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Kudoh K, Fukuda N, Akita K, Kudoh T, Takamaru N, Kurio N, Hayashi K, Ishikawa K, Miyamoto Y. Reconstruction of rabbit mandibular bone defects using carbonate apatite honeycomb blocks with an interconnected porous structure. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2022; 34:2. [PMID: 36586041 PMCID: PMC9805415 DOI: 10.1007/s10856-022-06710-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Carbonate apatite (CO3Ap) granules are useful as a bone substitute because they can be remodeled to new natural bone in a manner that conforms to the bone remodeling process. However, reconstructing large bone defects using CO3Ap granules is difficult because of their granular shape. Therefore, we fabricated CO3Ap honeycomb blocks (HCBs) with continuous unidirectional pores. We aimed to elucidate the tissue response and availability of CO3Ap HCBs in the reconstruction of rabbit mandibular bone defects after marginal mandibulectomy. The percentages of the remaining CO3Ap area and calcified bone area (newly formed bone) were estimated from the histological images. CO3Ap area was 49.1 ± 4.9%, 30.3 ± 3.5%, and 25.5 ± 8.8%, whereas newly formed bone area was 3.0 ± 0.6%, 24.3 ± 3.3%, and 34.7 ± 4.8% at 4, 8, and 12 weeks, respectively, after implantation. Thus, CO3Ap HCBs were gradually resorbed and replaced by new bone. The newly formed bone penetrated most of the pores in the CO3Ap HCBs at 12 weeks after implantation. By contrast, the granulation tissue scarcely invaded the CO3Ap HCBs. Some osteoclasts invaded the wall of CO3Ap HCBs, making resorption pits. Furthermore, many osteoblasts were found on the newly formed bone, indicating ongoing bone remodeling. Blood vessels were also formed inside most of the pores in the CO3Ap HCBs. These findings suggest that CO3Ap HCBs have good osteoconductivity and can be used for the reconstruction of large mandibular bone defects. The CO3Ap HCB were gradually resorbed and replaced by newly formed bone.
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Affiliation(s)
- Keiko Kudoh
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
| | - Naoyuki Fukuda
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kazuya Akita
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Takaharu Kudoh
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Natsumi Takamaru
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Naito Kurio
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Koichiro Hayashi
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kunio Ishikawa
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Youji Miyamoto
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
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Hothi H, Henckel J, Bergiers S, Di Laura A, Schlueter-Brust K, Hart A. Morphometric analysis of patient-specific 3D-printed acetabular cups: a comparative study of commercially available implants from 6 manufacturers. 3D Print Med 2022; 8:33. [PMID: 36342573 PMCID: PMC9639285 DOI: 10.1186/s41205-022-00160-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 10/25/2022] [Indexed: 11/09/2022] Open
Abstract
Background 3D printed patient-specific titanium acetabular cups are used to treat patients with massive acetabular defects. These have highly porous surfaces, with the design intent of enhancing bony fixation. Our aim was to characterise these porous structures in commercially available designs. Methods We obtained 12 final-production, patient-specific 3D printed acetabular cups that had been produced by 6 manufacturers. High resolution micro-CT imaging was used to characterise morphometric features of their porous structures: (1) strut thickness, 2) the depth of the porous layer, (3) pore size and (4) the level of porosity. Additionally, we computed the surface area of each component to quantify how much titanium may be in contact with patient tissue. Statistical comparisons were made between the designs. Results We found a variability between designs in relation to the thickness of the struts (0.28 to 0.65 mm), how deep the porous layers are (0.57 to 11.51 mm), the pore size (0.74 to 1.87 mm) and the level of porosity (34 to 85%). One manufacturer printed structures with different porosities between the body and flange; another manufacturer had two differing porous regions within the body of the cups. The cups had a median (range) surface area of 756.5 mm2 (348 – 1724). Conclusions There is a wide variability between manufacturers in the porous titanium structures they 3D print. We do not currently know whether there is an optimal porosity and how this variability will impact clinically on the integrity of bony fixation; this will become clearer as post market surveillance data is generated.
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Affiliation(s)
- Harry Hothi
- The Royal National Orthopaedic Hospital, Stanmore, HA74LP, UK.
| | - Johann Henckel
- The Royal National Orthopaedic Hospital, Stanmore, HA74LP, UK
| | - Sean Bergiers
- The Institute of Orthopaedics and Musculoskeletal Science, University College London, London, UK
| | - Anna Di Laura
- The Royal National Orthopaedic Hospital, Stanmore, HA74LP, UK
| | - Klaus Schlueter-Brust
- Department of Orthopaedic Surgery, St. Franziskus Hospital Köln, 50825, Cologne, Germany
| | - Alister Hart
- The Royal National Orthopaedic Hospital, Stanmore, HA74LP, UK.,The Institute of Orthopaedics and Musculoskeletal Science, University College London, London, UK
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Li S, He Y, Li J, Sheng J, Long S, Li Z, Jiang B, Fu H, Weng J, Wu J, Zheng W. Titanium scaffold loaded with strontium and copper double-doped hydroxyapatite can inhibit bacterial growth and enhance osteogenesis. J Biomater Appl 2022; 37:195-203. [PMID: 35594029 DOI: 10.1177/08853282221080525] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Co-doping of multiple ions can effectively adjust the biological properties of hydroxyapatite (HA) for various biomedical applications. In this study, we prepared Sr2+ and Cu2+ double-doped hollow HA and characterized them by SEM, EDS, XRD, FTIR, and other methods. We found that Sr2+ and Cu2+ were uniformly distributed in the hollow carbonic acid HA microspheres. As the proportion of metal elements increases, the microspherical appearance and crystallinity properties also change. In addition, we also prepared porous titanium scaffolds through 3D printing technology and constructed composite scaffolds of porous titanium scaffolds, Sr2+ and Cu2+ double-doped HA, and gelatin. In vitro cell experiments and bacterial experiments, the composite scaffolds, especially the 10%Cu-10%Sr- HA/Gel/Ti group scaffolds, have good biocompatibility and integration with bone tissues, promoting the proliferation and differentiation of BMSCs while having excellent antibacterial properties. These composite scaffolds can simultaneously achieve bone defect filling, osteoblast differentiation, and antibacterial functions, owning broad clinical application prospects.
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Affiliation(s)
- Shihong Li
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Yang He
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Jian Li
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Jun Sheng
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Shiwei Long
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Zhiqiang Li
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Bobo Jiang
- 56711Southwest Jiaotong University, Chengdu, China
| | - Hong Fu
- 56711Southwest Jiaotong University, Chengdu, China
| | - Jie Weng
- 56711Southwest Jiaotong University, Chengdu, China
| | - Juan Wu
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
| | - Wei Zheng
- 600870People's Liberation Army General Hospital of Western Theater Command, Chengdu, China
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Meena VK, Kalra P, Sinha RK. Finite element study on the influence of pore size and structure on stress shielding effect of additive manufactured spinal cage. Comput Methods Biomech Biomed Engin 2021; 25:566-577. [PMID: 34551629 DOI: 10.1080/10255842.2021.1970142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The stress shielding effect occurs when the orthopedic implant reduces the load delivered to the bone, causing inefficient stress transfer to the host bone. The usage of porous additive manufactured (AM) cages reduces the stress shielding effect and promotes bone ingrowth also. The purpose of this work is to study the stress and deformation on porous hybrid spinal cages under different loading conditions using Finite Element Analysis (FEA). The spinal cages consisting of three porous structures with pore sizes ranging from 0.4 to 0.6 mm were investigated for stress shielding and fatigue strength. The results showed a significant reduction in stress shielding for the studied designs and conclude that the pore size has a greater significant effect on stress shielding than the porous structure in spinal cages.
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Affiliation(s)
- Vijay Kumar Meena
- Biomedical Instrumentation, Central Scientific Instruments Organisation, Chandigarh, India.,Department of Production Engineering, Punjab Engineering College, Chandigarh, India
| | - Parveen Kalra
- Department of Production Engineering, Punjab Engineering College, Chandigarh, India
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Jíra A, Šejnoha M, Krejčí T, Vorel J, Řehounek L, Marseglia G. Mechanical Properties of Porous Structures for Dental Implants: Experimental Study and Computational Homogenization. MATERIALS 2021; 14:ma14164592. [PMID: 34443120 PMCID: PMC8398312 DOI: 10.3390/ma14164592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/06/2021] [Accepted: 08/10/2021] [Indexed: 11/24/2022]
Abstract
A combined experimental and numerical study on titanium porous microstructures intended to interface the bone tissue and the solid homogeneous part of a modern dental implant is presented. A specific class of trabecular geometries is compared to a gyroid structure. Limitations associated with the application of the adopted selective laser melting technology to small microstructures with a pore size of 500 μm are first examined experimentally. The measured effective elastic properties of trabecular structures made of Ti6Al4V material support the computational framework based on homogenization with the difference between the measured and predicted Young’s moduli of the Dode Thick structure being less than 5%. In this regard, the extended finite element method is promoted, particularly in light of the complex sheet gyroid studied next. While for plastic material-based structures a close match between experiments and simulations was observed, an order of magnitude difference was encountered for titanium specimens. This calls for further study and we expect to reconcile this inconsistency with the help of computational microtomography.
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Affiliation(s)
- Aleš Jíra
- Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic; (A.J.); (M.Š.); (T.K.); (J.V.); (L.Ř.)
| | - Michal Šejnoha
- Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic; (A.J.); (M.Š.); (T.K.); (J.V.); (L.Ř.)
| | - Tomáš Krejčí
- Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic; (A.J.); (M.Š.); (T.K.); (J.V.); (L.Ř.)
| | - Jan Vorel
- Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic; (A.J.); (M.Š.); (T.K.); (J.V.); (L.Ř.)
| | - Luboš Řehounek
- Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic; (A.J.); (M.Š.); (T.K.); (J.V.); (L.Ř.)
| | - Guido Marseglia
- High Technical School of Architecture, University of Seville, 41012 Sevilla, Spain
- Instituto de Matemáticas de la Universidad de Sevilla, University of Seville, 41012 Sevilla, Spain
- Correspondence:
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Shi X, Sun Y, Wang P, Ma Z, Liu H, Ning H. Compression properties and optimization design of SLM Ti6Al4V square pore tissue engineering scaffolds. Proc Inst Mech Eng H 2021; 235:1265-1273. [PMID: 34281449 DOI: 10.1177/09544119211028061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The tissue engineering technology provides a new way to solve bone defect. Porous scaffolds supply support and adhesion space for cells. Design of pore structure of scaffolds is one of the key points in tissue engineering scaffolds, because the structure affects the performance of scaffolds directly. In this paper, mechanical properties of square porous Ti6Al4V scaffolds are studied. By finite element simulation, it can be found that the support structure in vertical direction assumes main force, so the structure can be optimized through relative density mapping (RDM) method. The modified arch structures can improve bearing effect of structure with the same porosity. The designed structures are obtained by selective laser melting. Results of compressive strength indicate that the compressive strength decreases with the increase of porosity. When the porosity is between 40% and 60%, the error of compressive strength calculated by Gibson-Ashby model is below 8%. Moreover, the optimized structure clears a better bearing effect, and the bearing capacity can be increased by 20%-30% under the same porosity.
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Affiliation(s)
- Xiaoquan Shi
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Yazhou Sun
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Pengju Wang
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Ziyang Ma
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Haitao Liu
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Haohao Ning
- Department of Mechanical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang, China
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Li S, Wang T, Hu J, Li Z, Wang B, Wang L, Zhou Z. Surface porous poly-ether-ether-ketone based on three-dimensional printing for load-bearing orthopedic implant. J Mech Behav Biomed Mater 2021; 120:104561. [PMID: 33965810 DOI: 10.1016/j.jmbbm.2021.104561] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/16/2021] [Accepted: 04/19/2021] [Indexed: 02/07/2023]
Abstract
Poly-ether-ether-ketone (PEEK) possesses excellent biocompatibility and similar elastic modulus as bones but yet suffers from poor osseointegration. In order to balance PEEK's mechanical and osseointegration properties, a novel surface porous PEEK (SP-PEEK) is successfully fabricated by fused deposition modelling three-dimensional printing (FDM 3DP) and characterized by mechanical and osteogenesis in vitro tests. Moreover, the effects of pore diameter and pore layer number on the mechanical behaviors of SP-PEEK are investigated by theoretical model and numerical simulation. Comparison among experimental, theoretical and simulation results show good agreement. As pore diameter decreases, the equivalent strength and modulus become more sensitive to the decrease of pore layer number. In addition, the SP-PEEK exhibits the mechanical properties within the range of human trabecular bone and cortical bone, and thus can be tailored to mimic human bone by adjusting the pore diameter and pore layer number, which is benefit to mitigate stress shielding. The effects of pore diameter on the cell proliferation and osteogenic differentiation of SP-PEEK are tested by the co-culture of osteoblast precursor cells (MC3T3-E1) and SP-PEEK round discs. Results showcase that porous surface improves the osteogenesis in vitro, and the SP-PEEK group that the pore diameter is 0.6 mm exhibits optimal-performance osteogenesis in vitro.
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Affiliation(s)
- Shuai Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Tianyu Wang
- Department of Orthopedics, First Affiliated Hospital of Harbin Medical University, Harbin, 150001, China
| | - Jiqiang Hu
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zhibin Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Bing Wang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China.
| | - Lianchao Wang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
| | - Zhengong Zhou
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin, 150080, China
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The impact of multimodal pore size considered independently from porosity on mechanical performance and osteogenic behaviour of titanium scaffolds. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 124:112026. [PMID: 33947533 DOI: 10.1016/j.msec.2021.112026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/13/2021] [Accepted: 03/03/2021] [Indexed: 11/20/2022]
Abstract
Titanium porous scaffolds comprising multimodal pore ranges (i.e., uni-, bi-, tri-modal and random) were studied to evaluate the effect of pore size on osteoblastogenesis. The scaffolds were manufactured using spaceholder-powder metallurgy, and porosity and pore size were kept independent. Their mechanical and physical properties (i.e., stiffness, strength, total and open porosity) were determined. In a first step, unimodal porous samples were tested with a mouse osteoblastic clonal cell line to ascertain pore size and porosity effects on cellular behaviour. Their proliferation (via cell number and total protein content), differentiation (via ALP enzyme levels) and maturation potency (with gene markers (Runx2, osteocalcin) and cytoplasmatic calcium) were investigated. In a second step informed by the previous results, multimodal scaffolds were shortlisted according to a set of criteria that included stiffness similar to that of cortical or trabecular bone, high strength and high open porosity. Their bioactivity performance was then studied to assess the benefits of mixing different pore ranges. The study concludes that pre-osteoblasts cultivated in unimodal microstructures with a pore range 106-212 μm of 36% total (actual) porosity and 300-500 μm of 55% total (actual) porosity achieved the largest extent of maturation. Bimodal microstructures comprising small (106-212 μm) and large (300-500 μm) pore ranges, distinctively distributed within the volume, and 40% (actual) porosity outperformed others, including multimodal (i.e. three or more pore ranges) and non-porous samples. They displayed a synergistic effect over the unimodal distributions. This should be a consideration in the design of scaffolds for implantation and bioengineering applications.
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Pardo F, Bordini B, Castagnini F, Giardina F, Faldini C, Traina F. Are powder-technology-built stems safe? A midterm follow-up registry study. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:10. [PMID: 33471238 PMCID: PMC7817598 DOI: 10.1007/s10856-020-06481-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 12/18/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Powder technology was developed to bring together the mechanical features and high porosity of titanium. However, the high porosity may theoretically compromise mechanical resistance. Literature is deficient about the use and safety profile of cementless femoral implants built using additive manufacturing (in particular electron beam melting technology, EBM). The purpose of this study was to evaluate the survival rates and the reason for revisions (especially implant breakage) of the first two EBM-built stems at a mid-term follow-up, using a joint arthroplasty registry. METHODS The registry of Prosthetic Orthopedic Implant (RIPO) was investigated about cementless stems implanted from 2010 to 2017. Stems built with EBM technology (Parva and Pulchra stems; Adler Ortho, Milan, Italy) were compared to all the other cementless stems implanted during the same period, acting as control group. The survival rates and reasons for revision were assessed. RESULTS No stem breakage occurred. At 5-year follow-up, the survival rates of the two cohorts were not statistically different (96.8% EBM stems, 98.0% standard cementless stems; p > 0.05). In the EBM stems, aseptic loosening occurred in 1.7% of the cases at the latest follow-up. CONCLUSIONS This large cohort showed that mechanical resistance is not a concern in EBM stems at mid-term follow-up. However, larger populations and longer follow-ups are needed to further validate these results.
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Affiliation(s)
- Francesco Pardo
- Ortopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via G.C. Pupilli 1, Bologna, 40136, Italy.
| | - Barbara Bordini
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, Bologna, 40136, Italy
| | - Francesco Castagnini
- Ortopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via G.C. Pupilli 1, Bologna, 40136, Italy
| | - Federico Giardina
- Ortopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via G.C. Pupilli 1, Bologna, 40136, Italy
| | - Cesare Faldini
- Clinica Ortopedica e Traumatologica I, IRCCS Istituto Ortopedico Rizzoli, Via G.C. Pupilli 1, Bologna, 40136, Italy
- DIBINEM, University of Bologna, Bologna, Italy
| | - Francesco Traina
- Ortopedia-Traumatologia e Chirurgia Protesica e dei Reimpianti d'anca e di Ginocchio, IRCCS Istituto Ortopedico Rizzoli, Via G.C. Pupilli 1, Bologna, 40136, Italy
- DIBINEM, University of Bologna, Bologna, Italy
- University of Messina, Messina, Italy
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Frosch S, Nüsse V, Frosch KH, Lehmann W, Buchhorn G. Osseointegration of 3D porous and solid Ti-6Al-4V implants - Narrow gap push-out testing and experimental setup considerations. J Mech Behav Biomed Mater 2020; 115:104282. [PMID: 33348214 DOI: 10.1016/j.jmbbm.2020.104282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 11/29/2022]
Abstract
Porosity in titanium alloy materials improves the bony integration and mechanical properties of implants. In certain areas of application such as vertebral spacers or trabecular bone replacement (e.g. wedge augmentation in prosthetics), surface structures are desirable that promote bone integration and have biomechanical properties that are resistant to intraosseous load transfers and at the same time resemble the stiffness of bone to possible reduce the risk of stress shielding. In the present study, we investigated the biomechanical push-out behavior of an open-porous Ti-6Al-4V material that was produced in a space-holder and sintering method creating a 3-D through-pores trabecular design that corresponds with the inhomogeneity and size relationships of trabecular bone. The short-term and mid-term effects of the material properties on osseointegration in a biomechanical push-out study were compared to those of to a conventional solid Ti-6Al-4V material. In order to raise the measurement accuracy we implemented a strict study protocol. Pairs of cylindrical implants with a porosity of 49% and an average pore diameter of 400 μm and equal sized solid, corundum blasted devices as reference were bilaterally implanted press fit in the lateral femoral condyles of 14 rabbits. After sacrifice at 4 and 12 weeks, a push-out test was performed while the test set-up was designed to ensure conformity of implant axes and direction of applied force. Maximum holding force, Young's modulus, and mode of failure were recorded. Results of maximum push-out force (F-max) revealed a significant material effect (p < 0.05) in favor of porous implants after 4 weeks of osseohealing (6.39 vs. 3.36 N/mm2) as well as after 12 weeks of osseoremodeling (7.58 vs. 4.99 N/mm2). Evaluation of the failure mode resulted in three different types of displacement characteristics, which revealed a different mechanism of osseous anchoring between the two types of implants and substantiate the F-max and Young's modulus results. Conclusively, the porous implant offers surface properties that significantly improve its osseous stability compared to solid material under experimental conditions. In addition, we have optimized our study protocol for biomechanical push-out tests to produce precise and comparable results.
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Affiliation(s)
- Stephan Frosch
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Göttingen, Göttingen, Germany.
| | - Verena Nüsse
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Göttingen, Göttingen, Germany
| | - Karl-Heinz Frosch
- Department of Trauma and Orthopedic Surgery, University Medical Center Hamburg - Eppendorf, Hamburg, Germany
| | - Wolfgang Lehmann
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Göttingen, Göttingen, Germany
| | - Gottfried Buchhorn
- Department of Trauma Surgery, Orthopedics and Plastic Surgery, University Medical Center Göttingen, Göttingen, Germany
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3D printed porous PEEK created via fused filament fabrication for osteoconductive orthopaedic surfaces. J Mech Behav Biomed Mater 2020; 109:103850. [DOI: 10.1016/j.jmbbm.2020.103850] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 05/05/2020] [Indexed: 02/01/2023]
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12
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Akita K, Fukuda N, Kamada K, Kudoh K, Kurio N, Tsuru K, Ishikawa K, Miyamoto Y. Fabrication of porous carbonate apatite granules using microfiber and its histological evaluations in rabbit calvarial bone defects. J Biomed Mater Res A 2019; 108:709-721. [PMID: 31756282 DOI: 10.1002/jbm.a.36850] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023]
Abstract
Carbonate apatite (CO3 Ap) granules are known to show good osteoconductivity and replaced to new bone. On the other hand, it is well known that a porous structure allows bone tissue to penetrate its pores, and the optimal pore size for bone ingrowth is dependent on the composition and structure of the scaffold material. Therefore, the aim of this study was to fabricate various porous CO3 Ap granules through a two-step dissolution-precipitation reaction using CaSO4 as a precursor and 30-, 50-, 120-, and 205-μm diameter microfibers as porogen and to find the optimal pore size of CO3 Ap. Porous CO3 Ap granules were successfully fabricated with pore size 8.2-18.7% smaller than the size of the original fiber porogen. Two weeks after the reconstruction of rabbit calvarial bone defects using porous CO3 Ap granules, the largest amount of mature bone was seen to be formed inside the pores of CO3 Ap (120) [porous CO3 Ap granules made using 120-μm microfiber] followed by CO3 Ap (50) and CO3 Ap (30). At 4 and 8 weeks, no statistically significant difference was observed based on the pore size, even though largest amount of mature bone was formed in case of CO3 Ap (120). It is concluded, therefore, that the optimal pore size of the CO3 Ap is that of CO3 Ap (120), which is 85 μm.
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Affiliation(s)
- Kazuya Akita
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Naoyuki Fukuda
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kumiko Kamada
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Keiko Kudoh
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Naito Kurio
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Kanji Tsuru
- Section of Bioengineering, Fukuoka Dental College, Fukuoka, Japan
| | - Kunio Ishikawa
- Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Youji Miyamoto
- Department of Oral Surgery, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan
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13
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Chen L, Tang Y, Zhao K, Zha X, Liu J, Bai H, Wu Z. Fabrication of the antibiotic-releasing gelatin/PMMA bone cement. Colloids Surf B Biointerfaces 2019; 183:110448. [DOI: 10.1016/j.colsurfb.2019.110448] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/10/2019] [Accepted: 08/20/2019] [Indexed: 12/11/2022]
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14
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Tilton M, Armstrong A, Sanville J, Chin M, Hast MW, Lewis GS, Manogharan GP. Biomechanical Testing of Additive Manufactured Proximal Humerus Fracture Fixation Plates. Ann Biomed Eng 2019; 48:463-476. [PMID: 31555983 DOI: 10.1007/s10439-019-02365-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 09/12/2019] [Indexed: 01/24/2023]
Abstract
Achieving satisfactory fracture fixation in osteoporotic patients with unstable proximal humerus fractures remains a major clinical challenge. Varus collapse is one of the more prominent complications that may lead to screw cutout. This aim of this study was to compare the fixation provided by conventional locking plates with novel design concepts that are only feasible through additive manufacturing (AM) techniques. In addition to reversed engineered implants, two novel implant designs with integrated struts were included in the study to provide medial support to humeral head. The medial strut was either solid or included a porous lattice structure intended to promote bone ingrowth. Biomechanical tests were performed using low density synthetic bones with simulated 3-part comminuted fractures. Nondestructive torsion and compression were performed, followed by increasing cyclic loading. The relative displacements between the bone fragments were determined using a 3D motion capture system. The AM manufactured implants with medial strut showed significant reduction of varus displacement during the increasing cyclic loading when compared to conventional designs. AM reversed-engineered locking plates showed similar mechanical behavior to conventional plates with identical geometry. This study demonstrates the feasibility and potential of employing alternative design via AM for fixation of unstable comminuted proximal humerus fractures to reduce fragment displacement.
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Affiliation(s)
- Maryam Tilton
- Department of Mechanical Engineering, Pennsylvania State University, 232 Reber Bldg, University Park, PA, 16802, USA
| | - April Armstrong
- Department of Orthopaedics and Rehabilitation, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Jennifer Sanville
- Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew Chin
- Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael W Hast
- Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Gregory S Lewis
- Department of Orthopaedics and Rehabilitation, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Guha P Manogharan
- Department of Mechanical Engineering, Pennsylvania State University, 232 Reber Bldg, University Park, PA, 16802, USA.
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15
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Li P, Jiang W, Yan J, Hu K, Han Z, Wang B, Zhao Y, Cui G, Wang Z, Mao K, Wang Y, Cui F. A novel 3D printed cage with microporous structure and in vivo fusion function. J Biomed Mater Res A 2019; 107:1386-1392. [PMID: 30724479 DOI: 10.1002/jbm.a.36652] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/21/2019] [Accepted: 02/04/2019] [Indexed: 01/28/2023]
Affiliation(s)
- Peng Li
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Wei Jiang
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Jia Yan
- Institute of Printing and Packaging EngineeringBeijing Institute of Graphic Communication Beijing, 102600 China
| | - Kun Hu
- Institute of Printing and Packaging EngineeringBeijing Institute of Graphic Communication Beijing, 102600 China
| | - Zhenchuan Han
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Bo Wang
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Yongfei Zhao
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Geng Cui
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Zheng Wang
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Keya Mao
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Yan Wang
- Department of OrthopedicsChinese PLA General Hospital Beijing, 100853 China
| | - Fuzhai Cui
- Department of Materials Science and EngineeringTsinghua University Beijing, 100084 China
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16
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Wally ZJ, Haque AM, Feteira A, Claeyssens F, Goodall R, Reilly GC. Selective laser melting processed Ti6Al4V lattices with graded porosities for dental applications. J Mech Behav Biomed Mater 2019; 90:20-29. [DOI: 10.1016/j.jmbbm.2018.08.047] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/09/2018] [Accepted: 08/28/2018] [Indexed: 10/28/2022]
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17
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Encarnação IC, Sordi MB, Aragones Á, Müller CMO, Moreira AC, Fernandes CP, Ramos JV, Cordeiro MMR, Fredel MC, Magini RS. Release of simvastatin from scaffolds of poly(lactic‐co‐glycolic) acid and biphasic ceramic designed for bone tissue regeneration. J Biomed Mater Res B Appl Biomater 2019; 107:2152-2164. [DOI: 10.1002/jbm.b.34311] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/16/2018] [Accepted: 12/19/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Isis C. Encarnação
- Center for Research on Dental Implants (CEPID), Department of DentistryFederal University of Santa Catarina Florianópolis Brazil
| | - Mariane B. Sordi
- Center for Research on Dental Implants (CEPID), Department of DentistryFederal University of Santa Catarina Florianópolis Brazil
| | - Águedo Aragones
- Center for Research on Dental Implants (CEPID), Department of DentistryFederal University of Santa Catarina Florianópolis Brazil
- Ceramic & Composite Materials Research Laboratories (CERMAT), Department of Mechanical EngineeringFederal University of Santa Catarina Florianópolis Brazil
| | | | - Anderson C. Moreira
- Laboratory of Porous Media and Thermophysical Properties (LMPT)Department of Mechanical Engineering, Federal University of Santa Catarina Florianópolis Brazil
| | - Celso P. Fernandes
- Laboratory of Porous Media and Thermophysical Properties (LMPT)Department of Mechanical Engineering, Federal University of Santa Catarina Florianópolis Brazil
| | - Jeferson V. Ramos
- Laboratory of Porous Media and Thermophysical Properties (LMPT)Department of Mechanical Engineering, Federal University of Santa Catarina Florianópolis Brazil
| | - Mabel M. R. Cordeiro
- Center for Research on Dental Implants (CEPID), Department of DentistryFederal University of Santa Catarina Florianópolis Brazil
| | - Márcio C. Fredel
- Ceramic & Composite Materials Research Laboratories (CERMAT), Department of Mechanical EngineeringFederal University of Santa Catarina Florianópolis Brazil
| | - Ricardo S. Magini
- Center for Research on Dental Implants (CEPID), Department of DentistryFederal University of Santa Catarina Florianópolis Brazil
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18
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Experimental Characterization of the Primary Stability of Acetabular Press-Fit Cups with Open-Porous Load-Bearing Structures on the Surface Layer. METALS 2018. [DOI: 10.3390/met8100839] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background: Nowadays, hip cups are being used in a wide range of design versions and in an increasing number of units. Their development is progressing steadily. In contrast to conventional methods of manufacturing acetabular cups, additive methods play an increasingly central role in the development progress. Method: A series of eight modified cups were developed on the basis of a standard press-fit cup with a pole flattening and in a reduced version. The surface structures consist of repetitive open-pore load-bearing textural elements aligned right-angled to the cup surface. We used three different types of unit cells (twisted, combined and combined open structures) for constructing of the surface structure. All cups were manufactured using selective laser melting (SLM) of titanium powder (Ti6Al4V). To evaluate the primary stability of the press fit cups in the artificial bone cavity, pull-out and lever-out tests were conducted. All tests were carried out under exact fit conditions. The closed-cell polyurethane (PU) foam, which was used as an artificial bone cavity, was characterized mechanically in order to preempt any potential impact on the test results. Results and conclusions: The pull-out forces as well as the lever moments of the examined cups differ significantly depending on the elementary cells used. The best results in pull-out forces and lever-out moments are shown by the press-fit cups with a combined structure. The results for the assessment of primary stability are related to the geometry used (unit cell), the dimensions of the unit cell, and the volume and porosity responsible for the press fit. Corresponding functional relationships could be identified. The findings show that the implementation of reduced cups in a press-fit design makes sense as part of the development work.
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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: 134] [Impact Index Per Article: 22.3] [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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Schulze C, Weinmann M, Schweigel C, Keßler O, Bader R. Mechanical Properties of a Newly Additive Manufactured Implant Material Based on Ti-42Nb. MATERIALS 2018; 11:ma11010124. [PMID: 29342864 PMCID: PMC5793622 DOI: 10.3390/ma11010124] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/06/2018] [Accepted: 01/09/2018] [Indexed: 11/16/2022]
Abstract
The application of Ti-6Al-4V alloy or commercially pure titanium for additive manufacturing enables the fabrication of complex structural implants and patient-specific implant geometries. However, the difference in Young’s modulus of α + β-phase Ti alloys compared to the human bone promotes stress-shielding effects in the implant–bone interphase. The aim of the present study is the mechanical characterization of a new pre-alloyed β-phase Ti-42Nb alloy for application in additive manufacturing. The present investigation focuses on the mechanical properties of SLM-printed Ti-42Nb alloy in tensile and compression tests. In addition, the raw Ti-42Nb powder, the microstructure of the specimens prior to and after compression tests, as well as the fracture occurring in tensile tests are characterized by means of the SEM/EDX analysis. The Ti-42Nb raw powder exhibits a dendrite-like Ti-structure, which is melted layer-by-layer into a microstructure with a very homogeneous distribution of Nb and Ti during the SLM process. Tensile tests display Young’s modulus of 60.51 ± 3.92 GPa and an ultimate tensile strength of 683.17 ± 16.67 MPa, whereas, under a compressive load, a compressive strength of 1330.74 ± 53.45 MPa is observed. The combination of high mechanical strength and low elastic modulus makes Ti-42Nb an interesting material for orthopedic and dental implants. The spherical shape of the pre-alloyed material additionally allows for application in metal 3D printing, enabling the fabrication of patient-specific structural implants.
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Affiliation(s)
- Christian Schulze
- Biomechanics and Implant Technology Research Laboratory (FORBIOMIT), Department of Orthopaedics, University Medicine Rostock, Doberaner Straße 142, 18057 Rostock, Germany.
| | - Markus Weinmann
- H.C. Starck Tantalum and Niobium GmbH, Im Schleeke 78-91, 38642 Goslar, Germany.
| | - Christoph Schweigel
- Chair of Material Science, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Albert- Einstein- Str. 2, 18059 Rostock, Germany.
| | - Olaf Keßler
- Chair of Material Science, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Albert- Einstein- Str. 2, 18059 Rostock, Germany.
| | - Rainer Bader
- Biomechanics and Implant Technology Research Laboratory (FORBIOMIT), Department of Orthopaedics, University Medicine Rostock, Doberaner Straße 142, 18057 Rostock, Germany.
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21
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Periacetabular bone densitometry after total hip arthroplasty with highly porous titanium cups: a 2-year follow-up prospective study. Hip Int 2017; 27:551-557. [PMID: 28708200 DOI: 10.5301/hipint.5000509] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2017] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Trabecular Titanium is an advanced cellular solid structure, composed of regular multiplanar hexagonal interconnected cells that mimic the morphology of the trabecular bone. This biomaterial demonstrated improved mechanical properties and enhanced osteoinduction and osteoconduction in several in vitro and in vivo studies. The aim of this study was to assess Trabecular Titanium osseointegration by measuring periacetabular changes in bone mineral density (BMD) with dual-emission X-ray absorptiometry (DEXA). METHODS 89 patients (91 hips) underwent primary total hip arthroplasty (THA) with acetabular Trabecular Titanium cups. Clinical (Harris Hip Score (HHS), SF-36) and radiographic assessment were performed preoperatively, and postoperatively at 7 days and at 3, 6, 12 and 24 months. DEXA analysis was performed only postoperatively, using the BMD values measured at 7 days as baselines. RESULTS After an initial decrease from baseline to 6 months, BMD increased and progressively stabilised in all 3 regions of interest (ROIs). Median (IQR) HHS and SF-36 increased from 48 (39-62) and 49 (37-62) preoperatively to 99 (96-100) and 86 (79-92) at 24 months, indicating a considerable improvement in terms of pain relief, functional recovery and quality of life. BMD patterns and radiographic evaluation showed evident signs of periacetabular bone remodelling and osseointegration; all cups were stable at the final follow-up without radiolucent lines, loosening or osteolysis. No revisions were performed. CONCLUSIONS After an initial reduction in periacetabular BMD, all 3 ROIs exhibited stabilisation or slight recovery. Although clinical outcomes and functional recovery proved satisfactory, longer follow-ups are necessary to assess this cup long-term survivorship.
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22
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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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Cimatti B, Santos MAD, Brassesco MS, Okano LT, Barboza WM, Nogueira-Barbosa MH, Engel EE. Safety, osseointegration, and bone ingrowth analysis of PMMA-based porous cement on animal metaphyseal bone defect model. J Biomed Mater Res B Appl Biomater 2017; 106:649-658. [PMID: 28276202 DOI: 10.1002/jbm.b.33870] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 01/17/2017] [Accepted: 02/13/2017] [Indexed: 12/28/2022]
Abstract
Bone defects created after curettage of benign bone tumors are customarily filled with solid poly(methyl methacrylate) (PMMA) or other bone substitutes. In this study, we depicted a porous PMMA-based cement (produced by mixing sodium bicarbonate and citric acid) and evaluated the prospect of its clinic application. Cement samples were characterized by high-performance liquid chromatography (HPLC) coupled to mass spectrometry and its cytotoxicity evaluated in fibroblast cultures. Implantation in rabbits allowed the histologic analysis of bone, kidneys, and liver for toxicity and coagulation tests, and MRI images for hemostasis evaluation. Osseointegration was analyzed through radiography, microtomography (micro-CT), SEM, and histology of sheep specimens. Rabbit specimens were analyzed 1, 4, and 7 days after implantation of porous or solid bone cement in 6.0 mm femoral defects. Sheep specimens were analyzed 3 and 6 months after implantation or not of porous or solid cement in 15.0 mm subchondral tibial defects. The production process did not release any detectable toxic substance but slightly reduced fibroblast proliferation in vitro. Until 7 days after surgery, no local or systemic alterations could be detected in histology, or hematoma formation in histology or MRI. Sheep implants showed 6 mm linear ingrowth from the bone-cement interface and 20% bone ingrowth considering the whole defect area. Radiography, micro-CT, SEM, and histology confirmed these findings. We conclude that our porous PMMA-based cement is an attractive alternative treatment for bone defect filling that combines osseointegration and early weight bearing. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 649-658, 2018.
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Affiliation(s)
- Bruno Cimatti
- Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Mariana Avelino Dos Santos
- Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Maria Sol Brassesco
- Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Laura Tiemi Okano
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Wendell Monteiro Barboza
- Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Edgard Eduard Engel
- Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Suska F, Kjeller G, Tarnow P, Hryha E, Nyborg L, Snis A, Palmquist A. Electron Beam Melting Manufacturing Technology for Individually Manufactured Jaw Prosthesis: A Case Report. J Oral Maxillofac Surg 2016; 74:1706.e1-1706.e15. [DOI: 10.1016/j.joms.2016.03.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 01/26/2023]
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Stability of Uncemented Cups - Long-Term Effect of Screws, Pegs and HA Coating: A 14-Year RSA Follow-Up of Total Hip Arthroplasty. J Arthroplasty 2016; 31:156-61. [PMID: 26260783 DOI: 10.1016/j.arth.2015.07.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 02/01/2023] Open
Abstract
Screws, pegs and hydroxyapatite-coating are used to enhance the primary stability of uncemented cups. We present a 14-year follow-up of 48 hips randomized to four groups: press-fit only, press-fit plus screws, press-fit plus pegs and hydroxyapatite-coated cups. Radiostereometric migration measurements showed equally good stability regardless cup augmentation. The mean wear rate was high, 0.21 mm/year, with no differences between the groups. Seven hips had radiographical osteolysis but only in hips with augmented cups. Cups without screw-holes compared with cups with screw-holes resulted in better clinical outcome at the 14-year follow-up. Thus, augmentation of uncemented cups with screws, pegs, or hydroxyapatite did not appear to improve the long-term stability compared with press-fit only.
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26
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The effect of silver or gallium doped titanium against the multidrug resistant Acinetobacter baumannii. Biomaterials 2015; 80:80-95. [PMID: 26708086 DOI: 10.1016/j.biomaterials.2015.11.042] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 11/12/2015] [Accepted: 11/29/2015] [Indexed: 12/26/2022]
Abstract
Implant-related infection of biomaterials is one of the main causes of arthroplasty and osteosynthesis failure. Bacteria, such as the rapidly-emerging Multi Drug Resistant (MDR) pathogen Acinetobacter Baumannii, initiate the infection by adhering to biomaterials and forming a biofilm. Since the implant surface plays a crucial role in early bacterial adhesion phases, titanium was electrochemically modified by an Anodic Spark Deposition (ASD) treatment, developed previously and thought to provide osseo-integrative properties. In this study, the treatment was modified to insert gallium or silver onto the titanium surface, to provide antibacterial properties. The material was characterized morphologically, chemically, and mechanically; biological properties were investigated by direct cytocompatibility assay, Alkaline Phosphatase (ALP) activity, Scanning Electron Microscopy (SEM), and Immunofluorescent (IF) analysis; antibacterial activity was determined by counting Colony Forming Units, and viability assay. The various ASD-treated surfaces showed similar morphology, micrometric pore size, and uniform pore distribution. Of the treatments studied, gallium-doped specimens showed the best ALP synthesis and antibacterial properties. This study demonstrates the possibility of successfully doping the surface of titanium with gallium or silver, using the ASD technique; this approach can provide antibacterial properties and maintain high osseo-integrative potential.
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Basalah A, Esmaeili S, Toyserkani E. A novel additive manufacturing-based technique for developing bio-structures with conformal channels and encapsulated voids. Biomed Phys Eng Express 2015. [DOI: 10.1088/2057-1976/1/4/045007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Influence of Different Three-Dimensional Open Porous Titanium Scaffold Designs on Human Osteoblasts Behavior in Static and Dynamic Cell Investigations. MATERIALS 2015; 8:5490-5507. [PMID: 28793519 PMCID: PMC5455497 DOI: 10.3390/ma8085259] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/30/2015] [Accepted: 08/13/2015] [Indexed: 11/16/2022]
Abstract
In the treatment of osseous defects micro-structured three-dimensional materials for bone replacement serve as leading structure for cell migration, proliferation and bone formation. The scaffold design and culture conditions are crucial for the limited diffusion distance of nutrients and oxygen. In static culture, decreased cell activity and irregular distribution occur within the scaffold. Dynamic conditions entail physical stimulation and constant medium perfusion imitating physiological nutrient supply and metabolite disposal. Therefore, we investigated the influence of different scaffold configurations and cultivation methods on human osteoblasts. Cells were seeded on three-dimensional porous Ti-6Al-4V scaffolds manufactured with selective laser melting (SLM) or electron beam melting (EBM) varying in porosity, pore size and basic structure (cubic, diagonal, pyramidal) and cultured under static and dynamic conditions. Cell viability, migration and matrix production were examined via mitochondrial activity assay, fluorescence staining and ELISA. All scaffolds showed an increasing cell activity and matrix production under static conditions over time. Expectations about the dynamic culture were only partially fulfilled, since it enabled proliferation alike the static one and enhanced cell migration. Overall, the SLM manufactured scaffold with the highest porosity, small pore size and pyramidal basic structure proved to be the most suitable structure for cell proliferation and migration.
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Du D, Asaoka T, Ushida T, Furukawa KS. Fabrication and perfusion culture of anatomically shaped artificial bone using stereolithography. Biofabrication 2014; 6:045002. [DOI: 10.1088/1758-5082/6/4/045002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Wu SH, Li Y, Zhang YQ, Li XK, Yuan CF, Hao YL, Zhang ZY, Guo Z. Porous Titanium-6 Aluminum-4 Vanadium Cage Has Better Osseointegration and Less Micromotion Than a Poly-Ether-Ether-Ketone Cage in Sheep Vertebral Fusion. Artif Organs 2013; 37:E191-201. [PMID: 24147953 DOI: 10.1111/aor.12153] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Su-Hua Wu
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
| | - Yi Li
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
| | - Yong-Quan Zhang
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
| | - Xiao-Kang Li
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
| | - Chao-Fan Yuan
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
| | - Yu-Lin Hao
- Institute of Metal Research of Chinese Academy of Science; Shenyang China
| | - Zhi-Yong Zhang
- National Tissue Engineering Center of China; Shanghai China
| | - Zheng Guo
- Department of Orthopedics; Xijing Hospital; The Fourth Military Medical University; Xi'an China
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Benazzo F, Botta L, Scaffino MF, Caliogna L, Marullo M, Fusi S, Gastaldi G. Trabecular titanium can induce in vitro osteogenic differentiation of human adipose derived stem cells without osteogenic factors. J Biomed Mater Res A 2013; 102:2061-71. [PMID: 23894030 DOI: 10.1002/jbm.a.34875] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 07/01/2013] [Accepted: 07/12/2013] [Indexed: 01/25/2023]
Abstract
Trabecular Titanium (TT) is an innovative highly porous structure that imitates the morphology of trabecular bone with good mechanical properties. Adipose-derived stem cells are a multipotent cell population that can be used in regenerative medicine, in particular, for bone therapeutic applications. The ability of TT to induce the osteogenic differentiation of human adipose derived stem cells (hASCs) in the absence of osteogenic factors was evaluated using molecular biological, biochemical, and immunohistochemical methods. At 7 and 21 days from differentiation, the hASCs grown on TT scaffolds showed similar expressions of alkaline phosphatase (ALP) and Runx-2 both in the presence and in the absence of osteogenic factors, as well as at transcript and protein levels. hASCs cultured on monolayer in the presence of the medium obtained from the wells where hASCs/scaffold constructs were cultured in the absence of osteogenic factors differentiated towards the osteogenic phenotype: their gene and protein expression of ALP and Runx-2 was similar to that of the same cells cultured in the presence of osteogenic factors, and significantly higher than that of the ones cultured in growth medium.
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Affiliation(s)
- Francesco Benazzo
- Department of Orthopedics and Traumatology, IRCCS Policlinico San Matteo Foundation, University of Pavia, Italy
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Kato K, Ochiai S, Yamamoto A, Daigo Y, Honma K, Matano S, Omori K. Novel multilayer Ti foam with cortical bone strength and cytocompatibility. Acta Biomater 2013. [PMID: 23201016 DOI: 10.1016/j.actbio.2012.11.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The major functions required for load-bearing orthopaedic implants are load-bearing and mechanical or biological fixation with the surrounding bone. Porous materials with appropriate mechanical properties and adequate pore structure for fixation are promising candidates for load-bearing implant material. In previous work, the authors developed a novel titanium (Ti) foam sheet 1-2mm thick by an original slurry foaming method. In the present work, novel Ti foam is developed with mechanical properties compatible with cortical bone and biological fixation capabilities by layer-by-layer stacking of different foam sheets with volumetric porosities of 80% and 17%. The resulting multilayer Ti foam exhibited a Young's modulus of 11-12GPa and yield strength of 150-240MPa in compression tests. In vitro cell culture on the sample revealed good cell penetration in the higher-porosity foam (80% volumetric porosity), which reached 1.2mm for 21 days of incubation. Cell penetration into the high-porosity layers of a multilayer sample was good and not influenced by the lower-porosity layers. Calcification was also observed in the high-porosity foam, suggesting that this Ti foam does not inhibit bone formation. Contradictory requirements for high volumetric porosity and high strength were attained by role-sharing between the foam sheets of different porosities. The unique characteristics of the present multilayer Ti foam make them attractive for application in the field of orthopaedics.
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Affiliation(s)
- K Kato
- Mitsubishi Material Corp., 1-297 Kitabukuro-cho, Omiya-ku, Saitama 330-8508, Japan.
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Pore Geometry Regulates Early Stage Human Bone Marrow Cell Tissue Formation and Organisation. Ann Biomed Eng 2013; 41:917-30. [DOI: 10.1007/s10439-013-0748-z] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 01/20/2013] [Indexed: 11/25/2022]
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Wieding J, Jonitz A, Bader R. The Effect of Structural Design on Mechanical Properties and Cellular Response of Additive Manufactured Titanium Scaffolds. MATERIALS 2012. [PMCID: PMC5448937 DOI: 10.3390/ma5081336] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Restoration of segmental defects in long bones remains a challenging task in orthopedic surgery. Although autologous bone is still the ‘Gold Standard’ because of its high biocompatibility, it has nevertheless been associated with several disadvantages. Consequently, artificial materials, such as calcium phosphate and titanium, have been considered for the treatment of bone defects. In the present study, the mechanical properties of three different scaffold designs were investigated. The scaffolds were made of titanium alloy (Ti6Al4V), fabricated by means of an additive manufacturing process with defined pore geometry and porosities of approximately 70%. Two scaffolds exhibited rectangular struts, orientated in the direction of loading. The struts for the third scaffold were orientated diagonal to the load direction, and featured a circular cross-section. Material properties were calculated from stress-strain relationships under axial compression testing. In vitro cell testing was undertaken with human osteoblasts on scaffolds fabricated using the same manufacturing process. Although the scaffolds exhibited different strut geometry, the mechanical properties of ultimate compressive strength were similar (145–164 MPa) and in the range of human cortical bone. Test results for elastic modulus revealed values between 3.7 and 6.7 GPa. In vitro testing demonstrated proliferation and spreading of bone cells on the scaffold surface.
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Affiliation(s)
- Jan Wieding
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +49-381-494-9338; Fax: +49-381-494-9308
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Tarala M, Waanders D, Biemond JE, Hannink G, Janssen D, Buma P, Verdonschot N. The effect of bone ingrowth depth on the tensile and shear strength of the implant-bone e-beam produced interface. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:2339-2346. [PMID: 21858722 DOI: 10.1007/s10856-011-4419-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 08/08/2011] [Indexed: 05/31/2023]
Abstract
New technologies, such as selective electron beam melting, allow to create complex interface structures to enhance bone ingrowth in cementless implants. The efficacy of such structures can be tested in animal experiments. Although animal studies provide insight into the biological response of new structures, it remains unclear how ingrowth depth is related to interface strength. Theoretically, there could be a threshold of ingrowth, above which the interface strength does not further increase. To test the relationship between depth and strength we performed a finite element study on micro models with simulated uncoated and hydroxyapatite (HA) coated surfaces. We examined whether complete ingrowth is necessary to obtain a maximal interface strength. An increase in bone ingrowth depth did not always enhance the bone-implant interface strength. For the uncoated specimens a plateau was reached at 1,500 μm of ingrowth depth. For the specimens with a simulated HA coating, a bone ingrowth depth of 500 μm already yielded a substantial interface strength, and deeper ingrowth did not enhance the interface strength considerably. These findings may assist in optimizing interface morphology (its depth) and in judging the effect of bone ingrowth depth on interface strength.
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Affiliation(s)
- M Tarala
- Orthopaedic Research Laboratory, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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O'Flynn KP, Stanton KT. Optimisation of the enamelling of an apatite-mullite glass-ceramic coating on Ti6Al4V. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:2035-2044. [PMID: 21773840 DOI: 10.1007/s10856-011-4392-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 07/09/2011] [Indexed: 05/31/2023]
Abstract
Apatite-mullite glass-ceramics (AMGCs) are under investigation as a potential alternative to hydroxyapatite (HA) as a coating for cementless fixation of orthopaedic implants. These materials have tailorable mechanical and chemical properties that make them attractive for use as bioactive coatings. Here, AMGC coatings on Ti(6)Al(4)V were investigated to determine an improved heat treatment regime using a systematic examination of the different inputs: composition of glass, nucleation hold and crystallisation hold. An upper limit to the heat treatment temperature was determined by the α + β --> β of Ti(6)Al(4)V at 970°C. The glass composition was modified to produce different crystallisation temperatures and sintering characteristics. A glass was found that is fully crystalline below 970°C and has good sinterability. The effects of different heat treatment time and temperature combinations on the coating and substrate morphologies were examined and the most suitable combination determined. This sample was further investigated and was found to have qualitatively good adhesion and evidence of an interfacial reaction region between the coating and substrate indicating that a chemical reaction had occurred. Oxygen infiltration into the substrate was quantified and the new route was shown to result in a 63% reduction in penetration depth.
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Affiliation(s)
- Kevin P O'Flynn
- School of Mechanical and Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland
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Osteoinduction of porous Ti implants with a channel structure fabricated by selective laser melting. Acta Biomater 2011; 7:2327-36. [PMID: 21295166 DOI: 10.1016/j.actbio.2011.01.037] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 01/22/2011] [Accepted: 01/27/2011] [Indexed: 11/23/2022]
Abstract
Many studies have shown that certain biomaterials with specific porous structures can induce bone formation in non-osseous sites without the need for osteoinductive biomolecules, however, the mechanisms responsible for this phenomenon (intrinsic osteoinduction of biomaterials) remain unclear. In particular, to our knowledge the type of pore structure suitable for osteoinduction has not been reported in detail. In the present study we investigated the effects of interconnective pore size on osteoinductivity and the bone formation processes during osteoinduction. Selective laser melting was employed to fabricate porous Ti implants (diameter 3.3mm, length 15 mm) with a channel structure comprising four longitudinal square channels, representing pores, of different diagonal widths, 500, 600, 900, and 1200 μm (termed p500, p600, p900, and p1200, respectively). These were then subjected to chemical and heat treatments to induce bioactivity. Significant osteoinduction was observed in p500 and p600, with the highest observed osteoinduction occurring at 5mm from the end of the implants. A distance of 5mm probably provides a favorable balance between blood circulation and fluid movement. Thus, the simple architecture of the implants allowed effective investigation of the influence of the interconnective pore size on osteoinduction, as well as the relationship between bone quantity and its location for different pore sizes.
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Brailovski V, Prokoshkin S, Gauthier M, Inaekyan K, Dubinskiy S, Petrzhik M, Filonov M. Bulk and porous metastable beta Ti–Nb–Zr(Ta) alloys for biomedical applications. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2011. [DOI: 10.1016/j.msec.2010.12.008] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of implants to bone rather than fibrous tissue encapsulation. Surfaces properties such as chemistry and roughness play a determinant role in these biological interactions. Physicochemical features in the nanometer range may ultimately control the adsorption of proteins as well as the adhesion and differentiation of cells. Nanotechnologies are increasingly used for surface modifications of dental implants. Another approach to enhance osseointegration is the application of thin calcium phosphate (CaP) coatings. Bioactive CaP nanocrystals deposited on titanium implants are resorbable and stimulate bone apposition and healing. Future nanometer-controlled surfaces may ultimately direct the nature of peri-implant tissues and improve their clinical success rate.
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40
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Stem Cells Grown in Osteogenic Medium on PLGA, PLGA/HA, and Titanium Scaffolds for Surgical Applications. Bioinorg Chem Appl 2010:831031. [PMID: 21234383 PMCID: PMC3017899 DOI: 10.1155/2010/831031] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 09/15/2010] [Accepted: 10/27/2010] [Indexed: 12/17/2022] Open
Abstract
Pluripotent adipose tissue-derived stem cells (hASCs) can differentiate into various mesodermal cell types such as osteoblasts, chondroblasts, and myoblasts. We isolated hASCs from subcutaneous adipose tissue during orthopaedic surgery and induced the osteogenic differentiation for 28 days on three different synthetic scaffolds such as polylactide-co-glycolide (PLGA), polylactide-co-glycolide/hydroxyapatite (PLGA/HA), and trabecular titanium scaffolds (Ti6Al4V). Pore size can influence certain criteria such as cell attachment, infiltration, and vascularization. The aim of this study was to investigate the performance of PLGA and PLGA/HA scaffolds with a higher porosity, ranging between 75% and 84%, with respect to Ti scaffolds but with smaller pore size, seeded with hASCs to develop a model that could be used in the treatment of bone defects and fractures. Osteogenesis was assessed by ELISA quantitation of extracellular matrix protein expression, von Kossa staining, X-ray microanalysis, and scanning electron microscopy. The higher amount of protein matrix on the Ti scaffold with respect to PLGA and PLGA/HA leads to the conclusion that not only the type of material but the structure significantly affects cell proliferation.
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Gastaldi G, Asti A, Scaffino MF, Visai L, Saino E, Cometa AM, Benazzo F. Human adipose-derived stem cells (hASCs) proliferate and differentiate in osteoblast-like cells on trabecular titanium scaffolds. J Biomed Mater Res A 2010; 94:790-9. [PMID: 20336739 DOI: 10.1002/jbm.a.32721] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of stem cells in regenerative medicine is an appealing area of research that has received a great deal of interest in recent years. The population called human adipose tissue-derived stem cells (hASCs) share many of the characteristic of its counterpart of marrow including extensive proliferative potential and the ability to undergo multilineage differentiation along classical mesenchymal lineages: adipogenesis, chondrogenesis, osteogenesis, and myogenesis. The aim of this study was to evaluate with biochemical and morphological methods the adhesion and differentiation of hASCs grown on trabecular titanium scaffolds. The hASCs isolated from subcutaneous adipose tissue after digestion with collagenase were seeded on monolayer and on trabecular titanium scaffolds and incubated at 37 degrees C in 5% CO(2) with osteogenic medium or control medium.The results showed that hASCs were able to adhere to titanium scaffolds, to proliferate, to acquire an osteoblastic-like phenotype, and to produce a calcified extracellular matrix with protein, such as, decorin, fibronectin, osteocalcin, osteonectin, osteopontin, and type I collagen. These data suggest that this kind of scaffold/cells construct is effective to regenerate damaged tissue and to restore the function of bone tissue.
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Schumacher M, Deisinger U, Detsch R, Ziegler G. Indirect rapid prototyping of biphasic calcium phosphate scaffolds as bone substitutes: influence of phase composition, macroporosity and pore geometry on mechanical properties. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:3119-3127. [PMID: 20953674 DOI: 10.1007/s10856-010-4166-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 09/21/2010] [Indexed: 05/30/2023]
Abstract
While various materials have been developed for bone substitute and bone tissue engineering applications over the last decades, processing techniques meeting the high demands of scaffold shaping are still under development. Individually adapted and mechanically optimised scaffolds can be derived from calcium phosphate (CaP-) ceramics via rapid prototyping (RP). In this study, porous ceramic scaffolds with a periodic pattern of interconnecting pores were prepared from hydroxyapatite, β-tricalcium phosphate and biphasic calcium phosphates using a negative-mould RP technique. Moulds predetermining various pore patterns (round and square cross section, perpendicular and 60° inclined orientation) were manufactured via a wax printer and subsequently impregnated with CaP-ceramic slurries. Different pore patterns resulted in macroporosity values ranging from about 26.0-71.9 vol% with pore diameters of approximately 340 μm. Compressive strength of the specimens (1.3-27.6 MPa) was found to be mainly influenced by the phase composition as well as the macroporosity, both exceeding the influence of the pore geometry. A maximum was found for scaffolds with 60 wt% hydroxyapatite and 26.0 vol% open porosity. It has been shown that wax ink-jet printing allows to process CaP-ceramic into scaffolds with highly defined geometry, exhibiting strength values that can be adjusted by phase composition and pore geometry. This strength level is within and above the range of human cancellous bone. Therefore, this technique is well suited to manufacture scaffolds for bone tissue engineering.
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Affiliation(s)
- M Schumacher
- Friedrich-Baur-Research Institute for Biomaterials, University of Bayreuth, 95440, Bayreuth, Germany.
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Schander K, Arvidson K, Mustafa K, Hellem E, Bolstad AI, Finne-Wistrand A, Albertsson AC. Response of Bone and Periodontal Ligament Cells to Biodegradable Polymer Scaffolds In Vitro. J BIOACT COMPAT POL 2010. [DOI: 10.1177/0883911510383684] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this in vitro study, the initial response of human periodontal ligament (PDL) cells and alveolar osteoblast-like cells (HOB) to three biodegradable polymers with varying pore size and different mechanical properties were evaluated. Scaffolds were synthesized from poly(L-lactide), [poly(LLA)], poly(L-lactide-co-1,5-dioxepan-2-one), [poly(LLA-co-DXO)], poly(L-lactide-co-ε-caprolactone), and [poly(LLA-co-CL)] with pore sizes greater or less than 90 µm by salt leaching. Cells were obtained from patients undergoing routine oral surgery. After 2—4 passages, the cells were grown on scaffolds and in culture plates (control) for 3 h (PDL cells), 3 days (PDL cells and HOB), 10 and 14 days (HOB), respectively. The cellular morphology and spreading were determined by scanning electron microscopy (SEM) and the attachment and proliferation were evaluated by MTT assays. The SEM images revealed heterogeneous cellular morphology and good spreading. Cellular attachment and proliferation were significantly higher on poly(LLA-co-DXO) and poly(LLA-co-CL) than on poly(LLA) scaffolds (p = 0.003) and highest for poly(LLA-co-DXO). Expression of bone formation markers, collagen-I (COL-I), transforming growth factor-β 1 (TGF-β1), and osteocalcin (OCN), was determined by ELISA. The expression of COL-1 was similar for HOB and PDL cells, but significantly higher for pore size >90 µm while the HOB expression of TGFβ 1 and OCN was greater on poly(LLA-co-CL) and poly(LLA-co-DXO) than on poly(LLA) scaffolds.
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Affiliation(s)
- Kerstin Schander
- Department of Clinical Dentistry - Center for Clinical Dental Research, University of Bergen, Årstadveien 17, Bergen, N-5009, Norway,
| | - Kristina Arvidson
- Department of Clinical Dentistry - Center for Clinical Dental Research, University of Bergen, Årstadveien 17, Bergen, N-5009, Norway
| | - Kamal Mustafa
- Department of Clinical Dentistry - Center for Clinical Dental Research, University of Bergen, Årstadveien 17, Bergen, N-5009, Norway,
| | - Endre Hellem
- Department of Oral and Maxillofacial Surgery, Sørlandet Hospital, Arendal, N-484, Norway
| | - Anne Isine Bolstad
- Department of Clinical Dentistry - Periodontics, University of Bergen, Årstadveien 17, Bergen, N-5009, Norway
| | - Anna Finne-Wistrand
- Department of Fibre and Polymer Technology, Royal Institute of Technology, Stockholm, S-10044, Sweden
| | - Ann-Christine Albertsson
- Department of Fibre and Polymer Technology, Royal Institute of Technology, Stockholm, S-10044, Sweden
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Kunz F, Bergemann C, Klinkenberg ED, Weidmann A, Lange R, Beck U, Nebe JB. A novel modular device for 3-D bone cell culture and non-destructive cell analysis. Acta Biomater 2010; 6:3798-807. [PMID: 20227531 DOI: 10.1016/j.actbio.2010.03.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 03/08/2010] [Accepted: 03/08/2010] [Indexed: 12/31/2022]
Abstract
Synthetic materials have emerged as bone substitutes for filling bone defects of critical sizes. Because bone healing requires a mechanically resistant matrix (scaffold) attractive to osteogenic cells and must allow revascularization for nutrient and oxygen supply, scaffold-based strategies focus on the further development of chemical and physical qualities of the material. Cellular ingrowth towards the scaffold center is critical; therefore selective information from inner regions, in particular from the central part, is essential. In this paper we introduce a novel modular in vitro system for three-dimensional (3-D) in vitro bone cell cultures. This 3-D system is developed exclusively for in vitro research purposes, with special emphasis on the geometrical scaffold design (pore size, pore design). The system is composed of a stack of titanium slices which are mounted on a clamp and which enable the separate monitoring of cell growth patterns on every single slice of the slide stack. In this way we are able to gain selective information about the regulation of the cell physiology in the inner part of the 3-D construct which can be used for the development of an optimized scaffold design for orthopedic implants.
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Porous metallic structures for orthopaedic applications: a short review of materials and technologies. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s12570-010-0020-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities.
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Mangano C, Raspanti M, Traini T, Piattelli A, Sammons R. Stereo imaging and cytocompatibility of a model dental implant surface formed by direct laser fabrication. J Biomed Mater Res A 2009; 88:823-31. [PMID: 18481810 DOI: 10.1002/jbm.a.32033] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Direct laser fabrication (DLF) allows solids with complex geometry to be produced by sintering metal powder particles in a focused laser beam. In this study, 10 Ti6Al4V alloy model dental root implants were obtained by DLF, and surface characterization was carried out using stereo scanning electron microscopy to produce 3D reconstructions. The surfaces were extremely irregular, with approximately 100 microm deep, narrow intercommunicating crevices, shallow depressions and deep, rounded pits of widely variable shape and size, showing ample scope for interlocking with the host bone. Roughness parameters were as follows: R(t), 360.8 microm; R(z), 358.4 microm; R(a), 67.4 microm; and R(q), 78.0 microm. Disc specimens produced by DLF with an identically prepared surface were used for biocompatibility studies with rat calvarial osteoblasts: After 9 days, cells had attached and spread on the DLF surface, spanning across the crevices, and voids. Cell density was similar to that on a commercial rough microtextured surface but lower than on commercial smooth machined and smooth-textured grit-blasted, acid-etched surfaces. Human fibrin clot extension on the DLF surface was slightly improved by inorganic acid etching to increase the microroughness. With further refinements, DLF could be an economical means of manufacturing implants from titanium alloys.
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Kojima N, Ozawa S, Miyata Y, Hasegawa H, Tanaka Y, Ogawa T. High-throughput gene expression analysis in bone healing around titanium implants by DNA microarray. Clin Oral Implants Res 2008; 19:173-81. [PMID: 18184341 DOI: 10.1111/j.1600-0501.2007.01432.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Bone generation occurs around titanium implants; however, its underlying mechanisms are relatively unknown. We attempt to identify gene transcripts specifically upregulated in in vivo bone healing with titanium implants using DNA microarray. MATERIAL AND METHODS Titanium implants were placed into rat femurs, and total RNA was extracted from the implant-associated tissue at weeks 1, 2 and 4 of healing. As a control, RNA was extracted from the tissue undergoing osteotomy healing. The RNA samples were hybridized onto oligo DNA microarray. RESULTS Most of the 20,000 genes tested were expressed similarly in both the implant- and osteotomy-healing groups. Eighty-six genes were upregulated (>2-fold) in the implant-healing group compared with the osteotomy-healing group in at least one time point of healing. Twelve genes were upregulated in the implant healing at week 2 and earlier, while 31 genes were upregulated at week 2 and later. Only one gene was upregulated specifically at week 1, while three genes were consistently upregulated from weeks 1 to 4. The upregulated genes included collagenous and non-collagenous extracellular matrix (ECM)-related genes, proteoglycans and bone resorption-related genes. Pathway analysis revealed the involvement of ECM and receptor interaction in implant healing. CONCLUSIONS This study provides evidence that a set of gene transcripts is upregulated in the implant healing over the osteotomy healing, which seems to represent the coordinated biological events of long-lasting osteogenesis and bone remodeling required for osseointegration. Further studies are needed to identify the significance and biological roles of the transcripts in osseointegration. Proven reliability and usefulness of microarray technology should encourage future approaches to develop a high-throughput molecular assessment for osseointegration capacity of new implant surfaces.
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Affiliation(s)
- Norinaga Kojima
- Department of Prosthodontics, Aichi-Gakuin University School of Dentistry, Nagoya, Japan
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Pamula E, Bacakova L, Filova E, Buczynska J, Dobrzynski P, Noskova L, Grausova L. The influence of pore size on colonization of poly(L-lactide-glycolide) scaffolds with human osteoblast-like MG 63 cells in vitro. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:425-35. [PMID: 17607515 DOI: 10.1007/s10856-007-3001-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Accepted: 03/01/2007] [Indexed: 05/16/2023]
Abstract
A degradable copolymer of L-lactide and glycolide (PLG) was synthesized by ring opening polymerization using zirconium acetylacetonate [Zr(acac)(4)] as a biocompatible initiator. The structure of the copolymer was studied by nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). Porous scaffolds of defined microstructure were prepared by solvent casting/salt particulate leaching, which resulted in the creation of three types of scaffolds with the same porosity (87%+/-1%) but with different diameters of the pores (600, 200 and 40 microm) and degree of interconnectivity. The potential of the scaffolds for cell colonization was tested in a conventional static cell culture system using human osteoblast-like MG 63 cells. As revealed by conventional fluorescence and confocal microscopy on days 5 and 7 after seeding, the cells on the scaffolds of large or medium pore size infiltrated the inside part of the material, whereas on the scaffolds of small pore size, the cells were retained on the material surface. On day 7 after seeding, the highest number of cells was found on the scaffolds of the largest pore size (more than 120,000 cells per sample of the diameter 15 mm and thickness 2 mm), whereas on the scaffolds with medium and smallest pore diameter, the number of cells was almost three times lower and similar for both pore sizes. These results corresponded well with the incorporation of bromodeoxyuridine into newly synthesized DNA, which was significantly higher in cells on scaffolds of the largest pore size than on the material with medium and smallest pore diameter. As indicated by the MTT test, the mitochondrial activity in cells on scaffolds with medium pore size was similar to that on the material with the highest pore size, and significantly higher than on scaffolds of the smallest pore diameter. These results suggest that PLG scaffolds with the largest pore diameter (600 microm) and better pore interconnectivity are the most suitable for colonization with osteogenic cells.
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Affiliation(s)
- Elzbieta Pamula
- Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, Krakow 30-059, Poland.
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