responsible for its compliance and elasticity from all forms of degradation, principally oxidation and hydrolysis. These nanocomposites hence provide an optimal method by which these polymers may be strengthened whilst maintaining their elasticity, making them ideal as vascular prostheses particularly at low flow states.
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Affiliation(s)
- Ruben Y Kannan
- Biomaterials & Tissue Engineering Centre (BTEC), Academic Division of Surgical and Interventional Sciences, University College London, Rowland Hill, Hampstead, London NW3 2PF, UK
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Vara DS, Salacinski HJ, Kannan RY, Bordenave L, Hamilton G, Seifalian AM. Cardiovascular tissue engineering: state of the art. ACTA ACUST UNITED AC 2005; 53:599-612. [PMID: 16364812 DOI: 10.1016/j.patbio.2004.12.006] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Accepted: 12/03/2004] [Indexed: 11/18/2022]
Abstract
In patients requiring coronary or peripheral vascular bypass procedures, autogenous arterial or vein grafts remain as the conduit of choice even in the case of redo patients. It is in this class of redo patients that often natural tissue of suitable quality becomes unavailable; so that prosthetic material is then used. Prosthetic grafts are liable to fail due to graft occlusion caused by surface thrombogenicity and lack of elasticity. To prevent this, seeding of the graft lumen with endothelial cells has been undertaken and recent clinical studies have evidenced patency rates approaching reasonable vein grafts. Recent advances have also looked at developing a completely artificial biological graft engineered from the patient's cells with surface and viscoelastic properties similar to autogenous vessels. This review encompasses both endothelialisation of grafts and the construction of biological cardiovascular conduits.
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Affiliation(s)
- Dina S Vara
- Biomaterial and Tissue Engineering Centre (BTEC), University Department of Surgery, Royal Free and University College Medical School, University College London, Rowland Hill Street, London NW3 2PF, UK
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Taylor JE, Laity PR, Freeburn S, Wong SS, Norris K, Khunkamchoo P, Cable M, Andrews G, Johnson AF, Cameron RE. Effect of processing route and acetone pre-treatment on the biostability of pellethane materials used in medical device applications. Biomaterials 2005; 26:6467-76. [PMID: 15935471 DOI: 10.1016/j.biomaterials.2005.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Accepted: 04/07/2005] [Indexed: 11/24/2022]
Abstract
Thermoplastic polyurethanes, such as Pellethane 2363 80A (Pel80A) and Pellethane 2363 55D (Pel55D) are widely used in the medical device industry because of their biological and mechanical properties. However, premature failure in such devices has been observed and attributed to environmental stress cracking (ESC). The current work investigates the possibility of reducing ESC via bulk morphology manipulation. This can be achieved through various processing routes such as solvent-casting (SC) and hot-press quenching (HPQ). The effect of stress on the bulk morphology of Pel55D and Pel80A was evaluated using small-angle X-ray scattering (SAXS) in conjunction with tensile testing. SC samples exhibited greater phase separation compared with HPQ samples. Alignment of hard segment domains became apparent around the point of yield. Onset of ESC with respect to SC and HPQ routines was determined using the Zhao-Stokes glass-wool test with optical (OM) and environment scanning electron microscopy (ESEM). Improvement in biostability of Pel80A was found in HPQ samples compared to those that were SC. A secondary objective of this work was to investigate the effect of acetone pre-treatment on surface morphology. High resolution imaging of acetone treated and untreated SC Pel80A showed significant differences in surface morphology.
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Veleva AN, Khan SA, Cooper SL. Oxidative and hydrolytic stability of a novel acrylic terpolymer for biomedical applications. J Biomed Mater Res A 2005; 74:117-23. [PMID: 15924302 DOI: 10.1002/jbm.a.30349] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Oxidative and hydrolytic biostability assessment was carried out on a novel acrylic material made of hexamethyl methacrylate (HMA), methyl methacrylate (MMA), and methacrylic acid (MAA). To simulate the in vivo microenvironment, solutions of H2O2/CoCl2 and buffered solutions of cholesterol esterase (CE) and phospholipase A2 (PLA) were used. As controls, film specimens were incubated in deionized water. Samples were incubated in these solutions at 37 degrees C for 10 weeks before physical and mechanical properties were evaluated by size exclusion chromatography (SEC), 1H- nuclear magnetic resonance (1H-NMR), acid-base titration, and Instron tensile testing. The results from this study indicate excellent biostability of HMA-MMA-MAA terpolymers and thus their potential for use in biomedical devices for long-term implantation.
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Affiliation(s)
- Anka N Veleva
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA.
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Kannan RY, Salacinski HJ, Sales K, Butler P, Seifalian AM. The roles of tissue engineering and vascularisation in the development of micro-vascular networks: a review. Biomaterials 2005; 26:1857-75. [PMID: 15576160 DOI: 10.1016/j.biomaterials.2004.07.006] [Citation(s) in RCA: 254] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Accepted: 07/05/2004] [Indexed: 11/16/2022]
Abstract
The construction of tissue-engineered devices for medical applications is now possible in vitro using cell culture and bioreactors. Although methods of incorporating them back into the host are available, current constructs depend purely on diffusion which limits their potential. The absence of a vascular network capable of distributing oxygen and other nutrients within the tissue-engineered device is a major limiting factor in creating vascularised artificial tissues. Though bio-hybrid prostheses such as vascular bypass grafts and skin substitutes have already been developed and are being used clinically, the absence of a capillary bed linking the two systems remains the missing link. In this review, the different approaches currently being or that have been applied to vascularise tissues are identified and discussed.
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Affiliation(s)
- Ruben Y Kannan
- Biomaterials & Tissue Engineering Centre (BTEC), University Department of Surgery, Royal Free and University College Medical School, University College London, Rowland Hill Street, London NW3 2PF, UK
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Christenson EM, Dadsetan M, Wiggins M, Anderson JM, Hiltner A. Poly(carbonate urethane) and poly(ether urethane) biodegradation: in vivo studies. J Biomed Mater Res A 2005; 69:407-16. [PMID: 15127387 DOI: 10.1002/jbm.a.30002] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Several strategies have been used to increase the biostability of medical-grade polyurethanes while maintaining biocompatibility and mechanical properties. One approach is to chemically modify or replace the susceptible soft segment. Currently, poly(carbonate urethanes) (PCUs) are being evaluated as a replacement of poly(ether urethanes) (PEUs) in medical devices because of the increased oxidative stability of the polycarbonate soft segment. Preliminary in vivo and in vitro studies have reported improved biostability of PCUs over PEUs. Although several studies have reported evidence of in vitro degradation of these new polyurethanes, there has been no evidence of significant in vivo degradation that validates a degradation mechanism. In this study, the effect of soft segment chemistry on the phase morphology, mechanical properties, and in vivo response of commercial-grade PEU and PCU elastomers was examined. Results from dynamic mechanical testing and infrared spectroscopy suggested that the phase separation was better in PCU as compared with PEU. In addition, the higher modulus and reduced ultimate elongation of PCU was attributed to the reduced flexibility of the polycarbonate soft segment. Following material characterization, the in vivo biostability and biocompatibility of PEU and PCU were studied using a subcutaneous cage implant protocol. The results from the cage implant study and cell culture experiments indicated that monocytes adhere, differentiate, and fuse to form foreign body giant cells on both polyurethanes. It is now generally accepted that the reactive oxygen species released by these adherent macrophages and foreign body giant cells initiate PEU biodegradation. Attenuated total reflectance-Fourier transform infrared analysis of explanted samples provided evidence of chain scission and crosslinking in both polyurethanes. This indicated that the PCU was also susceptible to biodegradation by agents released from adherent cells. These results reinforce the need to evaluate and understand the biodegradation mechanisms of PCUs.
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Affiliation(s)
- Elizabeth M Christenson
- Center for Applied Polymer Research, and Department of Macomolecular Science, Case Western Reserve University, Cleveland, Ohio 44106, USA
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43
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Kannan RY, Salacinski HJ, Butler PE, Hamilton G, Seifalian AM. Current status of prosthetic bypass grafts: A review. J Biomed Mater Res B Appl Biomater 2005; 74:570-81. [PMID: 15889440 DOI: 10.1002/jbm.b.30247] [Citation(s) in RCA: 335] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Polymers such as Dacron and polytetrafluoroethylene (PTFE) have been used in high flow states with relative success but with limited application at lower flow states. Newer polymers with greater compliance, biomimicry, and ability to evolve into hybrid prostheses, suitable as smaller vessels, are now being introduced. In view of the advances in tissue engineering, this makes possible the creation of an ideal off-the-shelf bypass graft. We present a broad overview of the current state of prosthetic bypass grafts.
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Affiliation(s)
- Ruben Y Kannan
- Biomaterials & Tissue Engineering Centre, University Department of Surgery, Royal Free and University College Medical School, University College London, UK
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44
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Rashid ST, Salacinski HJ, Fuller BJ, Hamilton G, Seifalian AM. Engineering of bypass conduits to improve patency. Cell Prolif 2004; 37:351-66. [PMID: 15377334 PMCID: PMC6495671 DOI: 10.1111/j.1365-2184.2004.00318.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Accepted: 07/13/2004] [Indexed: 11/28/2022] Open
Abstract
For patients with severe coronary artery and distal peripheral vascular disease not amenable to angioplasty and lacking sufficient autologous vessels there is a pressing need for improvements to current surgical bypass options. It has been decades since any real progress in bypass material has reached mainstream surgical practice. This review looks at possible remedies to this situation. Options considered are methods to reduce prosthetic graft thrombogenicity, including endothelial cell seeding and developments of new prosthetic materials. The promise of tissue-engineered blood vessels is examined with a specific look at how peptides can improve cell adhesion to scaffolds.
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Affiliation(s)
- S T Rashid
- Biomaterials and Tissue Engineering Centre, University Department of Surgery, Royal Free and University College Medical School, University College London, Royal Free Hospital, London, UK
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45
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Karapinar K, Ulus AT, Tütün U, Aksöyek A, Apaydin N, Pamuk K, Can Z, Saritaş Z, Küçükay F, Arda K, Katircioğlu SF. Implantation of Novel Small-Diameter Polyurethane Vascular Prostheses Interposed in Canine Femoral and Carotid Arteries. Eur Surg Res 2004; 36:241-8. [PMID: 15263830 DOI: 10.1159/000078859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Accepted: 01/27/2004] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The performance of small-diameter (3-5-mm) vascular grafts still poses a challenge in the field of vascular surgery. We present here our preliminary experience with implanting unique small-sized polycarbonate urethane vascular grafts in 7 dogs. MATERIAL AND METHODS Each animal was implanted with 4 interposition grafts, 2 femoral and 2 carotid. No anti-thrombotic medication was administered. Doppler sonography was performed at 3-month intervals to examine for patency and flow characteristics. Animals were sacrificed electively at 3, 6 and 12 months. RESULTS At 3 months, all grafts were patent. After 6 months, 3 grafts occluded and at 1 year a further 6 grafts occluded. Hence 9 of 28 grafts occluded (67.9% patency). During the study, no correlation could be established between flow velocity or resistance index and occlusion. Histopathology showed intimal hyperplasia to be the cause of occlusion. CONCLUSIONS Compared to literature data on small-diameter grafts in the same position, ADIAM's Biomechanical grafts performed clearly better. Compliance data suggest a correlation between elastic compliance and patency.
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Affiliation(s)
- K Karapinar
- Department of Cardiovascular Surgery, SSK Diskapi Hospital, Ankara, Turkey
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46
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Rashid ST, Salacinski HJ, Button MJC, Fuller B, Hamilton G, Seifalian AM. Cellular engineering of conduits for coronary and lower limb bypass surgery: role of cell attachment peptides and pre-conditioning in optimising smooth muscle cells (SMC) adherence to compliant poly(carbonate-urea)urethane (MyoLink) scaffolds. Eur J Vasc Endovasc Surg 2004; 27:608-16. [PMID: 15121111 DOI: 10.1016/j.ejvs.2004.01.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE We are developing a hybrid arterial bypass graft of compliant poly(carbonate-urea)urethane (MyoLink), endothelial and smooth muscle cells (SMCs). To enhance adhesion of SMCs we assessed various attachment factors and the effect of pre-conditioning on cell retention. METHODS MyoLink segments were coated with either RGD, superfibronectin, fibronectin, fibronectin-like engineered polymer protein (FEPP), FEPP plus or type 1 collagen overnight. (111)Indium-radiolabelled SMCs were placed onto MyoLink segments for 48 h before being aspirated, then lavaged off. All grafts, aspirates and lavages were counted in a gamma counter. SMC viability on the MyoLink segments was also assessed for viability using the Alamar blue redox assay. Separately, MyoLink grafts lined with radiolabelled SMCs were divided into a pre-conditioned group, exposed to subarterial pulsatile flow whilst another group were held in static culture. After 1-week, grafts were exposed to arterial pulsatile flow whilst radioactivity was assessed using a gamma camera. RESULTS Only FEPP plus significantly enhanced SMC attachment: mean of 32+/-6% cell attachment compared to 21+/-5% for uncoated control. Cell viability was enhanced by all attachment factors except fibronectin. Pre-conditioning was shown to significantly enhance the retention of SMCs onto the MyoLink once exposed to pulsatile arterial flow: the final attachment was 57+/-7% for the static and 76+/-7% for the pre-conditioned group. CONCLUSIONS FEPP plus enhances SMC attachment to MyoLink. We believe this is because of its repeating sequences of RGD and its positive charge. Pre-conditioning enhances the retention of SMCs to MyoLink once exposed to pulsatile arterial flow.
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Affiliation(s)
- S T Rashid
- Vascular Unit, University Department of Surgery, Royal Free Hospital, Hampstead NHS Trust, London, UK
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Wiggins MJ, MacEwan M, Anderson JM, Hiltner A. Effect of soft-segment chemistry on polyurethane biostability duringin vitro fatigue loading. ACTA ACUST UNITED AC 2004; 68:668-83. [PMID: 14986322 DOI: 10.1002/jbm.a.20081] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effect of soft-segment chemistry on biostability of polyurethane elastomers was studied with a diaphragm-type film specimen under conditions of static and dynamic loading. During testing, the films were exposed to an H(2)O(2)/CoCl(2) solution, which simulated the oxidative component of the in vivo environment. Films treated for up to 24 days were evaluated by IR spectroscopy and by optical and scanning electron microscopy. Biostability of a poly(ether urethane) (PEU), which is known to undergo oxidative degradation, was compared with biostability of a poly(carbonate urethane) (PCU), which is thought to be more resistant to oxidation than PEU. Materials similar to PEU and PCU, in which the polyether or polycarbonate soft segment was partially replaced with poly(dimethylsiloxane) (PDMS), were also tested with the expectation that PDMS would improve soft-segment biostability. Oxidative degradation of the polyether soft segment of PEU was manifest chemically as chain scission and cross-linking and physically as surface pitting. Biaxial fatigue accelerated chemical degradation of PEU and eventually caused brittle stress cracking. In comparison, the polycarbonate soft segment was more stable to oxidation; there was minimal chemical or physical degradation of PCU, even in biaxial fatigue. Partial substitution of the polyether soft segment with PDMS enhanced oxidative stability of PEU. Although both strategies for modifying soft-segment chemistry improved the resistance to oxidative degradation, the outstanding mechanical properties of PEU were compromised to some extent.
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Affiliation(s)
- Michael J Wiggins
- Center for Applied Polymer Research, Case Western Reserve University, Cleveland, Ohio 44106, USA
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48
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Meng W, Hyun JY, Song DI, Kang IK. Surface modification andin vitro blood compatibilities of polyurethanes containingz-lysine segments in the main chain. J Appl Polym Sci 2003. [DOI: 10.1002/app.12904] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Salacinski HJ, Hamilton G, Seifalian AM. Surface functionalization and grafting of heparin and/or RGD by an aqueous-based process to a poly(carbonate-urea)urethane cardiovascular graft for cellular engineering applications. J Biomed Mater Res A 2003; 66:688-97. [PMID: 12918053 DOI: 10.1002/jbm.a.10020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
An aqueous-based process is reported for surface functionalization and grafting of anticoagulant and cell attachment moieties, such as heparin and/or arginine-glycine- aspartate (RGD) onto the lumenal surface of a prefabricated cardiovascular graft (5 mm i.d.) made of poly(carbonate- urea)urethane (MyoLink). It is a three-stage process, all aqueous: (1) hydroxylation using an azobis compound, particularly 2,2'-azobis(2-methylpropionamidine)dihydrochloride, which abstracts hydrogen via an electron transfer process from the polyurethane surface (strong oxygen purging); (2) grafting using the as-generated hydroxide groups to allow attachment of an acrylamide monomer using a conventional ceric ion technique (strong nitrogen purging); and (3) moiety attachment, preactivated with [1-ethyl-3-(3-dimethylaminopropyl)carbodiimide] in acidic solution. The technique was validated by attaching heparin and RGD/heparin to the MyoLink polymer. Following bonding, the graft segments were exposed to prolonged physiologic shear force in a flow circuit (10 h). The grafts first were analyzed by X-ray photoelectron spectroscopy (XPS) to determine the degree of attachment of the moieties and then by materials methods to assess whether any degradation of the graft material itself had occurred since polyurethanes with carbonate amorphous segments are readily susceptible to hydrolytic degradation following functionalization processes. XPS showed the moieties were present on the surface at a concentration of 10%. The S2p(3/2) states of sulfur indicated that there were high degrees of ionic covalent bonding, indicating high degrees of moiety bioactivity. Heparin was found to be present from the sulfur signal, namely NSO(3). RGD was found to be present from the nitrogen signal present at the binding energy of 399 eV. Macroscopic analysis and ESEM showed no signs of polyurethane degradation or small protuberances indicative of microgel formation. Quality control (QC) showed that the internal diameters and wall thicknesses of all the respective grafts postbonding remained within normal batch release limits (5 +/- 0.1mm, i.d.; 0.9 +/- 0.05 mm, wall thickness). Gel permeation chromatography (GPC) showed there were no statistical differences between the control, which was nonbonded (MN 45,300, MW 98,500, D 2.17) and all of the bonded samples, respectively (MN 41,800, MW 104,000, D 2.45). Radial tensile strength (RTS) analysis also showed that all of the respective samples postbonding (1.48N/mm) remained within batch release specifications (>1N/mm). A simple aqueous polymer surface functionalization and grafting technique has been developed for covalent bonding of anticoagulant and cell-attachment moieties onto poly(carbonate-urea)urethane(s) and has been validated by surface and materials analyses. The moieties were attached uniformly and were bioactive at a high surface density. No degradation in terms of a loss in mechanical properties was evident following bonding of the polyurethane.
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Affiliation(s)
- Henryk J Salacinski
- Tissue Engineering Center, University Department of Surgery, Royal Free and University College Medical School, University College London and the Royal Free Hospital, London NW3 2QG, United Kingdom
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50
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Deschamps AA, Grijpma DW, Feijen J. Phase separation and physical properties of PEO-containing poly(ether ester amide)s. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2003; 13:1337-52. [PMID: 12555900 DOI: 10.1163/15685620260449732] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Poly(ether ester amide) (PEEA) copolymers based on poly(ethylene glycol) (PEG), 1,4-butanediol, and dimethyl-7,12-diaza-6,13-dione-1,18-octadecanedioate (a diester-diamide monomer) were synthesized by a two-step polycondensation reaction. The obtained segmented copolymers are hydrophilic, with a water uptake of 24-340%. PEEA copolymers showed microphase separation, as observed by differential scanning calorimetry (DSC). The long spacing determined by small-angle X-ray scattering shows an increase in the hydrophilic domain size with increasing PEO content. By varying the copolymer composition, the E-modulus of PEEA could be varied between 61 and 427 MPa, with tensile strengths ranging from 12 to 39 MPa. The elongation at break can reach values up to 850%. The mechanical properties decrease with the uptake of water. However, PEEAs with a relatively low content of PEO still retain good tensile properties and are, in principle, suitable for biomedical applications.
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Affiliation(s)
- A A Deschamps
- Institute for Biomedical Technology (BMTI), Department of Polymer Chemistry and Biomaterials, Faculty of Chemical Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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