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Maintz M, Tourbier C, de Wild M, Cattin PC, Beyer M, Seiler D, Honigmann P, Sharma N, Thieringer FM. Patient-specific implants made of 3D printed bioresorbable polymers at the point-of-care: material, technology, and scope of surgical application. 3D Print Med 2024; 10:13. [PMID: 38639834 PMCID: PMC11031859 DOI: 10.1186/s41205-024-00207-0] [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: 01/05/2024] [Accepted: 03/04/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND Bioresorbable patient-specific additive-manufactured bone grafts, meshes, and plates are emerging as a promising alternative that can overcome the challenges associated with conventional off-the-shelf implants. The fabrication of patient-specific implants (PSIs) directly at the point-of-care (POC), such as hospitals, clinics, and surgical centers, allows for more flexible, faster, and more efficient processes, reducing the need for outsourcing to external manufacturers. We want to emphasize the potential advantages of producing bioresorbable polymer implants for cranio-maxillofacial surgery at the POC by highlighting its surgical applications, benefits, and limitations. METHODS This study describes the workflow of designing and fabricating degradable polymeric PSIs using three-dimensional (3D) printing technology. The cortical bone was segmented from the patient's computed tomography data using Materialise Mimics software, and the PSIs were designed created using Geomagic Freeform and nTopology software. The implants were finally printed via Arburg Plastic Freeforming (APF) of medical-grade poly (L-lactide-co-D, L-lactide) with 30% β-tricalcium phosphate and evaluated for fit. RESULTS 3D printed implants using APF technology showed surfaces with highly uniform and well-connected droplets with minimal gap formation between the printed paths. For the plates and meshes, a wall thickness down to 0.8 mm could be achieved. In this study, we successfully printed plates for osteosynthesis, implants for orbital floor fractures, meshes for alveolar bone regeneration, and bone scaffolds with interconnected channels. CONCLUSIONS This study shows the feasibility of using 3D printing to create degradable polymeric PSIs seamlessly integrated into virtual surgical planning workflows. Implementing POC 3D printing of biodegradable PSI can potentially improve therapeutic outcomes, but regulatory compliance must be addressed.
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Affiliation(s)
- Michaela Maintz
- Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland
- Institute for Medical Engineering and Medical Informatics IM², University of Applied Sciences and Arts Northwestern Switzerland FHNW, Hofackerstrasse 30, Muttenz, Switzerland
| | - Céline Tourbier
- Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland.
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland.
| | - Michael de Wild
- Institute for Medical Engineering and Medical Informatics IM², University of Applied Sciences and Arts Northwestern Switzerland FHNW, Hofackerstrasse 30, Muttenz, Switzerland
| | - Philippe C Cattin
- Department of Biomedical Engineering, Center of Medical Image Analysis and Navigation (CIAN), University of Basel, Hegenheimermattweg 167C, Allschwil, Basel, Switzerland
| | - Michel Beyer
- Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland
| | - Daniel Seiler
- Institute for Medical Engineering and Medical Informatics IM², University of Applied Sciences and Arts Northwestern Switzerland FHNW, Hofackerstrasse 30, Muttenz, Switzerland
| | - Philipp Honigmann
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland
- Department of Orthopaedic Surgery and Traumatology, Hand- and peripheral Nerve Surgery, Kantonsspital Baselland, Bruderholz| Liestal| Laufen, Switzerland
- Biomedical Engineering and Physics, Amsterdam UMC location University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
| | - Neha Sharma
- Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland
| | - Florian M Thieringer
- Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Spitalstrasse 21, Basel, Switzerland
- Department of Biomedical Engineering, Medical Additive Manufacturing Research Group (Swiss MAM), University of Basel, Hegenheimermattweg 167C, Allschwil, Switzerland
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Gottsauner M, Morawska MM, Tempel S, Müller-Gerbl M, Dalcanale F, de Wild M, Ettl T. Geometric Cuts by an Autonomous Laser Osteotome Increase Stability in Mandibular Reconstruction With Free Fibula Grafts: A Cadaver Study. J Oral Maxillofac Surg 2024; 82:235-245. [PMID: 37980939 DOI: 10.1016/j.joms.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/24/2023] [Accepted: 10/29/2023] [Indexed: 11/21/2023]
Abstract
BACKGROUND Nonunion and plate exposure represent a major complication after mandibular reconstruction with free fibula flaps. These drawbacks may be resolved by geometric osteotomies increasing intersegmental bone contact area and stability. PURPOSE The aim of this study was to compare intersegmental bone contact and stability of geometric osteotomies to straight osteotomies in mandibular reconstructions with free fibula grafts performed by robot-guided erbium-doped yttrium aluminum garnet laser osteotomy. STUDY DESIGN, SETTING, SAMPLE This cadaveric in-vitro study was performed on fresh frozen human skull and fibula specimens. Computed tomography (CT) scans of all specimens were performed for virtual planning of mandibular resections and three-segment fibula reconstructions. The virtual planning was implemented in a Cold Ablation Robot-guided Laser Osteotome. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE For predictor variables, straight and geometric puzzle-shaped osteotomies were designed at resection of the mandible and corresponding fibula reconstruction. MAIN OUTCOME VARIABLES The primary outcome variable was the stability of the reconstructed mandible investigated by shearing tests. Moreover, secondary outcome variables were the duration of the laser osteotomies, the contact surface area, and the accuracy of the reconstruction, both evaluated on postsurgical CT scans. COVARIATES Covariables were not applicable. ANALYSES Data were reported as mean values (± standard deviation) and were statistically analyzed using an independent-sample t-test at a significance level of α = 0.05. Root mean square deviation was tested for accuracy. RESULTS Eight skulls and 16 fibula specimens were used for the study. One hundred twelve successful laser osteotomies (96 straight and 16 geometrical) could be performed. Geometric osteotomies increased stability (110.2 ± 36.2 N vs 37.9 ± 20.1 N, P < .001) compared to straight osteotomies. Geometric osteotomy of the fibula took longer than straight osteotomies (10.9 ± 5.1 min vs 5.9 ± 2.2 min, P = .028) but could provide larger contact surface (431.2 ± 148.5 mm2 vs 226.1 ± 50.8 mm2, P = .04). Heat map analysis revealed a mean deviation between preoperational planning and postreconstructive CT scan of -0.8 ± 2.4 mm and a root mean square deviation of 2.51 mm. CONCLUSION AND RELEVANCE Mandibular resection and reconstruction by fibula grafts can be accurately performed by a Cold Ablation Robot-guided Laser Osteotome without need for cutting guides. Osteotomy planning with geometric cuts offers higher stability and an increased bone contact area, which may enhance healing of the reconstructed mandible.
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Affiliation(s)
- Maximilian Gottsauner
- Coordinator of the Head and Neck-Tumor-Center, Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany.
| | - Marta M Morawska
- Clinical Affairs Manager, Advanced Osteotomy Tools (AOT AG), Basel, Switzerland
| | - Simon Tempel
- Project Manager for Research & Development, Advanced Osteotomy Tools (AOT AG), Basel, Switzerland
| | - Magdalena Müller-Gerbl
- Director of the Department of Anatomy, Department of Anatomy, University of Basel, Basel, Switzerland
| | - Federico Dalcanale
- Scientist, Fachhochschule Nordwestschweiz, Institute for Medical Engineering and Medical Informatics, Muttenz, Switzerland
| | - Michael de Wild
- Head of the Division, Fachhochschule Nordwestschweiz, Institute for Medical Engineering and Medical Informatics, Muttenz, Switzerland
| | - Tobias Ettl
- Deputy Director, Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, Regensburg, Germany
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Lee SS, Du X, Smit T, Bissacco EG, Seiler D, de Wild M, Ferguson SJ. 3D-printed LEGO®-inspired titanium scaffolds for patient-specific regenerative medicine. Biomater Adv 2023; 154:213617. [PMID: 37678088 DOI: 10.1016/j.bioadv.2023.213617] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/08/2023] [Accepted: 09/02/2023] [Indexed: 09/09/2023]
Abstract
Despite the recent advances in 3D-printing, it is often difficult to fabricate implants that optimally fit a defect size or shape. There are some approaches to resolve this issue, such as patient-specific implant/scaffold designs based on CT images of the patients, however, this process is labor-intensive and costly. Especially in developing countries, affordable treatment options are required, while still not excluding these patient groups from potential material and manufacturing advances. Here, a selective laser melting (SLM) 3D-printing strategy was used to fabricate a hierarchical, LEGO®-inspired Assemblable Titanium Scaffold (ATS) system, which can be manually assembled in any shape or size with ease. A surgeon can quickly create a scaffold that would fit to the defect right before the implantation during the surgery. Additionally, the direct inclusion of micro- and macroporous structures via 3D-printing, as well as a double acid-etched surface treatment (ST) in the ATS, ensure biocompatibility, sufficient nutrient flow, cell migration and enhanced osteogenesis. Three different structures were designed (non-porous:NP, semi-porous:SP, ultra-porous:UP), 3D-printed with the SLM technique and then surface treated for the ST groups. After analyzing characteristics of the ATS such as printing quality, surface roughness and interconnected porosity, mechanical testing and finite element analysis (FEA) demonstrated that individual and stacked ATS have sufficient mechanical properties to withstand loading in a physiological system. All ATS showed high cell viability, and the SP and UP groups demonstrated enhanced cell proliferation rates compared to the NP group. Furthermore, we also verified that cells were well-attached and spread on the porous structures and successful cell migration between the ATS units was seen in the case of assemblies. The UP and SP groups exhibited higher calcium deposition and RT-qPCR proved higher osteogenic gene expression compared to NP group. Finally, we demonstrate a number of possible medical applications that reveal the potential of the ATS through assembly.
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Affiliation(s)
- Seunghun S Lee
- Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
| | - Xiaoyu Du
- Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Thijs Smit
- Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Elisa G Bissacco
- Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Daniel Seiler
- Institute for Medical Engineering and Medical Informatics IM(2), FHNW, Muttenz, Switzerland
| | - Michael de Wild
- Institute for Medical Engineering and Medical Informatics IM(2), FHNW, Muttenz, Switzerland
| | - Stephen J Ferguson
- Institute for Biomechanics, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
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Maevskaia E, Khera N, Ghayor C, Bhattacharya I, Guerrero J, Nicholls F, Waldvogel C, Bärtschi R, Fritschi L, Salamon D, Özcan M, Malgaroli P, Seiler D, de Wild M, Weber FE. Three-Dimensional Printed Hydroxyapatite Bone Substitutes Designed by a Novel Periodic Minimal Surface Algorithm Are Highly Osteoconductive. 3D Print Addit Manuf 2023; 10:905-916. [PMID: 37886403 PMCID: PMC10599419 DOI: 10.1089/3dp.2022.0134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Autologous bone remains the gold standard bone substitute in clinical practice. Therefore, the microarchitecture of newly developed synthetic bone substitutes, which reflects the spatial distribution of materials in the scaffold, aims to recapitulate the natural bone microarchitecture. However, the natural bone microarchitecture is optimized to obtain a mechanically stable, lightweight structure adapted to the biomechanical loading situation. In the context of synthetic bone substitutes, the application of a Triply Periodic Minimum Surface (TPMS) algorithm can yield stable lightweight microarchitectures that, despite their demanding architectural complexity, can be produced by additive manufacturing. In this study, we applied the TPMS derivative Adaptive Density Minimal Surfaces (ADMS) algorithm to produce scaffolds from hydroxyapatite (HA) using a lithography-based layer-by-layer methodology and compared them with an established highly osteoconductive lattice microarchitecture. We characterized them for compression strength, osteoconductivity, and bone regeneration. The in vivo results, based on a rabbit calvaria defect model, showed that bony ingrowth into ADMS constructs as a measure of osteoconduction depended on minimal constriction as it limited the maximum apparent pore diameter in these scaffolds to 1.53 mm. Osteoconduction decreased significantly at a diameter of 1.76 mm. The most suitable ADMS microarchitecture was as osteoconductive as a highly osteoconductive orthogonal lattice microarchitecture in noncritical- and critical-size calvarial defects. However, the compression strength and microarchitectural integrity in vivo were significantly higher for scaffolds with their microarchitecture based on the ADMS algorithm when compared with high-connectivity lattice microarchitectures. Therefore, bone substitutes with high osteoconductivity can be designed with the advantages of the ADMS-based microarchitectures. As TPMS and ADMS microarchitectures are true lightweight structures optimized for high mechanical stability with a minimal amount of material, such microarchitectures appear most suitable for bone substitutes used in clinical settings to treat bone defects in weight-bearing and non-weight-bearing sites.
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Affiliation(s)
- Ekaterina Maevskaia
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Nupur Khera
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Chafik Ghayor
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Indranil Bhattacharya
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Julien Guerrero
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Flora Nicholls
- Central Biological Laboratory, University Hospital Zurich, Zurich, Switzerland
| | | | | | | | | | - Mutlu Özcan
- Center of Dental Medicine, Division of Dental Biomaterials, Clinic for Reconstructive Dentistry, University of Zurich, Zurich, Switzerland
| | - Patrick Malgaroli
- Institute for Medical Engineering and Medical Informatics IM2, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, FHNW, Muttenz, Switzerland
| | - Daniel Seiler
- Institute for Medical Engineering and Medical Informatics IM2, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, FHNW, Muttenz, Switzerland
| | - Michael de Wild
- Institute for Medical Engineering and Medical Informatics IM2, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, FHNW, Muttenz, Switzerland
| | - Franz E. Weber
- Oral Biotechnology & Bioengineering, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
- CABMM, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland
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Maintz M, Msallem B, de Wild M, Seiler D, Herrmann S, Feiler S, Sharma N, Dalcanale F, Cattin P, Thieringer FM. Parameter optimization in a finite element mandibular fracture fixation model using the design of experiments approach. J Mech Behav Biomed Mater 2023; 144:105948. [PMID: 37348171 DOI: 10.1016/j.jmbbm.2023.105948] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/28/2023] [Accepted: 05/30/2023] [Indexed: 06/24/2023]
Abstract
Only a few mandibular bone finite element (FE) models have been validated in literature, making it difficult to assess the credibility of the models. In a comparative study between FE models and biomechanical experiments using a synthetic polyamide 12 (PA12) mandible model, we investigate how material properties and boundary conditions affect the FE model's accuracy using the design of experiments approach. Multiple FE parameters, such as contact definitions and the materials' elastic and plastic deformation characteristics, were systematically analyzed for an intact mandibular model and transferred to the fracture fixation model. In a second step, the contact definitions for the titanium screw and implant (S-I), implant and PA12 mandible (I-M), and interfragmentary (IF) PA12 segments were optimized. Comparing simulated deformations (from 0 to -5 mm) and reaction forces (from 10 to 1'415 N) with experimental results showed a strong sensitivity to FE mechanical properties and contact definitions. The results suggest that using the bonded definition for the screw-implant contact of the fracture plate is ineffective. The contact friction parameter set with the highest agreement was identified: titanium screw and implant μ = 0.2, implant and PA12 mandible μ = 0.2, interfragmentary PA12 mandible μ = 0.1. The simulated reaction force (RMSE = 26.60 N) and surface displacement data (RMSE = 0.19 mm) of the FE analysis showed a strong agreement with the experimental biomechanical data. The results were generated through parameter optimization which means that our findings need to be validated in the event of a new dataset with deviating anatomy. Conclusively, the predictive capability of the FE model can be improved by FE model calibration through experimental testing. Validated preoperative quasi-static FE analysis could allow engineers and surgeons to accurately estimate how the implant's choice and placement suit the patient's biomechanical needs.
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Affiliation(s)
- Michaela Maintz
- Medical Additive Manufacturing Research Group (Swiss MAM), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Basel, Switzerland; Institute for Medical Engineering and Medical Informatics IM(2), University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland.
| | - Bilal Msallem
- Medical Additive Manufacturing Research Group (Swiss MAM), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Basel, Switzerland
| | - Michael de Wild
- Institute for Medical Engineering and Medical Informatics IM(2), University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland
| | - Daniel Seiler
- Institute for Medical Engineering and Medical Informatics IM(2), University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland
| | | | - Stefanie Feiler
- Group of Applied Mathematics in Life Sciences, Initial and Continuing Education, University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland, AICOS Technologies Ltd., Allschwil, Switzerland
| | - Neha Sharma
- Medical Additive Manufacturing Research Group (Swiss MAM), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Basel, Switzerland
| | - Federico Dalcanale
- Institute for Medical Engineering and Medical Informatics IM(2), University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz, Switzerland
| | - Philippe Cattin
- Center of Medical Image Analysis and Navigation (CIAN), Department of Biomedical Engineering, University of Basel, Allschwil, Basel, Switzerland
| | - Florian Markus Thieringer
- Medical Additive Manufacturing Research Group (Swiss MAM), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland; Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Basel, Basel, Switzerland
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Abstract
Abstract
Patient-specific osteosynthesis plates can be used to reduce complications related to bone fracture treatment, such as infection, malocclusion and fatigue fractures of plates and screws. However, the implant design process is tedious. We propose a semi-automatic workflow to computationally design patient-specific titanium osteosynthesis plates for mandibular angle fractures. In this process, the plate stiffness is maximized while the mass is reduced. Two plate designs with different numbers of screw holes (implant #1 with four holes, implant #2 with eight holes) were generated with identical topology optimization settings and compared in a finite element model simulating various biomechanical masticatory loads. Differences in von Mises stresses in the implants and screws were observed. The load case of clenching the jaw on the opposite side of the fracture showed the highest stress distribution in implant #1 and higher peak stresses in implant #2. Stress concentrations were observed in sharp corners of the implant and could be reduced using local stress-based topology optimization. We conclude that the design process is an effective method to generate patientspecific implants.
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Affiliation(s)
- Michaela Maintz
- University of Applied Sciences and Arts Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute of Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, Muttenz , Switzerland
- Swiss MAM, University of Basel, Gewerbestrasse 14, Allschwil , Switzerland
| | - Daniel Seiler
- University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz , Switzerland
| | - Florian M. Thieringer
- Swiss MAM, Department of Biomedical Engineering, University of Basel, University Hospital Basel, Basel , Switzerland
| | - Michael de Wild
- University of Applied Sciences and Arts Northwestern Switzerland FHNW, Muttenz , Switzerland
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Rohr N, Brunner C, Bellon B, Fischer J, de Wild M. Characterization of a cotton-wool like composite bone graft material. J Mater Sci Mater Med 2022; 33:61. [PMID: 35849225 PMCID: PMC9293850 DOI: 10.1007/s10856-022-06682-3] [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] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Bone graft materials are applied in patients to augment bone defects and enable the insertion of an implant in its ideal position. However, the currently available augmentation materials do not meet the requirements of being completely resorbed and replaced by new bone within 3 to 6 months. A novel electrospun cotton-wool like material (Bonewool®, Zurich Biomaterials LLC, Zurich, Switzerland) consisting of biodegradable poly(lactic-co-glycolic) acid (PLGA) fibers with incorporated amorphous ß-tricalcium phosphate (ß-TCP) nanoparticles has been compared to a frequently used bovine derived hydroxyapatite (Bio-Oss®, Geistlich Pharma, Wolhusen, Switzerland) in vitro. The material composition was determined and the degradation behavior (calcium release and pH in different solutions) as well as bioactivity has been measured. Degradation behavior of PLGA/ß-TCP was generally more progressive than for Bio-Oss®, indicating that this material is potentially completely resorbable. Graphical abstract.
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Affiliation(s)
- Nadja Rohr
- Biomaterials and Technology, Clinic for Reconstructive Dentistry, University Center for Dental Medicine Basel, Basel, Switzerland.
| | - Claudia Brunner
- Biomaterials and Technology, Clinic for Reconstructive Dentistry, University Center for Dental Medicine Basel, Basel, Switzerland
- Private Practice, Oberentfelden, Switzerland
| | - Benjamin Bellon
- Department of Preclinical and Translational Research, Institut Straumann AG, Basel, Switzerland
| | - Jens Fischer
- Biomaterials and Technology, Clinic for Reconstructive Dentistry, University Center for Dental Medicine Basel, Basel, Switzerland
| | - Michael de Wild
- School of Life Sciences, Institute for Medical Engineering and Medical Informatics IM², University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
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Simeunovic S, Jung C, Mory D, Seiler D, Wild MD. Investigating dry electro-chemical polishing of titanium structures. Current Directions in Biomedical Engineering 2021. [DOI: 10.1515/cdbme-2021-2020] [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
With the introduction of novel automated polishing methods, more attention has recently been paid to postprocessing methods of metallic implants. One such method is the polishing process known as DryLyte®. The most significant difference to previous electropolishing methods is the use of solid organic polymer particles activated with sulfonic acid acting as the electrolyte. The solid particle electrolyte raises new question in terms of polishing results for small features as well as overall polishing quality of metallic surfaces. The aim of this study was to determine the quality of the polishing process for titanium rods with different initial surface roughness and with tapped holes in three different orientations (0°, 45°, 90°) by subjecting them to the DryLyte® polishing process for 30 min. In addition, the influence of the process parameters voltage and the anodic time T2 during the treatment on the resulting surface quality and the polishing efficiency was determined. In conclusion, the dry electrochemical finishing process has shown great smoothing capabilities for titanium even with small, tapped holes. The Ra values were lowered significantly throughout all titanium samples after 30 min polishing time.
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Affiliation(s)
- Sven Simeunovic
- University of applied Sciences and Arts Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute of Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, Muttenz , Switzerland
| | | | - Dominik Mory
- University of applied Sciences and Arts Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute of Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, Muttenz , Switzerland
| | - Daniel Seiler
- University of applied Sciences and Arts Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute of Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, Muttenz , Switzerland
| | - Michael de Wild
- University of applied Sciences and Arts Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute of Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, Muttenz , Switzerland
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Schuler F, Dany S, John C, Wild MD. Exploitation of transition temperatures of NiTi- SMA by adjusting SLM parameters. Current Directions in Biomedical Engineering 2021. [DOI: 10.1515/cdbme-2021-2016] [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
It is well known that the transition temperatures, e.g. the austenite peak temperature Ap, of NiTi Shape Memory Alloys (SMAs) can be adjusted by changing the alloy composition. This topic recently became more interesting due to the possibilities to produce SMA-parts by additive manufacturing, specifically by Selective Laser Melting (SLM). The potential of new designs and smart structures by so-called 4D-printing with locally adjusted transition temperatures Ap potentially opens up new applications and novel temperature-responsive medical devices. This work focuses on the SLM manufacturing parameters exposure time ET (scanning speed) and laser power P and their impact on the transition temperature Ap beyond the commonly used generic process parameter energy density ED. By systematical variation of process- and scan-parameters, the impact of the P, ET, sample orientation and layer height LH as well as interdependencies between them have been studied. A wide range of transition temperatures Ap between -20°C and 70°C has been reached from one starting material by varying ET. These findings potentially allow the manufacturing of smart devices with multi-stage deformation processes in a single 4Dprinted part.
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Affiliation(s)
- Felix Schuler
- University of Applied Sciences Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
| | - Sebastian Dany
- University of Applied Sciences Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
- Hochschule Hamm-Lippstadt, D-59063 Hamm , Germany
| | - Christoph John
- Department of Chemistry, University of Basel, Mattenstrasse 24a, CH-4058 Basel , Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland FHNW, School of Life Sciences HLS, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
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Müller S, Schwenk T, de Wild M, Dimitriou D, Rosso C. Increased Construct Stiffness With Meniscal Repair Sutures and Devices Increases the Risk of Cheese-Wiring During Biomechanical Load-to-Failure Testing. Orthop J Sports Med 2021; 9:23259671211015674. [PMID: 34189149 PMCID: PMC8209834 DOI: 10.1177/23259671211015674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 04/14/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Cheese-wiring, the suture that cuts through the meniscus, is a well-known issue in meniscal repair. So far, contributing factors are neither fully understood nor sufficiently studied. Hypothesis/Purpose: To investigate whether the construct stiffness of repair sutures and devices correlates with suture cut-through (cheese-wiring) during load-to-failure testing. Study Design: Controlled laboratory study. Methods: In 131 porcine menisci, longitudinal bucket-handle tears were repaired using either inside-out sutures (n = 66; No. 0 Ultrabraid, 2-0 Orthocord, 2-0 FiberWire, and 2-0 Ethibond) or all-inside devices (n = 65; FastFix360, Omnispan, and Meniscal Cinch). After cyclic loading, load-to-failure testing was performed. The mode of failure and construct stiffness were recorded. A receiver operating characteristic curve analysis was performed to define the optimal stiffness threshold for predicting meniscal repair failure by cheese-wiring. The 2-tailed t test and analysis of variance were used to test significance. Results: Loss of suture fixation was the most common mode of failure in all specimens (58%), except for the Omnispan, which failed most commonly because of anchor pull-through. The Omnispan demonstrated the highest construct stiffness (30.8 ± 3.5 N/mm), whereas the Meniscal Cinch (18.0 ± 8.8 N/mm) and Ethibond (19.4 ± 7.8 N/mm) demonstrated the lowest construct stiffness. The Omnispan showed significantly higher stiffness compared with the Meniscal Cinch (P < .001) and Ethibond (P = .02), whereas the stiffness of the Meniscal Cinch was significantly lower compared with that of the FiberWire (P = .01), Ultrabraid (P = .04), and FastFix360 (P = .03). While meniscal repair with a high construct stiffness more often failed by cheese-wiring, meniscal repair with a lower stiffness failed by loss of suture fixation, knot slippage, or anchor pull-through. Meniscal repair with a stiffness >26.5 N/mm had a 3.6 times higher risk of failure due to cheese-wiring during load-to-failure testing (95% CI, 1.4-8.2; P < .0001). Conclusion: Meniscal repair using inside-out sutures and all-inside devices with a higher construct stiffness (>26.5 N/mm) was more likely to fail through suture cut-through (cheese-wiring) than that with a lower stiffness (≤26.5 N/mm). Clinical Relevance: This is the first study investigating the impact of construct stiffness on meniscal repair failure by suture cut-through (cheese-wiring).
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Affiliation(s)
- Sebastian Müller
- Department of Orthopaedics and Traumatology, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Tanja Schwenk
- University of Basel, Basel, Switzerland.,Department of Medical Oncology, Kantonsspital Aarau, Aarau, Switzerland
| | - Michael de Wild
- Institute for Medical Engineering and Medical Informatics, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland
| | - Dimitris Dimitriou
- Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Claudio Rosso
- Department of Orthopaedics and Traumatology, University Hospital Basel, Basel, Switzerland.,Shoulder and Elbow Unit, ARTHRO Medics, Basel, Switzerland
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Wild MD, Dany S, John C, Schuler F. Smart 4D-printed implants and instruments. Current Directions in Biomedical Engineering 2020. [DOI: 10.1515/cdbme-2020-3053] [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
Selective laser melting (SLM) was used to manufacture smart programmed structures with customized properties made of biocompatible NiTi shape-memory alloy. A series of helixes was produced with systematically varied SLM process parameters Laser Exposure Time and Laser Power in order to specifically change the thermo-mechanical material properties of the 3D-structures. This innovation opens up the possibility to adjust the NiTi phase transformation temperature during the manufacturing process. This controllable property determines which of the two crystallographic phases martensite or austenite is present at a certain operating temperature and allows the mechanical properties to be adjusted: martensitic devices are soft and pseudo-plastic due to the shape-memory effect, whereas austenitic structures are pseudo-elastic. In a further step, the SLM process parameters were locally varied within 4Dprinted twin-helixes. As a result, the phases, respectively the mechanical properties of a single component were adjusted at different locations. The ratio of elastic to plastic deformation and the spring constant of the helix can be locally controlled. This allows, for example, the spatio-temporal programming of 3D-printed surgical instruments or implants that are stimuliresponsive.
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Affiliation(s)
- Michael de Wild
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
| | - Sebastian Dany
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
- Hochschule Hamm-Lippstadt, D-59063 Hamm , Germany
| | - Christoph John
- Department of Chemistry, University of Basel, Mattenstrasse 24a, CH-4058 Basel , Switzerland
| | - Felix Schuler
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical Engineering and Medical Informatics IM2, Hofackerstrasse 30, CH-4132 Muttenz , Switzerland
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Rosso C, Weber T, Dietschy A, de Wild M, Müller S. Three anchor concepts for rotator cuff repair in standardized physiological and osteoporotic bone: a biomechanical study. J Shoulder Elbow Surg 2020; 29:e52-e59. [PMID: 31594725 DOI: 10.1016/j.jse.2019.07.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 02/13/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 02/01/2023]
Abstract
BACKGROUND Previous biomechanical studies used single-pull destructive tests in line with the anchor and are limited by a great variability of bone density of cadaver samples. To overcome these limitations, a more physiological test setting was provided using titanium, bioresorbable, and all-suture anchors. METHODS In this controlled laboratory study, 3 anchor constructs were divided into 2 groups: physiological and osteoporotic. Sixty standardized artificial bone specimens (=10 for each anchor in each group) were used for biomechanical testing. The anchors were inserted at a 45° angle as during surgery. Cyclic loading for 1000 cycles followed by ultimate load-to-failure (ULTF) testing was performed. Elongation, ultimate load at failure, and the mode of failure were noted. RESULTS In the physiological group, the ULTF for the all-suture anchor (mean [standard deviation], 632.9 [96.8 N]) was found to be significantly higher than for the other anchors (titanium, 497.1 [50.5] N, and bioresorbable, 322.4 [3.1 N], P < .0001). The titanium anchor showed a significantly higher ULTF than the bioresorbable anchor (P < .0001). In the osteoporotic group, the all-suture anchor again showed a higher ULTF compared to the bioresorbable anchor (500.9 [50.6] N vs. 315.1 [11.3] N, P < .0001). In the osteoporotic group, cyclic loading revealed a higher elongation after 1000 loading cycles for the bioresorbable (0.40 [0.12] mm) compared to the titanium (0.22 [0.11] mm; P = .01) as well as the all-suture anchor (0.19 [0.15] mm, P = .003). CONCLUSION Regarding ULTF, the all-suture anchor outperformed the other anchors in physiological bone, but in osteoporotic bone, significance was reached only compared to the bioresorbable anchor. Although cyclic loading revealed significant differences, these might not be clinically relevant.
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Affiliation(s)
- Claudio Rosso
- ARTHRO Medics, Shoulder and Elbow Center, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - Timo Weber
- University of Basel, Basel, Switzerland; Orthopaedicum Loerrach, Loerrach, Germany
| | - Alain Dietschy
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Michael de Wild
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Sebastian Müller
- University of Basel, Basel, Switzerland; Department of Orthopaedics and Traumatology, University Hospital Basel, Basel, Switzerland
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Müller S, Flury R, Zimmermann S, de Wild M, Fogerty S, Lafosse L, Bongiorno V, Rosso C. The new LassoLoop360° technique for biomechanically superior tissue grip. Knee Surg Sports Traumatol Arthrosc 2019; 27:3962-3969. [PMID: 31254030 DOI: 10.1007/s00167-019-05604-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 06/24/2019] [Indexed: 11/26/2022]
Abstract
PURPOSE Suprapectoral tenodesis is a frequently used technique for treating pathologies of the long head of the biceps brachii (LHBB) tendon. However, so far, no Gold Standard treatment exist. Hence, the arthroscopic LassoLoop360 (LL360) technique is introduced aiming to provide secure fixation and improved biomechanical properties. It was hypothesized, that the LL360 technique would show superior biomechanical response to cyclic loading and ultimate load-to-failure testing compared to the commonly used simple Lasso Loop (SLL). METHODS Twenty-two porcine superficial flexor digitorum tendons were prepared using a No. 2 suture according to either the SLL or the LL360 technique. Displacement after cyclic loading (1.000 cycles) between 5 and 30 N, ultimate load-to-failure (ULTF), mode of failure as well as the construct stiffness were tested. RESULTS Significantly less displacement was found in the LL360 group (SLL 2.25 ± 0.51 mm; LL360 1.67 ± 0.37 mm; p = 0.01). Ultimate Load to Failure was significantly higher in the LL360 (168.6 ± 29.6 N) as compared to the SLL (124.1 ± 25.8 N, p = 0.02). The LL360 also revealed a significant higher stiffness compared to the SLL (SLL 13.1 ± 0.9 N/mm vs. LL360 19.1 ± 1.0 N/mm, p < 0.001). The most common mode of failure was the suture cutting through the tendon, with a significantly less suture cutting through for the LL360 compared with the SLL (p < 0.05). CONCLUSION The LassoLoop360-technique offers superior biomechanical characteristics regarding the tendon-suture-interface compared to the SLL. In the initial healing phase, the suture-tendon-interface is the most vulnerable part of the tendon-suture-anchor construct, the aim of this new technique is to reduce this weakest part of the chain (Ponce et al., Am J Sports Med 39:188-194, 2011). This technique may therefore be beneficial for arthroscopic suprapectoral biceps tenodesis at the entrance of the bicipital groove.
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Affiliation(s)
- Sebastian Müller
- Department of Orthopaedics and Traumatology, University Hospital Basel, Spitalstrasse 21, 4031, Basel, Switzerland.
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland.
| | - Rebekka Flury
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Simon Zimmermann
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland
| | - Michael de Wild
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Gründenstrasse 40, 4132, Muttenz, Switzerland
| | - Simon Fogerty
- Shoulder Clinic Calderdale and Huddersfield NHS Trust, Acre Street, Lindley, Huddersfield, HD3 3EA, UK
| | - Laurent Lafosse
- ALPS Surgery Institute, Clinique Générale, 4 Chemin de la Tour la Reine, 74000, Annecy, France
| | - Vito Bongiorno
- Polyclinique Notre Dame Draguignan, 345 Avenue Pierre Brossolette, 83300, Draguignan, France
| | - Claudio Rosso
- University of Basel, Petersplatz 1, 4003, Basel, Switzerland
- ARTHRO Medics, Shoulder and Elbow Center, Thannerstrasse 45, 4054, Basel, Switzerland
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de Wild M, Zimmermann S, Obrecht M, Dard M. Marker for the pre-clinical development of bone substitute materials. Current Directions in Biomedical Engineering 2017. [DOI: 10.1515/cdbme-2017-0151] [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
AbstractThin mechanically stable Ti-cages have been developed for the in-vivo application as X-ray and histology markers for the optimized evaluation of pre-clinical performance of bone graft materials. A metallic frame defines the region of interest during histological investigations and supports the identification of the defect site. This standardization of the procedure enhances the quality of pre-clinical experiments. Different models of thin metallic frameworks were designed and produced out of titanium by additive manufacturing (Selective Laser Melting). The productibility, the mechanical stability, the handling and suitability of several frame geometries were tested during surgery in artificial and in ex-vivo bone before a series of cages was preclinically investigated in the female Göttingen minipigs model. With our novel approach, a flexible process was established that can be adapted to the requirements of any specific animal model and bone graft testing.
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Affiliation(s)
- Michael de Wild
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
| | - Simon Zimmermann
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
| | - Marcel Obrecht
- Institut Straumann AG, Peter Merian-Weg 12, 4052 Basel, Switzerland
| | - Michel Dard
- Medical Affairs, Institut Straumann AG, Peter Merian-Weg 12, 4052 Basel, Switzerland
- New York University, College of Dentistry, Department of Periodontology and Implant Dentistry, New York, USA
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Abstract
AbstractThe clinical performance of an implant, e.g. for the treatment of large bone defects, depends on the implant material, anchorage, surface topography and chemistry, but also on the mechanical properties, like the stiffness. The latter can be adapted by the porosity. Whereas foams show isotropic mechanical properties, digitally modelled scaffolds can be designed with anisotropic behaviour. In this study, we designed and produced 3D scaffolds based on an orthogonal architecture and studied its angle-dependent stiffness. The aim was to produce scaffolds with different orientations of the microarchitecture by selective laser melting and compare the angle-specific mechanical behaviour with an in-silico simulation. The anisotropic characteristics of open-porous implants and technical limitations of the production process were studied.
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Affiliation(s)
- Jasmine Rüegg
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
| | - Ralf Schumacher
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
| | - Franz E Weber
- Universität Zürich, Zentrum für Zahnmedizin/MKG, Oral Biotechnology & Bioengineering, Plattenstrasse 11, 8032 Zürich, Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
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16
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Vogt N, Wozniak K, Salito A, Wild MD. Biocompatible wear-resistant thick ceramic coating. Current Directions in Biomedical Engineering 2016. [DOI: 10.1515/cdbme-2016-0010] [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
Sensitisation to immunologically active elements like chromium, cobalt or nickel and debris particle due to wear are serious problems for patients with metallic implants. We tested the approach of using a hard and thick ceramic coating as a wear-resistant protection of titanium implants, avoiding those sensitisation and foreign body problems. We showed that the process parameters strongly influence the coating porosity and, as a consequence, also its hardness.
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Affiliation(s)
- Nicola Vogt
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
| | - Katarzyna Wozniak
- Orchid Orthopaedics Switzerland, Täfernstrasse 39, CH-5405 Dättwil AG, Switzerland
| | - Armando Salito
- Orchid Orthopaedics Switzerland, Täfernstrasse 39, CH-5405 Dättwil AG, Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland, FHNW, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, CH-4132 Muttenz, Switzerland
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17
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Harrasser N, Gorkotte J, Obermeier A, Feihl S, Straub M, Slotta-Huspenina J, von Eisenhart-Rothe R, Moser W, Gruner P, de Wild M, Gollwitzer H, Burgkart R. A new model of implant-related osteomyelitis in the metaphysis of rat tibiae. BMC Musculoskelet Disord 2016; 17:152. [PMID: 27060078 PMCID: PMC4826501 DOI: 10.1186/s12891-016-1005-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/31/2016] [Indexed: 11/10/2022] Open
Abstract
Background Animal models serve as an important tool to understand peri-implant infection. Most of the models use high bacterial loads (>104 colony forming units, CFU) to provide high infection rates. Therefore these animals evolve rather similarly, making comparison between groups and statistical analysis possible. On the other hand, to mimic clinical constellation of surgery-related infections the use of low amounts of bacteria would be more advantageous. Methods We developed a metaphyseal rat model of peri-implant bone infection with low amount of bacterial loads (102 and 103 CFU of Staphylococcus aureus) and investigated osseointegration of the implants coated with hydroxyapatite (HA) and low-dosed HA-silver (HA-Ag). Non-infected implants served as controls. After 6 weeks rats were sacrificed and implants evaluated for osseointegration and infection. Results Infection of implanted devices was reliably induced, independently whether 102 or 103 CFU of S. aureus were inoculated and HA or HA-Ag coated implants were used. No systemic infection was present in any of the animals at the time of sacrifice, and no animal developed acute infection requiring premature sacrifice. All CFU counts of the implant and the bone at sacrifice were significantly higher than the inoculated load (p < .05). All sterilely inserted implants showed excellent osseointegration and no infection. Conclusions Our present study of a rat tibia model reliably induced osteomyelitis in the metaphysis with low-doses of bacteria. The addition of low-dosed Ag to the implant coating was not able to reduce the infection rates. The results demonstrate that it is possible to develop a model of implant-related osteomyelitis in rats with low amounts of bacteria to better mimic clinical constellations. No other promoters of infection besides insertion of the screw implant were used in this model.
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Affiliation(s)
- Norbert Harrasser
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.
| | - Johannes Gorkotte
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Andreas Obermeier
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Susanne Feihl
- Institute for Medical Microbiology and Immunology, Technical University of Munich, Trogerstr. 30, 81675, Munich, Germany
| | - Melanie Straub
- Institute of Pathology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Julia Slotta-Huspenina
- Institute of Pathology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Ruediger von Eisenhart-Rothe
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
| | - Walter Moser
- Atesos medical AG, Schachenallee 29, CH-5000, Aarau, Switzerland
| | - Philipp Gruner
- Medicoat AG, Almuesenacherstrasse 2a, CH-5506, Maegenwil, Switzerland
| | - Michael de Wild
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland
| | - Hans Gollwitzer
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany.,ATOS Clinic, Effnerstr.38, 81925, Munich, Germany
| | - Rainer Burgkart
- Clinic of Orthopedics and Sports Orthopedics, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich, Germany
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Wohlfender F, Rüegg J, Vogt N, Marek R, de Wild M. Track E. Bioprinting and Additive Manufacturing. BIOMED ENG-BIOMED TE 2016; 61:30-32. [DOI: 10.1515/bmt-2016-5003] [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] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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de Wild M, Amacher F, Bradbury CR, Molenberg A. Investigation of structural resorption behavior of biphasic bioceramics with help of gravimetry, μCT, SEM, and XRD. J Biomed Mater Res B Appl Biomater 2015; 104:546-53. [PMID: 25952407 DOI: 10.1002/jbm.b.33419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 12/10/2014] [Accepted: 03/04/2015] [Indexed: 11/08/2022]
Abstract
Resorbable bone substitute materials are widely used for bone augmentation after tumor resection, parallel to implant placement, or in critical size bone defects. In this study, the structural dissolution of a biphasic calcium phosphate bone substitute material with a hydroxyapatite (HA)/tricalcium phosphate (β-TCP) ratio of 60/40 was investigated by repeatedly placing porous blocks in EDTA solution at 37 °C. At several time points, the blocks were investigated by SEM, µCT, and gravimetry. It was found that always complete 2-3 µm sized grains were removed from the structure and that the β-TCP is dissolved more rapidly. This selective dissolution of the β-TCP grains was confirmed by XRD measurements. The blocks were eroded from the outside toward the center. The structure remained mechanically stable because the central part showed a delayed degradation and because the slower dissolving HA grains preserved the integrity of the structure.
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Affiliation(s)
- Michael de Wild
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Muttenz, Switzerland
| | - Fabienne Amacher
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Muttenz, Switzerland
| | - Christopher R Bradbury
- EMPA, Materials Technology, EMPA Thun, Switzerland.,Roche Diagnostics International Ltd, Rotkreuz, Switzerland
| | - Aart Molenberg
- Research and Testing, Institut Straumann AG, Basel, Switzerland.,DePuy Synthes, Oberdorf, Switzerland
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Karfeld-Sulzer LS, Ghayor C, Siegenthaler B, de Wild M, Leroux JC, Weber FE. N-methyl pyrrolidone/bone morphogenetic protein-2 double delivery with in situ forming implants. J Control Release 2015; 203:181-8. [PMID: 25697800 DOI: 10.1016/j.jconrel.2015.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 02/09/2015] [Accepted: 02/14/2015] [Indexed: 11/26/2022]
Abstract
Bone morphogenetic proteins (BMPs) are growth and differentiation factors involved during development in morphogenesis, organogenesis and later mainly in regeneration processes, in particular in bone where they are responsible for osteoinduction. For more than a decade, recombinant human (rh)BMP-2 has been used in the clinic for lumbar spinal fusion at non-physiological high dosages that appear to be causative for side effects, like male sterility. A possible strategy to reduce the effective amount of rhBMP-2 in the clinic is the co-delivery with an enhancer of BMPs' activity. In an earlier study, we showed that N-methylpyrrolidone (NMP) enhances BMP activity in vitro and in vivo. Here we report on the development of a slow and sustained double delivery of rhBMP-2 and NMP via an in situ forming implant based on poly(lactide-co-glycolide). The results showed that the release of NMP can be adjusted by varying the lactide/glycolide ratio and the polymer's molecular weight. The same applied to rhBMP-2, with release rates that could be sustained from two to three weeks. In the in vivo model of a critical size defect in the calvarial bone of rabbits, the implant containing 50mol% lactide performed better than the one having 75mol% lactide in terms of defect bridging and extent of bony regenerated area. In situ forming implants for the double delivery of the BMP enhancer NMP and rhBMP-2 appear to be promising delivery systems in bone regeneration.
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Affiliation(s)
- Lindsay S Karfeld-Sulzer
- University Hospital, Division of Cranio-Maxillofacial and Oral Surgery and University of Zurich, Center for Dental Medicine, Oral Biotechnology & Bioengineering, Frauenklinikstrasse 24, 8091 Zürich, Switzerland
| | - Chafik Ghayor
- University Hospital, Division of Cranio-Maxillofacial and Oral Surgery and University of Zurich, Center for Dental Medicine, Oral Biotechnology & Bioengineering, Frauenklinikstrasse 24, 8091 Zürich, Switzerland
| | - Barbara Siegenthaler
- University Hospital, Division of Cranio-Maxillofacial and Oral Surgery and University of Zurich, Center for Dental Medicine, Oral Biotechnology & Bioengineering, Frauenklinikstrasse 24, 8091 Zürich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Muttenz, Switzerland
| | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH, Zurich, Zurich, Switzerland
| | - Franz E Weber
- University Hospital, Division of Cranio-Maxillofacial and Oral Surgery and University of Zurich, Center for Dental Medicine, Oral Biotechnology & Bioengineering, Frauenklinikstrasse 24, 8091 Zürich, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Switzerland; CABMM, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland.
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Hoffmann W, Feliciano S, Martin I, de Wild M, Wendt D. Novel Perfused Compression Bioreactor System as an in vitro Model to Investigate Fracture Healing. Front Bioeng Biotechnol 2015; 3:10. [PMID: 25699254 PMCID: PMC4313709 DOI: 10.3389/fbioe.2015.00010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [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: 11/17/2014] [Accepted: 01/16/2015] [Indexed: 01/08/2023] Open
Abstract
Secondary bone fracture healing is a physiological process that leads to functional tissue regeneration via endochondral bone formation. In vivo studies have demonstrated that early mobilization and the application of mechanical loads enhances the process of fracture healing. However, the influence of specific mechanical stimuli and particular effects during specific phases of fracture healing remain to be elucidated. In this work, we have developed and provided proof-of-concept of an in vitro human organotypic model of physiological loading of a cartilage callus, based on a novel perfused compression bioreactor (PCB) system. We then used the fracture callus model to investigate the regulatory role of dynamic mechanical loading. Our findings provide a proof-of-principle that dynamic mechanical loading applied by the PCB can enhance the maturation process of mesenchymal stromal cells toward late hypertrophic chondrocytes and the mineralization of the deposited extracellular matrix. The PCB provides a promising tool to study fracture healing and for the in vitro assessment of alternative fracture treatments based on engineered tissue grafts or pharmaceutical compounds, allowing for the reduction of animal experiments.
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Affiliation(s)
- Waldemar Hoffmann
- Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland ; School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland , Muttenz , Switzerland
| | - Sandra Feliciano
- Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland
| | - Ivan Martin
- Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland
| | - Michael de Wild
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland , Muttenz , Switzerland
| | - David Wendt
- Department of Biomedicine, University Hospital Basel , Basel , Switzerland ; Department of Surgery, University Hospital Basel , Basel , Switzerland
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Braissant O, Chavanne P, de Wild M, Pieles U, Stevanovic S, Schumacher R, Straumann L, Wirz D, Gruner P, Bachmann A, Bonkat G. Novel microcalorimetric assay for antibacterial activity of implant coatings: The cases of silver-doped hydroxyapatite and calcium hydroxide. J Biomed Mater Res B Appl Biomater 2014; 103:1161-7. [DOI: 10.1002/jbm.b.33294] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 08/18/2014] [Accepted: 09/12/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Olivier Braissant
- Department of Urology; University Hospital Basel; CH-4031 Basel Switzerland
- Laboratory for Biomechanics and Biocalorimetry; Biozentrum - Pharmazentrum, University of Basel; CH-4056 Basel Switzerland
| | - Philippe Chavanne
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Michael de Wild
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Uwe Pieles
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Sabrina Stevanovic
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Ralf Schumacher
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Lukas Straumann
- University of Applied Sciences and Arts Northwestern Switzerland (FHNW); School of Life Sciences; CH-4132 Muttenz Switzerland
| | - Dieter Wirz
- Laboratory for Biomechanics and Biocalorimetry; Biozentrum - Pharmazentrum, University of Basel; CH-4056 Basel Switzerland
- Orthomerian; Gotthelfstrasse 105 4054 Basel Switzerland
| | - Philipp Gruner
- Medicoat AG; Almuesenacherstrasse 2a CH-5506 Mägenwil Switzerland
| | - Alexander Bachmann
- Department of Urology; University Hospital Basel; CH-4031 Basel Switzerland
- Laboratory for Biomechanics and Biocalorimetry; Biozentrum - Pharmazentrum, University of Basel; CH-4056 Basel Switzerland
| | - Gernot Bonkat
- Department of Urology; University Hospital Basel; CH-4031 Basel Switzerland
- Laboratory for Biomechanics and Biocalorimetry; Biozentrum - Pharmazentrum, University of Basel; CH-4056 Basel Switzerland
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Rosso C, Müller S, Buckland DM, Schwenk T, Zimmermann S, de Wild M, Valderrabano V. All-inside meniscal repair devices compared with their matched inside-out vertical mattress suture repair: introducing 10,000 and 100,000 loading cycles. Am J Sports Med 2014; 42:2226-33. [PMID: 24966304 DOI: 10.1177/0363546514538394] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [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] [Indexed: 01/31/2023]
Abstract
BACKGROUND All-inside arthroscopic meniscal repairs are favored by most clinicians because of their lower complication rate and decreased morbidity compared with inside-out techniques. Until now, only 1000 cycles have been used for biomechanical testing. HYPOTHESIS All-inside meniscal repairs will show inferior biomechanical response to cyclic loading (up to 100,000 cycles) and load-to-failure testing compared with inside-out suture controls. STUDY DESIGN Controlled laboratory study. METHODS Bucket-handle tears in 72 porcine menisci were repaired using the Omnispan and Fast-Fix 360 (all-inside devices) and Orthocord 2-0 and Ultrabraid 2-0 sutures (matched controls). Initial displacement, displacement after cyclic loading (100, 500, 1000, 2000, 5000, 10,000, and 100,000 cycles) between 5 and 20 N, ultimate load to failure, and mode of failure were recorded, as well as stiffness. RESULTS Initial displacement and displacement after cyclic loading were not different between the groups. The Omnispan repair demonstrated the highest load-to-failure force (mean ± SD, 151.3 ± 21.5 N) and was significantly stronger than all the other constructs (Orthocord 2-0, 105.5 ± 20.4 N; Ultrabraid 2-0, 93.4 ± 22.5 N; Fast-Fix 360, 76.6 ± 14.2 N) (P < .0001 for all). The Orthocord vertical inside-out mattress repair was significantly stronger than the Fast-Fix 360 repair (P = .003). The Omnispan (30.8 ± 3.5 N/mm) showed significantly higher stiffness compared with the Ultrabraid 2-0 (22.9 ± 6.9 N/mm, P < .0001) and Fast-Fix 360 (23.7 ± 3.9 N/mm, P = .001). The predominant mode of failure was suture failure. CONCLUSION All-inside meniscal devices show comparable biomechanical properties compared with inside-out suture repair in cyclic loading, even after 100,000 cycles. CLINICAL RELEVANCE Eight to 10 weeks of rehabilitation might not pose a problem for all repairs in this worst-case scenario.
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Affiliation(s)
- Claudio Rosso
- Orthopaedic Department, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Sebastian Müller
- Department of Traumatology, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Daniel M Buckland
- Orthopaedic Department, University Hospital Basel, University of Basel, Basel, Switzerland Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Tanja Schwenk
- Orthopaedic Department, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Simon Zimmermann
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Michael de Wild
- School of Life Sciences, Institute for Medical and Analytical Technologies, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
| | - Victor Valderrabano
- Orthopaedic Department, University Hospital Basel, University of Basel, Basel, Switzerland
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Hoffmann W, Bormann T, Rossi A, Müller B, Schumacher R, Martin I, de Wild M, Wendt D. Rapid prototyped porous nickel-titanium scaffolds as bone substitutes. J Tissue Eng 2014; 5:2041731414540674. [PMID: 25383165 PMCID: PMC4221926 DOI: 10.1177/2041731414540674] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [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: 04/07/2014] [Accepted: 05/22/2014] [Indexed: 01/19/2023] Open
Abstract
While calcium phosphate–based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel–titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel–titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel–titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel–titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel–titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel–titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold’s pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel–titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium.
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Affiliation(s)
- Waldemar Hoffmann
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland ; University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - Therese Bormann
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland ; Biomaterials Science Center, University of Basel, Basel, Switzerland
| | - Antonella Rossi
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland ; Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cagliari, Italy
| | - Bert Müller
- Biomaterials Science Center, University of Basel, Basel, Switzerland
| | - Ralf Schumacher
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - Ivan Martin
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - David Wendt
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland
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Bormann T, Schulz G, Deyhle H, Beckmann F, de Wild M, Küffer J, Münch C, Hoffmann W, Müller B. Combining micro computed tomography and three-dimensional registration to evaluate local strains in shape memory scaffolds. Acta Biomater 2014; 10:1024-34. [PMID: 24257506 DOI: 10.1016/j.actbio.2013.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 12/22/2022]
Abstract
Appropriate mechanical stimulation of bony tissue enhances osseointegration of load-bearing implants. Uniaxial compression of porous implants locally results in tensile and compressive strains. Their experimental determination is the objective of this study. Selective laser melting is applied to produce open-porous NiTi scaffolds of cubic units. To measure displacement and strain fields within the compressed scaffold, the authors took advantage of synchrotron radiation-based micro computed tomography during temperature increase and non-rigid three-dimensional data registration. Uniaxial scaffold compression of 6% led to local compressive and tensile strains of up to 15%. The experiments validate modeling by means of the finite element method. Increasing the temperature during the tomography experiment from 15 to 37°C at a rate of 4 K h(-1), one can locally identify the phase transition from martensite to austenite. It starts at ≈ 24°C on the scaffolds bottom, proceeds up towards the top and terminates at ≈ 34°C on the periphery of the scaffold. The results allow not only design optimization of the scaffold architecture, but also estimation of maximal displacements before cracks are initiated and of optimized mechanical stimuli around porous metallic load-bearing implants within the physiological temperature range.
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Affiliation(s)
- Therese Bormann
- Biomaterials Science Center, University of Basel, c/o University Hospital Basel, 4031 Basel, Switzerland; Institute for Medical and Analytical Technologies, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, 4032 Muttenz, Switzerland
| | - Georg Schulz
- Biomaterials Science Center, University of Basel, c/o University Hospital Basel, 4031 Basel, Switzerland
| | - Hans Deyhle
- Biomaterials Science Center, University of Basel, c/o University Hospital Basel, 4031 Basel, Switzerland
| | - Felix Beckmann
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht, Germany
| | - Michael de Wild
- Institute for Medical and Analytical Technologies, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, 4032 Muttenz, Switzerland
| | - Jürg Küffer
- Institute of Product and Production Engineering, School of Engineering, University of Applied Sciences and Arts Northwestern Switzerland, 5210 Windisch, Switzerland
| | - Christoph Münch
- Institute of Product and Production Engineering, School of Engineering, University of Applied Sciences and Arts Northwestern Switzerland, 5210 Windisch, Switzerland
| | - Waldemar Hoffmann
- Institute for Medical and Analytical Technologies, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, 4032 Muttenz, Switzerland
| | - Bert Müller
- Biomaterials Science Center, University of Basel, c/o University Hospital Basel, 4031 Basel, Switzerland.
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de Wild M, Schumacher R, Mayer K, Schkommodau E, Thoma D, Bredell M, Kruse Gujer A, Grätz KW, Weber FE. Bone regeneration by the osteoconductivity of porous titanium implants manufactured by selective laser melting: a histological and micro computed tomography study in the rabbit. Tissue Eng Part A 2013; 19:2645-54. [PMID: 23895118 DOI: 10.1089/ten.tea.2012.0753] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The treatment of large bone defects still poses a major challenge in orthopaedic and cranio-maxillofacial surgery. One possible solution could be the development of personalized porous titanium-based implants that are designed to meet all mechanical needs with a minimum amount of titanium and maximum osteopromotive properties so that it could be combined with growth factor-loaded hydrogels or cell constructs to realize advanced bone tissue engineering strategies. Such implants could prove useful for mandibular reconstruction, spinal fusion, the treatment of extended long bone defects, or to fill in gaps created on autograft harvesting. The aim of this study was to determine the mechanical properties and potential of bone formation of light weight implants generated by selective laser melting (SLM). We mainly focused on osteoconduction, as this is a key feature in bone healing and could serve as a back-up for osteoinduction and cell transplantation strategies. To that end, defined implants were produced by SLM, and their surfaces were left untreated, sandblasted, or sandblasted/acid etched. In vivo bone formation with the different implants was tested throughout calvarial defects in rabbits and compared with untreated defects. Analysis by micro computed tomography (μCT) and histomorphometry revealed that all generatively produced porous Ti structures were well osseointegrated into the surrounding bone. The histomorphometric analysis revealed that bone formation was significantly increased in all implant-treated groups compared with untreated defects and significantly increased in sand blasted implants compared with untreated ones. Bone bridging was significantly increased in sand blasted acid-etched scaffolds. Therefore, scaffolds manufactured by SLM should be surface treated. Bone augmentation beyond the original bone margins was only seen in implant-treated defects, indicating an osteoconductive potential of the implants that could be utilized clinically for bone augmentation purposes. Therefore, designed porous, lightweight structures have potential for bone regeneration and augmentation purposes, especially when complex and patient-specific geometries are essential.
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Affiliation(s)
- Michael de Wild
- 1 Institute for Medical and Analytical Technologies, School of Life Sciences, University of Applied Sciences Northwestern Switzerland , Muttenz, Switzerland
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Hofstetter W, Sehr H, Wild MD, Portenier J, Gobrecht J, Hunziker EB. Modulation of human osteoblasts by metal surface chemistry. J Biomed Mater Res A 2013; 101:2355-64. [DOI: 10.1002/jbm.a.34541] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 11/09/2012] [Accepted: 11/14/2012] [Indexed: 01/16/2023]
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Schuler M, Hamilton DW, Kunzler TP, Sprecher CM, de Wild M, Brunette DM, Textor M, Tosatti SGP. Comparison of the response of cultured osteoblasts and osteoblasts outgrown from rat calvarial bone chips to nonfouling KRSR and FHRRIKA-peptide modified rough titanium surfaces. J Biomed Mater Res B Appl Biomater 2009; 91:517-527. [PMID: 19582855 DOI: 10.1002/jbm.b.31425] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mimicking proteins found in the extracellular matrix (ECM) using specific peptide sequences is a well-known strategy for the design of biomimetic surfaces, but has not yet been widely exploited in the field of biomedical implants. This study investigated osteoblast and, as a control, fibroblast proliferation to novel consensus heparin-binding peptides sequences KRSR and FHRIKKA that were immobilized onto rough (particle-blasted and chemically etched) commercially pure titanium surfaces using a poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) molecular assembly system. This platform enabled a detailed study of specific cell-peptide interactions even in the presence of serum in the culture medium; thanks to the excellent nonfouling properties of the PLL-g-PEG surface. Cell-binding peptide sequence RGD in combination with KRSR or FHRRIKA was used to examine a potentially-enhanced or synergistic effect on osteoblast proliferation. Bare titanium and bioinactive surfaces (i.e., unfunctionalized PLL-g-PEG and scrambled KSSR, RFHARIK, and RDG) were used as control substrates. Additionally, in a newly developed experimental setup, freshly harvested bone chips from newborn rat calvariae were placed onto the same type of surfaces investigating size and pattern of osteoblast outgrowths. The findings of the current study demonstrated that the difference in osteoblast and fibroblast proliferation was influenced by surface topography more so than by the presence of surface-bound KRSR and FHRRIKA. On the other hand, in comparison with the control surfaces, osteoblast outgrowths from rat calvarial bone chips covered a significantly larger area on RGD, KRSR, and FHRRIKA surfaces after 8 days and also migrated in an isotropic way unlike cells on the bioinactive substrates. Furthermore, the stimulatory effect of 0.75 pmol cm(-2) RGD on osteoblast migration pattern could be enhanced when applied in combination with 2.25 pmol cm(-2) KRSR.
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Affiliation(s)
- Martin Schuler
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.,Institut Straumann AG, 4052 Basel, Switzerland
| | - Douglas W Hamilton
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Tobias P Kunzler
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | | | | | - Donald M Brunette
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Marcus Textor
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
| | - Samuele G P Tosatti
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
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Schuler M, Kunzler TP, de Wild M, Sprecher CM, Trentin D, Brunette DM, Textor M, Tosatti SGP. Fabrication of TiO2-coated epoxy replicas with identical dual-type surface topographies used in cell culture assays. J Biomed Mater Res A 2009; 88:12-22. [DOI: 10.1002/jbm.a.31720] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Schuler M, Owen GR, Hamilton DW, de Wild M, Textor M, Brunette DM, Tosatti SGP. Biomimetic modification of titanium dental implant model surfaces using the RGDSP-peptide sequence: a cell morphology study. Biomaterials 2006; 27:4003-15. [PMID: 16574219 DOI: 10.1016/j.biomaterials.2006.03.009] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Accepted: 03/09/2006] [Indexed: 10/24/2022]
Abstract
Surface topography and (bio)chemistry are key factors in determining cell response to an implant. We investigated cell adhesion and spreading patterns of epithelial cells, fibroblasts and osteoblasts on biomimetically modified, smooth and rough titanium surfaces. The RGD bioactive peptide sequence was immobilized via a non-fouling poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) molecular assembly system, which allowed exploitation of specific cell-peptide interactions even in the presence of serum. As control surfaces, bare titanium and bio-inactive surfaces (scrambled RDG and unfunctionalized PLL-g-PEG) were used. Our findings demonstrated that surface topography and chemistry directly influenced the attachment and morphology of all cell types tested. In general, an increase in cell number and more spread cells were observed on bioactive substrates (containing RGD) compared to bio-inactive surfaces. More fibroblasts were present on smooth than on rough topographies, whereas for osteoblasts the opposite tendency was observed. Epithelial cell attachment did not follow any regular pattern. Footprint areas for all cell types were significantly reduced on rough compared to smooth surfaces. Osteoblast attachment and footprint areas increased with increasing RGD-peptide surface density. However, no synergy (interaction) between RGD-peptide surface density and surface topography was observed for osteoblasts neither in terms of attachment nor footprint area.
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Affiliation(s)
- Martin Schuler
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
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Bonifazi D, Spillmann H, Kiebele A, de Wild M, Seiler P, Cheng F, Güntherodt HJ, Jung T, Diederich F. Supramolecular Patterned Surfaces Driven by Cooperative Assembly of C60 and Porphyrins on Metal Substrates. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200460562] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bonifazi D, Spillmann H, Kiebele A, de Wild M, Seiler P, Cheng F, Güntherodt HJ, Jung T, Diederich F. Supramolecular Patterned Surfaces Driven by Cooperative Assembly of C60 and Porphyrins on Metal Substrates. Angew Chem Int Ed Engl 2004; 43:4759-63. [PMID: 15366079 DOI: 10.1002/anie.200460562] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Davide Bonifazi
- Laboratorium für Organische Chemie, ETH-Hönggerberg, HCI, 8093 Zürich, Switzerland
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Affiliation(s)
- Michael de Wild
- National Center of Competence in Research on Nanoscale Science, Department of Physics and Astronomy, Universität Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
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de Wild M, Berner S, Suzuki H, Ramoino L, Baratoff A, Jung TA. Molecular Assembly and Self-Assembly: Molecular Nanoscience for Future Technologies. Chimia (Aarau) 2002. [DOI: 10.2533/000942902777680162] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
OBJECTIVE Our purpose was to investigate intrauterine insemination pregnancy rates after human spermatozoa exposure to platelet-activating factor. STUDY DESIGN Spermatozoa were incubated with platelet-activating factor in sperm-washing medium before intrauterine insemination. Patients whose sperm were incubated with sperm-washing medium alone served as controls. Pregnancy outcome was determined by ultrasonography (fetal heartbeat). RESULTS Patients whose sperm were treated with exogenous platelet-activating factor had a significantly (P <.05) higher pregnancy rate (40%) than patients (20%) not receiving treatment. CONCLUSION Inclusion of platelet-activating factor into a semen processing protocol, before intrauterine insemination, will significantly improve pregnancy rates. Platelet-activating factor may have a stimulatory effect on centriole-intact spermatozoa, enhancing their motility and fertilization success and resulting in improved pregnancy rates. Additional studies will elucidate the reproductive significance of platelet-activating factor activity in spermatozoa and its role in the establishment of pregnancy.
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Affiliation(s)
- M D Wild
- Medical University of South Carolina, Charleston, USA
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Roudebush WE, Wild MD, Maguire EH. Expression of the platelet-activating factor receptor in human spermatozoa: differences in messenger ribonucleic acid content and protein distribution between normal and abnormal spermatozoa. Fertil Steril 2000; 73:967-71. [PMID: 10785222 DOI: 10.1016/s0015-0282(00)00485-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To determine the expression and distribution of the platelet-activating factor (PAF) receptor in normal and abnormal specimens of human spermatozoa. DESIGN Prospective analysis of membrane-bound PAF receptors by immunofluorescence and PAF receptor messenger RNA by quantitated reverse transcription-polymerase chain reaction in normal and abnormal spermatozoa. SETTING University-based reproductive genetics laboratory. PATIENT(S) Men undergoing routine semen analysis. INTERVENTION(S) Normal and abnormal spermatozoa were exposed to rabbit anti-PAF receptor antibody, fluorescein isothiocyanate-conjugated goat anti-rabbit antibody, and fluorescent microscopy or subjected to RNA isolation by acid-phenol extraction and quantitated (MIMIC Construction Kit [Clontech Laboratories, Inc., Palo Alto, CA]) reverse transcription-polymerase chain reaction. MAIN OUTCOME MEASURE(S) Fluorescent intensities at six locations along spermatozoa (end piece, principal tail, midpiece, neck, proximal head, and acrosomal region) and PAF receptor expression (messenger RNA) levels. RESULT(S) Immunofluorescence demonstrated a significant difference in PAF receptor distribution between normal and abnormal human spermatozoa, specifically at the neck region. Additionally, abnormal spermatozoa were found to have statistically significantly more PAF receptor messenger RNA than normal spermatozoa. CONCLUSION(S) Platelet-activating factor receptor expression and distribution are significantly altered in abnormal spermatozoa and this may be the result of some defect in gene transcription.
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Affiliation(s)
- W E Roudebush
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina, USA.
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Abstract
OBJECTIVE Our purpose was to determine whether there are any differences in total ribonucleic acid content between normal and abnormal human spermatozoa. STUDY DESIGN Spermatozoa were obtained from men undergoing routine semen analysis at a university-based reproductive genetics laboratory. Specimens were classified as normal or abnormal according to World Health Organization criteria. Total ribonucleic acid was removed by acid-phenol extraction, and ribonucleic acid expression levels were determined by spectrophotometric analysis. RESULTS Abnormal spermatozoa were found to have significantly more ribonucleic acid (0.14 +/- 0.02 mg/10(6) spermatozoa) than normal spermatozoa (0.05 +/- 0.01 mg/10(6) spermatozoa; P <.001). CONCLUSION Ribonucleic acid content is significantly altered in abnormal spermatozoa, and this alteration may be the result of some defect in the posttranscriptional pathway.
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Affiliation(s)
- M D Wild
- Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston 29425, USA
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39
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Abstract
Little is known about the cellular distribution of paclitaxel in humans. In the present study we examined the distribution of [3H]-paclitaxel in human blood. When 1 microM paclitaxel was incubated with fresh blood at 37 degrees C, the platelet/plasma concentration ratio was 240 +/- 17 (mean +/- SEM), whereas the red blood cell (RBC)/plasma concentration ratio was only 0.59 +/- 0.05. In kinetics experiments using platelet-rich plasma, we observed that the platelet accumulation of paclitaxel was highly temperature- and concentration-dependent. Scatchard analysis of the 37 degrees C uptake data demonstrated a dissociation constant (Kapp) of 0.80 +/- 0.10 microM and a maximal binding capacity of 672 +/- 102 pmol/10(9) platelets. It is proposed that the platelet accumulation of paclitaxel reflects binding to microtubules and may serve as a useful model for binding to less accessible cellular sites.
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Affiliation(s)
- M D Wild
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston 29425, USA
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