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Rosenbusch L, Schuon R, Wilfling T, Krüger P, Lebahn K, John S, Sahmel O, Grabow N, Schulze M, Wree A, Schmitz KP, Stein T, Lenarz T, Paasche G. Investigation of Stent Prototypes for the Eustachian Tube in Human Donor Bodies. Bioengineering (Basel) 2023; 10:743. [PMID: 37370674 DOI: 10.3390/bioengineering10060743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/07/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023] Open
Abstract
Chronic otitis media is often connected to Eustachian tube dysfunction. As successful treatment cannot be guaranteed with the currently available options, the aim is to develop a stent for the Eustachian tube (ET). Over the course of this development, different prototypes were generated and tested in ex vivo experiments. Four different prototypes of an ET stent and one commercially available coronary stent were implanted in the ET of seven human donor bodies. The position of the stents was verified by cone beam CT. The implanted ETs were harvested, embedded in resin and ground at 200 µm steps. Resulting images of the single steps were used to generate 3D models. The 3D models were then evaluated regarding position of the stent in the ET, its diameters, amount of squeezing, orientation of the axes and other parameters. Virtual reconstruction of the implanted ET was successful in all cases and revealed one incorrect stent placement. The cross-section increased for all metal stents in direction from the isthmus towards the pharyngeal orifice of the ET. Depending on the individual design of the metal stents (open or closed design), the shape varied also between different positions along a single stent. In contrast, the cross-section area and shape remained constant along the polymeric prototype. With the current investigation, insight into the behavior of different prototypes of ET stents was gained, which can help in defining the specifications for the intended ET stent.
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Affiliation(s)
- Lena Rosenbusch
- Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Robert Schuon
- Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Tamara Wilfling
- Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Philipp Krüger
- Bess Pro GmbH, Gustav-Krone-Str. 7, 14167 Berlin, Germany
| | - Kerstin Lebahn
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany
| | | | - Olga Sahmel
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany
| | - Marko Schulze
- Institute of Anatomy, Rostock University Medical Center, 18057 Rostock, Germany
| | - Andreas Wree
- Institute of Anatomy, Rostock University Medical Center, 18057 Rostock, Germany
| | - Klaus-Peter Schmitz
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock, Germany
| | - Tobias Stein
- Bess Pro GmbH, Gustav-Krone-Str. 7, 14167 Berlin, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Gerrit Paasche
- Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
- Cluster of Excellence Hearing4all, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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Schröder G, Jabke B, Schulze M, Wree A, Martin H, Sahmel O, Doerell A, Kullen CM, Andresen R, Schober HC. A comparison, using X-ray micro-computed tomography, of the architecture of cancellous bone from the cervical, thoracic and lumbar spine using 240 vertebral bodies from 10 body donors. Anat Cell Biol 2021; 54:25-34. [PMID: 33583827 PMCID: PMC8017461 DOI: 10.5115/acb.20.269] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 11/29/2022] Open
Abstract
The vertebral trabecular bone has a complex three-dimensional microstructure with an inhomogeneous morphology. Correct identification and assessment of the weakest segments of the cancellous bone may lead to better prediction of fracture risk. The aim of this study was to compare cancellous bone from 240 vertebrae of the cervical, thoracic and lumbar spine of ten body donors with osteoporosis in regard to bone volume fraction (BVF), trabecular thickness, separation, trabecular number and degree of anisotropy, to ascertain why cervical vertebrae rarely fracture, even with severe osteoporosis. Samples were obtained from all vertebrae with a Jamshidi needle (8 Gauge). The investigations were performed with a micro-computed tomography (micro-CT) device (SKYSCAN 1172, RJL Micro & Analytic GmbH, Karlsdorf-Neuthard, Germany). Existing vertebral fractures and the bone mineral density of the lumbar spine were assessed with quantitative CT. Regarding the micro-CT parameters, statistically significant differences were observed between the various sections of the spine. We found a higher BVF, trabecular number and trabecular thickness, as well as a lower trabecular separation of the cervical vertebrae compared to other vertebrae. In addition, the degree of anisotropy in the cervical spine is lower than in the other spinal column sections. These results are age and sex dependent. Thus, the cervical spine has special structural features, whose causes must be determined in further investigations.
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Affiliation(s)
- Guido Schröder
- Clinic for Surgery, Department of Orthopedics and Trauma Surgery, Buetzow, Germany
| | - Benjamin Jabke
- Department of Internal Medicine, University Medical School Rostock, Rostock, Germany
| | - Marko Schulze
- Institute of Anatomy, University Medical School Rostock, Rostock, Germany
| | - Andreas Wree
- Institute of Anatomy, University Medical School Rostock, Rostock, Germany
| | - Heiner Martin
- Institute for Biomedical Engineering, University of Rostock, Rostock-Warnemuende, Germany
| | - Olga Sahmel
- Institute for Biomedical Engineering, University of Rostock, Rostock-Warnemuende, Germany
| | | | - Claus Maximilian Kullen
- Institute of Diagnostic and Interventional Radiology/Neuroradiology, Westkuestenklinikum Heide, Academic Teaching Hospital of the Universities of Kiel, Luebeck and Hamburg, Heide, Germany
| | - Reimer Andresen
- Institute of Diagnostic and Interventional Radiology/Neuroradiology, Westkuestenklinikum Heide, Academic Teaching Hospital of the Universities of Kiel, Luebeck and Hamburg, Heide, Germany
| | - Hans-Christof Schober
- Department of Internal Medicine IV, Municipal Hospital Suedstadt Rostock, Academic Teaching Hospital of the University of Rostock, Rostock, Germany
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Schröder G, Vivell LM, Spiegel S, Andresen R, Cullen CM, Wree A, Schulze M, Sahmel O, Martin H, Schober HC. A comparison, using Micro-CT, of the architecture of cancellous bone from the cervical, thoracic and lumbar spine using 480 vertebral bodies from 20 body donors. Bone Rep 2020. [DOI: 10.1016/j.bonr.2020.100391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Siewert S, Großmann S, Brandt-Wunderlich C, Dierke A, Stiehm M, Schmitz KP, Sahmel O, Kischkel S, Schmidt W, Grabow N, Stahnke T, Guthoff R. Development of a limbal fixation mechanism for a minimally invasive implantable glaucoma microstent. Current Directions in Biomedical Engineering 2020. [DOI: 10.1515/cdbme-2020-3056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Glaucoma represents a chronic eye disease that becomes increasingly prevalent worldwide. Therapies are commonly based on the reduction of intraocular pressure (IOP). Implant devices for micro-invasive glaucoma surgery (MIGS) represent a promising therapy option in refractory cases but suffer from limitations in long term efficacy or from dislocation associated complications. Our approach of an innovative drug-eluting glaucoma microstent for MIGS was presented previously. Within the current work we developed concepts and prototypes of a mechanism for the fixation of our glaucoma microstent in the region of the corneal limbus. A tripod and a haptics design of the fixation mechanism were developed and manufactured. Semifinished products were tested with regard to dimensional stability and mechanical properties according to the standard ANSI Z80.27-2014. Considering the mechanical properties of ocular target tissues, a gelatin based in vitro model for the measurement of microstent retention force was developed. Retention force testing of microstent prototypes in vitro resulted in a proof of concept for the fixation mechanism. Future studies will focus on the use of smaller fixation fibers, for example commercially available suture material, and on an overall miniaturization of the fixation mechanism enabling the use of our applicator device with a 22G x 1½” cannula.
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Affiliation(s)
- Stefan Siewert
- Institute for ImplantTechnology and Biomaterials e.V., Friedrich- Barnewitz-Str. 4, 18119 Rostock- Warnemünde , Germany
| | - Swen Großmann
- Institute for ImplantTechnology and Biomaterials e.V., 18119 Rostock- Warnemünde , Germany
| | | | - Ariane Dierke
- Institute for ImplantTechnology and Biomaterials e.V., 18119 Rostock- Warnemünde , Germany
| | - Michael Stiehm
- Institute for ImplantTechnology and Biomaterials e.V., 18119 Rostock- Warnemünde , Germany
| | - Klaus-Peter Schmitz
- Institute for ImplantTechnology and Biomaterials e.V., 18119 Rostock- Warnemünde , Germany
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock- Warnemünde , Germany
| | - Olga Sahmel
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock- Warnemünde , Germany
| | - Sabine Kischkel
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock- Warnemünde , Germany
| | - Wolfram Schmidt
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock- Warnemünde , Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock- Warnemünde , Germany
| | - Thomas Stahnke
- Department of Ophthalmology, Rostock University Medical Center, 18057 Rostock , Germany
| | - Rudolf Guthoff
- Department of Ophthalmology, Rostock University Medical Center, 18057 Rostock , Germany
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Gutteck N, Schilde S, Reichel M, Holtz A, Sahmel O, Hinz P, Kielstein H, Lange J, Delank KS, Martin H. Posterolateral plate fixation with Pantalarlock® is more stable than nail fixation in tibiotalocalcaneal arthrodesis in a biomechanical cadaver study. Foot Ankle Surg 2020; 26:328-333. [PMID: 31031148 DOI: 10.1016/j.fas.2019.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/07/2019] [Accepted: 04/09/2019] [Indexed: 02/04/2023]
Abstract
BACKGROUND Despite the promising results of ankle joint arthroplasty, the tibiotalocalcaneal (TTC) arthrodesis remains an established procedure in treatment of combined pathology of the ankle and subtalar joint. Despite the promising results in biomechanical investigations, nonunion rates of up to 24% are described in recent studies. The objective of this work was a comparative study of the biomechanical properties of the posterolateral plate fixation with retrograde intramedullary nail fixation. METHODS Twenty four fresh-frozen human lower leg specimens (12 pairs) were used for the comparative biomechanical testing. Every specimen was preconditioned with 100 N over 200 cycles. After every 250 cycles the force was increased by 50 N from 200 to 600 N. This was followed by cyclic loading in dorsi-/plantiflexion with 800 N for 3000 cycles. All specimens were subjected to bone densitometry (DXA) and computed tomography. RESULTS Significantly higher number of spacimens with nails (4) failed during the cycling testing in dorsi-/plantarflexion and futher two during the cyclic testing with 800 N. Two specimens with plates failed during the cyclic testing with 800 N. Statistical analysis showed that the specimens with the plate were significantly more stable in each test direction. The Pearson correlation demonstrated for the specimens with plate a linear relationship between the stiffness and the determined bone density. CONCLUSIONS The results demonstrate a significantly superior stiffness of the Pantalarlock®-plate in all testing directions compared with the HAN nail. Probably the position of the plate on the tension side of the joint and the combination of locking and lag screws provide the higher stiffness of the plate system. The correlation of the stiffness with bone density leads to more predictable results of the plate arthrodesis. We hope for a reduction of the pseudarthrosis rate and shorten the postoperative treatment phase. The authors expect advantages in the treatment of high risk patients with severe deformity of the ankle, bone defects, neuropathic deformity, poor bone quality and osteoporosis.
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Affiliation(s)
- N Gutteck
- Department for Orthopaedics and Traumatology, Martin-Luther-University, Halle-Wittenberg, Ernst-Grube Str. 40, 06120 Halle, Germany.
| | - S Schilde
- Department for Orthopaedics and Traumatology, Martin-Luther-University, Halle-Wittenberg, Ernst-Grube Str. 40, 06120 Halle, Germany
| | - M Reichel
- Department of the Mechanical Engineering and Marine Technology, Faculty at the University of Rostock, Albert-Einstein-Straße 2, 18059 Rostock, Germany
| | - A Holtz
- Department of the Mechanical Engineering and Marine Technology, Faculty at the University of Rostock, Albert-Einstein-Straße 2, 18059 Rostock, Germany
| | - O Sahmel
- Department of Medical Biotechnology, University of Rostock, F.-Barnewitz-Str. 4, 18119 Rostock, Germany
| | - P Hinz
- Clinic for Trauma and Recontructive Surgery, University of Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - H Kielstein
- Department for Anatomy and Cell Biology, Martin-Luther-University, Halle-Wittenberg, Große Steinstraße 52, 06108 Halle, Germany
| | - J Lange
- Clinic for Trauma and Recontructive Surgery, University of Greifswald, Ferdinand-Sauerbruch-Straße, 17475 Greifswald, Germany
| | - K S Delank
- Department for Orthopaedics and Traumatology, Martin-Luther-University, Halle-Wittenberg, Ernst-Grube Str. 40, 06120 Halle, Germany
| | - H Martin
- Department of Medical Biotechnology, University of Rostock, F.-Barnewitz-Str. 4, 18119 Rostock, Germany
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Sahmel O, Siewert S, Schmitz KP, Arbeiter D, Grabow N, Kreiner CF, Guthoff R. Extrusion as a manufacturing process for polymer micro-tubes for various bio-medical applications. Current Directions in Biomedical Engineering 2019. [DOI: 10.1515/cdbme-2019-0123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
In various biomedical applications extrusion represents a common manufacturing process for polymeric semi-finished products. Extrusion allows the processing of a wide range of biomaterials, as well as different cross-sectional geometries. The present work focuses on the development of an extrusion process for polymer micro-tubes used for medical devices manufacturing, e.g. microstents for minimally invasive glaucoma therapy. Semi-finished products were manufactured by means of extrusion and dip-coating. Morphology was investigated using biaxial laser measurement and scanning electron microscopy (SEM). For the analysis of mechanical and thermal properties of the specimens uniaxial tensile testing and differential scanning calorimetry (DSC) were performed. While dip-coated micro-tubes reveal a smooth and homogeneous surface, SEM micrographs of extruded micro-tubes exhibit some longitudinal grooves. Mechanical properties of extruded and dip-coated micro-tubes are comparable, so that the presented extrusion process can be regarded suitable for the manufacturing of polymer microtubes in a sub-millimeter scale. A future improvement of nozzle design will allow for a smooth surface of extruded semi-finished products.
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Affiliation(s)
- Olga Sahmel
- Institute for Biomedical Engineering, Rostock University Medical Center, Friedrich- Barnewitz-Str. 4, Rostock , Germany
| | - Stefan Siewert
- Institute for ImplantTechnology and Biomaterials e.V., Friedrich-Barnewitz-Str. 4, 18119 Rostock- Warnemünde , Germany
| | - Klaus-Peter Schmitz
- Institute for ImplantTechnology and Biomaterials e.V., Friedrich-Barnewitz-Str. 4, 18119 Rostock- Warnemünde , Germany
- Institute for Biomedical Engineering, Rostock University Medical Center, Friedrich-Barnewitz-Str. 4, 18119 Rostock , Germany
| | - Daniela Arbeiter
- Institute for Biomedical Engineering, Rostock University Medical Center, Friedrich-Barnewitz-Str. 4, 18119 Rostock , Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, Friedrich-Barnewitz-Str. 4, 18119 Rostock , Germany
| | - Christine Friederike Kreiner
- KreCo Kreiner Consulting Society for scientific and technical project management mbH, 16761 Hennigsdorf , Germany
| | - Rudolf Guthoff
- Department of Ophthalmology, Rostock University Medical Center, Doberaner Str. 140, 18057 Rostock , Germany
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Sahmel O, Arbeiter D, Schümann K, Grabow N, Siewert S, Schmitz KP. Optimization of manufacturing processes for biodegradable polymeric stents regarding improved mechanical properties. Current Directions in Biomedical Engineering 2018. [DOI: 10.1515/cdbme-2018-0140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractAlthough current drug eluting stents show low risks of in-stent restenosis and stent thrombosis, the presence of a permanent foreign body inside the vessel represents a major limitation. In order to overcome this limitation, stents made of biodegradable polymeric materials are currently being developed. The present work describes an optimized fabrication process for tubular semi-finished products for manufacturing of stents made of poly-L-lactide (PLLA). The impact of the haul-off speed as a major parameter during extrusion processing on the cross-sectional area of tubular specimens was analyzed. It could be shown that the crosssection of the extrudate, in particular the tubing diameter and wall thickness, can be adjusted by varying haul-off speed. In a subsequent blow molding process the influence of the holding time on polymer cold crystallization was analyzed. Thermal properties of the polymeric material after processing were examined by differential scanning calorimetry (DSC). The results showed that there is almost no cold crystallization using a holding time of at least 20 minutes. The investigations showed that semi-finished products with variable geometry and improved mechanical properties can be produced with the described extrusion and blow molding process.
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Affiliation(s)
- Olga Sahmel
- 1Institute for Biomedical Engineering, Rostock University Medical Center Rostock,Rostock, Germany
| | - Daniela Arbeiter
- 1Institute for Biomedical Engineering, Rostock University Medical Center Rostock,Rostock, Germany
| | - Kerstin Schümann
- 1Institute for Biomedical Engineering, Rostock University Medical Center Rostock,Rostock, Germany
| | - Niels Grabow
- 1Institute for Biomedical Engineering, Rostock University Medical Center Rostock,Rostock, Germany
| | - Stefan Siewert
- 2Institute for ImplantTechnology and Biomaterials,Rostock, Germany
| | - Klaus-Peter Schmitz
- 3Institute for ImplantTechnology and Biomaterials,Rostock, Germany
- 1Institute for Biomedical Engineering, Rostock University Medical Center Rostock,Rostock, Germany
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Illner S, Sahmel O, Siewert S, Eickner T, Grabow N. Rheological analysis of hybrid hydrogels during polymerization processes. Current Directions in Biomedical Engineering 2017. [DOI: 10.1515/cdbme-2017-0148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractDevelopment of new implant coatings with temperature-controlled drug release to treat infections after device implantation can be triggered by highly elastic hydrogels with adequate stability and adhesive strength in the swollen state. By using an ionic liquid (IL [ViPrIm]+[Br]−) as additive to N-isopropylacrylamide (NIPAAm) unique effects on volumetric changes and mechanical properties as well as thermoresponsive drug release of the obtained hybrid hydrogels were observed. In this context, rheological measurements allow the monitoring of gelation processes as well as chemical, mechanical, and thermal treatments and effects of additives. Hybrid hydrogels of pNIPAAm and poly (ionic liquid) (PIL) were prepared by radical emulsion polymerization with N,N′-methylenebis(acrylamide) as 3D crosslinking agent. By varying monomer, initiator and crosslinker amounts the multi-compound system during polymerization was monitored by oscillatory time sweep experiments. The time dependence of the storage modulus (G′) and the loss modulus (G″) was measured, whereby the intersection of G′ and G″ indicates the sol-gel transition. Viscoelastic behavior and complex viscosity of crosslinked and non-crosslinked hydrogels were obtained. Within material characterization rheology can be used to determine process capability and optimal working conditions. For biomedical applications complete hydrogelation inter-connecting all compounds can be received providing the possibility to process mechanically stable, swellable implant coatings or wound closures.
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Affiliation(s)
- Sabine Illner
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany
| | - Olga Sahmel
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany
| | - Stefan Siewert
- Institute for Implant Technology and Biomaterials e.V. and Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany
| | - Thomas Eickner
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, University Medical Center Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde, Germany
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Arbeiter D, Schümann K, Sahmel O, Eickner T, Schmitz KP, Grabow N. The effect of thermal treatment on the mechanical properties of PLLA tubular specimens. Current Directions in Biomedical Engineering 2016. [DOI: 10.1515/cdbme-2016-0009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractConventional permanent stent systems for vascular applications are associated with long-term risks, such as restenosis and thrombosis. To overcome these limitations, novel approaches using various biodegradable materials for stent construction have been investigated. In this context, thermal treatment of polymer materials is investigated to adjust the mechanical properties of biodegradable stents. In this work polymeric tubular specimens of biodegradable poly(L-lactide) (PLLA) were extruded and subjected to a molding process using different temperatures above glass transition temperature TG. Physicochemical properties of the molded samples were analyzed using DSC measurements and uniaxial tensile tests. The molding process resulted in a weakening of the PLLA tubular specimens with a simultaneous increase in the degree of crystallinity (χ).
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Affiliation(s)
- Daniela Arbeiter
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
| | - K. Schümann
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
| | - O. Sahmel
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
| | - T. Eickner
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
| | - K.-P. Schmitz
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
| | - N. Grabow
- 1Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Friedrich-Barnewitz-Str. 4, 18119 Rostock-Warnemünde
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