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Mahmud Z, Nasrin A, Hassan M, Gomes VG. 3D‐printed polymer
nanocomposites with carbon quantum dots for enhanced properties and in situ monitoring of cardiovascular stents. POLYM ADVAN TECHNOL 2021. [DOI: 10.1002/pat.5572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zaheri Mahmud
- School of Chemical and Biomolecular Engineering The University of Sydney Sydney New South Wales Australia
| | - Aklima Nasrin
- School of Chemical and Biomolecular Engineering The University of Sydney Sydney New South Wales Australia
| | - Mahbub Hassan
- School of Chemical and Biomolecular Engineering The University of Sydney Sydney New South Wales Australia
| | - Vincent G. Gomes
- School of Chemical and Biomolecular Engineering The University of Sydney Sydney New South Wales Australia
- Nano Institute The University of Sydney Sydney New South Wales Australia
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Coutinho IT, Maia-Obi LP, Champeau M. Aspirin-Loaded Polymeric Films for Drug Delivery Systems: Comparison between Soaking and Supercritical CO 2 Impregnation. Pharmaceutics 2021; 13:824. [PMID: 34199551 PMCID: PMC8229088 DOI: 10.3390/pharmaceutics13060824] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 12/11/2022] Open
Abstract
Polymeric implants loaded with drugs can overcome the disadvantages of oral or injection drug administration and deliver the drug locally. Several methods can load drugs into polymers. Herein, soaking and supercritical CO2 (scCO2) impregnation methods were employed to load aspirin into poly(l-lactic acid) (PLLA) and linear low-density polyethylene (LLDPE). Higher drug loadings (DL) were achieved with scCO2 impregnation compared to soaking and in a shorter time (3.4 ± 0.8 vs. 1.3 ± 0.4% for PLLA; and 0.4 ± 0.5 vs. 0.6 ± 0.5% for LLDPE), due to the higher swelling capacity of CO2. The higher affinity of aspirin explained the higher DL in PLLA than in LLDPE. Residual solvent was detected in LLDPE prepared by soaking, but within the FDA concentration limits. The solvents used in both methods acted as plasticizers and increased PLLA crystallinity. PLLA impregnated with aspirin exhibited faster hydrolysis in vitro due to the catalytic effect of aspirin. Finally, PLLA impregnated by soaking showed a burst release because of aspirin crystals on the PLLA surface, and released 100% of aspirin within 60 days, whereas the PLLA prepared with scCO2 released 60% after 74 days by diffusion and PLLA erosion. Hence, the scCO2 impregnation method is adequate for higher aspirin loadings and prolonged drug release.
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Affiliation(s)
| | | | - Mathilde Champeau
- Center of Engineering, Modeling and Applied Social Sciences, Federal University of ABC, Santo Andre 09210-580, Brazil; (I.T.C.); (L.P.M.-O.)
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Liu P, Zhang D, Dai Y, Lin J, Li Y, Wen C. Microstructure, mechanical properties, degradation behavior, and biocompatibility of porous Fe-Mn alloys fabricated by sponge impregnation and sintering techniques. Acta Biomater 2020; 114:485-496. [PMID: 32738505 DOI: 10.1016/j.actbio.2020.07.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/18/2020] [Accepted: 07/26/2020] [Indexed: 12/26/2022]
Abstract
In this study, porous iron (Fe)-manganese (Mn) alloys with high porosity were successfully prepared by sponge impregnation and sintering (SIS). The compositions of the porous Fe-Mn alloys were strongly dependent on the sintering temperature, and the Mn content was ~44, 30, and 12 wt.% for alloys sintered at 1100, 1150, and 1200 °C, respectively. The porous Fe-Mn alloys exhibited a well-interconnected porous structure with ~85% porosity and average pore size ranging from 375 to 500 um. The porous Fe-44Mn and Fe-30Mn alloys were mainly composed of a γ-austenite phase, while the porous Fe-12Mn was composed of an α-ferrite phase. The yield strength and elastic modulus of the porous Fe-Mn alloys ranged from 6 to 10 MPa and from 0.12 to 0.37 GPa, respectively, similar to those of cancellous bone. The degradation rate of the porous Fe-Mn alloys decreased over time during immersion in simulated body fluid (SBF), and was 1.0 mm/year for Fe-44Mn, 0.81 mm/year for Fe-30Mn, 0.41 mm/year for Fe-12Mn, and 0.33 mm/year for pure Fe after 14 d SBF immersion. Moreover, the porous Fe-Mn alloys exhibited good biocompatibility with clearly enhanced cell proliferation after direct culturing of osteoblastic MC3T3-E1 cells for 7 d. Thus, these porous Fe-Mn alloys can be anticipated to be promising biodegradable implant materials. STATEMENT OF SIGNIFICANCE: This work reports on porous Fe-Mn alloys with high porosity, suitable mechanical properties and degradation rate, and good biocompatibility. The porous alloys prepared by sponge impregnation and sintering exhibited a well-interconnected porous structure with ~85% porosity and average pore size ranging from 375 to 500 um. The yield strength and elastic modulus of the porous alloys ranged from 6 to 10 MPa and from 0.12 to 0.37 GPa, respectively, similar to those of cancellous bone. The degradation rates in simulated body fluid (SBF) were ~1.0 mm/year for Fe-44Mn, 0.81 mm/year for Fe-30Mn, and 0.41 mm/year for Fe-12Mn, respectively. Moreover, the porous Fe-Mn alloys exhibited good biocompatibility with enhanced cell proliferation after direct culturing of osteoblastic MC3T3-E1 cells.
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Affiliation(s)
- Peifeng Liu
- School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Dechuang Zhang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - Yilong Dai
- Key Laboratory of Materials Design and Preparation Technology of Hunan Province, Xiangtan University, Xiangtan 411105, Hunan, China
| | - Jianguo Lin
- Key Laboratory of Materials Design and Preparation Technology of Hunan Province, Xiangtan University, Xiangtan 411105, Hunan, China.
| | - Yuncang Li
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Cuie Wen
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia.
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Song K, Bi Y, Zhao H, Wu T, Xu F, Zhao G. Structural optimization and finite element analysis of poly‐
l
‐lactide acid coronary stent with improved radial strength and acute recoil rate. J Biomed Mater Res B Appl Biomater 2020; 108:2754-2764. [DOI: 10.1002/jbm.b.34605] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/02/2020] [Accepted: 03/01/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Kai Song
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
| | - Yuying Bi
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Haibin Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
- Shenzhen Research Institute of Shandong University, Shenzhen Guangdong China
| | - Tim Wu
- Dongguan TT Medical Inc. Guangdong China
- Biomedical Engineering and Biotechnology University of Massachusetts Lowell Massachusetts
| | - Feng Xu
- Department of Emergency Medicine, Qilu Hospital, Shandong University Jinan China
| | - Guoqun Zhao
- Key Laboratory for Liquid‐Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering Shandong University Jinan China
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Shishatskaya EI, Menzyanova NG, Shumilova AA. The effect of the chemical composition and structure of polymer films made from resorbable polyhydroxyalkanoates on blood cell response. Int J Biol Macromol 2019; 141:765-775. [DOI: 10.1016/j.ijbiomac.2019.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/23/2019] [Accepted: 09/04/2019] [Indexed: 01/13/2023]
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6
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Biodegradable stents for coronary artery disease treatment: Recent advances and future perspectives. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2018; 91:163-178. [DOI: 10.1016/j.msec.2018.04.100] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 04/11/2018] [Accepted: 04/28/2018] [Indexed: 12/24/2022]
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Bakola V, Karagkiozaki V, Tsiapla AR, Pappa F, Moutsios I, Pavlidou E, Logothetidis S. Dipyridamole-loaded biodegradable PLA nanoplatforms as coatings for cardiovascular stents. NANOTECHNOLOGY 2018; 29:275101. [PMID: 29629708 DOI: 10.1088/1361-6528/aabc69] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cardiovascular stents are commonly used for the treatment of cardiovascular diseases that in developed societies are the most frequent causes of mortality and morbidity. In recent years, thorough research and development of drug-eluting stents has been done, with emphasis on coronary stenting to avoid the most common complication, in-stent thrombosis. Dipyridamole (DPM) is a medication that inhibits blood clot formation. Drug delivery nanoplatforms consisting of biodegradable polymers can be fabricated via electrospinning deposition, known for its cost-effective and versatile advantages, that produces fibrous scaffolds that are able to sustain and control drug release. A novel drug delivery nanosystem of polylactic acid fibrous scaffold loaded with the anti-platelet drug DPM was fabricated by electrospinning as coating for cardiovascular stents. The surface morphology and topography that were evaluated via atomic force microscopy, scanning electron microscopy and optical microscopy, were found to be good and suitable for tissue engineering. Contact angle measurements established the hydrophobic behavior of these fibrous nanoplatforms. Drug-release kinetics and degradation studies were conducted and revealed a sustained and controllable release of DPM, through this fibrous matrix over time. Finally, cytotoxicity studies took place to evaluate the cytocompatibility of the scaffold that confirmed its compatible behavior. The successful performance of this nanoplatform can lead to it being a valuable tool for atherosclerosis treatment.
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Affiliation(s)
- V Bakola
- Nanotechnology Lab LTFN (Lab for Thin Films-Nanobiomaterials-Nanosystems-Nanometrology) Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece. BL Nanobiomed P.C. Thessaloniki, Greece
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Sotoudehbagha P, Sheibani S, Khakbiz M, Ebrahimi-Barough S, Hermawan H. Novel antibacterial biodegradable Fe-Mn-Ag alloys produced by mechanical alloying. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2018; 88:88-94. [PMID: 29636142 DOI: 10.1016/j.msec.2018.03.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 12/11/2017] [Accepted: 03/11/2018] [Indexed: 10/17/2022]
Abstract
Various compositions and synthesis methods of biodegradable iron-based alloys have been studied aiming for the use of temporary medical implants. However, none is focused on nano-structured alloy and on adding antibacterial property to the alloy. In this study, new Fe-30Mn-(1-3)Ag alloys were synthesized by means of mechanical alloying and assessed for their microstructure, mechanical properties, corrosion rate, antibacterial activity and cytotoxicity. Results showed that the alloy with 3 wt% Ag content displayed the highest relative density, shear strength, micro hardness and corrosion rate. However, optimum cytotoxicity and the antibacterial activity were reached by the alloy with 1 wt% Ag content. The compositional and processing effects of the alloys' properties are further discussed in this work.
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Affiliation(s)
- Pedram Sotoudehbagha
- Division of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, Karegar Ave., P.O. Box 14395-1561, Tehran, Iran
| | - Saeed Sheibani
- School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Mehrdad Khakbiz
- Division of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, Karegar Ave., P.O. Box 14395-1561, Tehran, Iran.
| | - Somayeh Ebrahimi-Barough
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hendra Hermawan
- Department of Mining, Metallurgical and Materials Engineering, CHU de Quebec Research Center, Laval University, Quebec City, Canada
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Vurugonda U, Rednam P, Sinha M. Development of biodegradable scaffold using polylactic acid and polycaprolactone for cardiovascular application. INT J POLYM MATER PO 2017. [DOI: 10.1080/00914037.2017.1297945] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Upender Vurugonda
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research, Ahmedabad, Gandhinagar, Gujarat, India
| | - PoornaJyothi Rednam
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research, Ahmedabad, Gandhinagar, Gujarat, India
| | - Mukty Sinha
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research, Ahmedabad, Gandhinagar, Gujarat, India
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Li J, Ding J, Liu T, Liu JF, Yan L, Chen X. Poly(lactic acid) Controlled Drug Delivery. INDUSTRIAL APPLICATIONS OF POLY(LACTIC ACID) 2017. [DOI: 10.1007/12_2017_11] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Dutau H, Musani AI, Laroumagne S, Darwiche K, Freitag L, Astoul P. Biodegradable Airway Stents - Bench to Bedside: A Comprehensive Review. Respiration 2015; 90:512-521. [PMID: 26613524 DOI: 10.1159/000442054] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/22/2015] [Indexed: 04/13/2024] Open
Abstract
Airway stents are indicated to treat symptomatic narrowing or to close fistulas of the central airways. They are generally divided into two types: the silicone stents and the metallic stents. Unlike in malignancies, removability is a major objective of temporary stenting in benign conditions, which poses the challenge of a new rigid bronchoscopic procedure under general anesthesia and stent removal with all its attendant risks and costs. The concept of a biodegradable (BD) stent that could maintain the patency of an airway for a predetermined duration of time is very appealing. These BD stents would gradually degrade and eventually vanish from the airway once they are no longer needed. Such stents are currently an area of intense research. Another very promising concept of drug delivery with such stents is also a very exciting area of current research. The aim of this comprehensive review is to discuss all pertinent available literature on the use of BD materials in various clinical applications and to extensively review all animal and humans trials involving BD airway stents.
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Affiliation(s)
- Hervé Dutau
- Thoracic Oncology, Pleural Diseases and Interventional Pulmonology Department, North University Hospital, Marseille, France
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Ketoprofen-eluting biodegradable ureteral stents by CO2 impregnation: In vitro study. Int J Pharm 2015; 495:651-9. [DOI: 10.1016/j.ijpharm.2015.08.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/11/2015] [Accepted: 08/13/2015] [Indexed: 11/18/2022]
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Soares JS, Moore JE. Biomechanical Challenges to Polymeric Biodegradable Stents. Ann Biomed Eng 2015; 44:560-79. [DOI: 10.1007/s10439-015-1477-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/26/2015] [Indexed: 10/23/2022]
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Sgarioto M, Adhikari R, Gunatillake PA, Moore T, Patterson J, Nagel MD, Malherbe F. High Modulus Biodegradable Polyurethanes for Vascular Stents: Evaluation of Accelerated in vitro Degradation and Cell Viability of Degradation Products. Front Bioeng Biotechnol 2015; 3:52. [PMID: 26000274 PMCID: PMC4422008 DOI: 10.3389/fbioe.2015.00052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/27/2015] [Indexed: 01/13/2023] Open
Abstract
We have recently reported the mechanical properties and hydrolytic degradation behavior of a series of NovoSorb™ biodegradable polyurethanes (PUs) prepared by varying the hard segment (HS) weight percentage from 60 to 100. In this study, the in vitro degradation behavior of these PUs with and without extracellular matrix (ECM) coating was investigated under accelerated hydrolytic degradation (phosphate buffer saline; PBS/70°C) conditions. The mass loss at different time intervals and the effect of aqueous degradation products on the viability and growth of human umbilical vein endothelial cells (HUVEC) were examined. The results showed that PUs with HS 80% and below completely disintegrated leaving no visual polymer residue at 18 weeks and the degradation medium turned acidic due to the accumulation of products from the soft segment (SS) degradation. As expected the PU with the lowest HS was the fastest to degrade. The accumulated degradation products, when tested undiluted, showed viability of about 40% for HUVEC cells. However, the viability was over 80% when the solution was diluted to 50% and below. The growth of HUVEC cells is similar to but not identical to that observed with tissue culture polystyrene standard (TCPS). The results from this in vitro study suggested that the PUs in the series degraded primarily due to the SS degradation and the cell viability of the accumulated acidic degradation products showed poor viability to HUVEC cells when tested undiluted, however particles released to the degradation medium showed cell viability over 80%.
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Affiliation(s)
- Melissa Sgarioto
- Faculty of Life and Social Sciences, Swinburne University of Technology , Hawthorn, VIC , Australia ; UMR CNRS 7338 Biomécanique et Bioingénierie, Centre de Recherches de Royallieu, Université de Technologie de Compiègne , Compiègne , France
| | - Raju Adhikari
- CSIRO Manufacturing Flagship , Clayton, VIC , Australia
| | | | - Tim Moore
- PolyNovo Biomaterials Pty Ltd. , Port Melbourne, VIC , Australia
| | - John Patterson
- Faculty of Life and Social Sciences, Swinburne University of Technology , Hawthorn, VIC , Australia
| | - Marie-Danielle Nagel
- UMR CNRS 7338 Biomécanique et Bioingénierie, Centre de Recherches de Royallieu, Université de Technologie de Compiègne , Compiègne , France
| | - François Malherbe
- Faculty of Life and Social Sciences, Swinburne University of Technology , Hawthorn, VIC , Australia
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Francis A, Yang Y, Virtanen S, Boccaccini AR. Iron and iron-based alloys for temporary cardiovascular applications. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2015; 26:138. [PMID: 25716025 DOI: 10.1007/s10856-015-5473-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/20/2015] [Indexed: 06/04/2023]
Abstract
In the last decade, biodegradable metals have emerged as a topic of interest for particular biomedical applications which require high strength to bulk ratio, including for cardiovascular stents. The advantages of biodegradable materials are related to the reduction of long term risks associated with the presence of permanent metal implants, e.g. chronic inflammation and in-stent restenosis. From a structural point of view, the analysis of the literature reveals that iron-based alloys used as temporary biodegradable stents have several advantages over Mg-based alloys in terms of ductility and strength. Efforts on the modification and tunability of iron-based alloys design and compositions have been mainly focused on controlling the degradation rate while retaining the mechanical integrity within a reasonable period. The early pre-clinical results of many iron-based alloys seem promising for future implants developments. This review discusses the available literature focusing mainly on: (i) Fe and Fe-based alloys design and fabrication techniques; (ii) in vitro and in vivo performance; (iii) cytotoxicity and cell viability tests.
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Affiliation(s)
- A Francis
- Department of Advanced Materials, Central Metallurgical R&D Institute (CMRDI), P.O. Box 87, Helwan, Cairo, Egypt,
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Silingardi R, Lauricella A, Coppi G, Nicolosi E, Gennai S, Coppi G. Midterm Results of Endovascular Treatment of Superficial Femoral Artery Disease with Biodegradable Stents: Single-Center Experience. J Vasc Interv Radiol 2015; 26:374-81.e1. [DOI: 10.1016/j.jvir.2014.10.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 10/19/2014] [Accepted: 10/24/2014] [Indexed: 11/24/2022] Open
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He D, Liu W, Zhang T. The development of carotid stent material. INTERVENTIONAL NEUROLOGY 2015; 3:67-77. [PMID: 26019710 PMCID: PMC4439791 DOI: 10.1159/000369480] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Endovascular angioplasty with stenting is a promising option for treating carotid artery stenosis. There exist a rapidly increasing number of different stent types with different materials. The bare-metal stent is the most commonly used stent with acceptable results, but it leaves us with the problems of thrombosis and restenosis. The drug-eluting stent is a breakthrough as it has the ability to reduce the restenosis rate, but the problem of late thrombosis still has to be addressed. The biodegradable stent disappears after having served its function. However, restenosis and degradation rates remain to be studied. In this article, we review every stent material with its characteristics, clinical results and complications and point out the standards of an ideal carotid stent.
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Affiliation(s)
- Dongsheng He
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Wenhua Liu
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Tao Zhang
- College of Engineering and Applied Science, Nanjing University, Nanjing, China
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Lange D, Bidnur S, Hoag N, Chew BH. Ureteral stent-associated complications--where we are and where we are going. Nat Rev Urol 2014; 12:17-25. [PMID: 25534997 DOI: 10.1038/nrurol.2014.340] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Ureteral stents are one of the most commonly used devices in the treatment of benign and malignant urological diseases. However, they are associated with common complications including encrustation, infection, pain and discomfort caused by ureteral tissue irritation and possibly irregular peristalsis. In addition, stent migration and failure due to external compression by malignancies or restenosis occur, albeit less frequently. As these complications restrict optimal stent function, including maintenance of adequate urine drainage and alleviation of hydronephrosis, novel stent materials and designs are required. In recent years, progress has been made in the development of drug-eluting expandable metal stents and biodegradable stents. New engineering technologies are being investigated to provide stents with increased biocompatibility, decreased susceptibility to encrustation and improved drug-elution characteristics. These novel stent characteristics might help eliminate some of the common complications associated with ureteral stenting and will be an important step towards understanding the behaviour of stents within the urinary tract.
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Affiliation(s)
- Dirk Lange
- The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada
| | - Samir Bidnur
- The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada
| | - Nathan Hoag
- The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada
| | - Ben H Chew
- The Stone Centre at Vancouver General Hospital, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada
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Kim SY, Kim M, Kim MK, Lee H, Lee DK, Lee DH, Yang SG. Paclitaxel-eluting nanofiber-covered self-expanding nonvascular stent for palliative chemotherapy of gastrointestinal cancer and its related stenosis. Biomed Microdevices 2014; 16:897-904. [PMID: 25135441 DOI: 10.1007/s10544-014-9894-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Self-expanding non-vascular metal stents (SEMS) is now a choice of treatment for tumor-induced obstructive symptoms of gastrointestinal tract. But in-growing tumor causes re-stenosis. Here, we studied a paclitaxel-eluting nanofiber-covered stent for palliative chemotherapy of gastrointestinal cancer and its related stenosis. In vivo and in vitro feasibility of nanofiber-covered nonvascular stent was evaluated in this study. Nanofiber-covered stent released paclitaxel (PTX) in controlled manner for 30 days. PTX-NFM significantly inhibited the growth of CT-26 colon cancer in comparison with PTX injection. PTX maintained higher tumor concentrations over 1.0 μg/ml for more than 14 days without systemic exposure. TUNEL and H&E staining proved locally concentrated PTX induced the higher apoptosis than PTX injection. In this way, PTX-eluting nanofiber-covered stent possibly inhibits in-growth of cancer and extends patency of stent. Clinical feasibility of PTX-eluting nanofiber nonvascular stent for cholangiocarcinoma and gastrointestinal cancers will be investigated in further studies.
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Affiliation(s)
- Se-Yoon Kim
- Utah-Inha DDS and Advanced Therapeutics Research Center, Incheon, 406-840, Republic of Korea
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Wang Y, Zhang X. Vascular restoration therapy and bioresorbable vascular scaffold. Regen Biomater 2014; 1:49-55. [PMID: 26816624 PMCID: PMC4669005 DOI: 10.1093/rb/rbu005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 08/22/2014] [Indexed: 12/31/2022] Open
Abstract
This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s, metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s, to bioresorbable vascular scaffold (BVS) technology in large-scale development in recent years. The history, the current stage, the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy. The criteria of materials selection, design and processing principles of BVS, and the corresponding clinical trial results are also summarized in this article.
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Affiliation(s)
- Yunbing Wang
- National Engineering Research Center For Biomaterials, Sichuan University, Chengdu 610064, China
| | - Xingdong Zhang
- National Engineering Research Center For Biomaterials, Sichuan University, Chengdu 610064, China
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Sgarioto M, Adhikari R, Gunatillake PA, Moore T, Malherbe F, Nagel MD, Patterson J. Properties andin vitroevaluation of high modulus biodegradable polyurethanes for applications in cardiovascular stents. J Biomed Mater Res B Appl Biomater 2014; 102:1711-9. [DOI: 10.1002/jbm.b.33137] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 01/16/2014] [Accepted: 02/25/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Melissa Sgarioto
- Swinburne University of Technology; Faculty of Life and Social Sciences; Hawthorn, Victoria 3122 Australia
- Université de Technologie de Compiègne, UMR CNRS 7338 Biomécanique et Bioingénierie, Centre de Recherches de Royallieu; Compiègne Cedex France
| | - Raju Adhikari
- CSIRO Materials Science and Engineering, Clayton South MDC; Victoria 3169 Australia
| | | | - Tim Moore
- PolyNovo Biomaterials Pty Ltd, Port Melbourne; Victoria 3207 Australia
| | - François Malherbe
- Swinburne University of Technology; Faculty of Life and Social Sciences; Hawthorn, Victoria 3122 Australia
| | - Marie-Danielle Nagel
- Université de Technologie de Compiègne, UMR CNRS 7338 Biomécanique et Bioingénierie, Centre de Recherches de Royallieu; Compiègne Cedex France
| | - John Patterson
- Swinburne University of Technology; Faculty of Life and Social Sciences; Hawthorn, Victoria 3122 Australia
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Abstract
For more than 10 years, balloon-expandable intravascular stents have become an integral part of treatment for obstructive vascular lesions in children and adults with congenital heart disease. The initial problems with stents, such as sharp edges, rigid frame and unacceptable shortening when over-expanded have been overcome to a large extent with the newer designs. The problems related to delivery of stents, such as stent migration, balloon rupture, flaring of the edges of the stent, rupture of vessels and milking of the stent off the balloon, have also been overcome by newer designs of balloons. The failure of growth of balloon-expandable stents with the growth of the child is managed by redilation with or without additional stenting and newer growth stents. Self-expanding stents are not appropriate for use in growing children due to the limitation of their maximum diameters. The development of biodegradable stents may overcome these disadvantages in the future. Various new developments have recently occurred. Covered stents are ideal for treating acute vessel rupture and in isolating vascular aneurysms. Drug-eluting stents may prevent restenosis, but have not been used in children. Valved stents are a recent innovation for the treatment of regurgitant pulmonary valves.
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Affiliation(s)
- Shakeel Ahmed Qureshi
- Department of Pediatric Cardiology, Guy's Hospital, 11th Floor Guy's Tower, St Thomas Street, London SE1 9RT, UK.
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24
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Maamoun W. Safety and efficacy of biodegradable polymer-coated biolimus-eluting stents. Egypt Heart J 2013. [DOI: 10.1016/j.ehj.2012.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Thakkar A, Raval A, Mandal R, Parmar S, Jariwala A, Tailor J, Mehta A. Development and Evaluation of Drug Eluting Stent Having Biphasic Release From a Single Layer of Biodegradable Polymer. J Med Device 2013. [DOI: 10.1115/1.4023414] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In stent restenosis is the major disadvantage of percutaneous transluminal angioplasty. To overcome this limitation, drug eluting stents were introduced. We have developed novel sirolimus eluting stent using biocompatible and biodegradable polymer matrix. Developed stent have biphasic release profile for sirolimus from a single layer of polymer matrix, having blend of slow and fast degrading polymers. Coating integrity of coated stents were evaluated after crimping and postexpansion with the help of scanning electron microscopy while thickness of coated stent was measured using destructive test method. This shows that drug-polymers bilayer was uniformly coated with the average thickness of 5.2 μms. There was no deformation after crimping and expansion of the stent. We have also measured in vitro and in vivo release profiles of sirolimus from stents which shows biphasic release characteristics, i.e., initial burst period followed by sustained release. In vitro release profile is well correlated with in vivo release in blood and arterial tissues. Developed stents showed good efficacy and safety in porcine coronary artery model.
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Affiliation(s)
| | | | - Ramila Mandal
- Sahajanand Medical Technologies Pvt. Ltd., Surat, India
| | | | | | - Jaynish Tailor
- Sahajanand Medical Technologies Pvt. Ltd., Surat, 395004, India
| | - Anita Mehta
- L. M. College of Pharmacy, Ahmedabad, 380009, India
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Shen Y, Lu F, Hou J, Shen Y, Guo S. Incorporation of paclitaxel solid dispersions with poloxamer188 or polyethylene glycol to tune drug release from poly(ϵ-caprolactone) films. Drug Dev Ind Pharm 2012; 39:1187-96. [DOI: 10.3109/03639045.2012.704042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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27
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Rong HJ, Chen WL, Guo SR, Lei L, Shen YY. PCL films incorporated with paclitaxel/5-fluorouracil: Effects of formulation and spacial architecture on drug release. Int J Pharm 2012; 427:242-51. [DOI: 10.1016/j.ijpharm.2012.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 01/12/2012] [Accepted: 02/05/2012] [Indexed: 11/29/2022]
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28
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Jabara R, Pendyala L, Geva S, Chen J, Chronos N, Robinson K. Novel fully bioabsorbable salicylate-based sirolimus-eluting stent. EUROINTERVENTION 2012; 5 Suppl F:F58-64. [PMID: 22100678 DOI: 10.4244/eijv5ifa10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIMS The concept of fully biodegradable stents has emerged as an attractive alternative to current permanent metallic stents, mainly as a potential solution to avoid late stent thrombotic events. We sought to evaluate a novel, fully bioabsorbable sirolimus-eluting stent (SES) synthesised entirely from a unique salicylic-acid polymer, in a clinically relevant animal model. METHODS AND RESULTS Fully biodegradable balloon-expandable stents (n=45) were implanted in a porcine coronary arteries using quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) to optimise stent apposition. Dose density of sirolimus was 8.3 µg/mm of stent length with in vitro studies demonstrating elution over 30 days and complete stent degradation over 12 months. Animals were terminated at 7, 14, 30, 90, and 180 days for complete histological analysis. Optical coherence tomography (OCT) was also performed for the 90- and 180-days samples. All stents were deployed successfully without notable mechanical difficulties. Angiographic diameter stenosis (DS) was 20±16%, 24±4%, and 23±17%, at one, three, and six months, respectively. In parallel, IVUS showed good stent apposition with DS of 21±9%, 25±7%, and 18±3%; and area stenosis (AS) of 35±13%, 33±7%, and 32±4% at one, three, and six months,respectively. OCT further demonstrated good stent apposition with DS of 28±7% and 20±6%, and AS of 37±10% and 33±13% at three and six months, respectively. OCT showed reduction of stent thickness by 23% from three to six months. Histologic analysis confirmed these in vivo findings and revealed a favourable healing process of absorbable stent incorporation into the arterial wall, without excessive thrombotic or inflammatory reactions. CONCLUSIONS This study shows favourable vascular compatibility and efficacy for a novel fully bioabsorbable salicylate-based SES. This device has good mechanical performance during deployment and stays well-apposed to the vessel wall at long-term follow-up. These initial results are highly encouraging and support progress into more extensive preclinical studies as well as early clinical testing.
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Affiliation(s)
- Refat Jabara
- Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem, Israel.
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Yashar P, Hopkins LN. Instrumentation in neurosurgery: nurturing the trend toward minimalism. World Neurosurg 2012; 80:240-2. [PMID: 22381330 DOI: 10.1016/j.wneu.2011.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 11/18/2011] [Indexed: 11/16/2022]
Affiliation(s)
- Parham Yashar
- Department of Neurosurgery, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, USA; Department of Radiology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, USA; Department of Neurosurgery, Gates Vascular Institute, Kaleida Health, Buffalo, New York, USA
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Can E, Udenir G, Kanneci AI, Kose G, Bucak S. Investigation of PLLA/PCL blends and paclitaxel release profiles. AAPS PharmSciTech 2011; 12:1442-53. [PMID: 22038476 DOI: 10.1208/s12249-011-9714-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 10/10/2011] [Indexed: 11/30/2022] Open
Abstract
Blends of poly (L-lactide) (PLLA) and poly (ε-caprolactone) (PCL) with and without paclitaxel were prepared via solution casting. DSC analysis as well as SEM analysis of the PLLA/PCL blend solution cast films showed that these blends are all phase separated.%PLLA crystallinity was found to increase with increasing PCL content (up till 15 wt.%). The PCL phase is found to homogeneously disperse in the PLLA matrix as spherical domains where the pore diameters of the PCL domains significantly increased with increasing PCL content. The degradation profiles matched with the slower degrading component PCL rather than PLLA and also increasing PCL content of the blends increased the degradation rate relatively. The increased crystallinity of the PLLA phase with increasing PCL contents confirmed that the degradation occurred through PCL phase. Cell proliferation on PLLA/PCL blends showed that all these blends were suitable for the support of cellular growth. Apoptosis assay with the paclitaxel-loaded PLLA/PCL blends showed an increase in cell death throughout 7 days of incubation where the cell death was increased with increasing PCL contents. This was attributed to the faster release of paclitaxel which was at least partially affected by the faster degradation rate at increasing PCL contents. The paclitaxel release was shown to be degradation controlled in the initial stages followed by a faster diffusion-controlled release in the later stages. These polymer blends were found to be very suitable paclitaxel release agents for which the paclitaxel release times can be altered with the composition of the blend and the film thickness.
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Lei L, Liu X, Shen YY, Liu JY, Tang MF, Wang ZM, Guo SR, Cheng L. Zero-order release of 5-fluorouracil from PCL-based films featuring trilayered structures for stent application. Eur J Pharm Biopharm 2011; 78:49-57. [DOI: 10.1016/j.ejpb.2011.01.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 12/10/2010] [Accepted: 01/11/2011] [Indexed: 11/15/2022]
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Tiroch KA, Byrne RA, Kastrati A. Pharmacological prevention and management of restenosis. Expert Opin Pharmacother 2010; 11:1855-72. [DOI: 10.1517/14656566.2010.485610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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33
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Moore JE, Soares JS, Rajagopal KR. Biodegradable Stents: Biomechanical Modeling Challenges and Opportunities. Cardiovasc Eng Technol 2010. [DOI: 10.1007/s13239-010-0005-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Advances in stent design have led to a substantial increase in the use of stents for a variety of malignant and benign strictures in the gastrointestinal tract and biliary system. Whereas early stents were mostly composed of plastic, the majority of contemporary stents are self-expanding metal stents that are composed of either nitinol or stainless steel. These stents are able to exert an adequate expansile force and, at the same time, are highly flexible and biocompatible. Covered stents have been introduced to minimize tumor ingrowth through the metal mesh but are associated with higher rates for spontaneous migration. This has led to the development of covered stents with uncovered ends and stents with both covered and uncovered layers. Drug-eluting and biodegradable stents are also likely to become available in the near future. Although stents appear to be the preferred form of palliation for some patients with advanced cancer, many patients will benefit from a multidisciplinary approach that usually includes surgeons and oncologists.
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Affiliation(s)
- Hoon Jai Chun
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
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35
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Sarısözen C, Arıca B, Hıncal AA, Çalış S. Development of biodegradable drug releasing polymeric cardiovascular stents andin vitroevaluation. J Microencapsul 2009; 26:501-12. [DOI: 10.1080/02652040802465792] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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36
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Han DW, Lee JJ, Jung DY, Park JC, Hyon SH. Development of epigallocatechin gallate-eluting polymeric stent and its physicochemical, biomechanical and biological evaluations. Biomed Mater 2009; 4:044104. [DOI: 10.1088/1748-6041/4/4/044104] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Kraitzer A, Kloog Y, Zilberman M. Approaches for prevention of restenosis. J Biomed Mater Res B Appl Biomater 2008; 85:583-603. [PMID: 18098192 DOI: 10.1002/jbm.b.30974] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Coronary artery disease is characterized by a narrowing (stenosis) of the arteries that supply blood to the tissue of the heart. Continued restriction of blood flow manifests itself as angina and ultimately myocardial infarction (heart attack) for the patient. Heart bypass was once the only treatment for this condition, but over the years percutaneous coronary intervention (PCI) has become an increasingly attractive alternative to medical therapy and surgical revascularization for the treatment of coronary artery disease. A vascular stent is a medical device designed to serve as a temporary or permanent internal scaffold, to maintain or increase the lumen of a blood vessel. Metallic coronary stents were first introduced to prevent arterial dissections and to eliminate vessel recoil and intimal hyperplasia associated with PCI. Further advancement in the treatment of coronary artery disease is the development of drug-eluting stents that dramatically reduce the incidence of in-stent restenosis to less than 5%. Local drug delivery offers the advantages of allowing a relatively high local concentration of drug at the treatment site while minimizing systemic toxic effect. This review describes approaches for prevention of restenosis. It focuses on drugs for prevention of restenosis, bare metal stents, and drug-eluting stents. It also describes recent advances in bioresorbable stents. One of the chapters is dedicated to our novel composite bioresorbable drug-eluting fibers, designed to be used as basic elements in drug-eluting stents.
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Affiliation(s)
- Amir Kraitzer
- Department of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel
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38
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Kraitzer A, Ofek L, Schreiber R, Zilberman M. Long-term in vitro study of paclitaxel-eluting bioresorbable core/shell fiber structures. J Control Release 2008; 126:139-48. [DOI: 10.1016/j.jconrel.2007.11.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 11/13/2007] [Accepted: 11/16/2007] [Indexed: 10/22/2022]
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39
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Zilberman M, Kraitzer A. Paclitaxel-eluting composite fibers: drug release and tensile mechanical properties. J Biomed Mater Res A 2008; 84:313-23. [PMID: 17607755 DOI: 10.1002/jbm.a.31286] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
New core/shell fiber structures loaded with paclitaxel were developed and studied. These composite fibers are ideal for forming thin, delicate, biomedically important structures for various applications. Possible applications include fiber-based endovascular stents that mechanically support blood vessels while delivering drugs for preventing restenosis directly to the blood vesel wall, or drug delivery systems for treatment of cancer. The core/shell fiber structures were formed by "coating" dense core fibers with porous paclitaxel-containing poly(DL-lactic-co-glycolic acid) (PDLGA) structures. Shell preparation ("coating") was performed by freeze-drying water in oil emulsions. The present study focused on the effects of the emulsion's formulation (composition) and processing conditions on the paclitaxel release profile and on the fibers' tensile mechanical properties. In general, the porous PDLGA shell released approximately 40% of the paclitaxel, with most of the release occurring during the first 30 days. The main release mechanism during the tested period is diffusion, rather than polymer degradation. The release rate and quantity increased with increased drug content or decreased polymer content, whereas the organic:aqueous phase ratio had practically no effect on the release profile. These new composite fibers are strong and flexible enough to be used as basic elements for stents. We demonstrated that proper selection of processing conditions based on kinetic and thermodynamic considerations can yield polymer/drug systems with the desired drug release behavior and good mechanical properties.
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Affiliation(s)
- Meital Zilberman
- Department of Biomedical Engineering, Faculty of Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel.
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40
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Waksman R, Pakala R, Baffour R, Seabron R, Hellinga D, Tio FO. Short-term effects of biocorrodible iron stents in porcine coronary arteries. J Interv Cardiol 2007; 21:15-20. [PMID: 18086136 DOI: 10.1111/j.1540-8183.2007.00319.x] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Biocorrodible iron stents carry the potential to overcome limitations, such as chronic inflammation and premature recoil, posed by biodegradable polymer and magnesium alloy stents. This study aimed to test the safety and efficacy of biocorrodible iron stents in porcine coronary arteries. METHODS Iron stents and cobalt chromium stents were randomly deployed in the coronary arteries of juvenile domestic pigs. Animals were sacrificed at 28 days, and the vessels were fixed and processed for histochemistry. RESULTS At 28 days, iron stents started to show signs of degradation without evidence of stent particle embolization or thrombosis without traces of excess inflammation, or fibrin deposition. At 28 days, the surface of the iron stent struts was black to brown and the vascular wall adjacent to the iron stent had a brownish tinge. There were no statistically significant differences in any of the measured parameters between segments implanted with iron and cobalt chromium stents. There were also no adverse effects in the persistent areas. CONCLUSION The current study demonstrates that stents made of biocorrodible iron are safe. In some of the measured parameters, such as intimal thickness, intimal area, and percentage occlusion, there was a trend in favor of the iron stents.
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Affiliation(s)
- Ron Waksman
- Cardiovascular Research Institute, Washington Hospital Center, Washington, DC 20010, USA.
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41
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Sharkawi T, Cornhill F, Lafont A, Sabaria P, Vert M. Intravascular bioresorbable polymeric stents: a potential alternative to current drug eluting metal stents. J Pharm Sci 2007; 96:2829-37. [PMID: 17979210 DOI: 10.1002/jps.20957] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Stent implantation following angioplasty is the standard treatment of coronary artery disease necessitating interventional procedures. The use of stents as a platform for local drug delivery is a popular strategy to achieve local pharmacological treatment to the diseased artery. Drug eluting stents (DES) are now largely preferred to bare metal stents when stent implantation is necessary. Lately, there have been several reports questioning the long-term safety of DES. An alternative to these drug eluting metal stents are bioresorbable polymeric stents (BPS) because of the many advantages of bioresorbable material. However, the fundamental differences in polymeric and metallic materials make the development of such an alternative a significant challenge. This review discusses the different advantages of BPS and the many constrains and requirements of such devices. An up to date commented review of published data concerning BPS is presented. Considerations are given on using BPS as local drug delivery systems as well as on evaluating BPS performances.
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Affiliation(s)
- Tahmer Sharkawi
- Artificial Biopolymer Research Center, UMR CNRS 5473, Faculty of Pharmacy, University of Montpellier 1, 15 av Charles Flahaut, 34093 Montpellier, Cedex, France.
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42
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Abstract
Despite the development and progression of metallic stents, many concerns still remain because of their permanent nature. Although metallic stents are effective in preventing recoil and late restenosis after coronary angioplasty, they continue to have limitations such as stent thrombosis and mismatch of the stent to the vessel size. Thus, the concept of bioabsorbable stents has emerged as an alternative to permanent metal stents. This review will outline concepts, material designs, preclinical, and initial clinical experimental studies with bioabsorbable stents.
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Affiliation(s)
- Ron Waksman
- Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
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43
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Uurto I, Kotsar A, Isotalo T, Mikkonen J, Martikainen PM, Kellomäki M, Törmälä P, Tammela TLJ, Talja M, Salenius JP. Tissue biocompatibility of new biodegradable drug-eluting stent materials. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2007; 18:1543-7. [PMID: 17437066 DOI: 10.1007/s10856-007-3060-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Accepted: 06/05/2006] [Indexed: 05/14/2023]
Abstract
Drug-eluting stents are a recent innovation for endovascular and endourethral purposes. The aim of this study was to assess the biocompatibility of new biodegradable drug-eluting stent materials in vivo. Rods made of SR-PLDLA (self-reinforced poly-96L,4D: -lactic acid) covered with P(50L/50D)LA and rods made of 96L/4D SR-PLA and covered with P(50L/50D)LA including indomethacin 3.3 microg/mm(2)or dexamethasone 1.5 microg/mm(2), were inserted into the dorsal muscles of 20 rabbits serving as test animals. Rods made of silicone and organotin-positive polyvinylchloride were used as negative and positive controls. The animals were sacrificed after 1 week, 1 month, 2 months or 4 months. Histological changes attributable to the operative trauma were seen in all specimens at 1 week and 1 month. At 2 months both dexamethasone and indomethacin induced less fibrosis than the plain SR-PLDLA covered with P(50L/50D)LA without drug. At 4 months dexamethasone induced both chronic inflammatory changes and foreign body reaction, whereas the reactions in the indomethacin and drug-free plain SR-PLDLA groups were insignificant. The new biodegradable drug-eluting stent materials are highly biocompatible. Drug-eluting biodegradable stents may offer a promising new treatment modality for vascular and urethral diseases. However, further studies are needed to demonstrate their feasibility and efficacy.
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Affiliation(s)
- Ilkka Uurto
- Department of Surgery, Satakunta Central Hospital, Pori, Finland.
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Cardinal KO, Bonnema GT, Hofer H, Barton JK, Williams SK. Tissue-engineered vascular grafts as in vitro blood vessel mimics for the evaluation of endothelialization of intravascular devices. ACTA ACUST UNITED AC 2007; 12:3431-8. [PMID: 17518679 DOI: 10.1089/ten.2006.12.3431] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The accelerating use of minimally invasive procedures for the treatment of cardiovascular disease, and the commensurate development of intravascular devices such as stents, has lead to a high demand for preclinical assessment techniques. A 3-dimensional in vitro blood vessel mimic (BVM) would be ideal for device testing before animal or clinical studies. This is possible based on current capabilities for the creation of tissue-engineered vascular grafts (TEVGs). Using an established method of pressure-sodding human endothelial cells onto a polymer scaffold, a BVM was created in an in vitro bioreactor system under flow. Scanning electron microscopy and immunohistochemistry verified a cellular lining and revealed a luminal monolayer of endothelial cells. After BVM development, bare metal stents were deployed. Stented and unstented BVMs were evaluated using fluorescent nuclear staining and optical coherence tomography (OCT). En face and cross-sectional evaluation of bisbenzimide-stained nuclei revealed cellular coverage of the stent surfaces. Cross-sectional evaluation using OCT also illustrated a cellular layer developing over the stent struts. These data support the use of TEVGs as in vitro BVMs for pre-clinical evaluation of the endothelial cell response to stents and endovascular devices.
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Karakayali F, Haberal N, Tufan H, Hasirci N, Basaran O, Sevmis S, Akdur A, Kiziltay A, Haberal M. Evaluation of neointimal hyperplasia on tranilast-coated synthetic vascular grafts: an experimental study. J INVEST SURG 2007; 20:167-73. [PMID: 17613691 DOI: 10.1080/08941930701365101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular smooth muscle cell induced by platelet-derived growth factor (PDGF) and transforming growth factor-beta1 (TGF-beta1). We investigated the local effect of tranilast on neointimal hyperplasia using tranilast-coated prosthetic grafts. The inner sides of the thin-walled polytetrafluoroethylene (PTFE) grafts were coated with chitosan and tranilast containing chitosan solution. Wistar albino rats (32) were used in the study. Patches (1 x 2 mm) for vascular grafts were prepared. Three groups were tested: group 1 (n = 12; tranilast coated), group 2 (n = 10; adhesive-only film-layer-coated), and group 3 (n = 10; normal ePTFE patch grafts sutured to the carotid arteries of the rats). Recipient sites of the carotid arteries were excised 4 weeks after surgery. All sections were examined histologically for graft patency, thrombus formation, and neointimal thickness. Expression of PDGF, fibroblast growth factor, and TGF-beta1 on cross-sections of the neointima were evaluated by immunohistochemistry. No significant differences were found regarding mean neointimal thicknesses. PDGF and TGF-beta-1 expressions were significantly lower in group 1. Although a decrease in local effect of tranilast was observed for growth factor expressions at a drug concentration of 0.05 mg/cm(2), a significant reduction in neointimal hyperplasia was not achieved. The coating concentration of 0.05 mg/cm(2) may have been too low to produce an antiproliferative effect. Given our promising results, further studies are recommended and planned using different drug concentrations and time intervals.
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Affiliation(s)
- Feza Karakayali
- Department of General Surgery, Baskent University Faculty of Medicine, Ankara, Turkey
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Sternberg K, Kramer S, Nischan C, Grabow N, Langer T, Hennighausen G, Schmitz KP. In vitro study of drug-eluting stent coatings based on poly(L-lactide) incorporating cyclosporine A - drug release, polymer degradation and mechanical integrity. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2007; 18:1423-32. [PMID: 17387586 DOI: 10.1007/s10856-007-0148-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Accepted: 04/12/2006] [Indexed: 05/14/2023]
Abstract
In this study, absorbable polymer stent coatings for localized drug delivery based on poly(L-lactide) (PLLA) and cyclosporine A (CsA) were developed and tested in vitro. Metallic stents were coated with different compositions of PLLA/CsA (70/30, 60/40, 50/50% w/w) and beta-sterilized. The specimens were used to assess the drug release kinetics with HPLC. Sterilization influenced polymer degradation was measured with GPC. Mechanical integrity of the stent coatings was studied with SEM. The interconnection of the coated stents with a balloon-catheter was characterized by the measurement of stent dislodgment force. A migration assay was used to determine the inhibitory effect of the model drug CsA on smooth muscle cell (SMC) migration. The release of CsA was established over time periods up to 24 days in sodium chloride solution and in porcine blood plasma. An inhibition of SMC migration (max. 26-33%) was found for CsA concentrations of 4 x 10(-5) to 4 x 10(-7) mol/l. Marked molecular weight reduction (70-80%) of the PLLA matrix occurred after beta-sterilization. We also observed a substantial decrease of in vitro degradation time. The maintenance of the mechanical integrity of the polymer coating during crimping and dilation of the specimens could be verified, and a sufficient stent dislodgment force of 0.8-0.9 N was measured.
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Affiliation(s)
- Katrin Sternberg
- Institute for Biomedical Engineering, University of Rostock, Ernst-Heydemann-Str. 6, 18057 Rostock, Germany.
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Abstract
Permanent metallic stents are associated with limitations such as continued mechanical stress, transfer to the tissue, and continued biological interaction with the surrounding tissue. They are also associated with late stent thrombosis and artifacts when non-invasive technologies such as MRI and MSCT are used. The potential advantages of bioabsorbable polymeric or metallic stents are to leave no stent behind, they are fully compatible with MRI and MSCT imaging, and are not associated with late stent thrombosis. This review covers the different stent programs as they move from bench to bed and clinical trials. Bioabsorbable stents are considered the next frontier of stenting and we will discuss their potential to fulfill this promise in interventional cardiology.
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Affiliation(s)
- Ron Waksman
- Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
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Soares JS, Moore JE, Rajagopal KR. Theoretical Modeling of Cyclically Loaded, Biodegradable Cylinders. MODELING OF BIOLOGICAL MATERIALS 2007. [DOI: 10.1007/978-0-8176-4411-6_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Mani G, Feldman MD, Patel D, Agrawal CM. Coronary stents: a materials perspective. Biomaterials 2006; 28:1689-710. [PMID: 17188349 DOI: 10.1016/j.biomaterials.2006.11.042] [Citation(s) in RCA: 410] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 11/29/2006] [Indexed: 12/21/2022]
Abstract
The objective of this review is to describe the suitability of different biomaterials as coronary stents. This review focuses on the following topics: (1) different materials used for stents, (2) surface characteristics that influence stent-biology interactions, (3) the use of polymers in stents, and (4) drug-eluting stents, especially those that are commercially available.
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Affiliation(s)
- Gopinath Mani
- Department of Biomedical Engineering, College of Engineering, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 0619, USA
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Cardinal KO, Bonnema GT, Hofer H, Barton JK, Williams SK. Tissue-engineered vascular grafts as in vitro blood vessel mimics for the evaluation of endothelialization of intravascular devices. TISSUE ENGINEERING 2006; 12:3431-3438. [PMID: 17518679 DOI: 10.1089/ten.2006.12.ft-268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The accelerating use of minimally invasive procedures for the treatment of cardiovascular disease, and the commensurate development of intravascular devices such as stents, has lead to a high demand for preclinical assessment techniques. A 3-dimensional in vitro blood vessel mimic (BVM) would be ideal for device testing before animal or clinical studies. This is possible based on current capabilities for the creation of tissue-engineered vascular grafts (TEVGs). Using an established method of pressure-sodding human endothelial cells onto a polymer scaffold, a BVM was created in an in vitro bioreactor system under flow. Scanning electron microscopy and immunohistochemistry verified a cellular lining and revealed a luminal monolayer of endothelial cells. After BVM development, bare metal stents were deployed. Stented and unstented BVMs were evaluated using fluorescent nuclear staining and optical coherence tomography (OCT). En face and cross-sectional evaluation of bisbenzimide-stained nuclei revealed cellular coverage of the stent surfaces. Cross-sectional evaluation using OCT also illustrated a cellular layer developing over the stent struts. These data support the use of TEVGs as in vitro BVMs for pre-clinical evaluation of the endothelial cell response to stents and endovascular devices.
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