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Omar O, Rydén L, Wamied AR, Al-Otain I, Alhawaj H, Abuohashish H, Al-Qarni F, Emanuelsson L, Johansson A, Palmquist A, Thomsen P. Molecular mechanisms of poor osseointegration in irradiated bone: In vivo study in a rat tibia model. J Clin Periodontol 2024; 51:1236-1251. [PMID: 38798064 DOI: 10.1111/jcpe.14021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 04/30/2024] [Accepted: 05/15/2024] [Indexed: 05/29/2024]
Abstract
AIM Radiotherapy is associated with cell depletion and loss of blood supply, which are linked to compromised bone healing. However, the molecular events underlying these effects at the tissue-implant interface have not been fully elucidated. This study aimed to determine the major molecular mediators associated with compromised osseointegration due to previous exposure to radiation. MATERIALS AND METHODS Titanium implants were placed in rat tibiae with or without pre-exposure to 20 Gy irradiation. Histomorphometric, biomechanical, quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay analyses were performed at 1 and 4 weeks after implantation. RESULTS The detrimental effects of irradiation were characterized by reduced bone-implant contact and removal torque. Furthermore, pre-exposure to radiation induced different molecular dysfunctions such as (i) increased expression of pro-inflammatory (Tnf) and osteoclastic (Ctsk) genes and decreased expression of the bone formation (Alpl) gene in implant-adherent cells; (ii) increased expression of bone formation (Alpl and Bglap) genes in peri-implant bone; and (iii) increased expression of pro-inflammatory (Tnf) and pro-fibrotic (Tgfb1) genes in peri-implant soft tissue. The serum levels of pro-inflammatory, bone formation and bone resorption proteins were greater in the irradiated rats. CONCLUSIONS Irradiation causes the dysregulation of multiple biological activities, among which perturbed inflammation seems to play a common role in hindering osseointegration.
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Affiliation(s)
- Omar Omar
- Department of Biomedical Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Louise Rydén
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Ibrahim Al-Otain
- Radiation Oncology, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Hussain Alhawaj
- Department of Environmental Health Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Hatem Abuohashish
- Department of Biomedical Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Faisal Al-Qarni
- Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Lena Emanuelsson
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anna Johansson
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Palmquist
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Peter Thomsen
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Johansson ML, Omar O, Trobos M, Jonhede S, Peters H, Hultcrantz M, Thomsen P. Non-invasive sampling procedure revealing the molecular events at different abutments of bone-anchored hearing systems–A prospective clinical pilot study. Front Neurosci 2022; 16:1058689. [DOI: 10.3389/fnins.2022.1058689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022] Open
Abstract
PurposeTo investigate the molecular activities in different compartments around the bone-anchored hearing system (BAHS) with either electropolished or machined abutments and to correlate these activities with clinical and microbiological findings.Materials and methodsTwelve patients received machined or electropolished abutments after implant installation of BAHS. Peri-abutment fluid and tissue were collected from baseline to 12 months. Gene expression of cytokines and factors related to tissue healing and inflammation, regeneration and remodelling, as well as bacterial recognition were determined using quantitative-polymerase chain reaction (qPCR). The clinical status was evaluated using the Holgers scoring system, and bacterial colonisation was investigated by culturing.ResultsThe gene expression of inflammatory cytokines (IL-8, IL-1β, and IL-10) and bacteria-related Toll-like receptors (2 and 4) was higher in the peri-abutment fluid than at baseline and in the peri-abutment tissue at 3 and 12 months. Conversely, the expression of genes related to tissue regeneration (Coll1a1 and FOXO1) was higher in the tissue samples than in the peri-abutment fluid at 3 and 12 months. Electropolished abutments triggered higher expression of inflammatory cytokines (IL-8 and IL-1β) (in peri-abutment fluid) and regeneration factor FOXO1 (in peri-abutment tissue) than machined abutments. Several cytokine genes in the peri-abutment fluid correlated positively with the detection of aerobes, anaerobes and Staphylococcus species, as well as with high Holger scores.ConclusionThis study provides unprecedented molecular information on the biological processes of BAHS. Despite being apparently healed, the peri-abutment fluid harbours prolonged inflammatory activity in conjunction with the presence of different bacterial species. An electropolished abutment surface appears to be associated with stronger proinflammatory activity than that with a machined surface. The analysis of the peri-abutment fluid deserves further verification as a non-invasive sampling and diagnostic procedure of BAHS.
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Karazisis D, Omar O, Petronis S, Thomsen P, Rasmusson L. Molecular Response to Nanopatterned Implants in the Human Jaw Bone. ACS Biomater Sci Eng 2021; 7:5878-5889. [PMID: 34851620 PMCID: PMC8672355 DOI: 10.1021/acsbiomaterials.1c00861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Implant surface modification by nanopatterning is an interesting route for enhancing osseointegration in humans. Herein, the molecular response to an intentional, controlled nanotopography pattern superimposed on screw-shaped titanium implants is investigated in human bone. When clinical implants are installed, additional two mini-implants, one with a machined surface (M) and one with a machined surface superimposed with a hemispherical nanopattern (MN), are installed in the posterior maxilla. In the second-stage surgery, after 6-8 weeks, the mini-implants are retrieved by unscrewing, and the implant-adherent cells are subjected to gene expression analysis using quantitative polymerase chain reaction (qPCR). Compared to those adherent to the machined (M) implants, the cells adherent to the nanopatterned (MN) implants demonstrate significant upregulation (1.8- to 2-fold) of bone-related genes (RUNX2, ALP, and OC). No significant differences are observed in the expression of the analyzed inflammatory and remodeling genes. Correlation analysis reveals that older patient age is associated with increased expression of proinflammatory cytokines (TNF-α and MCP-1) on the machined implants and decreased expression of pro-osteogenic factor (BMP-2) on the nanopatterned implants. Controlled nanotopography, in the form of hemispherical 60 nm protrusions, promotes gene expressions related to early osteogenic differentiation and osteoblastic activity in implant-adherent cells in the human jaw bone.
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Affiliation(s)
- Dimitrios Karazisis
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden.,Department of Oral and Maxillofacial Surgery, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Omar Omar
- Department of Biomedical Dental Sciences, College of Dentistry, Imam Abdulrahman bin Faisal University, Dammam 34212, Saudi Arabia
| | - Sarunas Petronis
- Chemistry, Biomaterials and Textiles, RISE Research Institutes of Sweden, 501 15 Borås, Sweden
| | - Peter Thomsen
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Lars Rasmusson
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden.,Department of Oral and Maxillofacial Surgery, Sahlgrenska Academy, University of Gothenburg, 405 30 Gothenburg, Sweden.,Maxillofacial Unit, Linköping University Hospital, 581 85 Linköping, Sweden
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Shah FA, Ruscsák K, Palmquist A. 50 years of scanning electron microscopy of bone-a comprehensive overview of the important discoveries made and insights gained into bone material properties in health, disease, and taphonomy. Bone Res 2019; 7:15. [PMID: 31123620 PMCID: PMC6531483 DOI: 10.1038/s41413-019-0053-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 02/06/2023] Open
Abstract
Bone is an architecturally complex system that constantly undergoes structural and functional optimisation through renewal and repair. The scanning electron microscope (SEM) is among the most frequently used instruments for examining bone. It offers the key advantage of very high spatial resolution coupled with a large depth of field and wide field of view. Interactions between incident electrons and atoms on the sample surface generate backscattered electrons, secondary electrons, and various other signals including X-rays that relay compositional and topographical information. Through selective removal or preservation of specific tissue components (organic, inorganic, cellular, vascular), their individual contribution(s) to the overall functional competence can be elucidated. With few restrictions on sample geometry and a variety of applicable sample-processing routes, a given sample may be conveniently adapted for multiple analytical methods. While a conventional SEM operates at high vacuum conditions that demand clean, dry, and electrically conductive samples, non-conductive materials (e.g., bone) can be imaged without significant modification from the natural state using an environmental scanning electron microscope. This review highlights important insights gained into bone microstructure and pathophysiology, bone response to implanted biomaterials, elemental analysis, SEM in paleoarchaeology, 3D imaging using focused ion beam techniques, correlative microscopy and in situ experiments. The capacity to image seamlessly across multiple length scales within the meso-micro-nano-continuum, the SEM lends itself to many unique and diverse applications, which attest to the versatility and user-friendly nature of this instrument for studying bone. Significant technological developments are anticipated for analysing bone using the SEM.
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Affiliation(s)
- Furqan A. Shah
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Krisztina Ruscsák
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Palmquist
- Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Murase K, Stenlund P, Thomsen P, Lausmaa J, Palmquist A. Three-dimensional modeling of removal torque and fracture progression around implants. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:104. [PMID: 29961132 PMCID: PMC6028867 DOI: 10.1007/s10856-018-6108-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
In the present study, a model for simulations of removal torque experiments was developed using finite element method. The interfacial retention and fracturing of the surrounding material caused by the surface features during torque was analyzed. It was hypothesized that the progression of removal torque and the phases identified in the torque response plot represents sequential fractures at the interface. The 3-dimensional finite element model fairly accurately predicts the torque required to break the fixation of acid-etched implants, and also provides insight to how sequential fractures progress downwards along the implant side.
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Affiliation(s)
- Kohei Murase
- Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Patrik Stenlund
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden.
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- RISE Research Institutes of Sweden AB, Gothenburg, Sweden.
| | - Peter Thomsen
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jukka Lausmaa
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
- RISE Research Institutes of Sweden AB, Gothenburg, Sweden
| | - Anders Palmquist
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Palmquist A. A multiscale analytical approach to evaluate osseointegration. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:60. [PMID: 29736606 PMCID: PMC5938308 DOI: 10.1007/s10856-018-6068-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/18/2018] [Indexed: 06/08/2023]
Abstract
Osseointegrated implants are frequently used in reconstructive surgery, both in the dental and orthopedic field, restoring physical function and improving the quality of life for the patients. The bone anchorage is typically evaluated at micrometer resolution, while bone tissue is a dynamic composite material composed of nanoscale collagen fibrils and apatite crystals, with defined hierarchical levels at different length scales. In order to understand the bone formation and the ultrastructure of the interfacial tissue, analytical strategies needs to be implemented enabling multiscale and multimodal analyses of the intact interface. This paper describes a sample preparation route for successive analyses allowing assessment of the different hierarchical levels of interest, going from macro to nano scale and could be implemented on single samples. Examples of resulting analyses of different techniques on one type of implant surface is given, with emphasis on correlating the length scale between the different techniques. The bone-implant interface shows an intimate contact between mineralized collagen bundles and the outermost surface of the oxide layer, while bone mineral is found in the nanoscale surface features creating a functionally graded interface. Osteocytes exhibit a direct contact with the implant surface via canaliculi that house their dendritic processes. Blood vessels are frequently found in close proximity to the implant surface either within the mineralized bone matrix or at regions of remodeling.
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Affiliation(s)
- Anders Palmquist
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
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Schoeman MA, Oostlander AE, Rooij KE, Valstar ER, Nelissen RG. Peri-prosthetic tissue cells show osteogenic capacity to differentiate into the osteoblastic lineage. J Orthop Res 2017; 35:1732-1742. [PMID: 27714894 PMCID: PMC5573935 DOI: 10.1002/jor.23457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/29/2016] [Indexed: 02/04/2023]
Abstract
During the process of aseptic loosening of prostheses, particulate wear debris induces a continuous inflammatory-like response resulting in the formation of a layer of fibrous peri-prosthetic tissue at the bone-prosthesis interface. The current treatment for loosening is revision surgery which is associated with a high-morbidity rate, especially in old patients. Therefore, less invasive alternatives are necessary. One approach could be to re-establish osseointegration of the prosthesis by inducing osteoblast differentiation in the peri-prosthetic tissue. Therefore, the aim of this study was to investigate the capacity of peri-prosthetic tissue cells to differentiate into the osteoblast lineage. Cells isolated from peri-prosthetic tissue samples (n = 22)-obtained during revision surgeries-were cultured under normal and several osteogenic culture conditions. Osteogenic differentiation was assessed by measurement of Alkaline Phosphatse (ALP), mineralization of the matrix and expression of several osteogenic genes. Cells cultured in osteogenic medium showed a significant increase in ALP staining (p = 0.024), mineralization of the matrix (p < 0.001) and ALP gene expression (p = 0.014) compared to normal culture medium. Addition of bone morphogenetic proteins (BMPs), a specific GSK3β inhibitor (GIN) or a combination of BMP and GIN to osteogenic medium could not increase ALP staining, mineralization, and ALP gene expression. In one donor, addition of GIN was required to induce mineralization of the matrix. Overall, we observed a high-inter-donor variability in response to osteogenic stimuli. In conclusion, peri-prosthetic tissue cells, cultured under osteogenic conditions, can produce alkaline phosphatase and mineralized matrix, and therefore show characteristics of differentiation into the osteoblastic lineage. © 2016 The Authors. Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 35:1732-1742, 2017.
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Affiliation(s)
| | | | - Karien Ede Rooij
- Department of OrthopaedicsLeiden University Medical CenterLeidenThe Netherlands
| | - Edward R. Valstar
- Department of OrthopaedicsLeiden University Medical CenterLeidenThe Netherlands
- Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials EngineeringDelft University of TechnologyDelftThe Netherlands
| | - Rob G.H.H. Nelissen
- Department of OrthopaedicsLeiden University Medical CenterLeidenThe Netherlands
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Xiu P, Jia Z, Lv J, Yin C, Cheng Y, Zhang K, Song C, Leng H, Zheng Y, Cai H, Liu Z. Tailored Surface Treatment of 3D Printed Porous Ti6Al4V by Microarc Oxidation for Enhanced Osseointegration via Optimized Bone In-Growth Patterns and Interlocked Bone/Implant Interface. ACS APPLIED MATERIALS & INTERFACES 2016; 8:17964-17975. [PMID: 27341499 DOI: 10.1021/acsami.6b05893] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
3D printed porous titanium (Ti) holds enormous potential for load-bearing orthopedic applications. Although the 3D printing technique has good control over the macro-sturctures of porous Ti, the surface properties that affect tissue response are beyond its control, adding the need for tailored surface treatment to improve its osseointegration capacity. Here, the one step microarc oxidation (MAO) process was applied to a 3D printed porous Ti6Al4V (Ti64) scaffold to endow the scaffold with a homogeneous layer of microporous TiO2 and significant amounts of amorphous calcium-phosphate. Following the treatment, the porous Ti64 scaffolds exhibited a drastically improved apatite forming ability, cyto-compatibility, and alkaline phosphatase activity. In vivo test in a rabbit model showed that the bone in-growth at the untreated scaffold was in a pattern of distance osteogenesis by which bone formed only at the periphery of the scaffold. In contrast, the bone in-growth at the MAO-treated scaffold exhibited a pattern of contact osteogenesis by which bone formed in situ on the entire surface of the scaffold. This pattern of bone in-growth significantly increased bone formation both in and around the scaffold possibly through enhancement of bone formation and disruption of bone remodeling. Moreover, the implant surface of the MAO-treated scaffold interlocked with the bone tissues through the fabricated microporous topographies to generate a stronger bone/implant interface. The increased osteoinetegration strength was further proven by a push out test. MAO exhibits a high efficiency in the enhancement of osteointegration of porous Ti64 via optimizing the patterns of bone in-growth and bone/implant interlocking. Therefore, post-treatment of 3D printed porous Ti64 with MAO technology might open up several possibilities for the development of bioactive customized implants in orthopedic applications.
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Affiliation(s)
- Peng Xiu
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Zhaojun Jia
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Jia Lv
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Chuan Yin
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Yan Cheng
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
| | - Ke Zhang
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Chunli Song
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Huijie Leng
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Yufeng Zheng
- Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University , Beijing 100871, People's Republic of China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, People's Republic of China
| | - Hong Cai
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
| | - Zhongjun Liu
- Department of Orthopedics, Peking University Third Hospital , Beijing 100191, People's Republic of China
- Beijing Key Laboratory of Spinal Diseases , Beijing 100191, People's Republic of China
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Shah FA, Johansson ML, Omar O, Simonsson H, Palmquist A, Thomsen P. Laser-Modified Surface Enhances Osseointegration and Biomechanical Anchorage of Commercially Pure Titanium Implants for Bone-Anchored Hearing Systems. PLoS One 2016; 11:e0157504. [PMID: 27299883 PMCID: PMC4907497 DOI: 10.1371/journal.pone.0157504] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 05/31/2016] [Indexed: 12/24/2022] Open
Abstract
Osseointegrated implants inserted in the temporal bone are a vital component of bone-anchored hearing systems (BAHS). Despite low implant failure levels, early loading protocols and simplified procedures necessitate the application of implants which promote bone formation, bone bonding and biomechanical stability. Here, screw-shaped, commercially pure titanium implants were selectively laser ablated within the thread valley using an Nd:YAG laser to produce a microtopography with a superimposed nanotexture and a thickened surface oxide layer. State-of-the-art machined implants served as controls. After eight weeks' implantation in rabbit tibiae, resonance frequency analysis (RFA) values increased from insertion to retrieval for both implant types, while removal torque (RTQ) measurements showed 153% higher biomechanical anchorage of the laser-modified implants. Comparably high bone area (BA) and bone-implant contact (BIC) were recorded for both implant types but with distinctly different failure patterns following biomechanical testing. Fracture lines appeared within the bone ~30-50 μm from the laser-modified surface, while separation occurred at the bone-implant interface for the machined surface. Strong correlations were found between RTQ and BIC and between RFA at retrieval and BA. In the endosteal threads, where all the bone had formed de novo, the extracellular matrix composition, the mineralised bone area and osteocyte densities were comparable for the two types of implant. Using resin cast etching, osteocyte canaliculi were observed directly approaching the laser-modified implant surface. Transmission electron microscopy showed canaliculi in close proximity to the laser-modified surface, in addition to a highly ordered arrangement of collagen fibrils aligned parallel to the implant surface contour. It is concluded that the physico-chemical surface properties of laser-modified surfaces (thicker oxide, micro- and nanoscale texture) promote bone bonding which may be of benefit in situations where large demands are imposed on biomechanically stable interfaces, such as in early loading and in compromised conditions.
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Affiliation(s)
- Furqan A. Shah
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Martin L. Johansson
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
- Oticon Medical AB, Askim, Sweden
| | - Omar Omar
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Hanna Simonsson
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
- Oticon Medical AB, Askim, Sweden
| | - Anders Palmquist
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Peter Thomsen
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden
- BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
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Karazisis D, Ballo AM, Petronis S, Agheli H, Emanuelsson L, Thomsen P, Omar O. The role of well-defined nanotopography of titanium implants on osseointegration: cellular and molecular events in vivo. Int J Nanomedicine 2016; 11:1367-82. [PMID: 27099496 PMCID: PMC4824366 DOI: 10.2147/ijn.s101294] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose Mechanisms governing the cellular interactions with well-defined nanotopography are not well described in vivo. This is partly due to the difficulty in isolating a particular effect of nanotopography from other surface properties. This study employed colloidal lithography for nanofabrication on titanium implants in combination with an in vivo sampling procedure and different analytical techniques. The aim was to elucidate the effect of well-defined nanotopography on the molecular, cellular, and structural events of osseointegration. Materials and methods Titanium implants were nanopatterned (Nano) with semispherical protrusions using colloidal lithography. Implants, with and without nanotopography, were implanted in rat tibia and retrieved after 3, 6, and 28 days. Retrieved implants were evaluated using quantitative polymerase chain reaction, histology, immunohistochemistry, and energy dispersive X-ray spectroscopy (EDS). Results Surface characterization showed that the nanotopography was well defined in terms of shape (semispherical), size (79±6 nm), and distribution (31±2 particles/µm2). EDS showed similar levels of titanium, oxygen, and carbon for test and control implants, confirming similar chemistry. The molecular analysis of the retrieved implants revealed that the expression levels of the inflammatory cytokine, TNF-α, and the osteoclastic marker, CatK, were reduced in cells adherent to the Nano implants. This was consistent with the observation of less CD163-positive macrophages in the tissue surrounding the Nano implant. Furthermore, periostin immunostaining was frequently detected around the Nano implant, indicating higher osteogenic activity. This was supported by the EDS analysis of the retrieved implants showing higher content of calcium and phosphate on the Nano implants. Conclusion The results show that Nano implants elicit less periimplant macrophage infiltration and downregulate the early expression of inflammatory (TNF-α) and osteoclastic (CatK) genes. Immunostaining and elemental analyses show higher osteogenic activity at the Nano implant. It is concluded that an implant with the present range of well-defined nanocues attenuates the inflammatory response while enhancing mineralization during osseointegration.
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Affiliation(s)
- Dimitrios Karazisis
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden; Department of Oral and Maxillofacial Surgery, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Ahmed M Ballo
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden; Department of Oral Health Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, BC, Canada
| | - Sarunas Petronis
- BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden; Department of Chemistry, Materials and Surfaces, SP Technical Research Institute of Sweden, Borås, Sweden
| | - Hossein Agheli
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Lena Emanuelsson
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Peter Thomsen
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
| | - Omar Omar
- Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; BIOMATCELL, VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden
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11
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Shanbhag S, Shanbhag V, Stavropoulos A. Genomic analyses of early peri-implant bone healing in humans: a systematic review. Int J Implant Dent 2015; 1:5. [PMID: 27747627 PMCID: PMC5005705 DOI: 10.1186/s40729-015-0006-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/27/2015] [Indexed: 01/22/2023] Open
Abstract
Objective The objective of the study was to systematically review the literature for studies reporting gene expression analyses (GEA) of the biological processes involved in early human peri-implant bone healing. Methods Electronic databases (MEDLINE, EMBASE) were searched in duplicate. Controlled and uncontrolled studies reporting GEA of human peri-implant tissues - including ≥5 patients and ≥2 time points - during the first 4 weeks of healing were eligible for inclusion. Methodological quality and risk of bias were also assessed. Results Four exploratory studies were included in reporting GEA of either tissues attached to SLA or SLActive implants after 4 to 14 days or cells attached to TiOBlast or Osseospeed implants after 3 to 7 days. A total of 111 implants from 43 patients were analyzed using validated array methods; however, considerable heterogeneity and risk of bias were detected. A consistent overall pattern of gene expression was observed; genes representing an immuno-inflammatory response were overexpressed at days 3 to 4, followed by genes representing osteogenic processes at day 7. Genes representing bone remodeling, angiogenesis, and neurogenesis were expressed concomitantly with osteogenesis. Several regulators of these processes, such as cytokines, growth factors, transcription factors, and signaling pathways, were identified. Implant surface properties seemed to influence the healing processes at various stages via differential gene expression. Conclusion Limited evidence from gene expression studies in humans indicates that osteogenic processes commence within the first post-operative week and they appear influenced at various stages by implant surface properties.
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Affiliation(s)
- Siddharth Shanbhag
- Department of Periodontology, Faculty of Odontology, Malmö University, Carl Gustafs väg 34, 214 21, Malmö, Sweden.,Centre for Oral Rehabilitation & Implant Dentistry, 1 Laxmi Niwas, 87 Bajaj Road, Vile Parle West, Mumbai, 400056, India
| | - Vivek Shanbhag
- Centre for Oral Rehabilitation & Implant Dentistry, 1 Laxmi Niwas, 87 Bajaj Road, Vile Parle West, Mumbai, 400056, India
| | - Andreas Stavropoulos
- Department of Periodontology, Faculty of Odontology, Malmö University, Carl Gustafs väg 34, 214 21, Malmö, Sweden.
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Gene profiling of bone around orthodontic mini-implants by RNA-sequencing analysis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:538080. [PMID: 25759820 PMCID: PMC4339713 DOI: 10.1155/2015/538080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 01/23/2015] [Indexed: 11/03/2022]
Abstract
This study aimed to evaluate the genes that were expressed in the healing bones around SLA-treated titanium orthodontic mini-implants in a beagle at early (1-week) and late (4-week) stages with RNA-sequencing (RNA-Seq). Samples from sites of surgical defects were used as controls. Total RNA was extracted from the tissue around the implants, and an RNA-Seq analysis was performed with Illumina TruSeq. In the 1-week group, genes in the gene ontology (GO) categories of cell growth and the extracellular matrix (ECM) were upregulated, while genes in the categories of the oxidation-reduction process, intermediate filaments, and structural molecule activity were downregulated. In the 4-week group, the genes upregulated included ECM binding, stem cell fate specification, and intramembranous ossification, while genes in the oxidation-reduction process category were downregulated. GO analysis revealed an upregulation of genes that were related to significant mechanisms, including those with roles in cell proliferation, the ECM, growth factors, and osteogenic-related pathways, which are associated with bone formation. From these results, implant-induced bone formation progressed considerably during the times examined in this study. The upregulation or downregulation of selected genes was confirmed with real-time reverse transcription polymerase chain reaction. The RNA-Seq strategy was useful for defining the biological responses to orthodontic mini-implants and identifying the specific genetic networks for targeted evaluations of successful peri-implant bone remodeling.
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Wazen RM, Kuroda S, Nishio C, Sellin K, Brunski JB, Nanci A. Gene expression profiling and histomorphometric analyses of the early bone healing response around nanotextured implants. Nanomedicine (Lond) 2013; 8:1385-95. [PMID: 23286527 DOI: 10.2217/nnm.12.167] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED While in vitro studies have shown that nanoscale surface modifications influence cell fate and activity, there is little information on how they modulate healing at the bone-implant interface. AIM This study aims to investigate the effect of nanotopography at early time intervals when critical events for implant integration occur. MATERIALS & METHODS Untreated and sulfuric acid/hydrogen peroxide-treated machined-surface titanium alloy implants were placed in rat tibiae. Samples were processed for DNA microarray analysis and histomorphometry. RESULTS At both 3 and 5 days, the gene expression profile of the healing tissue around nanotextured implants differed from that around machined-surface implants or control empty holes, and were accompanied by an increase in bone-implant contact on day 5. While some standard pathways such as the immune response predominated, a number of unclassified genes were also implicated. CONCLUSION Nanotexture elicits an initial gene response that is more complex than suspected so far and favors healing at the bone-implant interface.
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Affiliation(s)
- Rima M Wazen
- Laboratory for the Study of Calcified Tissues & Biomaterials, Department of Stomatology, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
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14
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Novel Implant Coating Agent Promotes Gene Expression of Osteogenic Markers in Rats during Early Osseointegration. Int J Biomater 2012. [PMID: 23193408 PMCID: PMC3501934 DOI: 10.1155/2012/579274] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to evaluate the early bone response around laminin-1-coated titanium implants. Forty-five rats distributed in three equally sized groups were provided with one control (turned) and one test (laminin-1-coated) implant and were sacrificed after 3, 7, and 21 days. Real-time reverse-transcriptase polymerase chain reaction was performed for osteoblast markers (alkaline phosphatase, runt-related transcription factor 2, osteocalcin, type I collagen, and bone morphogenic protein 2), osteoclast markers (cathepsin K and tartrate-resistant acid phosphatase), inflammation markers (tumor necrosis factor α, interleukin 1β and interleukin 10), and integrin β1. Bone implant contact (BIC) and bone area (BA) were assessed and compared to the gene expression. After 3 days, the expression of bone markers was higher for the control group. After 7 days, the expression of integrin β1 and osteogenic markers was enhanced for the test group, while cathepsin K and inflammation markers were down-regulated. No significant differences in BIC or BA were detected between test and control at any time point. As a conclusion, implant coating with laminin-1 altered gene expression in the bone-implant interface. However, traditional evaluation methods, as histomorphometry, were not adequately sensitive to detect such changes due to the short follow-up time.
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Orsini E, Salgarello S, Martini D, Bacchelli B, Quaranta M, Pisoni L, Bellei E, Joechler M, Ottani V. Early healing events around titanium implant devices with different surface microtopography: a pilot study in an in vivo rabbit model. ScientificWorldJournal 2012; 2012:349842. [PMID: 22545015 PMCID: PMC3322675 DOI: 10.1100/2012/349842] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/21/2011] [Indexed: 11/17/2022] Open
Abstract
In the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA) at very early experimental times. The tested devices were titanium plate-like implants with flattened wide lateral sides and jagged narrow sides. Because of these implant shape and placement site, the device gained a firm mechanical stability but the largest portion of the implant surface lacked direct contact with host bone and faced a wide peri-implant space rich in marrow tissue, intentionally created in order to study the interfacial interaction between metal surface and biological microenvironment. The insertion of titanium devices into the proximal tibia elicited a sequence of healing events. Newly formed bone proceeded through an early distance osteogenesis, common to both surfaces, and a delayed contact osteogenesis which seemed to follow different patterns at the two surfaces. In fact, SLA devices showed a more osteoconductive behavior retaining a less dense blood clot, which might be earlier and more easily replaced, and leading to a surface-conditioning layer which promotes osteogenic cell differentiation and appositional new bone deposition at the titanium surface. This model system is expected to provide a starting point for further investigations which clarify the early cellular and biomolecular events occurring at the metal surface.
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Affiliation(s)
- Ester Orsini
- Department of Human Anatomical Sciences and Physiopathology of Locomotor Apparatus, Human Anatomy Section, University of Bologna, via Irnerio 48, 40126 Bologna, Italy.
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Omar O, Suska F, Lennerås M, Zoric N, Svensson S, Hall J, Emanuelsson L, Nannmark U, Thomsen P. The influence of bone type on the gene expression in normal bone and at the bone-implant interface: experiments in animal model. Clin Implant Dent Relat Res 2011; 13:146-56. [PMID: 19438950 DOI: 10.1111/j.1708-8208.2009.00195.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Studies on the biological processes in different bone types and the reaction of different bone types to biomaterials are often hindered because of the difficulties in sampling procedures and lack of sensitive techniques. PURPOSE The purpose was to assess the suitability of quantitative polymerase chain reaction (qPCR) for investigation of the biological differences between cortical and trabecular bone types and their responses to biomaterials. MATERIALS AND METHODS Gene expression of selected markers in rat bone samples from different locations was evaluated. Samples were harvested by trephines from the trabecular femoral epiphysis, cortico-trabecular proximal tibial metaphysic, and the cortical distal tibial metaphysis. Gene expression was also evaluated at the surfaces of anodically oxidized implants retrieved from cortical and trabecular sites after 3 days of implantation. mRNA in the bone samples and in the tissue associated with the implant surfaces was extracted and quantified using qPCR. Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), alkaline phosphatase (ALP), osteocalcin (OC), tartrate-resistant acid phosphatase (TRAP), cathepsin K (CATK), and 18S ribosomal subunits (18S) were analyzed. RESULTS In the bone samples, higher expression of ALP, OC, TRAP, and CATK was found in femoral epiphysis compared to proximal or distal tibial metaphysis, indicating a higher turnover in the trabecular bone. On the other hand, TNF-α and IL-1β showed higher expression in both tibia sites compared with the femur site, which suggests higher inflammatory potential in the cortical bone. In response to the oxidized implants trabecular bone expressed a higher level of IL-1β, whereas the implants in cortical bone were associated with higher expression of ALP and OC. CONCLUSION There are biological differences between cortical and trabecular bone types, both in the normal steady-state condition and in response to biomaterials. Such differences can be characterized and discriminated quantitatively using a sensitive technique such as qPCR.
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Affiliation(s)
- Omar Omar
- Department of Biomaterials, Sahlgrenska Academy at University of Göteborg, Sweden.
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Palmquist A, Grandfield K, Norlindh B, Mattsson T, Brånemark R, Thomsen P. Bone-titanium oxide interface in humans revealed by transmission electron microscopy and electron tomography. J R Soc Interface 2011; 9:396-400. [PMID: 21849383 DOI: 10.1098/rsif.2011.0420] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Osseointegration, the direct contact between an implant surface and bone tissue, plays a critical role in interfacial stability and implant success. Analysis of interfacial zones at the micro- and nano-levels is essential to determine the extent of osseointegration. In this paper, a series of state-of-the-art microscopy techniques are used on laser-modified implants retrieved from humans. Partially laser-modified implants were retrieved after two and a half months' healing and processed for light and electron microscopy. Light microscopy showed osseointegration, with bone tissue growing both towards and away from the implant surface. Transmission electron microscopy revealed an intimate contact between mineralized bone and the laser-modified surface, including bone growth into the nano-structured oxide. This novel observation was verified by three-dimensional Z-contrast electron tomography, enabling visualization of an apatite layer, with different crystal direction compared with the apatite in the bone tissue, encompassing the nano-structured oxide. In conclusion, the present study demonstrates the nano-scale osseointegration and bonding between apatite and surface-textured titanium oxide. These observations provide novel data in human specimens on the ultrastructure of the titanium-bone interface.
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Affiliation(s)
- Anders Palmquist
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
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Lin Z, Rios HF, Volk SL, Sugai JV, Jin Q, Giannobile WV. Gene expression dynamics during bone healing and osseointegration. J Periodontol 2010; 82:1007-17. [PMID: 21142982 DOI: 10.1902/jop.2010.100577] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Understanding the molecular features of bone repair and osseointegration may aid in the development of therapeutics to improve implant outcomes. The purpose of this investigation is to determine the gene expression dynamics during alveolar bone repair and implant osseointegration. METHODS An implant osseointegration preclinical animal model was used whereby maxillary defects were created at the time of oral implant placement, while a tooth extraction socket healing model was established on the contralateral side of each animal. The surrounding tissues in the zone of the healing defects were harvested during regeneration for temporal evaluation using histology, immunohistochemistry, laser capture microdissection, and quantitative reverse transcription-polymerase chain reaction for the identification of a panel of 17 putative genes associated with wound repair. RESULTS In both models, three distinct expression patterns were displayed: 1) genes that are slowly increased during the healing process, such as bone morphogenetic protein 4, runt-related transcription factor 2, and osteocalcin; 2) genes that are upregulated at the early stage of healing and then downregulated at later stages, such as interleukin and chemokine (C-X-C motif) ligands 2 and 5; and 3) genes that are constitutively expressed over time, such as scleraxis. Although some similarities between osseointegration and tooth extraction socket were seen, distinct features developed and triggered a characteristic coordinated expression and orchestration of transcription factors, growth factors, extracellular matrix molecules, and chemokines. CONCLUSIONS Characterization of these events contributes to a better understanding of cooperative molecular dynamics in alveolar bone healing, and highlights potential pathways that could be further explored for the enhancement of osseous regenerative strategies.
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Affiliation(s)
- Zhao Lin
- Division of Periodontology, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA
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Palmquist A, Omar OM, Esposito M, Lausmaa J, Thomsen P. Titanium oral implants: surface characteristics, interface biology and clinical outcome. J R Soc Interface 2010; 7 Suppl 5:S515-27. [PMID: 20591849 DOI: 10.1098/rsif.2010.0118.focus] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bone-anchored titanium implants have revolutionized oral healthcare. Surface properties of oral titanium implants play decisive roles for molecular interactions, cellular response and bone regeneration. Nevertheless, the role of specific surface properties, such as chemical and phase composition and nanoscale features, for the biological in vivo performance remains to be established. Partly, this is due to limited transfer of state-of-the-art preparation techniques to complex three-dimensional geometries, analytical tools and access to minute, intact interfacial layers. As judged by the available results of a few randomized clinical trials, there is no evidence that any particular type of oral implant has superior long-term success. Important insights into the recruitment of mesenchymal stem cells, cell-cell communication at the interface and high-resolution imaging of the interface between the surface oxide and the biological host are prerequisites for the understanding of the mechanisms of osseointegration. Strategies for development of the next generation of material surface modifications for compromised tissue are likely to include time and functionally programmed properties, pharmacological modulation and incorporation of cellular components.
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Affiliation(s)
- Anders Palmquist
- BIOMATCELL Vinn Excellence Center for Biomaterials and Cell Therapy, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
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Omar O, Lennerås M, Svensson S, Suska F, Emanuelsson L, Hall J, Nannmark U, Thomsen P. Integrin and chemokine receptor gene expression in implant-adherent cells during early osseointegration. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:969-80. [PMID: 19856201 DOI: 10.1007/s10856-009-3915-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 10/13/2009] [Indexed: 05/21/2023]
Abstract
The mechanisms of early cellular recruitment and interaction to titanium implants are not well understood. The aim of this study was to investigate the expression of pro-inflammatory cytokines, chemokines and adhesion markers during the first 24 h of implantation. Anodically oxidized and machined titanium implants were inserted in rat tibia. After 3, 12, and 24 h the implants were unscrewed and analyzed with quantitative polymerase chain reaction. Immunohistochemistry and scanning electron microscopy revealed different cell types, morphology and adhesion at the two implant surfaces. A greater amount of cells, as indicated by higher expression of small subunit ribosomal RNA (18S), was detected on the oxidized surface. Higher expression of CXC chemokine receptor-4 (at 12 h) and integrins, alphav (at 12 h), beta1 (at 24 h) and beta2 (at 12 and 24 h) was detected at the oxidized surfaces. Significantly higher tumor necrosis factor-alpha (at 3 h) and interleukin-1beta (at 24 h) expression was demonstrated for the machined surface. It is concluded that material surface properties rapidly modulate the expression of receptors important for the recruitment and adhesion of cells which are crucial for the inflammatory and regenerative processes at implant surfaces in vivo.
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Affiliation(s)
- Omar Omar
- Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden.
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