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Tissue Integration and Biological Cellular Response of SLM-Manufactured Titanium Scaffolds. METALS 2020. [DOI: 10.3390/met10091192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background: SLM (Selective Laser Melting)–manufactured Titanium (Ti) scaffolds have a significant value for bone reconstructions in the oral and maxillofacial surgery field. While their mechanical properties and biocompatibility have been analysed, there is still no adequate information regarding tissue integration. Therefore, the aim of this study is a comprehensive systematic assessment of the essential parameters (porosity, pore dimension, surface treatment, shape) required to provide the long-term performance of Ti SLM medical implants. Materials and methods: A systematic literature search was conducted via electronic databases PubMed, Medline and Cochrane, using a selection of relevant search MeSH terms. The literature review was conducted using the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Results: Within the total of 11 in vitro design studies, 9 in vivo studies, and 4 that had both in vitro and in vivo designs, the results indicated that SLM-generated Ti scaffolds presented no cytotoxicity, their tissue integration being assured by pore dimensions of 400 to 600 µm, high porosity (75–88%), hydroxyapatite or SiO2–TiO2 coating, and bioactive treatment. The shape of the scaffold did not seem to have significant importance. Conclusions: The SLM technique used to fabricate the implants offers exceptional control over the structure of the base. It is anticipated that with this technique, and a better understanding of the physical interaction between the scaffold and bone tissue, porous bases can be tailored to optimize the graft’s integrative and mechanical properties in order to obtain structures able to sustain osseous tissue on Ti.
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52
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Zheng Y, Han Q, Wang J, Li D, Song Z, Yu J. Promotion of Osseointegration between Implant and Bone Interface by Titanium Alloy Porous Scaffolds Prepared by 3D Printing. ACS Biomater Sci Eng 2020; 6:5181-5190. [PMID: 33455268 DOI: 10.1021/acsbiomaterials.0c00662] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Titanium alloy prostheses have been widely used for the treatment of orthopedic diseases, in which the interconnected porosity and appropriate pore size are crucial for the osseointegration capacity. Three-dimensional (3D) printing technology provides an efficient method to construct prosthesis scaffolds with controllable internal and surface structure, but printing high-porosity (>60%) scaffolds with pore diameters below 300 μm as implants structures has not yet been studied. In this work, four types of titanium alloy scaffolds with interconnected porosity more than 70% were successfully prepared by selective laser melting (SLM). The actual mean pore sizes of cylindrical scaffolds are 542, 366, 202, and 134 μm. Through the in vitro characterization of the scaffolds, in vivo experiments, and mechanical experiments, it is concluded that as the scaffold pore diameter decreases, the titanium alloy scaffold with diameter of 202 μm has the strongest osseointegration ability and is also the most stable one with the surrounding bone. These findings provide a reference for the clinical pore-size design of porous scaffolds with optimal bone growth stability on the surface of the titanium alloy implant.
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Affiliation(s)
- Yuhao Zheng
- Department of Sports Medicine, First Hospital of Jilin University, Changchun 130021, P. R. China.,State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.,International Center of Future Science, Jilin University, Changchun 130012, P. R. China
| | - Qing Han
- Department of Joint Surgery, Orthopedic Medical Center, Second Hospital of Jilin University, Changchun 130000, P. R. China
| | - Jincheng Wang
- Department of Joint Surgery, Orthopedic Medical Center, Second Hospital of Jilin University, Changchun 130000, P. R. China
| | - Dongdong Li
- Key Laboratory of Automobile Materials of MOE, Department of Materials Science and Engineering, Jilin University, Changchun 130012, P. R. China
| | - Zhiming Song
- Department of Sports Medicine, First Hospital of Jilin University, Changchun 130021, P. R. China
| | - Jihong Yu
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.,International Center of Future Science, Jilin University, Changchun 130012, P. R. China
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53
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Additively Manufactured Continuous Cell-Size Gradient Porous Scaffolds: Pore Characteristics, Mechanical Properties and Biological Responses In Vitro. MATERIALS 2020; 13:ma13112589. [PMID: 32517161 PMCID: PMC7321598 DOI: 10.3390/ma13112589] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/30/2020] [Accepted: 06/04/2020] [Indexed: 12/17/2022]
Abstract
Porous scaffolds with graded open porosity combining a morphology similar to that of bone with mechanical and biological properties are becoming an attractive candidate for bone grafts. In this work, scaffolds with a continuous cell-size gradient were studied from the aspects of pore properties, mechanical properties and bio-functional properties. Using a mathematical method named triply periodic minimal surfaces (TPMS), uniform and graded scaffolds with Gyroid and Diamond units were manufactured by selective laser melting (SLM) with Ti-6Al-4V, followed by micro-computer tomography (CT) reconstruction, mechanical testing and in vitro evaluation. It was found that gradient scaffolds were preferably replicated by SLM with continuous graded changes in surface area and pore size, but their pore size should be designed to be ≥ 450 μm to ensure good interconnectivity. Both the Gyroid and Diamond structures have superior strength compared to cancellous bones, and their elastic modulus is comparable to the bones. In comparison, Gyroid exhibits better performances than Diamond in terms of the elastic modulus, ultimate strength and ductility. In vitro cell culture experiments show that the gradients provide an ideal growth environment for osteoblast growth in which cells survive well and distribute uniformly due to biocompatibility of the Ti-6Al-4V material, interconnectivity and suitable pore size.
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54
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Mehrian M, Lambrechts T, Papantoniou I, Geris L. Computational Modeling of Human Mesenchymal Stromal Cell Proliferation and Extra-Cellular Matrix Production in 3D Porous Scaffolds in a Perfusion Bioreactor: The Effect of Growth Factors. Front Bioeng Biotechnol 2020; 8:376. [PMID: 32411692 PMCID: PMC7201129 DOI: 10.3389/fbioe.2020.00376] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 04/06/2020] [Indexed: 01/20/2023] Open
Abstract
Stem cell expansion on 3D porous scaffolds cultured in bioreactor systems has been shown to be beneficial for maintenance of the original cell functionality in tissue engineering strategies (TE). However, the production of extracellular matrix (ECM) makes harvesting the progenitor cell population from 3D scaffolds a challenge. Medium composition plays a role in stimulating cell proliferation over extracellular matrix (ECM) production. In this regard, a computational model describing tissue growth inside 3D scaffolds can be a great tool in designing optimal experimental conditions. In this study, a computational model describing cell and ECM growth in a perfusion bioreactor is developed, including a description of the effect of a (generic) growth factor on the biological processes taking place inside the 3D scaffold. In the model, the speed of cell and ECM growth depends on the flow-induced shear stress, curvature and the concentrations of oxygen, glucose, lactate, and growth factor. The effect of the simulated growth factor is to differentially enhance cell proliferation over ECM production. After model calibration with historic in-house data, a multi-objective optimization procedure is executed aiming to minimize the total experimental cost whilst maximizing cell growth during culture. The obtained results indicate there are multiple optimum points for the medium refreshment regime and the initial growth factor concentration where a trade-off is made between the final amount of cells and the culture cost. Finally, the model is applied to experiments reported in the literature studying the effects of perfusion-based cell culture and/or growth factor supplementation on cell expansion. The qualitative similarities between the simulation and experimental results, even in the absence of proper model calibration, reinforces the generic character of the proposed modeling framework. The model proposed in this study can contribute to the cost efficient production of cell-based TE products, ultimately contributing to their affordability and accessibility.
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Affiliation(s)
- Mohammad Mehrian
- Biomechanics Research Unit, GIGA In silico Medicine, University of Liège, Liège, Belgium.,Prometheus, The Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Toon Lambrechts
- Prometheus, The Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.,M3-BIORES, KU Leuven, Leuven, Belgium
| | - Ioannis Papantoniou
- Prometheus, The Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.,Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium.,Institute of Chemical Engineering Sciences (ICEHT), Foundation for Research and Technology - Hellas (FORTH), Patras, Greece
| | - Liesbet Geris
- Biomechanics Research Unit, GIGA In silico Medicine, University of Liège, Liège, Belgium.,Prometheus, The Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium.,Biomechanics Section, KU Leuven, Leuven, Belgium
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55
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Razzi F, Fratila-Apachitei LE, Fahy N, Bastiaansen-Jenniskens YM, Apachitei I, Farrell E, Zadpoor AA. Immunomodulation of surface biofunctionalized 3D printed porous titanium implants. ACTA ACUST UNITED AC 2020; 15:035017. [PMID: 32069447 DOI: 10.1088/1748-605x/ab7763] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Additive manufacturing (AM) techniques have provided many opportunities for the rational design of porous metallic biomaterials with complex and precisely controlled topologies that give rise to unprecedented combinations of mechanical, physical, and biological properties. These favorable properties can be enhanced by surface biofunctionalization to enable full tissue regeneration and minimize the risk of implant-associated infections (IAIs). There is, however, an increasing need to investigate the immune responses triggered by surface biofunctionalized AM porous metals. Here, we studied the immunomodulatory effects of AM porous titanium (Ti-6Al-4V) printed using selective laser melting, and of two additional groups consisting of AM implants surface biofunctionalized using plasma electrolytic oxidation (PEO) with/without silver nanoparticles. The responses of human primary macrophages and human mesenchymal stromal cells (hMSCs) were studied in terms of cell viability, cell morphology and biomarkers of macrophage polarization. Non-treated AM porous titanium triggered a strong pro-inflammatory response in macrophages, albeit combined with signs of anti-inflammatory effects. The PEO treatment of AM porous titanium implants showed a higher potential to induce polarization towards a pro-repair macrophage phenotype. We detected no cytotoxicity against hMSCs in any of the groups. However, the incorporation of silver nanoparticles resulted in strong cytotoxicity against attached macrophages. The results of this study indicate the potential immunomodulatory effects of the AM porous titanium enhanced with PEO treatment, and point towards caution and further research when using silver nanoparticles for preventing IAIs.
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Affiliation(s)
- F Razzi
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD, Delft, The Netherlands. Department of Oral and Maxillofacial Surgery, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands
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56
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Koolen M, Amin Yavari S, Lietaert K, Wauthle R, Zadpoor AA, Weinans H. Bone Regeneration in Critical-Sized Bone Defects Treated with Additively Manufactured Porous Metallic Biomaterials: The Effects of Inelastic Mechanical Properties. MATERIALS 2020; 13:ma13081992. [PMID: 32344664 PMCID: PMC7215733 DOI: 10.3390/ma13081992] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 02/05/2023]
Abstract
Additively manufactured (AM) porous metallic biomaterials, in general, and AM porous titanium, in particular, have recently emerged as promising candidates for bone substitution. The porous design of such materials allows for mimicking the elastic mechanical properties of native bone tissue and showed to be effective in improving bone regeneration. It is, however, not clear what role the other mechanical properties of the bulk material such as ductility play in the performance of such biomaterials. In this study, we compared the bone tissue regeneration performance of AM porous biomaterials made from the commonly used titanium alloy Ti6Al4V-ELI with that of commercially pure titanium (CP-Ti). CP-Ti was selected because of its high ductility as compared to Ti6Al4V-ELI. Critical-sized (6 mm diameter) femoral defects in rats were treated with implants made from both Ti6Al4V-ELI and CP-Ti. Bone regeneration was assessed up to 11 weeks using micro-CT scanning. The regenerated bone volume was assessed ex vivo followed by histology and biomechanical testing to assess osseointegration of the implants. The bony defects treated with AM CP-Ti implants generally showed higher volumes of regenerated bone as compared to those treated with AM Ti6Al4V-ELI. The torsional strength of the two titanium groups were similar however, and both considerably lower than those measured for intact bony tissue. These findings show the importance of material type and ductility of the bulk material in the ability for bone tissue regeneration of AM porous biomaterials.
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Affiliation(s)
- Marianne Koolen
- Department of Orthopaedics, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands
| | - Saber Amin Yavari
- Department of Orthopaedics, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands
| | - Karel Lietaert
- 3D Systems Healthcare, 3D Systems Leuven, 3001 Leuven, Belgium
| | - Ruben Wauthle
- 3D Systems Healthcare, 3D Systems Leuven, 3001 Leuven, Belgium
| | - Amir A Zadpoor
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CN Delft, The Netherlands
| | - Harrie Weinans
- Department of Orthopaedics, University Medical Centre Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CN Delft, The Netherlands
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57
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Effects of Surface Topography and Chemistry on Polyether-Ether-Ketone (PEEK) and Titanium Osseointegration. Spine (Phila Pa 1976) 2020; 45:E417-E424. [PMID: 31703050 DOI: 10.1097/brs.0000000000003303] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An in vivo study examining the functional osseointegration of smooth, rough, and porous surface topographies presenting polyether-ether-ketone (PEEK) or titanium surface chemistry. OBJECTIVE To investigate the effects of surface topography and surface chemistry on implant osseointegration. SUMMARY OF BACKGROUND DATA Interbody fusion devices have been used for decades to facilitate fusion across the disc space, yet debate continues over their optimal surface topography and chemistry. Though both factors influence osseointegration, the relative effects of each are not fully understood. METHODS Smooth, rough, and porous implants presenting either a PEEK or titanium surface chemistry were implanted into the proximal tibial metaphyses of 36 skeletally mature male Sprague Dawley rats. At 8 weeks, animals were euthanized and bone-implant interfaces were subjected to micro-computed tomography analysis (n = 12), histology (n = 4), and biomechanical pullout testing (n = 8) to assess functional osseointegration and implant fixation. RESULTS Micro-computed tomography analysis demonstrated that bone ingrowth was 38.9 ± 2.8% for porous PEEK and 30.7 ± 3.3% for porous titanium (P = 0.07). No differences in fixation strength were detected between porous PEEK and porous titanium despite titanium surfaces exhibiting an overall increase in bone-implant contact compared with PEEK (P < 0.01). Porous surfaces exhibited increased fixation strength compared with smooth and rough surfaces regardless of surface chemistry (P < 0.05). Across all groups both surface topography and chemistry had a significant overall effect on fixation strength (P < 0.05), but topography accounted for 65.3% of the total variance (ω = 0.65), whereas surface chemistry accounted for 5.9% (ω = 0.06). CONCLUSIONS The effect of surface topography (specifically porosity) dominated the effect of surface chemistry in this study and could lead to further improvements in orthopedic device design. The poor osseointegration of existing smooth PEEK implants may be linked more to their smooth surface topography rather than their material composition. LEVEL OF EVIDENCE N/A.
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58
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Zhao D, Tang F, Min L, Lu M, Wang J, Zhang Y, Zhao K, Zhou Y, Luo Y, Tu C. Intercalary Reconstruction of the "Ultra-Critical Sized Bone Defect" by 3D-Printed Porous Prosthesis After Resection of Tibial Malignant Tumor. Cancer Manag Res 2020; 12:2503-2512. [PMID: 32308487 PMCID: PMC7152541 DOI: 10.2147/cmar.s245949] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/13/2020] [Indexed: 02/05/2023] Open
Abstract
Purpose This study aimed to evaluate the early stability, limb function, and mechanical complications of 3D-printed porous prosthetic reconstruction for "ultra-critical sized bone defects" following intercalary tibial tumor resections. Methods This study defined an "ultra-critical sized bone defect" in the tibia when the length of segmental defect in the tibia was >15.0 cm or >60% of the full tibia and the length of the residual fragment in proximal or distal tibia was between 0.5 cm and 4.0 cm. Thus, five patients with "ultra-critical sized bone defects" following an intercalary tibial malignant tumor resection treated with 3D-printed porous prosthesis between June 2014 and June 2018 were retrospectively reviewed. Patient information, implants design and fabrication, surgical procedures, and early clinical outcome data were collected and evaluated. Results Among the five patients, three were male and two were female, with an average age of 30.2 years. Pathological diagnoses were two osteosarcomas, one Ewing sarcoma, one pseudo-myogenic hemangioendothelioma, and one undifferentiated pleomorphic sarcoma . The average length of the bone defects following tumor resection was 22.8cm, and the average length of ultra-short residual bone was 2.65cm (range=0.6cm-3.8cm). The mean follow-up time was 27.6 months (range=14.0-62.0 months). Early biological fixation was achieved in all five patients. The average time of clinical osseointegration at the bone-porous interface was 3.2 months. All patients were reported to be pain free and have no limitations in their walking distance. No prosthetic mechanical complications were observed. Conclusion Reconstruction of the "ultra-critical sized bone defect" after an intercalary tibial tumor resection using 3D-printed porous prosthesis achieved satisfactory overall early biological fixation and limb function. Excellent primary stability and the following rigid biological fixation were key factors for success. The outcomes of this study were supposed to support further clinical application and evaluation of 3D-printed porous prosthetic reconstruction for "ultra-critical sized bone defects" in the tibia.
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Affiliation(s)
- Dingyun Zhao
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Fan Tang
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Li Min
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Minxun Lu
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Jie Wang
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Yuqi Zhang
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Kun Zhao
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China.,Department of Orthopeadics, Tianjin Fifth Central Hospital, Tianjin 300450, People's Republic of China
| | - Yong Zhou
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Yi Luo
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
| | - Chongqi Tu
- Department of Orthopeadics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, People's Republic of China
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Shimizu Y, Fujibayashi S, Yamaguchi S, Mori S, Kitagaki H, Shimizu T, Okuzu Y, Masamoto K, Goto K, Otsuki B, Kawai T, Morizane K, Kawata T, Matsuda S. Bioactive effects of strontium loading on micro/nano surface Ti6Al4V components fabricated by selective laser melting. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 109:110519. [PMID: 32228917 DOI: 10.1016/j.msec.2019.110519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/27/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022]
Abstract
Selective laser melting (SLM) titanium alloys require surface modification to achieve early bone-bonding. This study investigated the effects of solution and heat treatment to induce the sustained release of strontium (Sr) ions from SLM Ti6Al4V implants (Sr-S64). The results were compared with a control group comprising an untreated surface [SLM pure titanium (STi) and SLM Ti6Al4V (S64)] and a treated surface to induce the release of calcium (Ca) ions from SLM Ti6Al4V (Ca-S64). The surface-treated materials showed homogenous nanoscale network formation on the original micro-topographical surface and formed bone-like apatite on the surface in a simulated body fluid within 3 days. In vitro evaluation using MC3T3-E1 cells showed that the cells were viable on Sr-S64 surface, and Sr-S64 enhanced cell adhesion-related and osteogenic differentiation-related genes expression. In vivo rabbit tibia model, Sr-S64 provided significantly greater bone-bonding strength and bone-implant contact area than those in controls (STi and S64) in the early phase (2-4 weeks) after implantation; however, there was no statistical difference between Ca-S64 and controls. In conclusion, Sr solution and heat treatment was a safe and effective method to enhance early bone-bonding ability of S-64 by improving the surface characteristics and sustained delivery for Sr.
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Affiliation(s)
- Yu Shimizu
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
| | - Shunsuke Fujibayashi
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Seiji Yamaguchi
- Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan
| | - Shigeo Mori
- Osaka Yakin Kogyo Co., Ltd., 4-4-28 Zuiko, Higashiyodogawa-ku, Osaka 533-0005, Japan
| | - Hisashi Kitagaki
- Osaka Yakin Kogyo Co., Ltd., 4-4-28 Zuiko, Higashiyodogawa-ku, Osaka 533-0005, Japan
| | - Takayoshi Shimizu
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yaichiro Okuzu
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kazutaka Masamoto
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Koji Goto
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Bungo Otsuki
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Toshiyuki Kawai
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kazuaki Morizane
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Tomotoshi Kawata
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Shuichi Matsuda
- Department of Orthopaedic Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan
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60
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Hayashi K, Munar ML, Ishikawa K. Effects of macropore size in carbonate apatite honeycomb scaffolds on bone regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 111:110848. [PMID: 32279778 DOI: 10.1016/j.msec.2020.110848] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 02/13/2020] [Accepted: 03/12/2020] [Indexed: 01/23/2023]
Abstract
The pore architecture of scaffolds is a critical factor for angiogenesis and bone regeneration. Although the effects of scaffold macropore size have been investigated, most scaffolds feature macropores with poor uniformity and interconnectivity, and other parameters (e.g., microporosity, chemical composition, and strut thickness) differ among scaffolds. To clarify the threshold of effective macropore size, we fabricated honeycomb scaffolds (HCSs) with distinct macropore (i.e., channel) sizes (~100, ~200, and ~300 μm). The HCSs were composed of AB-type carbonate apatite with ~8.5% carbonate ions, i.e., the same composition as human bone mineral. Their honeycomb architecture displayed uniformly sized and orderly arranged channels with extremely high interconnectivity, and all the HCSs displayed ~100-μm-thick struts and 0.06 cm3 g-1 of micropore volume. The compressive strengths of HCSs with ~100-, ~200-, and ~300-μm channels were higher than those of reported scaffolds, and decreased with increasing channel size: 62 ± 6, 55 ± 9, and 43 ± 8 MPa, respectively. At four weeks after implantation in rabbit femur bone defects, new bone and blood vessels were formed in all the channels of these HCSs. Notably, the ~300-μm channels were extensively occupied by new bone. We demonstrated that high interconnectivity and uniformity of channels can decrease the threshold of effective macropore size, enabling the scaffolds to maintain high mechanical properties and osteogenic ability and serve as implants for weight-bearing areas.
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Affiliation(s)
- Koichiro Hayashi
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan.
| | - Melvin L Munar
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan
| | - Kunio Ishikawa
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan
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Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure. J Orthop Surg Res 2020; 15:40. [PMID: 32028970 PMCID: PMC7006186 DOI: 10.1186/s13018-019-1489-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 11/27/2019] [Indexed: 01/22/2023] Open
Abstract
Background Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function. Methods A unit cell of titanium alloy was designed to mimick trabecular structure. The controlled microarchitecture refers to a repeating array of unit-cells, composed of titanium alloy, which make up the scaffold structure. Five kinds of unit cell mimicking trabecular structure with different pore sizes and porosity were obtained by modifying the strut sizes of the cell and scaling the cell as a whole. The titanium alloy trabecular structure was fabricated by 3D printing based on Electron Beam Melting (EBM). The paper characterized the difference between the designs and fabrication of trabecular structures, as well as mechanical properties and the progressive collapse behavior and failure mechanism of the scaffold. Results The actual porosities of the EBM-produced bone trabeculae are lower than the designed, and the load capacity of a bearing is related to the porosity of the structure. The larger the porosity of the structure, the smaller the stiffness and the worse the load capacity is. The fracture interface of the trabecular structure under compression is at an angle of 45o with respect to the compressive axis direction, which conforms to Tresca yield criterion. The trabeculae-mimicked unit cell is anisotropy. Under quasi-static loading, loading speed has no effect on mechanical performance of bone trabecular specimens. There is no difference of the mechanical performance at various orientations and sites in metallic workspace. The elastic modulus of the scaffold decreases by 96%–93% and strength reduction 96%–91%, compared with titanium alloy dense metals structure. The apparent elastic modulus of the unit-cell-repeated scaffold is 0.39–0.618 GPa, which is close to that of natural bone and stress shielding can be reduced. Conclusion We have systematically studied the structural design, fabrication and mechanical behavior of a 3D printed titanium alloy scaffold mimicking trabecula bone. This study will be benefit of the application of prostheses with proper structures and functions.
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The effect of strontium and silicon substituted hydroxyapatite electrochemical coatings on bone ingrowth and osseointegration of selective laser sintered porous metal implants. PLoS One 2020; 15:e0227232. [PMID: 31923253 PMCID: PMC6953817 DOI: 10.1371/journal.pone.0227232] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/13/2019] [Indexed: 11/20/2022] Open
Abstract
Additive manufactured, porous bone implants have the potential to improve osseointegration and reduce failure rates of orthopaedic devices. Substantially porous implants are increasingly used in a number of orthopaedic applications. HA plasma spraying-a line of sight process-cannot coat the inner surfaces of substantially porous structures, whereas electrochemical deposition of calcium phosphate can fully coat the inner surfaces of porous implants for improved bioactivity, but the osseous response of different types of hydroxyapatite (HA) coatings with ionic substitutions has not been evaluated for implants in the same in vivo model. In this study, laser sintered Ti6Al4V implants with pore sizes of Ø 700 μm and Ø 1500 μm were electrochemically coated with HA, silicon-substituted HA (SiHA), and strontium-substituted HA (SrHA), and implanted in ovine femoral condylar defects. Implants were retrieved after 6 weeks and histological and histomorphometric evaluation were compared to electrochemically coated implants with uncoated and HA plasma sprayed controls. The HA, SiHA and SrHA coatings had Ca:P, Ca:(P+Si) and (Ca+Sr):P ratios of 1.53, 1.14 and 1.32 respectively. Electrochemically coated implants significantly promoted bone attachment to the implant surfaces of the inner pores and displayed improved osseointegration compared to uncoated scaffolds for both pore sizes (p<0.001), whereas bone ingrowth was restricted to the surface for HA plasma coated or uncoated implants. Electrochemically coated HA implants achieved the highest osseointegration, followed by SrHA coated implants, and both coatings exhibited significantly more bone growth than plasma sprayed groups (p≤0.01 for all 4 cases). SiHA had significantly more osseointegration when compared against the uncoated control, but no significant difference compared with other coatings. There was no significant difference in ingrowth or osseointegration between pore sizes, and the bone-implant-contact was significantly higher in the electrochemical HA than in SiHA or SrHA. These results suggest that osseointegration is insensitive to pore size, whereas surface modification through the presence of an osteoconductive coating plays an important role in improving osseointegration, which may be critically important for extensively porous implants.
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Nouri-Goushki M, Mirzaali MJ, Angeloni L, Fan D, Minneboo M, Ghatkesar MK, Staufer U, Fratila-Apachitei LE, Zadpoor AA. 3D Printing of Large Areas of Highly Ordered Submicron Patterns for Modulating Cell Behavior. ACS APPLIED MATERIALS & INTERFACES 2020; 12:200-208. [PMID: 31794179 PMCID: PMC6953469 DOI: 10.1021/acsami.9b17425] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fabricating large areas of geometrically complex and precisely controlled topographies is required for the studies of cell behavior on patterned surfaces. Direct laser writing (DLW) is an advanced 3D-fabrication technique, which facilitates the manufacturing of structures within various scales (from a few hundred nanometers to millimeters). However, this method requires improvements in the accuracy and reproducibility of the submicron and nanoscale features that are printed over a large area. Here, we present a scheme to both improve the uniformity of the printed submicron patterns and decrease the printing time. The effects of various processing parameters (e.g., laser power and writing field) on the dimensions and uniformity of submicron pillars as well as on their Young's modulus and surface wettability were assessed. Decreasing the writing field to 33 × 33 μm2 significantly improved the uniformity of submicron pillars that were printed over an area of 4 mm2 in a single-step process. Preosteoblast cells (MC3T3-E1) were used to assess the cytocompatibility of the used material (IP-L780 resin) with a focus on cell morphology, cell proliferation, cytoskeletal organization, and the elastic modulus of the cells. The cells cultured for 2 days on the submicron pillars showed a polarized shape and a higher Young's modulus of the area corresponding to the nucleus relative to those cultured on flat surfaces. Taken together, the results of the current study clearly show that the submicron patterns created using DLW are both cytocompatible and could modulate the morphology and mechanical properties of cells. This work paves the way for direct printing of submicron features with controlled Young's moduli over large areas in a single-step process, which is necessary for systematically studying how such patterns modulate cellular functions.
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Influence of HIP Treatment on Mechanical Properties of Ti6Al4V Scaffolds Prepared by L-PBF Process. METALS 2019. [DOI: 10.3390/met9121267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To improve biocompatibility and mechanical compatibility, post-treatment is necessary for porous scaffolds of bone tissue engineering. Hot isostatic pressing (HIP) is introduced into post-treatment of metal implants to enhance their mechanical properties by eliminating residual stress and pores. Additionally, oxide film formed on the material surface can be contributed to improve its biocompatibility. Ti6Al4V porous scaffolds fabricated by laser-powder bed fusion (L-PBF) process is studied in this paper, their mechanical properties are measured by pressure test, and the macroscopic surface morphology and microstructure are observed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). After HIP treatment, an oxide layer of 0.8 μm thickness forms on the surface of Ti6Al4V porous scaffolds and the microstructure of Ti6Al4V transforms from α’ phase to α + β dual-phase, as expected. However, the pressure test results of Ti6Al4V porous scaffolds show a definitely different variation trend of mechanical properties from solid parts, unexpectedly. Concerning Ti6Al4V porous scaffolds, the compression stiffness and critical stress improves clearly using HIP treatment, and the fracture morphology shows obvious brittle fracture. Both the strengthening and brittleness transition of Ti6Al4V porous scaffolds result from the formation of an oxide layer and an oxygen atom diffusion layer. The critical stress of Ti6Al4V porous scaffolds can be calculated by fully considering these two strengthening layers. To obtain a porous scaffold with specific mechanical properties, the effect of post-treatment should be considered during structural design.
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Han Q, Wang C, Chen H, Zhao X, Wang J. Porous Tantalum and Titanium in Orthopedics: A Review. ACS Biomater Sci Eng 2019; 5:5798-5824. [PMID: 33405672 DOI: 10.1021/acsbiomaterials.9b00493] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Porous metal is metal with special porous structures, which can offer high biocompatibility and low Young's modulus to satisfy the need for orthopedic applications. Titanium and tantalum are the most widely used porous metals in orthopedics due to their excellent biomechanical properties and biocompatibility. Porous titanium and tantalum have been studied and applied for a long history until now. Here in this review, various manufacturing methods of titanium and tantalum porous metals are introduced. Application of these porous metals in different parts of the body are summarized, and strengths and weaknesses of these porous metal implants in clinical practice are discussed frankly for future improvement from the viewpoint of orthopedic surgeons. Then according to the requirements from clinics, progress in research for clinical use is illustrated in four aspects. Various creative designs of microporous and functionally gradient structure, surface modification, and functional compound systems of porous metal are exhibited as reference for future research. Finally, the directions of orthopedic porous metal development were proposed from the clinical view based on the rapid progress of additive manufacturing. Controllable design of both macroscopic anatomical bionic shape and microscopic functional bionic gradient porous metal, which could meet the rigorous mechanical demand of bone reconstruction, should be developed as the focus. The modification of a porous metal surface and construction of a functional porous metal compound system, empowering stronger cell proliferation and antimicrobial and antineoplastic property to the porous metal implant, also should be taken into consideration.
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Affiliation(s)
- Qing Han
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, 130000 Jilin Province, China
| | - Chenyu Wang
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, 130000 Jilin Province, China
| | - Hao Chen
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, 130000 Jilin Province, China
| | - Xue Zhao
- Department of Endocrine and Metabolism, The First Hospital of Jilin University, Changchun, 130000 Jilin Province, China
| | - Jincheng Wang
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, 130000 Jilin Province, China
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Watcharajittanont N, Putson C, Pripatnanont P, Meesane J. Layer-by-layer electrospun membranes of polyurethane/silk fibroin based on mimicking of oral soft tissue for guided bone regeneration. ACTA ACUST UNITED AC 2019; 14:055011. [PMID: 31342923 DOI: 10.1088/1748-605x/ab3502] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Guided bone regeneration is an effective method that can enhance bone volume at a defect site of the mandible before material implantation. Layer-by-layer electrospun membranes of polyurethane/silk fibroin (SF) were fabricated to mimic oral soft tissue. The electrospun polyurethane fibers were initially fabricated into a membrane. Next, the polyurethane layer was covered with electrospun SF fibers at different thicknesses. Then, the SF layer was covered with electrospun polyurethane fibers. Afterward, the morphologies of the membranes were observed and analyzed by scanning electron microscopy. The physical properties of the membranes were evaluated from the contact angle and mechanical properties. The biological performances were evaluated by observing cell adhesion, viability and proliferation, alkaline phosphatase activity, and calcium content. The results demonstrated that the membrane with a thin SF core showed better physical properties and mechanical performance than the thicker SF cores. Finally, the results deduced that the membrane with a thin SF core was promising for guided bone regeneration.
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Affiliation(s)
- Nattawat Watcharajittanont
- Institute of Biomedical Engineering, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
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Willemsen K, Nizak R, Noordmans HJ, Castelein RM, Weinans H, Kruyt MC. Challenges in the design and regulatory approval of 3D-printed surgical implants: a two-case series. LANCET DIGITAL HEALTH 2019; 1:e163-e171. [PMID: 33323186 DOI: 10.1016/s2589-7500(19)30067-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND Additive manufacturing or three-dimensional (3D) printing of metal implants can provide novel solutions for difficult-to-treat conditions, yet legislation concerning patient-specific implants complicates the implementation of these techniques in daily practice. In this Article, we share our acquired knowledge of the logistical and legal challenges associated with the use of patient-specific 3D-printed implants to treat spinal instabilities. METHODS Two patients with semiurgent cases of spinal instability presented to our hospital in the Netherlands. In case 1, severe kyphotic deformity of the thoracic spine due to neurofibromatosis type 1 had led to incomplete paralysis, and a strong metallic strut extending from C6 to T11 was deemed necessary to provide long-term anterior support. In case 2, the patient presented with progressive paralysis caused by cervicothoracic dissociation due to vanishing bone disease. As the C5-T1 vertebral bodies had mostly vanished, an implant spanning the anterior spine from C4 to T2 was required. Because of the complex and challenging nature of both cases, conventional approaches were deemed inadequate; instead, patient-specific implants were designed with use of CT scans and computer-aided design software, and 3D printed in titanium with direct metal printing. For each implant, to ensure patient safety, a comprehensive technical file (describing the clinical substantiation, technical and design considerations, risk analysis, manufacturing process, and labelling) was produced in collaboration with a university department certified for the development and manufacturing of medical devices. Because the implants were categorised as custom-made or personalised devices under the EU Medical Device Regulation, the usual procedures for review and approval of medical devices by a notified body were not required. Finite-element analyses, compression strength tests, and cadaveric experiments were also done to ensure the devices were safe to use. FINDINGS The planning, design, production, and insertion of the 3D-printed personalised implant took around 6 months in the first patient, but, given the experience from the first case, only took around 6 weeks in the second patient. In both patients, the surgeries went as planned and good positioning of each implant was confirmed. Both patients were discharged home within 1 week after the surgery. In the first patient, a fatigue fracture occured in one of the conventional posterior fusion rods after 10 months, which we repaired, without any deformation of the spine or signs of failure of the personalised implant observed. No other adverse events occurred up to 25 months of follow-up in case 1 and 6 months of follow-up in case 2. INTERPRETATION Patient-specific treatment approaches incorporating 3D-printed implants can be helpful in carefully selected cases when conventional methods are not an option. Comprehensive and efficient interactions between medical engineers and physicians are essential to establish well designed frameworks to navigate the logistical and regulatory aspects of technology development to ensure the safety and legal validity of patient-specific treatments. The framework described here could encourage physicians to treat (once untreatable) patients with novel personalised techniques. FUNDING Interreg VA Flanders-The Netherlands programme, Applied and Engineering Sciences research programme, the Netherlands Organisation for Scientific Research, and the Dutch Arthritis Foundation VIDEO ABSTRACT.
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Affiliation(s)
- Koen Willemsen
- Department of Orthopaedics, University Medical Centre Utrecht, Utrecht, Netherlands.
| | - Razmara Nizak
- Department of Orthopaedics, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Herke Jan Noordmans
- Department of Medical Technology and Clinical Physics, University Medical Centre Utrecht, Utrecht, Netherlands
| | - René M Castelein
- Department of Orthopaedics, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Harrie Weinans
- Department of Orthopaedics, University Medical Centre Utrecht, Utrecht, Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Moyo C Kruyt
- Department of Orthopaedics, University Medical Centre Utrecht, Utrecht, Netherlands
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Wang H, Su K, Su L, Liang P, Ji P, Wang C. Comparison of 3D-printed porous tantalum and titanium scaffolds on osteointegration and osteogenesis. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 104:109908. [PMID: 31499974 DOI: 10.1016/j.msec.2019.109908] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/23/2019] [Accepted: 06/20/2019] [Indexed: 12/16/2022]
Abstract
Metals such as Ta (tantalum) and Ti (titanium) have been popularly used as a bone substitute or implants in orthopedic surgery and dentistry, since they have excellent corrosion. For manufacturing porous implants with precise structure, SLM (Selective laser melting), which is one of the 3D (three-dimensional) printing techniques, is always be chosen. To compare biological performances between porous Ta and Ti implants, we designed them with the same porosity, pore shape, pore size, and pore distribution via CAD (computer aided design), and then produced them by SLM. It was shown that the equivalent stress of porous Ta and Ti were 393.62 ± 1.39 MPa and 139.75 ± 14.50 MPa, and their Young's modulus were 3.10 ± 0.03GPa and 5.42 ± 0.07GPa, respectively. Meanwhile, we investigated their biological performance with hBMMSCs (human Bone marrow mesenchymal stem cells) in vitro. The results revealed that both two scaffolds were in favor of hBMMSCs proliferation and osteogenic differentiation. In addition, porous scaffolds were implanted in the femur bone defects rabbits in vivo showed the both porous scaffolds were beneficial to the bone ingrowth and bone-implant fixation. In summary, porous Ta has an equivalent biological performance as traditional porous Ti implants in small bone defect repair. Taken together, porous Ta is a promising material for bone regeneration.
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Affiliation(s)
- Han Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Kexin Su
- Stomatological Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
| | - Leizheng Su
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
| | - Panpan Liang
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Ping Ji
- Stomatological Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
| | - Chao Wang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China.
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Bose S, Traxel KD, Vu AA, Bandyopadhyay A. Clinical significance of three-dimensional printed biomaterials and biomedical devices. MRS BULLETIN 2019; 44:494-504. [PMID: 31371848 PMCID: PMC6675023 DOI: 10.1557/mrs.2019.121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Three-dimensional printing (3DP) is becoming a standard manufacturing practice for a variety of biomaterials and biomedical devices. This layer-by-layer methodology provides the ability to fabricate parts from computer-aided design files without the need for part-specific tooling. Three-dimensional printed medical components have transformed the field of medicine through on-demand patient care with specialized treatment such as local, strategically timed drug delivery, and replacement of once-functioning body parts. Not only can 3DP technology provide individualized components, it also allows for advanced medical care, including surgical planning models to aid in training and provide temporary guides during surgical procedures for reinforced clinical success. Despite the advancement in 3DP technology, many challenges remain for forward progress, including sterilization concerns, reliability, and reproducibility. This article offers an overview of biomaterials and biomedical devices derived from metals, ceramics, polymers, and composites that can be three-dimensionally printed, as well as other techniques related to 3DP in medicine, including surgical planning, bioprinting, and drug delivery.
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Affiliation(s)
- Susmita Bose
- W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, USA
| | - Kellen D Traxel
- W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, USA
| | - Ashley A Vu
- W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, USA
| | - Amit Bandyopadhyay
- W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, USA
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Li J, Li W, Li Z, Wang Y, Li R, Tu J, Jin G. In vitro and in vivo evaluations of the fully porous Ti6Al4V acetabular cups fabricated by a sintering technique. RSC Adv 2019; 9:6724-6732. [PMID: 35518492 PMCID: PMC9061126 DOI: 10.1039/c9ra00638a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 02/21/2019] [Indexed: 11/21/2022] Open
Abstract
A type of canine fully porous Ti6Al4V acetabular cup was fabricated by a well-controlled powder sintering technique. The traditional hydroxyapatite-coated (HA-coated) cups were also prepared as the control. The characteristics, mechanical and biological properties of the two types of cups were evaluated by scanning electron microscopy, mechanical tests, finite element analysis and canine total hip arthroplasty (THA). Results showed that the porous cup had high porosity and large pore size with good mechanical properties without obvious stress shielding, and it had sufficient safety for implantation according to the finite element analysis. Both groups showed good biocompatibility and osteogenic ability after the THA surgeries, but the porous group had more bone ingrowth and higher bone-implant contact rate according to the micro-CT and histopathologic results. Therefore, the canine fully porous Ti6Al4V acetabular cup fabricated by the sintering technique could provide sufficient space and adequate mechanical support without obvious stress shielding effect for bone ingrowth. Compared with the traditional HA-coated cup, the porous cup may be more effective in achieving in vivo stability, which could contribute to reducing the risk of aseptic loosening.
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Affiliation(s)
- Ji Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Wei Li
- Department of Rehabilitation, Beijing Rehabilitation Hospital, Capital Medical University Xixiazhuang, Badachu Road, Shijingshan District Beijing 100144 China
| | - Zhongli Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Yuxing Wang
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Ruiling Li
- State Key Laboratory of Materials, Department of Materials Science and Engineering, Zhejiang University Hangzhou 310027 China
| | - Jiangping Tu
- State Key Laboratory of Materials, Department of Materials Science and Engineering, Zhejiang University Hangzhou 310027 China
| | - Gong Jin
- ZhongAoHuiCheng Technology Co. No. 20 Kechuang Road, Economic and Technological Development Zone Beijing 100176 China
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Non-Auxetic Mechanical Metamaterials. MATERIALS 2019; 12:ma12040635. [PMID: 30791595 PMCID: PMC6416644 DOI: 10.3390/ma12040635] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/16/2022]
Abstract
The concept of "mechanical metamaterials" has become increasingly popular, since their macro-scale characteristics can be designed to exhibit unusual combinations of mechanical properties on the micro-scale. The advances in additive manufacturing (AM, three-dimensional printing) techniques have boosted the fabrication of these mechanical metamaterials by facilitating a precise control over their micro-architecture. Although mechanical metamaterials with negative Poisson's ratios (i.e., auxetic metamaterials) have received much attention before and have been reviewed multiple times, no comparable review exists for architected materials with positive Poisson's ratios. Therefore, this review will focus on the topology-property relationships of non-auxetic mechanical metamaterials in general and five topological designs in particular. These include the designs based on the diamond, cube, truncated cube, rhombic dodecahedron, and the truncated cuboctahedron unit cells. We reviewed the mechanical properties and fatigue behavior of these architected materials, while considering the effects of other factors such as those of the AM process. In addition, we systematically analyzed the experimental, computational, and analytical data and solutions available in the literature for the titanium alloy Ti-6Al-4V. Compression dominated lattices, such as the (truncated) cube, showed the highest mechanical properties. All of the proposed unit cells showed a normalized fatigue strength below that of solid titanium (i.e., 40% of the yield stress), in the range of 12⁻36% of their yield stress. The unit cells discussed in this review could potentially be applied in bone-mimicking porous structures.
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Li J, Li Z, Wang Q, Shi Y, Li W, Fu Y, Jin G. Sintered porous Ti6Al4V scaffolds incorporated with recombinant human bone morphogenetic protein-2 microspheres and thermosensitive hydrogels can enhance bone regeneration. RSC Adv 2019; 9:1541-1550. [PMID: 35518032 PMCID: PMC9059563 DOI: 10.1039/c8ra10200g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/08/2019] [Indexed: 11/21/2022] Open
Abstract
A well-controlled powder sintering technique was used to fabricate porous Ti6Al4V scaffold. The thermosensitive chitosan thioglycolic acid (CS-TA) hydrogel was used as a carrier to inject recombinant human bone morphogenetic protein-2 (rhBMP-2) microspheres into pores of the Ti6Al4V scaffold at 37 °C, and then the porous Ti6Al4V/rhBMP-2 loaded hydrogel composite was obtained. The bare Ti6Al4V scaffold was used as the control. The characteristics and mechanical properties of the scaffold, rheological properties of the hydrogels and the rhBMP-2 loaded hydrogel, the release of the rhBMP-2 loaded hydrogel, and the biological properties of the two types of samples were evaluated by in vitro and in vivo tests. Results indicated that the sintered porous Ti6Al4V had high porosity, large pore size with good mechanical properties. The hydrogel and rhBMP-2 loaded hydrogel showed thermosensity. The rhBMP-2 loaded hydrogel showed a stable and extended release profile without too high burst release of rhBMP-2. Both groups showed good biocompatibility and osteogenic ability. However, according to the results of cell tests and implantation, the group with rhBMP-2 loaded hydrogel had significantly higher cell proliferation rate, faster bone growth speed, and more bone ingrowth at every time point. Therefore, the sintered porous Ti6Al4V scaffolds incorporated with rhBMP-2 microspheres and CS-TA hydrogel was effective in enhancing the bone regeneration, and prospects a good candidate for application in orthopedics.
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Affiliation(s)
- Ji Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Zhongli Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Qi Wang
- Department of Orthopedics, Characteristic Medical Center of PAP Tianjin 300162 China
| | - Yueyi Shi
- Department of Stomatology, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China
| | - Wei Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Yangmu Fu
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Gong Jin
- ZhongAoHuiCheng Technology Co. No. 20 Kechuang Road, Economic and Technological Development Zone Beijing 100176 China
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Kelly CN, Evans NT, Irvin CW, Chapman SC, Gall K, Safranski DL. The effect of surface topography and porosity on the tensile fatigue of 3D printed Ti-6Al-4V fabricated by selective laser melting. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 98:726-736. [PMID: 30813077 DOI: 10.1016/j.msec.2019.01.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 01/02/2019] [Accepted: 01/07/2019] [Indexed: 10/27/2022]
Abstract
Additive manufacturing (3D printing) is emerging as a key manufacturing technique in medical devices. Selective laser melted (SLM) Ti-6Al-4V implants with interconnected porosity have become widespread in orthopedic applications where porous structures encourage bony ingrowth and the stiffness of the implant can be tuned to reduce stress shielding. The SLM technique allows high resolution control over design, including the ability to introduce porosity with spatial variations in pore size, shape, and connectivity. This study investigates the effect of construct design and surface treatment on tensile fatigue behavior of 3D printed Ti-6Al-4V. Samples were designed as solid, solid with an additional surface porous layer, or fully porous, while surface treatments included commercially available rotopolishing and SILC cleaning. All groups were evaluated for surface roughness and tested in tension to failure under monotonic and cyclic loading profiles. Surface treatments were shown to reduce surface roughness for all sample geometries. However, only fatigue behavior of solid samples was improved for treated as compared to non-treated surfaces Irrespective of surface treatment and resulting surface roughness, the fatigue strength of 3D printed samples containing bulk or surface porosity was approximately 10% of the ultimate tensile strength of identical 3D printed porous material. This study highlights the relative effect of surface treatment in solid and porous printed samples and the inherent decrease in fatigue properties of 3D printed porous samples designed for osseointegration.
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Affiliation(s)
- Cambre N Kelly
- Department of Biomedical Engineering, Duke University, United States of America
| | - Nathan T Evans
- School of Materials Science and Engineering, Georgia Institute of Technology, United States of America
| | - Cameron W Irvin
- School of Materials Science and Engineering, Georgia Institute of Technology, United States of America; Renewable Bioproducts Institute, Georgia Institute of Technology, United States of America
| | - Savita C Chapman
- Department of Biomedical Engineering, Georgia Institute of Technology, United States of America
| | - Ken Gall
- Department of Mechanical Engineering and Materials Science, Duke University, United States of America
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Abstract
Additively manufactured (AM, =3D printed) porous metallic biomaterials with topologically ordered unit cells have created a lot of excitement and are currently receiving a lot of attention given their great potential for improving bone tissue regeneration and preventing implant-associated infections.
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Affiliation(s)
- Amir A. Zadpoor
- Department of Biomechanical Engineering
- Faculty of Mechanical, Maritime, and Materials Engineering
- Delft University of Technology (TU Delft)
- Delft
- The Netherlands
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75
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Burton HE, Eisenstein NM, Lawless BM, Jamshidi P, Segarra MA, Addison O, Shepherd DE, Attallah MM, Grover LM, Cox SC. The design of additively manufactured lattices to increase the functionality of medical implants. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 94:901-908. [DOI: 10.1016/j.msec.2018.10.052] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 09/25/2018] [Accepted: 10/12/2018] [Indexed: 12/22/2022]
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76
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Marin E, Horiguchi S, Zanocco M, Boschetto F, Rondinella A, Zhu W, Bock RM, McEntire BJ, Adachi T, Bal BS, Pezzotti G. Bioglass functionalization of laser-patterned bioceramic surfaces and their enhanced bioactivity. Heliyon 2018; 4:e01016. [PMID: 30560211 PMCID: PMC6288463 DOI: 10.1016/j.heliyon.2018.e01016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 11/05/2018] [Accepted: 12/04/2018] [Indexed: 11/29/2022] Open
Abstract
The surfaces of silicon nitride (β-Si3N4) and zirconia toughened alumina (ZTA) were patterned using a high-energy laser source, which operated at a wavelength of 1064 nm. The patterning procedure yielded a series regular, cylindrical cavities 500 and 300 μm in diameter and depth, respectively. These cavities were subsequently filled with bioglass mixed with different fractions of Si3N4 powder (0, 5, and 10 mol.%) to obtain bioactive functionalized bioceramic surfaces. The laser-patterned samples were first characterized using several spectroscopic techniques before and after functionalization, and then tested in vitro with respect to their osteoconductivity using a human osteosarcoma cell line (SaOS-2). After in vitro testing, fluorescence microscopy was used to address the biological response and to estimate osteopontin and osteocalcin protein contents and distributions. The presence of bioglass greatly enhanced the biological response of both ceramic surfaces, but mainly induced production of inorganic apatite. On the other hand, the addition of minor fraction of Si3N4 into the bioglass-filled holes greatly enhanced bio-mineralization and stimulated the SaOS-2 cells to produce higher amounts of bone extracellular matrix (collagen and proteins), thus enhancing the osteopontin to osteocalcin ratio. It was also observed that the presence of a fraction of Si3N4 in the powder mixture filling the holes bestowed more uniform cell colonization on the otherwise bioinert ZTA surface.
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Affiliation(s)
- Elia Marin
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
- Department of Dental Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Satoshi Horiguchi
- Department of Dental Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Matteo Zanocco
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
| | - Francesco Boschetto
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
| | - Alfredo Rondinella
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
| | - Wenliang Zhu
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
| | - Ryan M. Bock
- Amedica Corporation, 1885 West 2100 South, Salt Lake City, UT, USA
| | | | - Tetsuya Adachi
- Department of Dental Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-8566, Japan
| | - B. Sonny Bal
- Amedica Corporation, 1885 West 2100 South, Salt Lake City, UT, USA
- Department of Orthopaedic Surgery, University of Missouri, Columbia, MO, USA
| | - Giuseppe Pezzotti
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
- Department of Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, 465 Kajii-cho, Kawaramachi dori, 602-0841 Kyoto, Japan
- Department of Orthopedic Surgery, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku-ku, 160-0023 Tokyo, Japan
- The Center for Advanced Medical Engineering and Informatics, Osaka University, Yamadaoka, Suita, 565-0871 Osaka, Japan
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77
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Torstrick FB, Lin AS, Potter D, Safranski DL, Sulchek TA, Gall K, Guldberg RE. Porous PEEK improves the bone-implant interface compared to plasma-sprayed titanium coating on PEEK. Biomaterials 2018; 185:106-116. [DOI: 10.1016/j.biomaterials.2018.09.009] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 08/31/2018] [Accepted: 09/07/2018] [Indexed: 12/14/2022]
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Individual response variations in scaffold-guided bone regeneration are determined by independent strain- and injury-induced mechanisms. Biomaterials 2018; 194:183-194. [PMID: 30611115 PMCID: PMC6345626 DOI: 10.1016/j.biomaterials.2018.11.026] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/31/2018] [Accepted: 11/15/2018] [Indexed: 01/15/2023]
Abstract
This study explored the regenerative osteogenic response in the distal femur of sheep using scaffolds having stiffness values within, and above and below, the range of trabecular bone apparent modulus. Scaffolds 3D-printed from stiff titanium and compliant polyamide were implanted into a cylindrical metaphyseal defect 15 × 15 mm. After six weeks, bone ingrowth varied between 7 and 21% of the scaffold pore volume and this was generally inversely proportional to scaffold stiffness. The individual reparative response considerably varied among the animals, which could be divided into weak and strong responders. Notably, bone regeneration specifically within the interior of the scaffold was inversely proportional to scaffold stiffness and was strain-driven in strongly-responding animals. Conversely, bone regeneration at the periphery of the defect was injury-driven and equal in all scaffolds and in all strongly- and weakly-responding animals. The observation of the strain-driven response in some, but not all, animals highlights that scaffold compliance is desirable for triggering host bone regeneration, but scaffold permanence is important for the load-bearing, structural role of the bone-replacing device. Indeed, scaffolds may benefit from being nonresorbable and mechanically reliable for those unforeseeable cases of weakly responding recipients.
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79
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Li J, Li Z, Li R, Shi Y, Wang H, Wang Y, Jin G. In vitro and in vivo evaluations of mechanical properties, biocompatibility and osteogenic ability of sintered porous titanium alloy implant. RSC Adv 2018; 8:36512-36520. [PMID: 35558944 PMCID: PMC9088853 DOI: 10.1039/c8ra07518b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 10/19/2018] [Indexed: 11/23/2022] Open
Abstract
A new sintering technique using Ti6Al4V powder suspension was performed to prepare porous Ti6Al4V alloys. The porous alloys could be fabricated with different porosities and pore sizes by controlling the quantity and size of spacer particles added to the Ti6Al4V powder. The characteristics and biological properties of the porous Ti6Al4V with two different porosities were evaluated by mechanical tests, cell tests and implantation. Dense Ti6Al4V was used as the control. Compared with the control group, the porous Ti6Al4V showed good biocompatibility and osteogenic ability, which makes this type of porous alloy a good prospective material for biomedical application. And compared with 50% porosity, the alloy with 75% porosity had the optimal mechanical properties, and suitable pore size and porosity, which allowed more bone ingrowth.
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Affiliation(s)
- Ji Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Zhongli Li
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Ruiling Li
- State Key Laboratory of Materials, Department of Materials Science and Engineering, Zhejiang University Hangzhou 310027 China
| | - Yueyi Shi
- Department of Stomatology, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China
| | - Haoran Wang
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Yuxing Wang
- Department of Orthopedics, General Hospital of PLA No. 28 Fuxing Road, Haidian District Beijing 100853 China +86 010 66938306 +86 010 66938306
| | - Gong Jin
- ZhongAoHuiCheng Technology Co. No. 20 Kechuang Road, Economic and Technological Development Zone Beijing 100176 China
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80
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Unfocused shockwaves for osteoinduction in bone substitutes in rat cortical bone defects. PLoS One 2018; 13:e0200020. [PMID: 29969479 PMCID: PMC6029785 DOI: 10.1371/journal.pone.0200020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/18/2018] [Indexed: 11/19/2022] Open
Abstract
Bone substitutes are frequently used in clinical practice but often exhibit limited osteoinductivity. We hypothesized that unfocused shockwaves enhance the osteoinductivity of bone substitutes and improve osteointegration and angiogenesis. Three different bone substitutes, namely porous tricalcium phosphate, porous hydroxyapatite and porous titanium alloy, were implanted in a critical size (i.e. 6-mm) femoral defect in rats. The femora were treated twice with 1500 shockwaves at 2 and 4 weeks after surgery and compared with non-treated controls. The net volume of de novo bone in the defect was measured by microCT-scanning during 11-weeks follow-up. Bone ingrowth and angiogenesis in the bone substitutes was examined at 5 and 11 weeks using histology. It was shown that hydroxyapatite and titanium both had an increase of bone ingrowth with more bone in the shockwave group compared to the control group, whereas resorption was seen in tricalcium phosphate bone substitutes over time and this was insensitive to shockwave treatment. In conclusion, hydroxyapatite and titanium bone substitutes favour from shockwave treatment, whereas tricalcium phosphate does not. This study shows that osteoinduction and osteointegration of bone substitutes can be influenced with unfocused shockwave therapy, but among other factors depend on the type of bone substitute, likely reflecting its mechanical and biological properties.
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81
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do Prado RF, Esteves GC, Santos ELDS, Bueno DAG, Cairo CAA, Vasconcellos LGOD, Sagnori RS, Tessarin FBP, Oliveira FE, Oliveira LDD, Villaça-Carvalho MFL, Henriques VAR, Carvalho YR, De Vasconcellos LMR. In vitro and in vivo biological performance of porous Ti alloys prepared by powder metallurgy. PLoS One 2018; 13:e0196169. [PMID: 29771925 PMCID: PMC5957353 DOI: 10.1371/journal.pone.0196169] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/06/2018] [Indexed: 11/18/2022] Open
Abstract
Titanium (Ti) and Ti-6 Aluminium-4 Vanadium alloys are the most common materials in implants composition but β type alloys are promising biomaterials because they present better mechanical properties. Besides the composition of biomaterial, many factors influence the performance of the biomaterial. For example, porous surface may modify the functional cellular response and accelerate osseointegration. This paper presents in vitro and in vivo evaluations of powder metallurgy-processed porous samples composed by different titanium alloys and pure Ti, aiming to show their potential for biomedical applications. The porous surfaces samples were produced with different designs to in vitro and in vivo tests. Samples were characterized with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and elastic modulus analyses. Osteogenic cells from newborn rat calvaria were plated on discs of different materials: G1—commercially pure Ti group (CpTi); G2—Ti-6Al-4V alloy; G3—Ti-13 Niobium-13 Zirconium alloy; G4—Ti-35 Niobium alloy; G5—Ti-35 Niobium-7 Zirconium-5 Tantalum alloy. Cell adhesion and viability, total protein content, alkaline phosphatase activity, mineralization nodules and gene expression (alkaline phosphatase, Runx-2, osteocalcin and osteopontin) were assessed. After 2 and 4 weeks of implantation in rabbit tibia, bone ingrowth was analyzed using micro-computed tomography (μCT). EDS analysis confirmed the material production of each group. Metallographic and SEM analysis revealed interconnected pores, with mean pore size of 99,5μm and mean porosity of 42%, without significant difference among the groups (p>0.05). The elastic modulus values did not exhibit difference among the groups (p>0.05). Experimental alloys demonstrated better results than CpTi and Ti-6Al-4V, in gene expression and cytokines analysis, especially in early experimental periods. In conclusion, our data suggests that the experimental alloys can be used for biomedical application since they contributed to excellent cellular behavior and osseointegration besides presenting lower elastic modulus.
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Affiliation(s)
- Renata Falchete do Prado
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
- * E-mail: ,
| | - Gabriela Campos Esteves
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Evelyn Luzia De Souza Santos
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Daiane Acácia Griti Bueno
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Carlos Alberto Alves Cairo
- Division of Materials, Air and Space Institute, Praça Mal. do Ar Eduardo Gomes, São José dos Campos, São Paulo, Brazil
| | - Luis Gustavo Oliveira De Vasconcellos
- Department of Prosthodontic and Dental Material, Institute of Science and Technology São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Renata Silveira Sagnori
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (Unicamp), Piracicaba, São Paulo, Brazil
| | - Fernanda Bastos Pereira Tessarin
- Department of Restorative Dentistry, Institute of Science and Technology São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Felipe Eduardo Oliveira
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Luciane Dias De Oliveira
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Maria Fernanda Lima Villaça-Carvalho
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | | | - Yasmin Rodarte Carvalho
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
| | - Luana Marotta Reis De Vasconcellos
- Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, São Paulo, Brazil
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82
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Ran Q, Yang W, Hu Y, Shen X, Yu Y, Xiang Y, Cai K. Osteogenesis of 3D printed porous Ti6Al4V implants with different pore sizes. J Mech Behav Biomed Mater 2018; 84:1-11. [PMID: 29709846 DOI: 10.1016/j.jmbbm.2018.04.010] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/21/2018] [Accepted: 04/11/2018] [Indexed: 01/02/2023]
Abstract
Selective laser melting (SLM) is one of the three-dimensional (3D) printing techniques that manufacturing versatile porous scaffolds with precise architectures for potential orthopedic application. To understand how the pore sizes of porous Ti6Al4V scaffolds affect their biological performances, we designed and fabricated porous Ti6Al4V implants with straightforward pore dimensions (500, 700, and 900 µm) via SLM, termed as p500, p700, and p900 respectively. The morphological characteristics of Ti6Al4V scaffolds were assessed showing that the actual pore sizes of these scaffolds were 401 ± 26 µm, 607 ± 24 µm, 801 ± 33 µm, respectively. The mechanical properties of Ti6Al4V scaffolds were also evaluated showing that they were comparable to that of bone tissues. Meanwhile, the effect of pore size on biological responses was systematically investigated in vitro and in vivo. It was verified that 3D printing technique was able to fabricate porous Ti6Al4V implants with proper mechanical properties analogous to human bone. The in vitro results revealed that scaffolds with appropriate pore dimension were conducive to cell adhesion, proliferation and early differentiation. Furthermore, the porous Ti6Al4V scaffolds were implanted into the rabbit femur to investigate bone regeneration performance, the in vivo experiment showed the p700 sample was in favor of bone ingrowth into implant pores and bone-implant fixation stability. Taken together, the biological performance of p700 group with actual pore size of about 600 µm was superior to other two groups. The obtained findings provide basis to individually design and fabricate suitable porous Ti6Al4V with specific geometries for orthopedic application.
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Affiliation(s)
- Qichun Ran
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China
| | - Weihu Yang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China.
| | - Yan Hu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China
| | - Xinkun Shen
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China
| | - Yonglin Yu
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China
| | - Yang Xiang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China
| | - Kaiyong Cai
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, PR China.
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83
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Mechanical Properties and In Vitro Behavior of Additively Manufactured and Functionally Graded Ti6Al4V Porous Scaffolds. METALS 2018. [DOI: 10.3390/met8040200] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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84
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Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review. Appl Bionics Biomech 2018; 2018:1654782. [PMID: 29487626 PMCID: PMC5816891 DOI: 10.1155/2018/1654782] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/26/2017] [Indexed: 02/07/2023] Open
Abstract
Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed.
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85
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Li Y, Zhou J, Pavanram P, Leeflang M, Fockaert L, Pouran B, Tümer N, Schröder KU, Mol J, Weinans H, Jahr H, Zadpoor A. Additively manufactured biodegradable porous magnesium. Acta Biomater 2018; 67:378-392. [PMID: 29242158 DOI: 10.1016/j.actbio.2017.12.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/01/2017] [Accepted: 12/04/2017] [Indexed: 01/11/2023]
Abstract
An ideal bone substituting material should be bone-mimicking in terms of mechanical properties, present a precisely controlled and fully interconnected porous structure, and degrade in the human body to allow for full regeneration of large bony defects. However, simultaneously satisfying all these three requirements has so far been highly challenging. Here we present topologically ordered porous magnesium (WE43) scaffolds based on the diamond unit cell that were fabricated by selective laser melting (SLM) and satisfy all the requirements. We studied the in vitro biodegradation behavior (up to 4 weeks), mechanical properties and biocompatibility of the developed scaffolds. The mechanical properties of the AM porous WE43 (E = 700-800 MPa) scaffolds were found to fall into the range of the values reported for trabecular bone even after 4 weeks of biodegradation. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), electrochemical tests and µCT revealed a unique biodegradation mechanism that started with uniform corrosion, followed by localized corrosion, particularly in the center of the scaffolds. Biocompatibility tests performed up to 72 h showed level 0 cytotoxicity (according to ISO 10993-5 and -12), except for one time point (i.e., 24 h). Intimate contact between cells (MG-63) and the scaffolds was also observed in SEM images. The study shows for the first time that AM of porous Mg may provide distinct possibilities to adjust biodegradation profile through topological design and open up unprecedented opportunities to develop multifunctional bone substituting materials that mimic bone properties and enable full regeneration of critical-size load-bearing bony defects. STATEMENT OF SIGNIFICANCE The ideal biomaterials for bone tissue regeneration should be bone-mimicking in terms of mechanical properties, present a fully interconnected porous structure, and exhibit a specific biodegradation behavior to enable full regeneration of bony defects. Recent advances in additive manufacturing have resulted in biomaterials that satisfy the first two requirements but simultaneously satisfying the third requirement has proven challenging so far. Here we present additively manufactured porous magnesium structures that have the potential to satisfy all above-mentioned requirements. Even after 4 weeks of biodegradation, the mechanical properties of the porous structures were found to be within those reported for native bone. Moreover, our comprehensive electrochemical, mechanical, topological, and biological study revealed a unique biodegradation behavior and the limited cytotoxicity of the developed biomaterials.
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86
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Ahmadi S, Hedayati R, Li Y, Lietaert K, Tümer N, Fatemi A, Rans C, Pouran B, Weinans H, Zadpoor A. Fatigue performance of additively manufactured meta-biomaterials: The effects of topology and material type. Acta Biomater 2018; 65:292-304. [PMID: 29127065 DOI: 10.1016/j.actbio.2017.11.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 11/03/2017] [Accepted: 11/07/2017] [Indexed: 01/13/2023]
Abstract
Additive manufacturing (AM) techniques enable fabrication of bone-mimicking meta-biomaterials with unprecedented combinations of topological, mechanical, and mass transport properties. The mechanical performance of AM meta-biomaterials is a direct function of their topological design. It is, however, not clear to what extent the material type is important in determining the fatigue behavior of such biomaterials. We therefore aimed to determine the isolated and modulated effects of topological design and material type on the fatigue response of metallic meta-biomaterials fabricated with selective laser melting. Towards that end, we designed and additively manufactured Co-Cr meta-biomaterials with three types of repeating unit cells and three to four porosities per type of repeating unit cell. The AM meta-biomaterials were then mechanically tested to obtain their normalized S-N curves. The obtained S-N curves of Co-Cr meta-biomaterials were compared to those of meta-biomaterials with same topological designs but made from other materials, i.e. Ti-6Al-4V, tantalum, and pure titanium, available from our previous studies. We found the material type to be far more important than the topological design in determining the normalized fatigue strength of our AM metallic meta-biomaterials. This is the opposite of what we have found for the quasi-static mechanical properties of the same meta-biomaterials. The effects of material type, manufacturing imperfections, and topological design were different in the high and low cycle fatigue regions. That is likely because the cyclic response of meta-biomaterials depends not only on the static and fatigue strengths of the bulk material but also on other factors that may include strut roughness, distribution of the micro-pores created inside the struts during the AM process, and plasticity. STATEMENT OF SIGNIFICANCE Meta-biomaterials are a special class of metamaterials with unusual or unprecedented combinations of mechanical, physical (e.g. mass transport), and biological properties. Topologically complex and additively manufactured meta-biomaterials have been shown to improve bone regeneration and osseointegration. The mechanical properties of such biomaterials are directly related to their topological design and material type. However, previous studies of such biomaterials have largely neglected the effects of material type, instead focusing on topological design. We show here that neglecting the effects of material type is unjustified. We studied the isolated and combined effects of topological design and material type on the normalized S-N curves of metallic bone-mimicking biomaterials and found them to be more strongly dependent on the material type than topological design.
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87
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Abstract
Additive manufacturing (3D printing) has found many applications in healthcare including fabrication of biomaterials as well as bioprinting of tissues and organs. Additively manufactured (AM) biomaterials may possess arbitrarily complex micro-architectures that give rise to novel mechanical, physical, and biological properties. The mechanical behavior of such porous biomaterials including their quasi-static mechanical properties and fatigue resistance is not yet well understood. It is particularly important to understand the relationship between the designed micro-architecture (topology) and the resulting mechanical properties. The current special issue is dedicated to understanding the mechanical behavior of AM biomaterials. Although various types of AM biomaterials are represented in the special issue, the primary focus is on AM porous metallic biomaterials. As a prelude to this special issue, this editorial reviews some of the latest findings in the mechanical behavior of AM porous metallic biomaterials so as to describe the current state-of-the-art and set the stage for the other studies appearing in the issue. Some areas that are important for future research are also briefly mentioned.
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Affiliation(s)
- Amir A Zadpoor
- Additive Manufacturing Laboratory, Department of Biomechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands.
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88
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Mehrian M, Guyot Y, Papantoniou I, Olofsson S, Sonnaert M, Misener R, Geris L. Maximizing neotissue growth kinetics in a perfusion bioreactor: An in silico strategy using model reduction and Bayesian optimization. Biotechnol Bioeng 2017; 115:617-629. [DOI: 10.1002/bit.26500] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/14/2017] [Accepted: 11/20/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Mohammad Mehrian
- Biomechanics Research Unit; GIGA In Silico Medicine; University of Liège; Liège Belgium
- Prometheus; The Division of Skeletal Tissue Engineering; KU Leuven; Leuven Belgium
| | - Yann Guyot
- Biomechanics Research Unit; GIGA In Silico Medicine; University of Liège; Liège Belgium
- Prometheus; The Division of Skeletal Tissue Engineering; KU Leuven; Leuven Belgium
| | - Ioannis Papantoniou
- Prometheus; The Division of Skeletal Tissue Engineering; KU Leuven; Leuven Belgium
- Skeletal Biology and Engineering Research Center; KU Leuven; Leuven Belgium
| | - Simon Olofsson
- Department of Computing; Imperial College London; London United Kingdom
| | - Maarten Sonnaert
- Prometheus; The Division of Skeletal Tissue Engineering; KU Leuven; Leuven Belgium
- Department of Metallurgy and Materials Engineering; KU Leuven; Leuven Belgium
| | - Ruth Misener
- Department of Computing; Imperial College London; London United Kingdom
| | - Liesbet Geris
- Biomechanics Research Unit; GIGA In Silico Medicine; University of Liège; Liège Belgium
- Prometheus; The Division of Skeletal Tissue Engineering; KU Leuven; Leuven Belgium
- Biomechanics Section; KU Leuven; Leuven Belgium
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89
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Grau M, Matena J, Teske M, Petersen S, Aliuos P, Roland L, Grabow N, Murua Escobar H, Gellrich NC, Haferkamp H, Nolte I. In Vitro Evaluation of PCL and P(3HB) as Coating Materials for Selective Laser Melted Porous Titanium Implants. MATERIALS 2017; 10:ma10121344. [PMID: 29168794 PMCID: PMC5744279 DOI: 10.3390/ma10121344] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 11/01/2017] [Accepted: 11/20/2017] [Indexed: 11/16/2022]
Abstract
Titanium is widely used as a bone implant material due to its biocompatibility and high resilience. Since its Young’s modulus differs from bone tissue, the resulting “stress shielding” could lead to scaffold loosening. However, by using a scaffold-shaped geometry, the Young’s modulus can be adjusted. Also, a porous geometry enables vascularisation and bone ingrowth inside the implant itself. Additionally, growth factors can improve these effects. In order to create a deposit and release system for these factors, the titanium scaffolds could be coated with degradable polymers. Therefore, in the present study, synthetic poly-ε-caprolactone (PCL) and the biopolymer poly(3-hydroxybutyrate) (P(3HB)) were tested for coating efficiency, cell adhesion, and biocompatibility to find a suitable coating material. The underlying scaffold was created from titanium by Selective Laser Melting (SLM) and coated with PCL or P(3HB) via dip coating. To test the biocompatibility, Live Cell Imaging (LCI) as well as vitality and proliferation assays were performed. In addition, cell adhesion forces were detected via Single Cell Force Spectroscopy, while the coating efficiency was observed using environmental scanning electron microscopy (ESEM) and energy-dispersive X-ray (EDX) analyses. Regarding the coating efficiency, PCL showed higher values in comparison to P(3HB). Vitality assays revealed decent vitality values for both polymers, while values for PCL were significantly lower than those for blank titanium. No significant differences could be observed between PCL and P(3HB) in proliferation and cell adhesion studies. Although LCI observations revealed decreasing values in cell number and populated area over time on both polymer-coated scaffolds, these outcomes could be explained by the possibility of coating diluent residues accumulating in the culture medium. Overall, both polymers fulfill the requirements regarding biocompatibility. Nonetheless, since only PCL coating ensured the maintenance of the porous implant structure, it is preferable to be used as a coating material for creating a deposit and release system for growth factors.
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Affiliation(s)
- Michael Grau
- Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, D-30559 Hannover, Germany.
- Division of Medicine Clinic III, Hematology, Oncology and Palliative Medicine, University of Rostock, D-18057 Rostock, Germany.
| | - Julia Matena
- Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, D-30559 Hannover, Germany.
- Division of Medicine Clinic III, Hematology, Oncology and Palliative Medicine, University of Rostock, D-18057 Rostock, Germany.
| | - Michael Teske
- Institute for Biomedical Engineering, Rostock University Medical Center, D-18119 Rostock, Germany.
| | - Svea Petersen
- Faculty of Engineering and Computer Science, University of Applied Sciences, D-49076 Osnabrueck, Germany.
| | - Pooyan Aliuos
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, D-30625 Hannover, Germany.
| | - Laura Roland
- Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, D-30559 Hannover, Germany.
- Division of Medicine Clinic III, Hematology, Oncology and Palliative Medicine, University of Rostock, D-18057 Rostock, Germany.
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, D-18119 Rostock, Germany.
| | - Hugo Murua Escobar
- Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, D-30559 Hannover, Germany.
- Division of Medicine Clinic III, Hematology, Oncology and Palliative Medicine, University of Rostock, D-18057 Rostock, Germany.
| | - Nils-Claudius Gellrich
- Clinic for Cranio-Maxillo-Facial Surgery, Hannover Medical School, D-30625 Hannover, Germany.
| | - Heinz Haferkamp
- Institut fuer Werkstoffkunde, Leibniz Universitaet Hannover, D-30823 Garbsen, Germany.
| | - Ingo Nolte
- Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, D-30559 Hannover, Germany.
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90
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Lattice Structures and Functionally Graded Materials Applications in Additive Manufacturing of Orthopedic Implants: A Review. JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING 2017. [DOI: 10.3390/jmmp1020013] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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91
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Bray JP, Kersley A, Downing W, Crosse KR, Worth AJ, House AK, Yates G, Coomer AR, Brown IWM. Clinical outcomes of patient-specific porous titanium endoprostheses in dogs with tumors of the mandible, radius, or tibia: 12 cases (2013–2016). J Am Vet Med Assoc 2017; 251:566-579. [DOI: 10.2460/javma.251.5.566] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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92
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Bakhshandeh S, Gorgin Karaji Z, Lietaert K, Fluit AC, Boel CH, Vogely HC, Vermonden T, Hennink WE, Weinans H, Zadpoor AA, Amin Yavari S. Simultaneous Delivery of Multiple Antibacterial Agents from Additively Manufactured Porous Biomaterials to Fully Eradicate Planktonic and Adherent Staphylococcus aureus. ACS APPLIED MATERIALS & INTERFACES 2017; 9:25691-25699. [PMID: 28696671 PMCID: PMC5553095 DOI: 10.1021/acsami.7b04950] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 07/11/2017] [Indexed: 05/21/2023]
Abstract
Implant-associated infections are notoriously difficult to treat and may even result in amputation and death. The first few days after surgery are the most critical time to prevent those infections, preferably through full eradication of the micro-organisms entering the body perioperatively. That is particularly important for patients with a compromised immune system such as orthopedic oncology patients, as they are at higher risk for infection and complications. Full eradication of bacteria is, especially in a biofilm, extremely challenging due to the toxicity barrier that prevents delivery of high doses of antibacterial agents. This study aimed to use the potential synergistic effects of multiple antibacterial agents to prevent the use of toxic levels of these agents and achieve full eradication of planktonic and adherent bacteria. Silver ions and vancomycin were therefore simultaneously delivered from additively manufactured highly porous titanium implants with an extremely high surface area incorporating a bactericidal coating made from chitosan and gelatin applied by electrophoretic deposition (EPD). The presence of the chitosan/gelatin (Ch+Gel) coating, Ag, and vancomycin (Vanco) was confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The release of vancomycin and silver ions continued for at least 21 days as measured by inductively coupled plasma (ICP) and UV-spectroscopy. Antibacterial behavior against Staphylococcus aureus, both planktonic and in biofilm, was evaluated for up to 21 days. The Ch+Gel coating showed some bactericidal behavior on its own, while the loaded hydrogels (Ch+Gel+Ag and Ch+Gel+Vanco) achieved full eradication of both planktonic and adherent bacteria without causing significant levels of toxicity. Combining silver and vancomycin improved the release profiles of both agents and revealed a synergistic behavior that further increased the bactericidal effects.
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Affiliation(s)
- S. Bakhshandeh
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - Z. Gorgin Karaji
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Mechanical Engineering, Kermanshah
University of Technology, Kermanshah, Iran
| | - K. Lietaert
- 3D Systems - LayerWise NV, 3001 Leuven, Belgium
- Department of Metallurgy and Materials
Engineering, KU Leuven, 3000 Leuven, Belgium
| | - A. C. Fluit
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
| | - C. H.
E. Boel
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
| | - H. C. Vogely
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
| | - T. Vermonden
- Department of Pharmaceutics, Utrecht Institute of Pharmaceutical
Sciences (UIPS), Utrecht University, 3512 JE Utrecht, The Netherlands
| | - W. E. Hennink
- Department of Pharmaceutics, Utrecht Institute of Pharmaceutical
Sciences (UIPS), Utrecht University, 3512 JE Utrecht, The Netherlands
| | - H. Weinans
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - A. A. Zadpoor
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - S. Amin Yavari
- Department of Orthopedics, Department of Medical Microbiology, and Department of
Rheumatology, University Medical Centre
Utrecht, 3584 CX Utrecht, The Netherlands
- Department of Biomechanical Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands
- E-mail: , . Tel: +31-88-7559025
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93
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Rana M, Chin SJ, Muecke T, Kesting M, Groebe A, Riecke B, Heiland M, Gellrich NC. Increasing the accuracy of mandibular reconstruction with free fibula flaps using functionalized selective laser-melted patient-specific implants: A retrospective multicenter analysis. J Craniomaxillofac Surg 2017; 45:1212-1219. [DOI: 10.1016/j.jcms.2017.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 01/25/2017] [Accepted: 04/10/2017] [Indexed: 11/30/2022] Open
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94
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Tan N, Liu X, Cai Y, Zhang S, Jian B, Zhou Y, Xu X, Ren S, Wei H, Song Y. The influence of direct laser metal sintering implants on the early stages of osseointegration in diabetic mini-pigs. Int J Nanomedicine 2017; 12:5433-5442. [PMID: 28814861 PMCID: PMC5546787 DOI: 10.2147/ijn.s138615] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background High failure rates of oral implants have been reported in diabetic patients due to the disruption of osseointegration. The aim of this study was to investigate whether direct laser metal sintering (DLMS) could improve osseointegration in diabetic animal models. Methods Surface characterizations were carried out on two types of implants. Cell morphology and the osteogenic-related gene expression of MG63 cells were observed under conditions of DLMS and microarc oxidation (MAO). A diabetes model in mini-pigs was established by intravenous injection of streptozotocin (150 mg/kg), and a total of 36 implants were inserted into the mandibular region. Micro-computed tomography (micro-CT) and histologic evaluations were performed 3 and 6 months after implantation. Results The Ra (the average of the absolute height of all points) of MAO surface was 2.3±0.3 µm while the DLMS surface showed the Ra of 27.4±1.1 µm. The cells on DLMS implants spread out more podia than those on MAO implants through cell morphology analysis. Osteogenic-related gene expression was also dramatically increased in the DLMS group. Obvious improvement was observed in the micro-CT and Van Gieson staining analyses of DLMS implants compared with MAO at 3 months, although this difference disappeared by 6 months. DLMS implants showed a higher bone–implant contact percentage (33.2%±11.2%) at 3 months compared with MAO group (18.9%±7.3%) while similar results were showed at 6 months between DLMS group (42.8%±10.1%) and MAO group (38.3%±10.8%). Conclusion The three-dimensional environment of implant surfaces with highly porous and fully interconnected channel and pore architectures can improve cell spreading and accelerate the progress of osseointegration in diabetic mini-pigs.
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Affiliation(s)
- Naiwen Tan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China.,Department of Stomatology, Hospital 463 of PLA, Xi'an, Shaanxi, China
| | - Xiangwei Liu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yanhui Cai
- Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Sijia Zhang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Bo Jian
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yuchao Zhou
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiaoru Xu
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shuai Ren
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Hongbo Wei
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yingliang Song
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Xi'an, Shaanxi, China.,Department of Implant Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, China
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95
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Cox SC, Jamshidi P, Eisenstein NM, Webber MA, Burton H, Moakes RJA, Addison O, Attallah M, Shepherd DE, Grover LM. Surface Finish has a Critical Influence on Biofilm Formation and Mammalian Cell Attachment to Additively Manufactured Prosthetics. ACS Biomater Sci Eng 2017; 3:1616-1626. [DOI: 10.1021/acsbiomaterials.7b00336] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
| | | | - Neil M. Eisenstein
- Royal Centre for Defence Medicine, Birmingham Research Park, Vincent Drive, Edgbaston B15 2SQ, United Kingdom
| | - Mark A. Webber
- Institute of Food Research, Norwich
Research Park, Norwich NR4 7UG, United Kingdom
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96
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Osseointegration assessment of extrusion printed Ti6Al4V scaffold towards accelerated skeletal defect healing via tissue in-growth. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.bprint.2017.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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97
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Kim HJ, Kang KT, Park SC, Kwon OH, Son J, Chang BS, Lee CK, Yeom JS, Lenke LG. Biomechanical advantages of robot-assisted pedicle screw fixation in posterior lumbar interbody fusion compared with freehand technique in a prospective randomized controlled trial-perspective for patient-specific finite element analysis. Spine J 2017; 17:671-680. [PMID: 27867080 DOI: 10.1016/j.spinee.2016.11.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 10/19/2016] [Accepted: 11/14/2016] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT There have been conflicting results on the surgical outcome of lumbar fusion surgery using two different techniques: robot-assisted pedicle screw fixation and conventional freehand technique. In addition, there have been no studies about the biomechanical issues between both techniques. PURPOSE This study aimed to investigate the biomechanical properties in terms of stress at adjacent segments using robot-assisted pedicle screw insertion technique (robot-assisted, minimally invasive posterior lumbar interbody fusion, Rom-PLIF) and freehand technique (conventional, freehand, open approach, posterior lumbar interbody fusion, Cop-PLIF) for instrumented lumbar fusion surgery. STUDY DESIGN This is an additional post-hoc analysis for patient-specific finite element (FE) model. PATIENT SAMPLE The sample is composed of patients with degenerative lumbar disease. OUTCOME MEASURES Intradiscal pressure and facet contact force are the outcome measures. METHODS Patients were randomly assigned to undergo an instrumented PLIF procedure using a Rom-PLIF (37 patients) or a Cop-PLIF (41), respectively. Five patients in each group were selected using a simple random sampling method after operation, and 10 preoperative and postoperative lumbar spines were modeled from preoperative high-resolution computed tomography of 10 patients using the same method for a validated lumbar spine model. Under four pure moments of 7.5 Nm, the changes in intradiscal pressure and facet joint contact force at the proximal adjacent segment following fusion surgery were analyzed and compared with preoperative states. RESULTS The representativeness of random samples was verified. Both groups showed significant increases in postoperative intradiscal pressure at the proximal adjacent segment under four moments, compared with the preoperative state. The Cop-PLIF models demonstrated significantly higher percent increments of intradiscal pressure at proximal adjacent segments under extension, lateral bending, and torsion moments than the Rom-PLIF models (p=.032, p=.008, and p=.016, respectively). Furthermore, the percent increment of facet contact force was significantly higher in the Cop-PLIF models under extension and torsion moments than in the Rom-PLIF models (p=.016 under both extension and torsion moments). CONCLUSIONS The present study showed the clinical application of subject-specific FE analysis in the spine. Even though there was biomechanical superiority of the robot-assisted insertions in terms of alleviation of stress increments at adjacent segments after fusion, cautious interpretation is needed because of the small sample size.
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Affiliation(s)
- Ho-Joong Kim
- Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam, 463-707, Republic of Korea
| | - Kyoung-Tak Kang
- Department of Mechanical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Sung-Cheol Park
- Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam, 463-707, Republic of Korea
| | - Oh-Hyo Kwon
- Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam, 463-707, Republic of Korea
| | - Juhyun Son
- Department of Mechanical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Bong-Soon Chang
- Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul, 110-744, Republic of Korea
| | - Choon-Ki Lee
- Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul, 110-744, Republic of Korea
| | - Jin S Yeom
- Spine Center and Department of Orthopaedic Surgery, Seoul National University College of Medicine and Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam, 463-707, Republic of Korea.
| | - Lawrence G Lenke
- Columbia University Department of Orthopedic Surgery, Division of Spinal Surgery, Spine Hospital at New York-Presbyterian/The Allen Hospital, 5141 Broadway, 3 Field West, New York, NY 10034, USA
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98
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Yang DH, Moon SW, Jang G, Park K, Yoo Y, Lee DW. Surface modification of titanium with β-CD/polydopamine for a controlled release of lovastatin, and its effect on the enhanced osteogenic activity. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2017.01.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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99
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Meyers N, Sukopp M, Jäger R, Steiner M, Matthys R, Lapatki B, Ignatius A, Claes L. Characterization of interfragmentary motion associated with common osteosynthesis devices for rat fracture healing studies. PLoS One 2017; 12:e0176735. [PMID: 28453556 PMCID: PMC5409164 DOI: 10.1371/journal.pone.0176735] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/14/2017] [Indexed: 01/21/2023] Open
Abstract
Rat models are widely used in preclinical studies investigating fracture healing. The interfragmentary movement at a fracture site is critical to the course of healing and therefore demands definition in order to aptly interpret the experimental results. Estimation of this movement requires knowledge of the fixation stiffness and loading. The characteristic loading for the rat femur has been estimated, but the stiffness of fixation used in rat studies has yet to be fully described. This study aimed to determine the 6 degree of freedom stiffness of four commonly used implants, two external fixators (RatExFix and UlmExFix), a locking plate, and a locking intramedullary nail, in all degrees of freedom and estimate the interfragmentary movement under specific physiological loads. The external fixator systems allow the greatest movement. Mounted 45° anterolateral on the femur, the RatExFix allows an average of 0.88 mm of motion in each anatomic direction while the stiffer UlmExFix allows about 0.6 mm of motion. The nail is far stiffer than the other implants investigated while the plate allows movement of an intermediate magnitude. Both the nail and plate demonstrate higher axial than shear stiffness. The relatively large standard deviations in external fixator shear motion imply strong dependence on bone axis alignment across the gap and the precise orientation of the specimen relative to the loading. The smaller standard deviation associated with the nail and plate results from improved alignment and minimization of the influence of rotational positioning of the specimen due to the reduced implant eccentricity relative to the specimen axis. These results show that the interfragmentary movement is complex and varies significantly between fixation devices but establishes a baseline for the evaluation of the results of different studies.
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Affiliation(s)
- Nicholaus Meyers
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
- * E-mail:
| | - Matthias Sukopp
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Rudolf Jäger
- Department of Orthodontics, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Malte Steiner
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | | | - Bernd Lapatki
- Department of Orthodontics, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
| | - Lutz Claes
- Institute of Orthopedic Research and Biomechanics, Center of Musculoskeletal Research Ulm, University Hospital Ulm, Ulm, Baden-Württemberg, Germany
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100
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Li S, Xie X, Yang X, Liu L, Tang X. [Research of enhanced green fluorescent protein gene transfer with ultrasound-mediated microbubble destruction in bone defects]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2017; 31:437-442. [PMID: 29798609 DOI: 10.7507/1002-1892.201611059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Objective To investigate the effect of ultrasonic irradiation time on enhanced green fluorescent protein (EGFP) gene transfection efficiency and local tissue in bone defects using ultrasound-mediated microbubble destruction. Methods Thirty 3-month-old New Zealand rabbits (2.5-3.0 kg in weight) were randomly divided into 5 groups ( n=6) and bone defect models were made on the right ulna. At 10 days after modeling, suspension of microbubbles and EGFP plasmids were locally injected (0.3 mL/kg) and then ultrasound was performed on defect at a frequency of 1 MHz, a intensity of 0.5 W/cm 2, and a duty ratio of 20% for 1, 2, 3, 4, and 5 minutes respectively (in 1, 2, 3, 4, and 5 minutes groups respectively). The survival condition was observed. Rabbits were sacrificed for gross observation at 7 days after transfer. The gene expression was observed by fluorescence staining. HE staining and transmission electron microscopy were used to observe the local tissue damage. Results The animals all survived. New soft tissue formed in bone defects area at 1 week after transfer, the surrounding muscle tissue was partly filled in it. Green fluorescence expression was observed in all rabbits. The expression was the strongest in 2 minutes group, and was the weakest in 1 minute group. The absorbance ( A) value showed significant differences when compared 1 minute and 2 minutes groups with other groups ( P<0.05), but no significant difference was found between 3, 4, and 5 minutes groups ( P>0.05). Tissue damage was observed in all groups and it was aggravated with the increase of irradiation time. Conclusion EGFP transfection efficiency in bone defect by ultrasound-mediated microbubble destruction is related to irradiation time. EGFP gene can be efficiently transfected without obvious toxicity at 1 MHz, 0.5W/cm 2, and duty ratio of 20% for 2 minutes in bone defects of rabbits.
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Affiliation(s)
- Shiwei Li
- Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Xiaoli Xie
- Department of Pediatric Surgery, Guangzhou Women and Children's Medical Center, Guangzhou Guangdong, 510623, P.R.China
| | - Xiaodong Yang
- Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Lijun Liu
- Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China
| | - Xueyang Tang
- Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu Sichuan, 610041,
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