1
|
Rahmani R, Lopes SI, Prashanth KG. Selective Laser Melting and Spark Plasma Sintering: A Perspective on Functional Biomaterials. J Funct Biomater 2023; 14:521. [PMID: 37888186 PMCID: PMC10607885 DOI: 10.3390/jfb14100521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/09/2023] [Accepted: 10/14/2023] [Indexed: 10/28/2023] Open
Abstract
Achieving lightweight, high-strength, and biocompatible composites is a crucial objective in the field of tissue engineering. Intricate porous metallic structures, such as lattices, scaffolds, or triply periodic minimal surfaces (TPMSs), created via the selective laser melting (SLM) technique, are utilized as load-bearing matrices for filled ceramics. The primary metal alloys in this category are titanium-based Ti6Al4V and iron-based 316L, which can have either a uniform cell or a gradient structure. Well-known ceramics used in biomaterial applications include titanium dioxide (TiO2), zirconium dioxide (ZrO2), aluminum oxide (Al2O3), hydroxyapatite (HA), wollastonite (W), and tricalcium phosphate (TCP). To fill the structures fabricated by SLM, an appropriate ceramic is employed through the spark plasma sintering (SPS) method, making them suitable for in vitro or in vivo applications following minor post-processing. The combined SLM-SPS approach offers advantages, such as rapid design and prototyping, as well as assured densification and consolidation, although challenges persist in terms of large-scale structure and molding design. The individual or combined application of SLM and SPS processes can be implemented based on the specific requirements for fabricated sample size, shape complexity, densification, and mass productivity. This flexibility is a notable advantage offered by the combined processes of SLM and SPS. The present article provides an overview of metal-ceramic composites produced through SLM-SPS techniques. Mg-W-HA demonstrates promise for load-bearing biomedical applications, while Cu-TiO2-Ag exhibits potential for virucidal activities. Moreover, a functionally graded lattice (FGL) structure, either in radial or longitudinal directions, offers enhanced advantages by allowing adjustability and control over porosity, roughness, strength, and material proportions within the composite.
Collapse
Affiliation(s)
- Ramin Rahmani
- CiTin—Centro de Interface Tecnológico Industrial, 4970-786 Arcos de Valdevez, Portugal;
- proMetheus, Instituto Politécnico de Viana do Castelo (IPVC), 4900-347 Viana do Castelo, Portugal
| | - Sérgio Ivan Lopes
- CiTin—Centro de Interface Tecnológico Industrial, 4970-786 Arcos de Valdevez, Portugal;
- ADiT-Lab, Instituto Politécnico de Viana do Castelo (IPVC), 4900-347 Viana do Castelo, Portugal
| | - Konda Gokuldoss Prashanth
- Department of Mechanical and Industrial Engineering, Tallinn University of Technology, 19086 Tallinn, Estonia;
- CBCMT, School of Mechanical Engineering, Vellore Institute of Technology, Vellore 630014, Tamil Nadu, India
| |
Collapse
|
2
|
Volova LT, Kotelnikov GP, Shishkovsky I, Volov DB, Ossina N, Ryabov NA, Komyagin AV, Kim YH, Alekseev DG. 3D Bioprinting of Hyaline Articular Cartilage: Biopolymers, Hydrogels, and Bioinks. Polymers (Basel) 2023; 15:2695. [PMID: 37376340 DOI: 10.3390/polym15122695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
The musculoskeletal system, consisting of bones and cartilage of various types, muscles, ligaments, and tendons, is the basis of the human body. However, many pathological conditions caused by aging, lifestyle, disease, or trauma can damage its elements and lead to severe disfunction and significant worsening in the quality of life. Due to its structure and function, articular (hyaline) cartilage is the most susceptible to damage. Articular cartilage is a non-vascular tissue with constrained self-regeneration capabilities. Additionally, treatment methods, which have proven efficacy in stopping its degradation and promoting regeneration, still do not exist. Conservative treatment and physical therapy only relieve the symptoms associated with cartilage destruction, and traditional surgical interventions to repair defects or endoprosthetics are not without serious drawbacks. Thus, articular cartilage damage remains an urgent and actual problem requiring the development of new treatment approaches. The emergence of biofabrication technologies, including three-dimensional (3D) bioprinting, at the end of the 20th century, allowed reconstructive interventions to get a second wind. Three-dimensional bioprinting creates volume constraints that mimic the structure and function of natural tissue due to the combinations of biomaterials, living cells, and signal molecules to create. In our case-hyaline cartilage. Several approaches to articular cartilage biofabrication have been developed to date, including the promising technology of 3D bioprinting. This review represents the main achievements of such research direction and describes the technological processes and the necessary biomaterials, cell cultures, and signal molecules. Special attention is given to the basic materials for 3D bioprinting-hydrogels and bioinks, as well as the biopolymers underlying the indicated products.
Collapse
Affiliation(s)
- Larisa T Volova
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Gennadiy P Kotelnikov
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Igor Shishkovsky
- Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Dmitriy B Volov
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Natalya Ossina
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Nikolay A Ryabov
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Aleksey V Komyagin
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| | - Yeon Ho Kim
- RokitHealth Care Ltd., 9, Digital-ro 10-gil, Geumcheon-gu, Seoul 08514, Republic of Korea
| | - Denis G Alekseev
- Research and Development Institute of Biotechnologies, Samara State Medical University, Chapayevskaya St. 89, 443099 Samara, Russia
| |
Collapse
|
3
|
Corrosion Behavior of TiNi Alloy Fabricated by Selective Laser Melting in Simulated Saliva. COATINGS 2022. [DOI: 10.3390/coatings12060840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
In this work, TiNi samples were prepared by Selective Laser Melting (SLM) technology, and the influence of microstructure, fluoride ion, and pH value on corrosion behavior in a saline environment was investigated and compared with TiNi alloy fabricated by traditional forging technology. The results indicated that the corrosion resistance of the SLM sample was slightly superior to that of the wrought sample in a saline environment due to the uniform and dense oxide film formed on the SLM sample surface. However, in acidic Artificial Saliva Solution (ASS) containing fluoride ions, the corrosion current density of the SLM sample increased from 9.85 × 10−2 to 13.9 μA/cm2 because of the presence of F−. Fluorine ions disrupted the passive film on the surface, and the Ti-F compound formed in the film, which deteriorated the corrosion resistance of the SLM sample. The increase in fluoride concentration and the decrease in pH value could accelerate the corrosion of the SLM sample.
Collapse
|
4
|
Additive Manufacturing: An Opportunity for the Fabrication of Near-Net-Shape NiTi Implants. JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING 2022. [DOI: 10.3390/jmmp6030065] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Nickel–titanium (NiTi) is a shape-memory alloy, a type of material whose name is derived from its ability to recover its original shape upon heating to a certain temperature. NiTi falls under the umbrella of metallic materials, offering high superelasticity, acceptable corrosion resistance, a relatively low elastic modulus, and desirable biocompatibility. There are several challenges regarding the processing and machinability of NiTi, originating from its high ductility and reactivity. Additive manufacturing (AM), commonly known as 3D printing, is a promising candidate for solving problems in the fabrication of near-net-shape NiTi biomaterials with controlled porosity. Powder-bed fusion and directed energy deposition are AM approaches employed to produce synthetic NiTi implants. A short summary of the principles and the pros and cons of these approaches is provided. The influence of the operating parameters, which can change the microstructural features, including the porosity content and orientation of the crystals, on the mechanical properties is addressed. Surface-modification techniques are recommended for suppressing the Ni ion leaching from the surface of AM-fabricated NiTi, which is a technical challenge faced by the long-term in vivo application of NiTi.
Collapse
|
5
|
On-Growth and In-Growth Osseointegration Enhancement in PM Porous Ti-Scaffolds by Two Different Bioactivation Strategies: Alkali Thermochemical Treatment and RGD Peptide Coating. Int J Mol Sci 2022; 23:ijms23031750. [PMID: 35163682 PMCID: PMC8835960 DOI: 10.3390/ijms23031750] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 01/25/2022] [Accepted: 01/30/2022] [Indexed: 02/01/2023] Open
Abstract
A lack of primary stability and osteointegration in metallic implants may result in implant loosening and failure. Adding porosity to metallic implants reduces the stress shielding effect and improves implant performance, allowing the surrounding bone tissue to grow into the scaffold. However, a bioactive surface is needed to stimulate implant osteointegration and improve mechanical stability. In this study, porous titanium implants were produced via powder sintering to create different porous diameters and open interconnectivity. Two strategies were used to generate a bioactive surface on the metallic foams: (1) an inorganic alkali thermochemical treatment, (2) grafting a cell adhesive tripeptide (RGD). RGD peptides exhibit an affinity for integrins expressed by osteoblasts, and have been reported to improve osteoblast adhesion, whereas the thermochemical treatment is known to improve titanium implant osseointegration upon implantation. Bioactivated scaffolds and control samples were implanted into the tibiae of rabbits to analyze the effect of these two strategies in vivo regarding bone tissue regeneration through interconnected porosity. Histomorphometric evaluation was performed at 4 and 12 weeks after implantation. Bone-to-implant contact (BIC) and bone in-growth and on-growth were evaluated in different regions of interest (ROIs) inside and outside the implant. The results of this study show that after a long-term postoperative period, the RGD-coated samples presented higher quantification values of quantified newly formed bone tissue in the implant's outer area. However, the total analyzed bone in-growth was observed to be slightly greater in the scaffolds treated with alkali thermochemical treatment. These results suggest that both strategies contribute to enhancing porous metallic implant stability and osteointegration, and a combination of both strategies might be worth pursuing.
Collapse
|
6
|
Elhattab K, Hefzy MS, Hanf Z, Crosby B, Enders A, Smiczek T, Haghshenas M, Jahadakbar A, Elahinia M. Biomechanics of Additively Manufactured Metallic Scaffolds-A Review. MATERIALS (BASEL, SWITZERLAND) 2021; 14:6833. [PMID: 34832234 PMCID: PMC8625735 DOI: 10.3390/ma14226833] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 12/16/2022]
Abstract
This review paper is related to the biomechanics of additively manufactured (AM) metallic scaffolds, in particular titanium alloy Ti6Al4V scaffolds. This is because Ti6Al4V has been identified as an ideal candidate for AM metallic scaffolds. The factors that affect the scaffold technology are the design, the material used to build the scaffold, and the fabrication process. This review paper includes thus a discussion on the design of Ti6A4V scaffolds in relation to how their behavior is affected by their cell shapes and porosities. This is followed by a discussion on the post treatment and mechanical characterization including in-vitro and in-vivo biomechanical studies. A review and discussion are also presented on the ongoing efforts to develop predictive tools to derive the relationships between structure, processing, properties and performance of powder-bed additive manufacturing of metals. This is a challenge when developing process computational models because the problem involves multi-physics and is of multi-scale in nature. Advantages, limitations, and future trends in AM scaffolds are finally discussed. AM is considered at the forefront of Industry 4.0, the fourth industrial revolution. The market of scaffold technology will continue to boom because of the high demand for human tissue repair.
Collapse
Affiliation(s)
| | - Mohamed Samir Hefzy
- Department of Mechanical, Industrial & Manufacturing Engineering, College of Engineering, The University of Toledo, Toledo, OH 43606, USA; (K.E.); (Z.H.); (B.C.); (A.E.); (T.S.); (M.H.); (A.J.); (M.E.)
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Stepputat VN, Zeidler H, Safranchik D, Strokin E, Böttger-Hiller F. Investigation of Post-Processing of Additively Manufactured Nitinol Smart Springs with Plasma-Electrolytic Polishing. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4093. [PMID: 34361284 PMCID: PMC8347378 DOI: 10.3390/ma14154093] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 11/16/2022]
Abstract
Additive manufacturing of Nitinol is a promising field, as it can circumvent the challenges associated with its conventional production processes and unlock unique advantages. However, the accompanying surface features such as powder adhesions, spatters, ballings, or oxide discolorations are undesirable in engineering applications and therefore must be removed. Plasma electrolytic polishing (PeP) might prove to be a suitable finishing process for this purpose, but the effects of post-processing on the mechanical and functional material properties of additively manufactured Nitinol are still largely unresearched. This study seeks to address this issue. The changes on and in the part caused by PeP with processing times between 2 and 20 min are investigated using Nitinol compression springs manufactured by Laser Beam Melting. As a benchmark for the scanning electron microscope images, the differential scanning calorimetry (DSC) measurements, and the mechanical load test cycles, conventionally fabricated Nitinol springs of identical geometry with a medical grade polished surface are used. After 5 min of PeP, a glossy surface free of powder adhesion is achieved, which is increasingly levelled by further polishing. The shape memory properties of the material are retained without a shift in the transformation temperatures being detectable. The decreasing spring rate is primarily attributable to a reduction in the effective wire diameter. Consequently, PeP has proven to be an applicable and effective post-processing method for additively manufactured Nitinol.
Collapse
Affiliation(s)
- Vincent N. Stepputat
- Institute for Machine Elements, Engineering Design and Manufacturing (IMKF), Technische Universität Bergakademie Freiberg, Chair of Additive Manufacturing, Agricolastr. 1, 09599 Freiberg, Germany; (V.N.S.); (D.S.)
| | - Henning Zeidler
- Institute for Machine Elements, Engineering Design and Manufacturing (IMKF), Technische Universität Bergakademie Freiberg, Chair of Additive Manufacturing, Agricolastr. 1, 09599 Freiberg, Germany; (V.N.S.); (D.S.)
- Beckmann-Institut für Technologieentwicklung e. V., Annaberger Str. 73, 09111 Chemnitz, Germany;
| | - Daniel Safranchik
- Institute for Machine Elements, Engineering Design and Manufacturing (IMKF), Technische Universität Bergakademie Freiberg, Chair of Additive Manufacturing, Agricolastr. 1, 09599 Freiberg, Germany; (V.N.S.); (D.S.)
- Technion–Israel Institute of Technology, Technion City, Haifa 3200003, Israel;
| | - Evgeny Strokin
- Technion–Israel Institute of Technology, Technion City, Haifa 3200003, Israel;
| | - Falko Böttger-Hiller
- Beckmann-Institut für Technologieentwicklung e. V., Annaberger Str. 73, 09111 Chemnitz, Germany;
| |
Collapse
|
8
|
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.
Collapse
|
9
|
Dentistry 4.0 Concept in the Design and Manufacturing of Prosthetic Dental Restorations. Processes (Basel) 2020. [DOI: 10.3390/pr8050525] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The paper is a comprehensive but compact review of the literature on the state of illnesses of the human stomatognathic system, related consequences in the form of dental deficiencies, and the resulting need for prosthetic treatment. Types of prosthetic restorations, including implants, as well as new classes of implantable devices called implant-scaffolds with a porous part integrated with a solid core, as well as biological engineering materials with the use of living cells, have been characterized. A review of works on current trends in the technical development of dental prosthetics aiding, called Dentistry 4.0, analogous to the concept of the highest stage of Industry 4.0 of the industrial revolution, has been presented. Authors’ own augmented holistic model of Industry 4.0 has been developed and presented. The studies on the significance of cone-beam computed tomography (CBCT) in planning prosthetic treatment, as well as in the design and manufacture of prosthetic restorations, have been described. The presented and fully digital approach is a radical turnaround in both clinical procedures and the technologies of implant preparation using computer-aided design and manufacturing methods (CAD/CAM) and additive manufacturing (AM) technologies, including selective laser sintering (SLS). The authors’ research illustrates the practical application of the Dentistry 4.0 approach for several types of prosthetic restorations. The development process of the modern approach is being observed all over the world. The use of the principles of the augmented holistic model of Industry 4.0 in advanced dental engineering indicates a change in the traditional relationship between a dentist and a dental engineer. The overall conclusion demonstrates that it is inevitable and extremely beneficial to implement the idea of Dentistry 4.0 following the assumptions of the authors’ own, holistic Industry 4.0 model.
Collapse
|
10
|
Guzzi EA, Tibbitt MW. Additive Manufacturing of Precision Biomaterials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1901994. [PMID: 31423679 DOI: 10.1002/adma.201901994] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/27/2019] [Indexed: 06/10/2023]
Abstract
Biomaterials play a critical role in modern medicine as surgical guides, implants for tissue repair, and as drug delivery systems. The emerging paradigm of precision medicine exploits individual patient information to tailor clinical therapy. While the main focus of precision medicine to date is the design of improved pharmaceutical treatments based on "-omics" data, the concept extends to all forms of customized medical care. This includes the design of precision biomaterials that are tailored to meet specific patient needs. Additive manufacturing (AM) enables free-form manufacturing and mass customization, and is a critical enabling technology for the clinical implementation of precision biomaterials. Materials scientists and engineers can contribute to the realization of precision biomaterials by developing new AM technologies, synthesizing advanced (bio)materials for AM, and improving medical-image-based digital design. As the field matures, AM is poised to provide patient-specific tissue and organ substitutes, reproducible microtissues for drug screening and disease modeling, personalized drug delivery systems, as well as customized medical devices.
Collapse
Affiliation(s)
- Elia A Guzzi
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Mark W Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zürich, 8092, Zürich, Switzerland
| |
Collapse
|
11
|
Ozan S, Munir K, Biesiekierski A, Ipek R, Li Y, Wen C. Titanium Alloys, Including Nitinol. Biomater Sci 2020. [DOI: 10.1016/b978-0-12-816137-1.00018-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
12
|
An in vitro Study on the Biocompatibility of Titanium Implants Made by Selective Laser Melting. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-019-0105-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
13
|
Ortiz-Hernandez M, Rappe KS, Molmeneu M, Mas-Moruno C, Guillem-Marti J, Punset M, Caparros C, Calero J, Franch J, Fernandez-Fairen M, Gil J. Two Different Strategies to Enhance Osseointegration in Porous Titanium: Inorganic Thermo-Chemical Treatment Versus Organic Coating by Peptide Adsorption. Int J Mol Sci 2018; 19:ijms19092574. [PMID: 30200178 PMCID: PMC6163352 DOI: 10.3390/ijms19092574] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/08/2018] [Accepted: 08/25/2018] [Indexed: 01/24/2023] Open
Abstract
In this study, highly-interconnected porous titanium implants were produced by powder sintering with different porous diameters and open interconnectivity. The actual foams were produced using high cost technologies: Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), and spark plasma sintering, and the porosity and/or interconnection was not optimized. The aim was to generate a bioactive surface on foams using two different strategies, based on inorganic thermo-chemical treatment and organic coating by peptide adsorption, to enhance osseointegration. Porosity was produced using NaCl as a space holder and polyethyleneglicol as a binder phase. Static and fatigue tests were performed in order to determine mechanical behaviors. Surface bioactivation was performed using a thermo-chemical treatment or by chemical adsorption with peptides. Osteoblast-like cells were cultured and cytotoxicity was measured. Bioactivated scaffolds and a control were implanted in the tibiae of rabbits. Histomorphometric evaluation was performed at 4 weeks after implantation. Interconnected porosity was 53% with an average diameter of 210 µm and an elastic modulus of around 1 GPa with good mechanical properties. The samples presented cell survival values close to 100% of viability. Newly formed bone was observed inside macropores, through interconnected porosity, and on the implant surface. Successful bone colonization of inner structure (40%) suggested good osteoconductive capability of the implant. Bioactivated foams showed better results than non-treated ones, suggesting both bioactivation strategies induce osteointegration capability.
Collapse
Affiliation(s)
- Monica Ortiz-Hernandez
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Katrin S Rappe
- Departamento de Cirugía Animal, Facultad de Veterinaria, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Meritxell Molmeneu
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Carles Mas-Moruno
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Jordi Guillem-Marti
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Miquel Punset
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Cristina Caparros
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
- Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Jose Calero
- Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Metallurgical Engineering, Universitat Politècnica de Catalunya (UPC), 08019 Barcelona, Spain.
| | - Jordi Franch
- Departamento de Cirugía Animal, Facultad de Veterinaria, Universidad Autónoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Mariano Fernandez-Fairen
- Facultad de Odontología, Campus de Medicina y Ciencias de la Salud, Universidad Internacional de Cataluña (UIC), 08017 Barcelona, Spain.
| | - Javier Gil
- Facultad de Odontología, Campus de Medicina y Ciencias de la Salud, Universidad Internacional de Cataluña (UIC), 08017 Barcelona, Spain.
| |
Collapse
|
14
|
Osteochondral tissue repair in osteoarthritic joints: clinical challenges and opportunities in tissue engineering. Biodes Manuf 2018; 1:101-114. [PMID: 30533248 PMCID: PMC6267278 DOI: 10.1007/s42242-018-0015-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/09/2018] [Indexed: 01/01/2023]
Abstract
Osteoarthritis (OA), identified as one of the priorities for the Bone and Joint Decade, is one of the most prevalent joint diseases, which causes pain and disability of joints in the adult population. Secondary OA usually stems from repetitive overloading to the osteochondral (OC) unit, which could result in cartilage damage and changes in the subchondral bone, leading to mechanical instability of the joint and loss of joint function. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bone in the early stages of OA and have shown potential in restoring the joint’s function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available OC scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, none of these scaffolds has shown satisfactory clinical results. This article reviews the OC tissue structure and the design, manufacturing and performance of current OC scaffolds in treatment of OA. The findings demonstrate the importance of biological and biomechanical fixations of OC scaffolds to the host tissue in achieving an improved cartilage fill and a hyaline-like tissue formation. Achieving a strong and stable subchondral bone support that helps the regeneration of overlying cartilage seems to be still a grand challenge for the early treatment of OA.
Collapse
|
15
|
Tamaddon M, Liu C. Enhancing Biological and Biomechanical Fixation of Osteochondral Scaffold: A Grand Challenge. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1059:255-298. [PMID: 29736578 DOI: 10.1007/978-3-319-76735-2_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Osteoarthritis (OA) is a degenerative joint disease, typified by degradation of cartilage and changes in the subchondral bone, resulting in pain, stiffness and reduced mobility. Current surgical treatments often fail to regenerate hyaline cartilage and result in the formation of fibrocartilage. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bones in the early stage of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available osteochondral (OC) scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, some controversial results are often reported from both clinical trials and animal studies. The objective of this chapter is to report the scaffolds clinical requirements and performance of the currently available OC scaffolds that have been investigated both in animal studies and in clinical trials. The findings have demonstrated the importance of biological and biomechanical fixation of the OC scaffolds in achieving good cartilage fill and improved hyaline cartilage formation. It is concluded that improving cartilage fill, enhancing its integration with host tissues and achieving a strong and stable subchondral bone support for overlying cartilage are still grand challenges for the early treatment of OA.
Collapse
Affiliation(s)
- Maryam Tamaddon
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, UK
| | - Chaozong Liu
- Institute of Orthopaedics & Musculoskeletal Science, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, UK.
| |
Collapse
|
16
|
Bose S, Ke D, Sahasrabudhe H, Bandyopadhyay A. Additive manufacturing of biomaterials. PROGRESS IN MATERIALS SCIENCE 2018; 93:45-111. [PMID: 31406390 PMCID: PMC6690629 DOI: 10.1016/j.pmatsci.2017.08.003] [Citation(s) in RCA: 201] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Biomaterials are used to engineer functional restoration of different tissues to improve human health and the quality of life. Biomaterials can be natural or synthetic. Additive manufacturing (AM) is a novel materials processing approach to create parts or prototypes layer-by-layer directly from a computer aided design (CAD) file. The combination of additive manufacturing and biomaterials is very promising, especially towards patient specific clinical applications. Challenges of AM technology along with related materials issues need to be realized to make this approach feasible for broader clinical needs. This approach is already making a significant gain towards numerous commercial biomedical devices. In this review, key additive manufacturing methods are first introduced followed by AM of different materials, and finally applications of AM in various treatment options. Realization of critical challenges and technical issues for different AM methods and biomaterial selections based on clinical needs are vital. Multidisciplinary research will be necessary to face those challenges and fully realize the potential of AM in the coming days.
Collapse
Affiliation(s)
- Susmita Bose
- Corresponding authors. (S. Bose), (A. Bandyopadhyay)
| | | | | | | |
Collapse
|
17
|
Saedi S, Saghaian SE, Jahadakbar A, Shayesteh Moghaddam N, Taheri Andani M, Saghaian SM, Lu YC, Elahinia M, Karaca HE. Shape memory response of porous NiTi shape memory alloys fabricated by selective laser melting. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:40. [PMID: 29564560 DOI: 10.1007/s10856-018-6044-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/05/2018] [Indexed: 06/08/2023]
Abstract
Porous NiTi scaffolds display unique bone-like properties including low stiffness and superelastic behavior which makes them promising for biomedical applications. The present article focuses on the techniques to enhance superelasticity of porous NiTi structures. Selective Laser Melting (SLM) method was employed to fabricate the dense and porous (32-58%) NiTi parts. The fabricated samples were subsequently heat-treated (solution annealing + aging at 350 °C for 15 min) and their thermo-mechanical properties were determined as functions of temperature and stress. Additionally, the mechanical behaviors of the samples were simulated and compared to the experimental results. It is shown that SLM NiTi with up to 58% porosity can display shape memory effect with full recovery under 100 MPa nominal stress. Dense SLM NiTi could show almost perfect superelasticity with strain recovery of 5.65 after 6% deformation at body temperatures. The strain recoveries were 3.5, 3.6, and 2.7% for samples with porosity levels of 32%, 45%, and 58%, respectively. Furthermore, it was shown that Young's modulus (i.e., stiffness) of NiTi parts can be tuned by adjusting the porosity levels to match the properties of the bones.
Collapse
Affiliation(s)
- Soheil Saedi
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506-0503, USA.
| | - Sayed E Saghaian
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506-0503, USA
| | - Ahmadreza Jahadakbar
- Dynamic and Smart Systems Laboratory, Mechanical Industrial and Manufacturing Engineering Department, The University of Toledo, Toledo, OH, 43606, USA
| | - Narges Shayesteh Moghaddam
- Dynamic and Smart Systems Laboratory, Mechanical Industrial and Manufacturing Engineering Department, The University of Toledo, Toledo, OH, 43606, USA
| | - Mohsen Taheri Andani
- Dynamic and Smart Systems Laboratory, Mechanical Industrial and Manufacturing Engineering Department, The University of Toledo, Toledo, OH, 43606, USA
- Department of Mechanical Engineering, S.M. Wu Manufacturing Research Center, College of Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Sayed M Saghaian
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506-0503, USA
| | - Y Charles Lu
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506-0503, USA
| | - Mohammad Elahinia
- Dynamic and Smart Systems Laboratory, Mechanical Industrial and Manufacturing Engineering Department, The University of Toledo, Toledo, OH, 43606, USA
| | - Haluk E Karaca
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, 40506-0503, USA
| |
Collapse
|
18
|
Mechanical and shape memory properties of porous Ni 50.1Ti 49.9 alloys manufactured by selective laser melting. J Mech Behav Biomed Mater 2017; 68:224-231. [PMID: 28189977 DOI: 10.1016/j.jmbbm.2017.01.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 01/03/2017] [Accepted: 01/28/2017] [Indexed: 12/19/2022]
Abstract
Near equiatomic NiTi shape memory alloys were fabricated in dense and designed porous forms by Selective Laser Melting (SLM) and their mechanical and shape memory properties were systematically characterized. Particularly, the effects of pore morphology on their mechanical responses were investigated. Dense and porous NiTi alloys exhibited good shape memory effect with a recoverable strain of about 5% and functional stability after eight cycles of compression. The stiffness and residual plastic strain of porous NiTi were found to depend highly on the pore shape and the level of porosity. Since porous NiTi structures have lower elastic modulus and density than dense NiTi with still good shape memory properties, they are promising materials for lightweight structures, energy absorbers, and biomedical implants.
Collapse
|
19
|
Shirazi SFS, Gharehkhani S, Mehrali M, Yarmand H, Metselaar HSC, Adib Kadri N, Osman NAA. A review on powder-based additive manufacturing for tissue engineering: selective laser sintering and inkjet 3D printing. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2015; 16:033502. [PMID: 27877783 PMCID: PMC5099820 DOI: 10.1088/1468-6996/16/3/033502] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 03/16/2015] [Accepted: 03/16/2015] [Indexed: 05/02/2023]
Abstract
Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article.
Collapse
Affiliation(s)
- Seyed Farid Seyed Shirazi
- Department of Mechanical Engineering and Advanced Material Research Center, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Samira Gharehkhani
- Department of Mechanical Engineering and Advanced Material Research Center, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Mehdi Mehrali
- Department of Mechanical Engineering and Advanced Material Research Center, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Hooman Yarmand
- Department of Mechanical Engineering and Advanced Material Research Center, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | - Nahrizul Adib Kadri
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Noor Azuan Abu Osman
- Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
20
|
Xu JL, Bao LZ, Liu AH, Jin XJ, Tong YX, Luo JM, Zhong ZC, Zheng YF. Microstructure, mechanical properties and superelasticity of biomedical porous NiTi alloy prepared by microwave sintering. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 46:387-393. [PMID: 25492002 DOI: 10.1016/j.jallcom.2015.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 10/08/2014] [Accepted: 10/21/2014] [Indexed: 05/28/2023]
Abstract
Porous NiTi alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH4HCO3) as the space holder agent to adjust the porosity in the range of 22-62%. The effects of porosities on the microstructure, hardness, compressive strength, bending strength, elastic modulus, phase transformation temperature and superelasticity of the porous NiTi alloys were investigated. The results showed that the porosities and average pore sizes of the porous NiTi alloys increased with increasing the contents of NH4HCO3. The porous NiTi alloys consisted of nearly single NiTi phase, with a very small amount of two secondary phases (Ni3Ti, NiTi2) when the porosities are lower than 50%. The amount of Ni3Ti and NiTi2 phases increased with further increasing of the porosity proportion. The porosities had few effects on the phase transformation temperatures of the porous NiTi alloys. By increasing the porosities, all of the hardness, compressive strength, elastic modulus, bending strength and superelasticity of the porous NiTi alloys decreased. However, the compressive strength and bending strength were higher or close to those of natural bone and the elastic modulus was close to the natural bone. The superelastic recovery strain of the trained porous NiTi alloys could reach between 3.1 and 4.7% at the pre-strain of 5%, even if the porosity was up to 62%. Moreover, partial shape memory effect was observed for all porosity levels under the experiment conditions. Therefore, the microwave sintered porous NiTi alloys could be a promising candidate for bone implant.
Collapse
Affiliation(s)
- J L Xu
- School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, PR China; Jiangsu Provincial Key Lab for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003, PR China.
| | - L Z Bao
- School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, PR China
| | - A H Liu
- Jiangsu Provincial Key Lab for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003, PR China
| | - X J Jin
- School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Y X Tong
- Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001, PR China
| | - J M Luo
- School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Z C Zhong
- School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, PR China
| | - Y F Zheng
- State Key Laboratory for Turbulence and Complex System and Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, PR China.
| |
Collapse
|
21
|
Andani MT, Shayesteh Moghaddam N, Haberland C, Dean D, Miller MJ, Elahinia M. Metals for bone implants. Part 1. Powder metallurgy and implant rendering. Acta Biomater 2014; 10:4058-70. [PMID: 24956564 DOI: 10.1016/j.actbio.2014.06.025] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/08/2014] [Accepted: 06/11/2014] [Indexed: 11/24/2022]
Abstract
New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed.
Collapse
|
22
|
Lewis G. Properties of open-cell porous metals and alloys for orthopaedic applications. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:2293-2325. [PMID: 23851927 DOI: 10.1007/s10856-013-4998-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 06/21/2013] [Indexed: 06/02/2023]
Abstract
One shortcoming of metals and alloys used to fabricate various components of orthopaedic systems, such as the femoral stem of a total hip joint replacement and the tibial plate of a total knee joint replacement, is well-recognized. This is that the material modulus of elasticity (E') is substantially larger than that of the contiguous cancellous bone, a consequence of which is stress shielding which, in turn, has been postulated to be implicated in a cascade of events that culminates in the principal life-limiting phenomenon of these systems, namely, aseptic loosening. Thus, over the years, a host of research programs have focused on the synthesis of metallic biomaterials whose E' can be tailored to match that of cancellous bone. The present work is a review of the extant large volume of literature on these materials, which are called open-cell porous metals/alloys (or, sometimes, metal foams or cellular materials). As such, its range is wide, covering myriad aspects such as production methods, characterization studies, in vitro evaluations, and in vivo performance. The review also includes discussion of seven areas for future research, such as parametric studies of the influence of an assortment of process variables (such as the space holder material and the laser power in the space holder method and the laser-engineered net-shaping process, respectively) on various properties (notably, permeability, fatigue strength, and corrosion resistance) of a given porous metal/alloy, innovative methods of determining fatigue strength, and modeling of corrosion behavior.
Collapse
Affiliation(s)
- Gladius Lewis
- Department of Mechanical Engineering, The University of Memphis, Memphis, TN, 38152-3180, USA,
| |
Collapse
|
23
|
Cheng X, Li S, Murr L, Zhang Z, Hao Y, Yang R, Medina F, Wicker R. Compression deformation behavior of Ti–6Al–4V alloy with cellular structures fabricated by electron beam melting. J Mech Behav Biomed Mater 2012. [DOI: 10.1016/j.jmbbm.2012.10.005] [Citation(s) in RCA: 229] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Basalah A, Shanjani Y, Esmaeili S, Toyserkani E. Characterizations of additive manufactured porous titanium implants. J Biomed Mater Res B Appl Biomater 2012; 100:1970-9. [PMID: 22865677 DOI: 10.1002/jbm.b.32764] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 05/25/2012] [Accepted: 06/07/2012] [Indexed: 11/07/2022]
Abstract
This article describes physical, chemical, and mechanical characterizations of porous titanium implants made by an additive manufacturing method to gain insight into the correlation of process parameters and final physical properties of implants used in orthopedics. For the manufacturing chain, the powder metallurgy technology was combined with the additive manufacturing to fabricate the porous structure from the pure tanium powder. A 3D printing machine was employed in this study to produce porous bar samples. A number of physical parameters such as titanium powder size, polyvinyl alcohol (PVA) amount, sintering temperature and time were investigated to control the mechanical properties and porosity of the structures. The produced samples were characterized through porosity and shrinkage measurements, mechanical compression test and scanning electron microscopy (SEM). The results showed a level of porosity in the samples in the range of 31-43%, which is within the range of the porosity of the cancelluous bone and approaches the range of the porosity of the cortical bone. The results of the mechanical test showed that the compressive strength is in the wide range of 56-509 MPa implying the effect of the process parameters on the mechanical strengths. This technique of manufacturing of Ti porous structures demonstrated a low level of shrinkage with the shrinkage percentage ranging from 1.5 to 5%.
Collapse
Affiliation(s)
- Ahmad Basalah
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | | | | | | |
Collapse
|
25
|
de Peppo GM, Palmquist A, Borchardt P, Lennerås M, Hyllner J, Snis A, Lausmaa J, Thomsen P, Karlsson C. Free-form-fabricated commercially pure Ti and Ti6Al4V porous scaffolds support the growth of human embryonic stem cell-derived mesodermal progenitors. ScientificWorldJournal 2012; 2012:646417. [PMID: 22262956 PMCID: PMC3259715 DOI: 10.1100/2012/646417] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 10/15/2011] [Indexed: 12/14/2022] Open
Abstract
Commercially-pure titanium (cp-Ti) and the titanium-aluminum-vanadium alloy (Ti6Al4V) are widely used as reconstructive implants for skeletal engineering applications, due to their good mechanical properties, biocompatibility and ability to integrate with the surrounding bone. Electron beam melting technology (EBM) allows the fabrication of customized implants with tailored mechanical properties and high potential in the clinical practice. In order to augment the interaction with the biological tissue, stem cells have recently been combined with metallic scaffolds for skeletal engineering applications. We previously demonstrated that human embryonic stem cell-derived mesodermal progenitors (hES-MPs) hold a great potential to provide a homogeneous and unlimited supply of cells for bone engineering applications. This study demonstrates the effect of EBM-fabricated cp-Ti and Ti6Al4V porous scaffolds on hES-MPs behavior, in terms of cell attachment, growth and osteogenic differentiation. Displaying different chemical composition but similar surface properties, EBM-fabricated cp-Ti and Ti6Al4V scaffolds supported cell attachment and growth, and did not seem to alter the expression of genes involved in osteogenic differentiation and affect the alkaline phosphatase activity. In conclusion, interfacing hES-MPs to EBM-fabricated scaffolds may represent an interesting strategy for design of third-generation biomaterials, with the potential to promote implant integration in clinical conditions characterized by poor bone quality.
Collapse
Affiliation(s)
- G M de Peppo
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, P.O. Box 412, 41346 Göteborg, Sweden.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Neurohr AJ, Dunand DC. Shape-memory NiTi with two-dimensional networks of micro-channels. Acta Biomater 2011; 7:1862-72. [PMID: 21130189 DOI: 10.1016/j.actbio.2010.11.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 11/03/2010] [Accepted: 11/29/2010] [Indexed: 10/18/2022]
Abstract
A process was developed for fabricating arrays of micro-channels in shape-memory NiTi for bone implant applications, with a tailorable internal architecture expected to improve biomechanical compatibility and osseointegration. Ni-51.4 at.% Ti with 24-34 vol.% porosity was fabricated by electrochemical dissolution of parallel layers of steel wire meshes embedded within a NiTi matrix during hot pressing of NiTi powders. The resulting NiTi structures exhibit parallel layers of orthogonally interconnected micro-channels with 350-400 μm diameters that exactly replicate the steel meshes. When low-carbon steel wires are used, iron diffuses into the surrounding NiTi during the densification step, creating a Fe-enriched zone near the wires. For high-carbon steel wires, TiC forms at the steel/NiTi interface and inhibits iron diffusion but also depletes some titanium from the adjacent NiTi. In both cases, the NiTi regions near the micro-channels exhibit altered phase transformation characteristics. These NiTi structures with replicated networks of micro-channels have excellent potential as bone implants and scaffolds given: (i) the versatility in channel size, shape, fraction and spatial arrangement; (ii) their low stiffness (15-26 GPa), close to 12-17 GPa for cortical bone; (iii) their high compressive strength (420-600 MPa at 8-9% strain); and (iv) their excellent compressive strain recovery (91-94% of an applied strain of 6%) by a combination of elasticity, superelasticity and the shape-memory effect.
Collapse
|
27
|
Wu S, Liu X, Yeung K, Hu T, Xu Z, Chung JC, Chu PK. Hydrogen release from titanium hydride in foaming of orthopedic NiTi scaffolds. Acta Biomater 2011; 7:1387-97. [PMID: 20965283 DOI: 10.1016/j.actbio.2010.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 09/06/2010] [Accepted: 10/12/2010] [Indexed: 11/26/2022]
Abstract
Titanium hydride powders are utilized to enhance the foaming process in the formation of orthopedic NiTi scaffolds during capsule-free hot isostatic pressing. In order to study the formation mechanism, the thermal behavior of titanium hydride and hydrogen release during the heating process are systematically investigated in air and argon and under vacuum by X-ray diffraction (XRD), thermal analysis, including thermogravimetric analysis and differential scanning calorimetry, energy dispersive X-ray spectroscopy, and transmission electron microscopy. Our experiments reveal that hydrogen is continuously released from titanium hydride as the temperature is gradually increased from 300 to 700 °C. Hydrogen is released in two transitions: TiH1.924→TiH1.5/TiH1.7 between 300 °C and 400 °C and TiH1.5/TiH1.7→α-Ti between 400 °C and 600 °C. In the lower temperature range between 300 °C and 550 °C the rate of hydrogen release is slow, but the decomposition rate increases sharply above 550 °C. The XRD patterns obtained in air and under vacuum indicate that the surface oxide layer can deter hydrogen release. The pressure change is monitored in real time and the amount of hydrogen released is affected by the processing temperature and holding time. Holding processes at 425 °C, 480 °C, 500 °C, 550 °C, and 600 °C are found to significantly improve the porous structure in the NiTi scaffolds due to the stepwise release of hydrogen. NiTi scaffolds foamed by stepwise release of hydrogen are conducive to the attachment and proliferation of osteoblasts and the resulting pore size also favor in-growth of cells.
Collapse
|
28
|
Gittard SD, Narayan RJ. Laser direct writing of micro- and nano-scale medical devices. Expert Rev Med Devices 2010; 7:343-56. [PMID: 20420557 DOI: 10.1586/erd.10.14] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Laser-based direct writing of materials has undergone significant development in recent years. The ability to modify a variety of materials at small length scales and using short production times provides laser direct writing with unique capabilities for fabrication of medical devices. In many laser-based rapid prototyping methods, microscale and submicroscale structuring of materials is controlled by computer-generated models. Various laser-based direct write methods, including selective laser sintering/melting, laser machining, matrix-assisted pulsed-laser evaporation direct write, stereolithography and two-photon polymerization, are described. Their use in fabrication of microstructured and nanostructured medical devices is discussed. Laser direct writing may be used for processing a wide variety of advanced medical devices, including patient-specific prostheses, drug delivery devices, biosensors, stents and tissue-engineering scaffolds.
Collapse
Affiliation(s)
- Shaun D Gittard
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Campus Box 7115, Raleigh, NC 27695-7115, USA
| | | |
Collapse
|
29
|
Abstract
Bone tissue engineering is an emerging interdisciplinary field in Science, combining expertise in medicine, material science and biomechanics. Hard tissue engineering research is focused mainly in two areas, osteo and dental clinical applications. There is a lot of exciting research being performed worldwide in developing novel scaffolds for tissue engineering. Although, nowadays the majority of the research effort is in the development of scaffolds for non-load bearing applications, primarily using soft natural or synthetic polymers or natural scaffolds for soft tissue engineering; metallic scaffolds aimed for hard tissue engineering have been also the subject of in vitro and in vivo research and industrial development. In this article, descriptions of the different manufacturing technologies available to fabricate metallic scaffolds and a compilation of the reported biocompatibility of the currently developed metallic scaffolds have been performed. Finally, we highlight the positive aspects and the remaining problems that will drive future research in metallic constructs aimed for the reconstruction and repair of bone.
Collapse
Affiliation(s)
- Kelly Alvarez
- Center for Geo-Environmental Science, Faculty of Engineering and Resource Science, Akita University, 1-1 Tegata Gakuen-machi, Akita 010-8502, Japan; E-Mail:
| | - Hideo Nakajima
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
- Author to whom correspondence should be addressed; E-Mail: ; Tel. +81-6-6879-8435; Fax: +81-6-6879-8439
| |
Collapse
|