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Kulić M, Bagavac P, Bekić M, Krstulović-Opara L. Ex Vivo Biomechanical Bone Testing of Pig Femur as an Experimental Model. Bioengineering (Basel) 2024; 11:572. [PMID: 38927808 PMCID: PMC11200541 DOI: 10.3390/bioengineering11060572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
This study investigates the mechanical behavior of femur bones under loading conditions, focusing on the transition from elastic to plastic deformation and eventual fracture. The force-displacement curves reveal distinct phases of deformation, with an initial linear relationship indicating elastic behavior, followed by deviation from linearity marking the onset of plastic deformation. Fracture occurs beyond a critical load, leading to a sharp drop in the force-displacement curve. The maximum fracture force varies among specimens and is influenced by bone geometry, size, cross-sectional area, and cortical thickness. Post-failure analysis highlights additional insights into fracture mechanics and bone material toughness. Reinforcing bones with screws enhances their strength, which is evident in the higher fracture forces observed in force-displacement diagrams. Fixation procedures following fractures further increase bone strength. Comparing specimens with and without strengthening underscores the effectiveness of reinforcement methods in improving bone mechanical properties. After analyzing the results, it is evident that femur bones with reinforcement can withstand greater loads, and they can also absorb higher impact energies while remaining in the elastic deformation range and without suffering permanent plastic damage. This study provides valuable insights into bone biomechanics and the efficacy of reinforcement techniques in enhancing bone strength and fracture resistance.
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Affiliation(s)
| | - Petra Bagavac
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, 21000 Split, Croatia;
| | - Marijo Bekić
- Dubrovnik County Hospital, 20000 Dubrovnik, Croatia;
| | - Lovre Krstulović-Opara
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, 21000 Split, Croatia;
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Evrard R, Feyens M, Manon J, Lengelé B, Cartiaux O, Schubert T. Impact of NaOH based perfusion-decellularization protocol on mechanical resistance of structural bone allografts. Connect Tissue Res 2024:1-14. [PMID: 38781097 DOI: 10.1080/03008207.2024.2356586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024]
Abstract
INTRODUCTION To mitigate the post-operative complication rates associated with massive bone allografts, tissue engineering techniques have been employed to decellularize entire bones through perfusion with a sequence of solvents. Mechanical assessment was performed in order to compare conventional massive bone allografts and perfusion/decellularized massive bone allografts. MATERIAL AND METHODS Ten porcine femurs were included. Five were decellularized by perfusion. The remaining 5 were left untreated as the "control" group. Biomechanical testing was conducted on each bone, encompassing five different assessments: screw pull-out, 3-points bending, torsion, compression and Vickers indentation. RESULTS Under the experimental conditions of this study, all five destructive tested variables (maximum force until screw pull-out, maximum elongation until screw pull-out, energy to pull out the screw, fracture resistance in flexion and maximum constrain of compression) were statistically significantly superior in the control group. All seven nondestructive variables (Young's modulus in flexion, Young's modulus in shear stress, Young's modulus in compression, Elastic conventional limit in compression, lengthening to rupture in compression, resilience in compression and Vickers Hardness) showed no significant difference. DISCUSSION Descriptive statistical results suggest a tendency for the biomechanical characteristics of decellularized bone to decrease compared with the control group. However, statistical inferences demonstrated a slight significant superiority of the control group with destructive mechanical stresses. Nondestructive mechanical tests (within the elastic phase of Young's modulus) were not significantly different.
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Affiliation(s)
- Robin Evrard
- Institut de Recherche Expérimentale et Clinique, Neuro Musculo-Skeletal Lab, Université Catholique de Louvain, Bruxelles, Belgique
- Institut de Recherche Expérimentale et Clinique, Pôle Chirurgie Expérimentale et Transplantation, Université Catholique de Louvain, Bruxelles, Belgique
- Service de Chirurgie Orthopédique et Traumatologique, Cliniques Universitaires Saint-Luc, Bruxelles, Belgique
| | - Maxendre Feyens
- ECAM Brussels Engineering School, Haute Ecole ICHEC-ECAM-ISFSC, Bruxelles, Belgique
| | - Julie Manon
- Institut de Recherche Expérimentale et Clinique, Neuro Musculo-Skeletal Lab, Université Catholique de Louvain, Bruxelles, Belgique
- Service de Chirurgie Orthopédique et Traumatologique, Cliniques Universitaires Saint-Luc, Bruxelles, Belgique
- Institut de Recherche Expérimentale et Clinique, Pôle Morphologie, Université Catholique de Louvain, Bruxelles, Belgique
| | - Benoit Lengelé
- Institut de Recherche Expérimentale et Clinique, Pôle Morphologie, Université Catholique de Louvain, Bruxelles, Belgique
- Service de Chirurgie Plastique, Reconstructrice et Esthétique, Cliniques Universitaires Saint-Luc, Bruxelles, Belgique
| | - Olivier Cartiaux
- ECAM Brussels Engineering School, Haute Ecole ICHEC-ECAM-ISFSC, Bruxelles, Belgique
| | - Thomas Schubert
- Institut de Recherche Expérimentale et Clinique, Neuro Musculo-Skeletal Lab, Université Catholique de Louvain, Bruxelles, Belgique
- Service de Chirurgie Orthopédique et Traumatologique, Cliniques Universitaires Saint-Luc, Bruxelles, Belgique
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Ai T, Shang L, Li B, Li J, Qin R. Konjac Oligosaccharides Alleviated Ovariectomy-Induced Bone Loss through Gut Microbiota Modulation and Treg/Th17 Regulation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:7969-7979. [PMID: 38551374 DOI: 10.1021/acs.jafc.4c00281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Oligosaccharides from the plant Amorphophallus konjac were potentially effective in menopausal osteoporosis due to their prebiotic attributes. The present work mainly studied the regulation of konjac oligosaccharides (KOS) on menopausal bone loss. Experiments were carried out in ovariectomized (OVX) rats, and various contents of KOS were correlated with diet. After 3 months of treatment, the degree of osteoporosis was determined by bone mineral density and femoral microarchitecture. The research data showed that the 8% dietary KOS significantly alleviated bone loss in OVX rats, as it promoted the bone trabecular number by 134.2% and enhanced the bone bending stiffness by 103.1%. From the perspective of the gut-bone axis, KOS promoted gut barrier repair and decreased pro-inflammatory cytokines. Besides, KOS promoted the growth of Bifidobacterium longum and restored Treg/Th17 balance in bone marrow. The two aspects contributed to decreased osteoclastogenic activity and thus inhibited inflammation-related bone loss. This work extended current knowledge of prebiotic inhibition on bone loss and provide an alternative strategy for osteoporosis prevention.
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Affiliation(s)
- Tingyang Ai
- College of Life Science, South-Central Minzu University, Wuhan 430070, Hubei, China
- College of Food Science and Technology, Hubei Minzu University, Wuhan 445000, Hubei, China
| | - Longchen Shang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Bin Li
- College of Food Science and Technology, Hubei Minzu University, Wuhan 445000, Hubei, China
| | - Jing Li
- College of Food Science and Technology, Hubei Minzu University, Wuhan 445000, Hubei, China
| | - Rui Qin
- College of Life Science, South-Central Minzu University, Wuhan 430070, Hubei, China
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Nijland H, Zhu J, Kwee TC, Hao DJ, Jutte PC. Mechanical bone strength decreases considerably after microwave ablation-Ex-vivo and in-vivo analysis in sheep long bones. PLoS One 2023; 18:e0292177. [PMID: 37824490 PMCID: PMC10569504 DOI: 10.1371/journal.pone.0292177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 09/14/2023] [Indexed: 10/14/2023] Open
Abstract
BACKGROUND Bone metastases are on the rise due to longer survival of cancer patients. Local tumor control is required for pain relief. Microwave ablation (MWA) is a technique for minimally invasive local tumor treatment. Tumor tissue is destroyed by application of local hyperthermia to induce necrosis. Given the most common setting of palliative care, it is generally considered beneficial for patients to start mobilizing directly following treatment. No data on mechanical strength in long bones after MWA have been published so far. MATERIALS AND METHODS In- and ex-vivo experiments on sheep tibias were performed with MWA in various combinations of settings for time and power. During the in-vivo part sheep were sacrificed one or six weeks after ablation. Mechanical strength was examined with a three-point bending test for ablations in the diaphysis and with an indentation test for ablations in the metaphysis. RESULTS MWA does not decrease mechanical strength in the diaphysis. In the metaphysis strength decreased up to 50% six weeks after ablation, which was not seen directly after ablation. CONCLUSION MWA appears to decrease mechanical strength in long bone metaphysis up to 50% after six weeks, however strength remains sufficient for direct mobilization. The time before normal strength is regained after the remodeling phase is not known.
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Affiliation(s)
- Hendricus Nijland
- Department of Orthopaedic Surgery, University Medical Center Groningen, Groningen, The Netherlands
| | - Jinwen Zhu
- Department of Orthopaedic Surgery, HongHui Medical Center Xi’an, Xi’an, China
| | - Thomas C. Kwee
- Department of Radiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Ding-Jun Hao
- Department of Orthopaedic Surgery, HongHui Medical Center Xi’an, Xi’an, China
| | - Paul C. Jutte
- Department of Orthopaedic Surgery, University Medical Center Groningen, Groningen, The Netherlands
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Liu K, Wang S, Yalikun A, Ren P, Yusufu A. The accordion technique enhances bone regeneration via angiogenesis factor in a rat distraction osteogenesis model. Front Physiol 2023; 14:1259567. [PMID: 37745241 PMCID: PMC10514895 DOI: 10.3389/fphys.2023.1259567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 08/30/2023] [Indexed: 09/26/2023] Open
Abstract
Objective: The purpose of this study was to observe the effect of the accordion technique (AT) during the distraction phase on chondrogenesis and bone regeneration in a rat femoral distraction osteogenesis (DO) model, and investigate its potential mechanism for reducing the total treatment time of DO. Methods: Fifty-four male Sprague-Dawley (SD) rats that were specific-pathogen-free (SPF) were subjected to DO surgery on the right femur. The distraction rate was 0.5 mm/day for 10 days, following a latency period of 5 days. Rats were randomly divided into Control (no AT, n = 18), Group LA (low amplitude with AT, n = 18), and Group HA (high amplitude with AT, n = 18) according to different AT protocols in the distraction phase. Rats were respectively euthanized by anesthesia overdose at 2, 4 and 6 weeks of the consolidation phase, and the femurs were harvested. Digital radiography, micro-computed tomography (micro-CT), biomechanical tests, and histomorphological analysis were used to assess the quality of regenerated bone in the distraction area. Results: Digital radiographic, micro-CT, biomechanical tests, and histological analysis revealed an increase in early-stage callus formation (p < 0.05) and improved blood supply to the callus tissue in Group LA, as compared to both the Control and Group HA. The enhanced differentiation of fibrous and cartilaginous tissue into bone tissue was also observed in Group LA, leading to improved strength and stiffness (p < 0.05) of the regenerated bone at 6 weeks of the consolidation phase. The angiogenic (hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), p < 0.05) and osteogenic (runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and osteopontin (OPN), p < 0.05) biomarkers were higher expressed in Group LA at 2 and 4 weeks of consolidation phase, whereas decreased at 6 weeks of consolidation phase. Conclusion: The application of AT with low amplitude during the distraction phase can enhance chondrogenesis and bone regeneration by activating the angiogenesis factor pathway and upregulating the expression of osteogenic-related biomarkers such as HIF-1α, VEGF, RUNX2, OCN, and OPN.
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Affiliation(s)
| | | | | | - Peng Ren
- Department of Trauma and Microreconstructive Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Aihemaitijiang Yusufu
- Department of Trauma and Microreconstructive Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
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Fracture Healing in Elderly Mice and the Effect of an Additional Severe Blood Loss: A Radiographic and Biomechanical Murine Study. BIOENGINEERING (BASEL, SWITZERLAND) 2023; 10:bioengineering10010070. [PMID: 36671642 PMCID: PMC9855159 DOI: 10.3390/bioengineering10010070] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 01/07/2023]
Abstract
Femoral fractures and severe bleeding frequently occur in old patients showing a delayed healing. As there are no studies investigating the combined effect of high age and severe blood loss on fracture healing, this was examined radiographically and biomechanically in this study. Therefore, young and old male mice were randomly assigned to three operation groups. In the fracture group (Fx), external fixator and osteotomy were applied to the femur. The combined trauma group (THFx) additionally received a pressure-controlled hemorrhage. Sham animals were only implanted with arterial catheter and external fixator. Sacrifice was performed after three weeks and bone healing was evaluated radiologically via µCT, as well as biomechanically using a three-point bending test. A decreased share of callus/total bone volume was observed in old mice with blood loss compared to old Fx. Hemorrhagic shock also reduced the trabecular number in old mice compared to Fx and young THFx. Moreover, a lower elastic limit in old Sham mice without fracture was revealed. Fracture combined with a high loss of blood further reduced the elastic limit in old mice compared to isolated Fx in old animals. In conclusion, this study showed that severe blood loss has a higher negative effect in old mice compared to young ones.
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Decellularized vascularized bone grafts as therapeutic solution for bone reconstruction: A mechanical evaluation. PLoS One 2023; 18:e0280193. [PMID: 36638107 PMCID: PMC9838862 DOI: 10.1371/journal.pone.0280193] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 12/22/2022] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Large bone defects are challenging for surgeons. Available reimplanted bone substitutes can't properly restore optimal function along and long term osteointegration of the bone graft. Bone substitute based on the perfusion-decellularization technique seem to be interesting in order to overcome these limitations. We present here an evaluation of the biomechanics of the bones thus obtained. MATERIAL AND METHODS Two decellularization protocols were chosen for this study. One using Sodium Dodecyl Sulfate (SDS) (D1) and one using NaOH and H2O2 (D2). The decellularization was performed on porcine forearms. We then carried out compression, three-point bending, indentation and screw pull-out tests on each sample. Once these tests were completed, we compared the results obtained between the different decellularization protocols and with samples left native. RESULTS The difference in the means was similar between the tests performed on bones decellularized with the SDS protocol and native bones for pull-out test: +1.4% (CI95% [-10.5%- 12.4%]) of mean differences when comparing Native vs D1, compression -14.9% (CI95% [-42.7%- 12.5%]), 3-point bending -5.7% (CI95% [-22.5%- 11.1%]) and indentation -10.8% (CI95% [-19.5%- 4.6%]). Bones decellularized with the NaOH protocol showed different results from those obtained with the SDS protocol or native bones during the pull-out screw +40.7% (CI95% [24.3%- 57%]) for Native vs D2 protocol and 3-point bending tests +39.2% (CI95% [13.7%- 64.6%]) for Native vs D2 protocol. The other tests, compression and indentation, gave similar results for all our samples. CONCLUSION Vascularized decellularized grafts seem to be an interesting means for bone reconstruction. Our study shows that the decellularization method affects the mechanical results of our specimens. Some methods seem to limit these alterations and could be used in the future for bone decellularization.
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Hu Y, He Y, Fang J, Liu Y, Cao Y, Tong W, Chen W, Shao Z, Liu Y, Tian H. Wnt10b-overexpressing umbilical cord mesenchymal stem cells promote fracture healing via accelerated cartilage callus to bone remodeling. Bioengineered 2022; 13:10313-10323. [PMID: 35436412 PMCID: PMC9161882 DOI: 10.1080/21655979.2022.2062954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The aim of this study was to investigate whether HUCMSCsWnt10b could promote long bone fracture healing. Commercially-available HUCMSCsEmp (human umbilical cord mesenchymal stem cells transfected with empty vector) in hydrogel, HUCMSCsWnt10b in hydrogel and HUCMSCsWnt10b with the Wnt signaling pathway inhibitor IWR-1 were transplanted into the fracture site in a rat model of femoral fracture. We found that transplantation of HUCMSCsWnt10b significantly accelerated bone healing in a rat model of femoral fracture. Meanwhile, three-point bending test proved that the mechanical properties of the bone at the fracture site in the HUCMSCWnt10b treatment group were significantly better than those of the other treatment groups. To understand the cellular mechanism, we explored the viability of periosteal stem cells (PSCs), as they contribute the greatest number of osteoblast lineage cells to the callus. In line with in vivo data, we found that conditioned medium from HUCMSCsWnt10b enhanced the migration and osteogenic differentiation of PSCs. Furthermore, conditioned medium from HUCMSCsWnt10b also induced endothelial cells to form capillary-like structures in a tube formation assay, which was blocked by SU5416, an angiogenesis inhibitor, suggesting that enhanced vessel formation and growth also contribute to accelerated hard callus formation. In summary, our study demonstrates that HUCMSCsWnt10b promote fracture healing via accelerated hard callus formation, possibly due to enhanced osteogenic differentiation of PSCs and vessel growth. Therefore, HUCMSCsWnt10b may be a promising treatment for long bone fractures.
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Affiliation(s)
- Yuxiang Hu
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Yu He
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Jiarui Fang
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Yunlu Liu
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Yulin Cao
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Wei Tong
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Wei Chen
- Department of Orthopedics, The Third Hospital of Hebei Medical University, Shi Jiazhuang, Hebei, China.,Nhc Key Laboratory of Intelligent Orthopedic Equipment (The Third Hospital of Hebei Medical University), Shi Jiazhuang, Hebei, China
| | - Zengwu Shao
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Yong Liu
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
| | - Hongtao Tian
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei, China
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Matuszewska A, Nowak B, Nikodem A, Merwid-Ląd A, Wiatrak B, Tomkalski T, Jędrzejuk D, Szeląg E, Sozański T, Danielewski M, Jawień P, Ceremuga I, Szandruk-Bender M, Bolanowski M, Filipiak J, Szeląg A. Antiepileptic Stiripentol May Influence Bones. Int J Mol Sci 2021; 22:7162. [PMID: 34281215 PMCID: PMC8269345 DOI: 10.3390/ijms22137162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/27/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Bone structure abnormalities are increasingly observed in patients chronically treated with antiepileptic drugs (AEDs). The majority of the available data concern older conventional AEDs, while the amount of information regarding newer AEDs, including stiripentol, is limited. The aim of the study was to assess the effect of stiripentol on bones. For 24 weeks, male Wistar rats, received 0.9% sodium chloride (control group) or stiripentol (200 mg/kg/day) (STP group). In the 16th week of the study, we detected lower serum PINP levels in the STP group compared to the control group. In the 24th week, a statistically significant lower 1,25-dihydroxyvitamin D3 level, higher inorganic phosphate level and higher neutrophil gelatinase-associated lipocalin (NGAL) levels in serum were found in the STP group compared to the control. Micro X-ray computed tomography of the tibias demonstrated lower bone volume fraction, lower trabecular thickness, higher trabecular pattern factor and a higher structure model index in the stiripentol group. Considering the results of this experiment on rats which suggests that long-term administration of stiripentol may impair the cancellous bone microarchitecture, further prospective human studies seem to be justified. However, monitoring plasma vitamin D, calcium, inorganic phosphate and kidney function in patients on long-term stiripentol therapy may be suggested.
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Affiliation(s)
- Agnieszka Matuszewska
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Beata Nowak
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Anna Nikodem
- Department of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, ul. Ignacego Łukasiewicza 7/9, 50-371 Wrocław, Poland; (A.N.); (J.F.)
| | - Anna Merwid-Ląd
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Benita Wiatrak
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Tomasz Tomkalski
- Department of Endocrinology, Diabetology and Internal Medicine, Tadeusz Marciniak Lower Silesia Specialist Hospital—Centre for Medical Emergency, ul. Gen. Augusta Emila Fieldorfa 2, 54-049 Wrocław, Poland;
| | - Diana Jędrzejuk
- Department of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, wyb. Ludwika Pasteura 4, 50-367 Wrocław, Poland; (D.J.); (M.B.)
| | - Ewa Szeląg
- Department of Maxillofacial Orthopedics and Orthodontics Institute, Wroclaw University of Science and Technology, ul. Krakowska 26, 50-425 Wrocław, Poland;
| | - Tomasz Sozański
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Maciej Danielewski
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Paulina Jawień
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Ireneusz Ceremuga
- Department of Medical Biochemistry, Wroclaw Medical University, ul. Tytusa Chałubińskiego 10, 50-368 Wrocław, Poland;
| | - Marta Szandruk-Bender
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
| | - Marek Bolanowski
- Department of Endocrinology, Diabetes and Isotope Therapy, Wroclaw Medical University, wyb. Ludwika Pasteura 4, 50-367 Wrocław, Poland; (D.J.); (M.B.)
| | - Jarosław Filipiak
- Department of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, ul. Ignacego Łukasiewicza 7/9, 50-371 Wrocław, Poland; (A.N.); (J.F.)
| | - Adam Szeląg
- Department of Pharmacology, Wroclaw Medical University, ul. Jana Mikulicza-Radeckiego 2, 50-345 Wrocław, Poland; (B.N.); (A.M.-L.); (B.W.); (T.S.); (M.D.); (P.J.); (M.S.-B.); (A.S.)
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Biomechanical properties of the bone during implant placement. BMC Oral Health 2021; 21:86. [PMID: 33632191 PMCID: PMC7908763 DOI: 10.1186/s12903-021-01442-1] [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] [Received: 09/04/2020] [Accepted: 02/14/2021] [Indexed: 11/29/2022] Open
Abstract
Background In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement. Methods The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal–Wallis statistical test and as a post-hoc test Mann–Whitney U test was performed to analyze experimental results. Results According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal–Wallis test showed significant differences between the intact and predrilled bones. Conclusion The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.
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Is the 0.2%-Strain-Offset Approach Appropriate for Calculating the Yield Stress of Cortical Bone? Ann Biomed Eng 2021; 49:1747-1760. [PMID: 33479788 DOI: 10.1007/s10439-020-02719-2] [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] [Received: 09/09/2020] [Accepted: 12/28/2020] [Indexed: 11/26/2022]
Abstract
The 0.2% strain offset approach is mostly used to calculate the yield stress and serves as an efficient method for cross-lab comparisons of measured material properties. However, it is difficult to accurately determine the yield of the bone. Especially when computational models require accurate material parameters, clarification of the yield point is needed. We tested 24 cortical specimens harvested from six bovine femora in three-point bending mode, and 11 bovine femoral cortical specimens in the tensile mode. The Young's modulus and yield stress for each specimen derived from the specimen-specific finite element (FE) optimization method was regarded as the most ideal constitutive parameter. Then, the strain offset optimization method was used to find the strain offset closest to the ideal yield stress for the 24 specimens. The results showed that the 0 strain offsets underestimated (- 25%) the yield stress in bending and tensile tests, while the 0.2% strain offsets overestimated the yield stress (+ 65%) in three-point bending tests. Instead, the yield stress determined by 0.007 and 0.05% strain offset for bending and tensile loading respectively, can effectively characterize the biomechanical responses of the bone, thereby helping to build an accurate FE model.
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12
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Osuna LGG, Soares CJ, Vilela ABF, Irie MS, Versluis A, Soares PBF. Influence of bone defect position and span in 3-point bending tests: experimental and finite element analysis. Braz Oral Res 2020; 35:e001. [PMID: 33206774 DOI: 10.1590/1807-3107bor-2021.vol35.0001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/22/2020] [Indexed: 12/15/2022] Open
Abstract
Three-point bending test is the most common mechanical test used for quantifying the biomechanical quality of bone tissue and bone healing in small animals. However, there is a lack of standardization for evaluation of bone repair by cortical perforation. The aim of this study was to determine the influence of bone defect position in the proximal metaphysis of rat tibias during load application and different span configuration on the three-point bending test outcomes. Cortical defects with 1.6 mm diameter were created at a standardized location on the medial surface of 60 tibias of male Wistar rats. The animals were euthanized 7 days after surgery. Five specimens were used to create 3D models for finite element analysis using high-resolution micro-CT images. Two spans (6 and 10mm) and three positions of the bone defect in relation to the load application (upward, frontal and downward) were evaluated experimentally (n = 10) and in finite element analysis (n = 5). Maximum load (N) and stiffness (N/mm) were statistically analyzed with 2-way ANOVA and Tukey test (α = 0.05). The results demonstrated that span and orientation of the bone defect significantly influenced the fracture pattern, stress distribution and force versus displacement relation. Therefore, reliable outcome can be achieved creating the bone defect at 8 mm from the extremity of the proximal epiphysis; placing a 10 mm distance span and downward facing defect position to allow a better distribution of stress and more fracture patterns that reached the bone defect target area with less intra-group variability.
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Affiliation(s)
- Luis Gustavo Gonzalez Osuna
- Universidade Federal de Uberlândia - UFU, Department of Periodontology and Implantology, Uberlândia, MG, Brazil
| | - Carlos José Soares
- Universidade Federal de Uberlândia - UFU, Department of Operative Dentistry and Dental Materials, Uberlândia, MG, Brazil
| | - Andomar Bruno Fernandes Vilela
- Universidade Federal de Uberlândia - UFU, Department of Operative Dentistry and Dental Materials, Uberlândia, MG, Brazil
| | - Milena Suemi Irie
- Universidade Federal de Uberlândia - UFU, Department of Periodontology and Implantology, Uberlândia, MG, Brazil
| | - Antheunis Versluis
- University of Tennessee Health Science Center, College of Dentistry, Department of Bioscience Research, Memphis, TN, USA
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13
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Burrow K, Young W, Hammer N, Safavi S, Scholze M, McConnell M, Carne A, Barr D, Reid M, Bekhit AED. The Effect of the Supplementation of a Diet Low in Calcium and Phosphorus with Either Sheep Milk or Cow Milk on the Physical and Mechanical Characteristics of Bone using A Rat Model. Foods 2020; 9:E1070. [PMID: 32784633 PMCID: PMC7466322 DOI: 10.3390/foods9081070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 11/16/2022] Open
Abstract
This study assessed the effect of cow milk (CM) and sheep milk (SM) consumption on the micro-structure, mechanical function, and mineral composition of rat femora in a male weanling rat model. Male weanling rats were fed a basal diet with a 50% reduction in calcium and phosphorus content (low Ca/P-diet) supplemented with either SM or CM. Rats were fed for 28 days, after which the femora were harvested and stored. The femora were analyzed by μ-CT, three-point bending, and inductively coupled plasma-mass spectrometry (ICP-MS). The addition of either milk to the low Ca/P-diet significantly increased (p < 0.05) trabecular bone volume, trabecular bone surface density, trabecular number, cortical bone volume, and maximum force, when compared to rats that consumed only the low Ca/P-diet. The consumption of either milk resulted in a significant decrease (p < 0.05) in trabecular pattern factor, and cortical bone surface to volume ratio when compared to rats that consumed only the low Ca/P-diet. The results were achieved with a lower consumption of SM compared to that of CM (p < 0.05). This work indicates that SM and CM can help overcome the effects on bone of a restriction in calcium and phosphorus intake.
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Affiliation(s)
- Keegan Burrow
- Department of Wine, Food and Molecular Biosciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand
| | - Wayne Young
- AgResearch Ltd, Grasslands Research Centre, Private Bag 11008, Manawatu Mail Centre, Palmerston North 4442, New Zealand;
- Riddet Institute, Massey University, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - Niels Hammer
- Department of Macroscopic and Clinical Anatomy, Medical University of Graz, 8010 Graz, Austria;
- Department of Orthopaedic and Trauma Surgery, University of Leipzig, Liebigstraße 20, 04103 Leipzig, Germany
- Fraunhofer IWU, Nöthnitzer Straße 44, 01187 Dresden, Germany
| | - Sarah Safavi
- Department of Anatomy, University of Otago, PO Box 56, Dunedin 9054, New Zealand;
| | - Mario Scholze
- Institute of Materials Science and Engineering, Chemnitz University of Technology, Straße der Nationen, 62, 09111 Chemnitz, Germany;
| | - Michelle McConnell
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand;
| | - Alan Carne
- Department of Biochemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand;
| | - David Barr
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand; (D.B.); (M.R.)
| | - Malcolm Reid
- Department of Chemistry, University of Otago, PO Box 56, Dunedin 9054, New Zealand; (D.B.); (M.R.)
| | - Alaa El-Din Bekhit
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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14
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Lee SH, Kim JN, Shin KJ, Koh KS, Song WC. Three-dimensional microstructures of the intracortical canals in the animal model of osteoporosis. Anat Cell Biol 2020; 53:162-168. [PMID: 32647084 PMCID: PMC7343558 DOI: 10.5115/acb.19.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/20/2019] [Accepted: 12/18/2019] [Indexed: 12/11/2022] Open
Abstract
Osteoporosis is a major disease in aged women, increasing the risk for fractures accompanied by changes in the microarchitecture. The aim of this study was to investigate the three-dimensional (3D) histomorphology of femur diaphysis in the animal model for postmenopausal osteoporosis. The cortical bone of femur diaphysis of the rat was serially sectioned at a thickness of 5 mm and evaluated age-associated changes of the intracortical (osteonal) canal networks three-dimensionally. Cortical microstructures of 10-month old rats were not affected by ovariectomy. Intracortical canal networks were radial toward endosteal aspect and frequently interconnected across the neighboring canals with short arciform and irregular canals reminiscent for resorption spaces in ovarectomized 16-month old rats, contrary to intact canals in 16-month old control rat. Increased proportion of the periosteal circumference lamella and deformed endosteal regions with rare cortical canals hampered reconstructive histomorphology in ovarectomized rats of 26 month age. We have shown that 3D reconstruction of rat femur of the aged model over 16-month old is suitable methods that evaluate and microstructural change of the intracortical canals and cortical bone porosity by estrogen depletion.
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Affiliation(s)
- Shin-Hyo Lee
- Department of Anatomy, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Korea
| | - Jeong-Nam Kim
- Department of Biomedical Laboratory Science, Kyungnam College of Information & Technology, Busan, Korea
| | - Kang-Jae Shin
- Department of Anatomy and Cell Biology, Dong-A University School of Medicine, Busan, Korea
| | - Ki-Seok Koh
- Department of Anatomy, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Korea
| | - Wu-Chul Song
- Department of Anatomy, Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Korea
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15
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Klosterhoff BS, Kaiser J, Nelson BD, Karipott SS, Ruehle MA, Hollister SJ, Weiss JA, Ong KG, Willett NJ, Guldberg RE. Wireless sensor enables longitudinal monitoring of regenerative niche mechanics during rehabilitation that enhance bone repair. Bone 2020; 135:115311. [PMID: 32156664 PMCID: PMC7585453 DOI: 10.1016/j.bone.2020.115311] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/20/2020] [Accepted: 03/03/2020] [Indexed: 10/24/2022]
Abstract
Mechanical loads exerted on the skeleton during activities such as walking are important regulators of bone repair, but dynamic biomechanical signals are difficult to measure inside the body. The inability to measure the mechanical environment in injured tissues is a significant barrier to developing integrative regenerative and rehabilitative strategies that can accelerate recovery from fracture, segmental bone loss, and spinal fusion. Here we engineered an implantable strain sensor platform and longitudinally measured strain across a bone defect in real-time throughout rehabilitation. The results showed that load-sharing permitted by a load-sharing fixator initially delivered a two-fold increase in deformation magnitude, subsequently increased mineralized bridging by nearly three-fold, and increased bone formation by over 60%. These data implicate a critical role for early mechanical cues on the long term healing response as strain cycle magnitude at 1 week (before appreciable healing occurred) had a significant positive correlation with the long-term bone regeneration outcomes. Furthermore, we found that sensor readings correlated with the status of healing, suggesting a role for strain sensing as an X-ray-free healing assessment platform. Therefore, non-invasive strain measurements may possess diagnostic potential to evaluate bone repair and reduce clinical reliance on current radiation-emitting imaging methods. Together, this study demonstrates a promising framework to quantitatively develop and exploit mechanical rehabilitation strategies that enhance bone repair.
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Affiliation(s)
- Brett S Klosterhoff
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Jarred Kaiser
- Research Service, Atlanta VA Medical Center, Decatur, GA, United States of America; Department of Orthopaedics, Emory University, Atlanta, GA, United States of America
| | - Bradley D Nelson
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, United States of America
| | - Salil S Karipott
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, United States of America
| | - Marissa A Ruehle
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - Scott J Hollister
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - Jeffrey A Weiss
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States of America; Department of Orthopedics, University of Utah, Salt Lake City, UT, United States of America
| | - Keat Ghee Ong
- Department of Biomedical Engineering, Michigan Technological University, Houghton, MI, United States of America
| | - Nick J Willett
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America; Research Service, Atlanta VA Medical Center, Decatur, GA, United States of America; Department of Orthopaedics, Emory University, Atlanta, GA, United States of America; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
| | - Robert E Guldberg
- Knight Campus, University of Oregon, Eugene, OR, United States of America.
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16
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Zhao D, Liu R, Li G, Chen M, Shang P, Yang H, Jiang JX, Xu H. Connexin 43 Channels in Osteocytes Regulate Bone Responses to Mechanical Unloading. Front Physiol 2020; 11:299. [PMID: 32296345 PMCID: PMC7137730 DOI: 10.3389/fphys.2020.00299] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/16/2020] [Indexed: 01/01/2023] Open
Abstract
Connexin (Cx) 43 forms gap junctions and hemichannels that mediate communication between osteocytes and adjacent cells or the extracellular environment in bone, respectively. To investigate the role of each channel type in response to mechanical unloading, two transgenic mouse models overexpressing dominant-negative Cx43 predominantly in osteocytes driven by a 10 kb dentin matrix protein 1 (Dmp1) promoter were generated. The R76W mutation resulted in gap junction inhibition and enhancement of hemichannels, whereas the Δ130-136 mutation inhibited both gap junctions and hemichannels. Both mutations led to cortical bone loss with increased endocortical osteoclast activity during unloading. Increased periosteal osteoclasts with decreased apoptotic osteocytes were observed only in R76W mice. These findings indicated that inhibiting osteocytic Cx43 channels promotes bone loss induced by unloading, mainly in the cortical area; moreover, hemichannels protect osteocytes against apoptosis and promote periosteal bone remodeling, whereas gap junctions modulate endocortical osteoclast activity in response to unloading.
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Affiliation(s)
- Dezhi Zhao
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
| | - Ruofei Liu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
| | - Guobin Li
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
| | - Meng Chen
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
| | - Peng Shang
- Key Laboratory for Space Bioscience and Biotechnology, Research and Development Institute in Shenzhen, Northwestern Polytechnical University, Shenzhen, China
| | - Hui Yang
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
- Research Center of Special Environmental Biomechanics and Medical Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center, San Antonio, TX, United States
| | - Huiyun Xu
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
- Key Laboratory for Space Bioscience and Biotechnology, Research and Development Institute in Shenzhen, Northwestern Polytechnical University, Shenzhen, China
- Research Center of Special Environmental Biomechanics and Medical Engineering, Northwestern Polytechnical University, Xi’an, China
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17
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Brady RD, Wong KR, Robinson DL, Mychasiuk R, McDonald SJ, D'Cunha RA, Yamakawa GR, Sun M, Wark JD, Lee PVS, O'Brien TJ, Casillas-Espinosa PM, Shultz SR. Bone Health in Rats With Temporal Lobe Epilepsy in the Absence of Anti-Epileptic Drugs. Front Pharmacol 2019; 10:1278. [PMID: 31749702 PMCID: PMC6842946 DOI: 10.3389/fphar.2019.01278] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/07/2019] [Indexed: 01/18/2023] Open
Abstract
Rationale: Epilepsy patients often exhibit reduced bone mineral density and are at an increased risk of bone fracture. Whether these bone abnormalities are due to the use of anti-epileptic drugs (AED’s) or the disease itself is unknown. For example, although decreased bone health in epilepsy patients is generally attributed to the use of AED’s, seizures can also trigger a number of physiological processes that have the potential to affect bone. Therefore, to assess whether bone abnormalities occur in epilepsy in the absence of AED’s, the current study investigated mechanical characteristics and trabecular bone morphology in rats with chronic temporal lobe epilepsy. Methods: Ten-week old male Wistar rats underwent kainic acid-induced status epilepticus (SE; n = 7) or a sham procedure (n = 9). Rats were implanted with EEG recording electrodes at nine weeks post-SE, and video-EEG was continuously recorded for one week at 10- and 22-weeks post-SE to confirm that SE rats had spontaneous seizures. Open-field testing to assess locomotion was conducted at 23-weeks post-SE. At 24-weeks post-SE, rats were euthanized and tibia were extracted to determine trabecular morphology by micro-computed tomography (µCT), while femurs were used to investigate mechanical properties via 3-point bending. Results: All post-SE rats had spontaneous seizures at 10- and 22-weeks post-SE, while none of the sham rats had seizures. µCT trabecular analysis of tibia revealed no differences in total volume, bone volume, bone volume fraction, trabecular number, or trabecular separation between post-SE or sham rats, although post-SE rats did have increased trabecular thickness. There were also no group differences in total distance travelled in the open field suggesting that activity levels did not account for the increased trabecular thickness. In addition, no differences in mechanical properties of femurs were observed between the two groups. Conclusion: There was a lack of overt bone abnormalities in rats with chronic temporal lobe epilepsy in the absence of AED treatment. Although further studies are still needed, these findings may have important implications towards understanding the source (e.g., AED treatments) of bone abnormalities in epilepsy patients.
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Affiliation(s)
- Rhys D Brady
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Ker Rui Wong
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Dale L Robinson
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Stuart J McDonald
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, VIC, Australia
| | - Ryan A D'Cunha
- School of Medicine, Deakin University, Geelong, VIC, Australia
| | - Glenn R Yamakawa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - John D Wark
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Peter Vee Sin Lee
- Department of Biomedical Engineering, University of Melbourne, Parkville, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
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18
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Wang J, Yang J, Cheng X, Xiao R, Zhao Y, Xu H, Zhu Y, Yan Z, Ommati MM, Manthari RK, Wang J. Calcium Alleviates Fluoride-Induced Bone Damage by Inhibiting Endoplasmic Reticulum Stress and Mitochondrial Dysfunction. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:10832-10843. [PMID: 31464433 DOI: 10.1021/acs.jafc.9b04295] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Excessive fluoride mainly causes skeletal lesions. Recently, it has been reported that an appropriate level of calcium can alleviate fluorosis. However, the appropriate concentration and mechanism of calcium addition is unclear. Hence, we evaluated the histopathology and ultrastructure, DNA fragmentation, hormonal imbalances, biomechanical levels, and expression of apoptosis-related genes after treating the rats with 150 mg/L NaF and different concentrations of CaCO3. Our results suggested that NaF induced the histopathological and ultrastructural injury, with a concomitant increase in the DNA fragmentation (P < 0.05) and serum OC (17.5 ± 0.89 pmoL/L) at 120 days. In addition, the qRT-PCR and western blotting results indicated that NaF exposure upregulated the mRNA and protein expression of Bax, Calpain, Caspase 12, Caspase 9, Caspase 7, Caspase 3, CAD, PARP, and AIF while downregulated Bcl-2 (P < 0.01) and decreased the bone ultimate load by 27.1%, the ultimate stress by 10.1%, and the ultimate deformity by 23.3% at 120 days. However, 1% CaCO3 supplementation decreased the serum OC (14.7 ± 0.65 pmoL/L), bone F content (P < 0.01), and fracture and breakage of collagen fibers and changed the expression of endoplasmic reticulum pathway-related genes and proteins at 120 days. Further, 1% CaCO3 supplementation increased the bone ultimate load by 20.9%, the ultimate stress by 4.89%, and the ultimate deformity by 21.6%. In summary, we conclude that 1% CaCO3 supplementation alleviated fluoride-induced bone damage by inhibiting endoplasmic reticulum stress and mitochondrial dysfunction.
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19
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Postnatal development of the largest subterranean mammal (Bathyergus suillus): Morphology, osteogenesis, and modularity of the appendicular skeleton. Dev Dyn 2019; 248:1101-1128. [DOI: 10.1002/dvdy.81] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/25/2022] Open
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20
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Burrow K, Young W, Carne A, McConnell M, Hammer N, Scholze M, Bekhit AED. Consumption of sheep milk compared to cow milk can affect trabecular bone ultrastructure in a rat model. Food Funct 2019; 10:163-171. [PMID: 30516196 DOI: 10.1039/c8fo01598h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cow milk has a positive effect on bone health due to the effects of its protein, fat, lipid, vitamin, and mineral components. Sheep milk contains a unique composition of all of these components. However, to the best of our knowledge the benefits of sheep milk in relation to bone development have not been studied. The aim of the present study was to determine the effects of the consumption of sheep milk in comparison to cow milk on the structural and physical characteristics of growing bone in a rat model. Newly weaned male rats were fed either cow milk, sheep milk or sheep milk diluted to the same total solids content as cow milk for 28 days in addition to a basal chow. At the end of the feeding period animals were euthanized, the femora harvested and stored. The femora were analysed by μ-CT, mechanical bending tests, and ICP-MS. Rats consuming sheep milk in the trial were found to have significantly higher trabecular bone surface density and trabecular bone surface to volume ratio (p < 0.05) when compared to the rats consuming cow milk. No significant differences were observed in the mechanical properties and the mineral composition of the bones (p > 0.05). With the exception of Rb, which was found to be present in higher concentrations in rats consuming sheep milk (p < 0.05). Our results indicate that consumption of sheep milk may positively influence the structural integrity of bone, which may result in an enhancement of bone health.
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Affiliation(s)
- Keegan Burrow
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
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21
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Singh D, Rana A, Jhajhria SK, Garg B, Pandey PM, Kalyanasundaram D. Experimental assessment of biomechanical properties in human male elbow bone subjected to bending and compression loads. J Appl Biomater Funct Mater 2018; 17:2280800018793816. [DOI: 10.1177/2280800018793816] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Dilpreet Singh
- Centre for Biomedical Engineering, Indian Institute of Technology (IIT) Delhi, New Delhi, India
| | - Abhishek Rana
- Centre for Biomedical Engineering, Indian Institute of Technology (IIT) Delhi, New Delhi, India
| | - Saroj Kaler Jhajhria
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Bhavuk Garg
- Department of Orthopaedics, AIIMS, New Delhi, India
| | | | - Dinesh Kalyanasundaram
- Centre for Biomedical Engineering, Indian Institute of Technology (IIT) Delhi, New Delhi, India
- Department of Biomedical Engineering, AIIMS, New Delhi, India
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22
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Yang J, Meng X, Dong D, Xue Y, Chen X, Wang S, Shen Y, Zhang G, Shang P. Iron overload involved in the enhancement of unloading-induced bone loss by hypomagnetic field. Bone 2018; 114:235-245. [PMID: 29929042 DOI: 10.1016/j.bone.2018.06.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/15/2018] [Accepted: 06/17/2018] [Indexed: 10/28/2022]
Abstract
During deep-space exploration missions, astronauts will be exposed to abnormal space environments including microgravity and hypomagnetic field (HyMF) that is 10,000 times weaker than geomagnetic field (GMF). It is well known that microgravity in space can induce bone loss; however, it is ill-defined whether HyMF involved in this process. Herein, we aimed to investigate the combined effects of HyMF and microgravity on bone loss. A mouse model of hindlimb suspension (HLU) was adopted to simulate microgravity-induced bone loss, that was exposed to a hypomagnetic field of <300 nanotesla (nT) generated by a geomagnetic field-shielding chamber. Besides, a recent study showed that HLU induced bone loss was orchestrated by iron overload. Therefore, the changes of iron content in unloading-induced bone loss under HyMF condition were detected simultaneously. The results showed HyMF exacerbated the loss of bone mineral content (BMC), induced more detrimental effects on microstructure of cancellous bone but not cortical bone and yielded greater negative effects on biomechanical characteristics in mice femur under unloading status. Concomitantly, there was more iron accumulation in serum, liver, spleen and bone in the combined treatment group than in the separate unloading group or HyMF exposure group. These results showed that HyMF promoted additional bone loss in mice femur during mechanical unloading, and the potential mechanism may be involved in inducing iron overload of mice.
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Affiliation(s)
- Jiancheng Yang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xiaofeng Meng
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Dandan Dong
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yanru Xue
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xin Chen
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Shenghang Wang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Ying Shen
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Gejing Zhang
- School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China
| | - Peng Shang
- Research & Development Institute in Shenzhen, Northwestern Polytechnical University, Shenzhen 518057, China; Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environment Biophysics, Northwestern Polytechnical University, Xi'an 710072, China.
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Prodinger PM, Bürklein D, Foehr P, Kreutzer K, Pilge H, Schmitt A, Eisenhart-Rothe RV, Burgkart R, Bissinger O, Tischer T. Improving results in rat fracture models: enhancing the efficacy of biomechanical testing by a modification of the experimental setup. BMC Musculoskelet Disord 2018; 19:243. [PMID: 30025531 PMCID: PMC6053723 DOI: 10.1186/s12891-018-2155-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 06/25/2018] [Indexed: 01/06/2023] Open
Abstract
Background Animal fracture models, primarily performed in rats, are crucial to investigate normal and pathological bone healing. However, results of biomechanical testing representing a major outcome measure show high standard deviations often precluding statistical significance. Therefore, the aim of our study was a systematical examination of biomechanical characteristics of rat femurs during three-point bending. Furthermore, we tried to reduce variation of results by individually adapting the span of bearing and loading areas to the bone’s length. Methods We examined 40 paired femurs of male Wistar-rats by DXA (BMD and BMC of the whole femur) and pQCT-scans at the levels of bearing and loading areas of the subsequent biomechanical three-point bending test. Individual adjustment of bearing and loading bars was done respecting the length of each specimen. Subgroups of light (< 400 g, n = 22) and heavy (> 400 g, n = 18) animals were formed and analysed separately. We furthermore compared the results of the individualised bending-setting to 20 femurs tested with a fix span of 15 mm. Results Femurs showed a length range of 34 to 46 mm. The failure loads ranged from 116 to 251 N (mean 175.4 ± 45.2 N; heavy animals mean 221 ± 18.9 N; light animals mean 138.1 ± 16.4 N) and stiffness ranged from 185 N/mm to 426 N/mm (mean 315.6 ± 63 N/mm; heavy animals mean 358.1 ± 34.64 N/mm; light animals mean 280.8 ± 59.85 N/mm). The correlation of densitometric techniques and failure loads was high (DXA R2 = 0.89 and pQCT R2 = 0.88). In comparison to femurs tested with a fix span, individual adaptation of biomechanical testing homogenized our data significantly. Most notably, the standard deviation of failure loads (221 ± 18.95 N individualized setting vs. 205.5 ± 30.36 N fixed) and stiffness (358.1 ± 34.64 N/mm individualized setting vs. 498.5 ± 104.8 N/mm fixed) was reduced by at least one third. Conclusions Total variation observed in any trait reflects biological and methodological variation. Precision of the method hence affects the statistical power of the study. By simply adapting the setting of the biomechanical testing, interindividual variation could be reduced, which improves the precision of the method significantly. Electronic supplementary material The online version of this article (10.1186/s12891-018-2155-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Peter Michael Prodinger
- Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Straße 22, 81675, Munich, Germany.
| | - Dominik Bürklein
- Abteilung für Fuß- und Sprunggelenkchirurgie, Klinik Volkach, Volkach, Germany
| | - Peter Foehr
- Abteilung für Biomechanik, Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
| | - Kilian Kreutzer
- Klinik für Mund-, Kiefer- und Gesichtschirurgie, Universitätsklinikum Hamburg Eppendorf, Hamburg, Germany
| | - Hakan Pilge
- Orthopädische Klinik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Andreas Schmitt
- Abteilung für Sportorthopädie, Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
| | - Rüdiger V Eisenhart-Rothe
- Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Straße 22, 81675, Munich, Germany
| | - Rainer Burgkart
- Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaninger Straße 22, 81675, Munich, Germany
| | - Oliver Bissinger
- Klinik für Mund-, Kiefer- und Gesichtschirurgie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany
| | - Thomas Tischer
- Orthopädische Klinik und Poliklinik der Universität Rostock, Rostock, Germany
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Meimandi-Parizi A, Oryan A, Gholipour H. Healing potential of nanohydroxyapatite, gelatin, and fibrin-platelet glue combination as tissue engineered scaffolds in radial bone defects of rats. Connect Tissue Res 2018; 59:332-344. [PMID: 29035127 DOI: 10.1080/03008207.2017.1387541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Different biomaterials have been used in orthopedic surgery. Evaluation of biomaterials for bone healing promotion has been a wide area of research of the orthopedic field. Sixty critical size defects of 5 mm long were bilaterally created in the radial diaphysis of 30 rats. The animals were randomly divided into six equal groups as empty defect, autograft, nanohydroxyapatite (nHA), Gelatin (Gel)-nHA, fibrin-platelet glue (FPG)-nHA, and Gel-FPG-nHA groups (n = 10 in each group). Radiographs of each forelimb were taken postoperatively on the 1st day and then at the 28th and 56th days post injury. After 56 days, the rats were euthanized and their harvested healing bone samples were evaluated by histopathology, scanning electron microscopy, and biomechanical testing. All the treated defects demonstrated significantly superior new bone formation, remodeling, and bone tissue volume. Moreover, the defects treated with FPG-nHA showed significantly higher ultimate load, yield load, and stiffness. The Gel-FPG-nHA moderately improved bone regeneration that was not close to the autograft in some parameters, whereas FPG-nHA significantly improved bone healing closely comparable with the autograft group in most parameters. In conclusion, although all the nHA-containing scaffolds had some beneficial effects on bone regeneration, the FPG-nHA scaffold was more effective in improving the structural and functional properties of the newly formed bone and was more osteoinductive than the Gel and was comparable to the autograft. Therefore, the FPG can be regarded as a promising option to be used in conjunction with mineral scaffolds for bone tissue engineering.
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Affiliation(s)
- Abdolhamid Meimandi-Parizi
- a Division of Surgery, Department of Clinical Sciences, School of Veterinary Medicine , Shiraz University , Shiraz , Iran
| | - Ahmad Oryan
- b Department of Pathology, School of Veterinary Medicine , Shiraz University , Shiraz , Iran
| | - Hojjat Gholipour
- a Division of Surgery, Department of Clinical Sciences, School of Veterinary Medicine , Shiraz University , Shiraz , Iran
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Montoya-Sanhueza G, Chinsamy A. Cortical bone adaptation and mineral mobilization in the subterranean mammal Bathyergus suillus (Rodentia: Bathyergidae): effects of age and sex. PeerJ 2018; 6:e4944. [PMID: 29910978 PMCID: PMC6001714 DOI: 10.7717/peerj.4944] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/21/2018] [Indexed: 01/08/2023] Open
Abstract
The patterns of bone modeling and mineral mobilization (skeletal homeostasis) among mammals other than humans and laboratory rodents are still poorly known. In this study we assessed the pattern of bone formation and bone resorption in the femur of a wild population of Cape dune molerats, Bathyergus suillus (n = 41) (Bathyergidae), a solitary subterranean mammal with a marked extended longevity among rodents, and which also lives in a naturally deficient state of vitamin D. In order to determine ontogenetic and sex effects on histomorphometric parameters of transversal undecalcified bone sections, two-way ANOVA, linear mixed-effects model and regression statistical analyses were performed. During ontogeny, B. suillus increased their cross sectional area, cortical area and cortical thickness, and most importantly, they showed scarce endosteal bone resorption which resulted in a retained medullary cavity size during ontogeny. This resulted in a positively imbalanced bone modeling, where bone formation considerably surpasses bone loss by almost 100-fold in adulthood. This differs markedly from other terrestrial mammals with relatively thin cortical walls. Regarding bone loss and remodeling, three main processes involving intracortical resorption were observed: modeling-related bone loss in early postnatal growth; secondary osteon formation occurring in both sexes; and subendosteal secondary reconstruction observed only in females. The latter is accompanied by females having six-fold more relative bone loss than males, which is evidenced by the development of enlarged resorption cavities (RCs) distributed circumferentially around the medullary cavity. Males have smaller, more circular and randomly distributed RCs. In general, our data indicate no age-related decline in mineral content in B. suillus, and provides strong support for a pattern of sexual dimorphism in skeletal homeostasis, similar to that occurring in humans and other mammals, with females losing more bone throughout aging as compared to males due to reproductive factors. Interestingly as well, despite the high mechanical loads experienced during burrow construction, bone remodeling in B. suillus is kept at very low levels throughout their lifespan, and dense Haversian tissue never forms. This study represents the first comprehensive assessment of skeletal homeostasis in a subterranean mammal, and it enables a better understanding of the complex processes governing the acquisition and maintenance of bone properties in this species with extraordinary fossorial adaptations.
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Affiliation(s)
- Germán Montoya-Sanhueza
- Department of Biological Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, Cape Town, Western Cape, South Africa
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Combining electrical stimulation and tissue engineering to treat large bone defects in a rat model. Sci Rep 2018; 8:6307. [PMID: 29679025 PMCID: PMC5910383 DOI: 10.1038/s41598-018-24892-0] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
Bone Tissue engineering (BTE) has recently been introduced as an alternative to conventional treatments for large non-healing bone defects. BTE approaches mimic autologous bone grafts, by combining cells, scaffold, and growth factors, and have the added benefit of being able to manipulate these constituents to optimize healing. Electrical stimulation (ES) has long been used to successfully treat non-healing fractures and has recently been shown to stimulate bone cells to migrate, proliferate, align, differentiate, and adhere to bio compatible scaffolds, all cell behaviors that could improve BTE treatment outcomes. With the above in mind we performed in vitro experiments and demonstrated that exposing Mesenchymal Stem Cells (MSC) + scaffold to ES for 3 weeks resulted in significant increases in osteogenic differentiation. Then in in vivo experiments, for the first time, we demonstrated that exposing BTE treated rat femur large defects to ES for 8 weeks, caused improved healing, as indicated by increased bone formation, strength, vessel density, and osteogenic gene expression. Our results demonstrate that ES significantly increases osteogenic differentiation in vitro and that this effect is translated into improved healing in vivo. These findings support the use of ES to help BTE treatments achieve their full therapeutic potential.
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Yang Y, Aghazadeh-Habashi A, Panahifar A, Wu Y, Bhandari KH, Doschak MR. Bone-targeting parathyroid hormone conjugates outperform unmodified PTH in the anabolic treatment of osteoporosis in rats. Drug Deliv Transl Res 2018; 7:482-496. [PMID: 28721611 DOI: 10.1007/s13346-017-0407-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Synthetic parathyroid hormone (PTH) is clinically indicated for the treatment of osteoporosis, through its anabolic effects on parathyroid hormone receptors (PTHRs), located on osteoblast cells. However, the bioavailability of PTH for bone cells is restricted by the short half-life of PTH and the widespread distribution of PTHRs in non-skeletal tissues. To impart affinity for mineralized bone surfaces, bisphosphonate (BP)-mediated PTH analogues were synthesized, characterized, and evaluated in vitro and in vivo. The successful synthesis of PTH-PEG-BP was identified on MALDI-ToF mass spectra; bone-targeting potential was evaluated by hydroxyapatite binding test; and receptor bioactivity was assessed in UMR-106 (rat osteosarcoma) cells that constitutively express PTHRs. Therapeutic efficacy was evaluated using ovariectomized rats that remained untreated for 8 weeks to allow development of osteopenia. Those rats then received daily subcutaneous injections of PTH-PEG-BP, thiol-BP vehicle, or unmodified PTH, and compared to sham-operated healthy rats at 0, 4, 8, 12, and 16 weeks. In vivo micro-CT was conducted on the proximal tibial metaphysis to measure microstructural bone parameters, and new bone formation was detected using dynamic labeling. Bone strength was assessed using three-point bending mechanical testing. Our study determined that PTH-PEG-BP conjugates significantly enhanced PTH targeting to the bone matrix while retaining full PTH bioactivity. Moreover, PTH-PEG-BP conjugates significantly increased trabecular bone quality, anabolic bone formation, and improved bone strength over systemically administered PTH alone. We highlight the promise of a novel class of bone-targeting anabolic compound for the treatment of osteoporosis and related bone disorders.
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Affiliation(s)
- Yang Yang
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada
| | - Ali Aghazadeh-Habashi
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada
| | - Arash Panahifar
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada
| | - Yuchin Wu
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada
| | - Krishna H Bhandari
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada
| | - Michael R Doschak
- Pharmaceutical Orthopaedic Research Laboratory, Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2N8, Canada.
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Whole bone testing in small animals: systematic characterization of the mechanical properties of different rodent bones available for rat fracture models. Eur J Med Res 2018; 23:8. [PMID: 29444703 PMCID: PMC5813325 DOI: 10.1186/s40001-018-0307-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/07/2018] [Indexed: 01/15/2023] Open
Abstract
Objectives Rat fracture models are extensively used to characterize normal and pathological bone healing. Despite, systematic research on inter- and intra-individual differences of common rat bones examined is surprisingly not available. Thus, we studied the biomechanical behaviour and radiological characteristics of the humerus, the tibia and the femur of the male Wistar rat—all of which are potentially available in the experimental situation—to identify useful or detrimental biomechanical properties of each bone and to facilitate sample size calculations. Methods 40 paired femura, tibiae and humeri of male Wistar rats (10–38 weeks, weight between 240 and 720 g) were analysed by DXA, pQCT scan and three-point-bending. Bearing and loading bars of the biomechanical setup were adapted percentually to the bone’s length. Subgroups of light (skeletal immature) rats under 400 g (N = 11, 22 specimens of each bone) and heavy (mature) rats over 400 g (N = 9, 18 specimens of each bone) were formed and evaluated separately. Results Radiologically, neither significant differences between left and right bones, nor a specific side preference was evident. Mean side differences of the BMC were relatively small (1–3% measured by DXA and 2.5–5% by pQCT). Over all, bone mineral content (BMC) assessed by DXA and pQCT (TOT CNT, CORT CNT) showed high correlations between each other (BMC vs. TOT and CORT CNT: R2 = 0.94–0.99). The load–displacement diagram showed a typical, reproducible curve for each type of bone. Tibiae were the longest bones (mean 41.8 ± 4.12 mm) followed by femurs (mean 38.9 ± 4.12 mm) and humeri (mean 29.88 ± 3.33 mm). Failure loads and stiffness ranged from 175.4 ± 45.23 N / 315.6 ± 63.00 N/mm for the femurs, 124.6 ± 41.13 N / 260.5 ± 59.97 N/mm for the humeri to 117.1 ± 33.94 N / 143.8 ± 36.99 N/mm for the tibiae. Smallest interindividual differences were observed in failure loads of the femurs (CV% 8.6) and tibiae (CV% 10.7) of heavy animals, light animals showed good consistency in failure loads of the humeri (CV% 7.7). Most consistent results of both sides (left vs. right) in failure loads were provided by the femurs of light animals (mean difference 4.0 ± 2.8%); concerning stiffness, humeri of heavy animals were most consistent (mean difference of 6.2 ± 5%). In general, the failure loads showed strong correlations to the BMC (R2 = 0.85–0.88) whereas stiffness correlated only moderate, except for the humerus (BMC vs. stiffness: R2 = 0.79). Discussion Altogether, the rat’s femur of mature specimens showed the most accurate and consistent radiological and biomechanical results. In synopsis with the common experimental use enabling comparison among different studies, this bone offers ideal biomechanical conditions for three point bending experiments. This can be explained by the combination of a superior aspect ratio and a round and long, straight morphology, which satisfies the beam criteria more than other bones tested. Electronic supplementary material The online version of this article (10.1186/s40001-018-0307-z) contains supplementary material, which is available to authorized users.
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Xu ZY, Liu YL, Lin JB, Cheng KL, Wang YG, Yao HL, Wu HY, Su WW, Shaw PC, Li PB. Preparative expression and purification of a nacreous protein N16 and testing its effect on osteoporosis rat model. Int J Biol Macromol 2018; 111:440-445. [PMID: 29329805 DOI: 10.1016/j.ijbiomac.2018.01.054] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/05/2018] [Accepted: 01/09/2018] [Indexed: 11/18/2022]
Abstract
N16, a nacreous protein isolated from Pinctada martensii, is related to nacreous layer formation. Our previous study indicated that N16 showed dual regulatory effects by inducing osteoblast biomineralization as well as inhibiting osteoclast formation. In order to obtain large quantity of N16 for animal experiment and clinical trial, a fermentation and preparative purification method was established. The N16 cDNA was cloned to a BL21(DE3)plysE-pET32a vector and grown in a 20 L fermenter. The medium, temperature, pH and dissolved oxygen (DO) were optimized. N16 was expressed in inclusion bodies. It was denatured and refolded in 8 M urea buffer and purified to 97% purity by passing through a gel filtration column. The glucocorticoid induced osteoporosis (GIO) rat model was used to investigate the anti-osteoporosis activity of N16 in vivo. Results showed that the decrease of the bone mineral density (BMD) and the ultimate load was significantly relieved after N16 treatment. N16 displayed dual regulatory effects by promoting osteogenesis as well as inhibiting bone resorption in vivo. Our work will contribute to further clinical studies on N16 for osteoporosis treatment.
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Affiliation(s)
- Zhen-Yan Xu
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yu-Ling Liu
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Jia-Bi Lin
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Ke-Ling Cheng
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yong-Gang Wang
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Hong-Liang Yao
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Hoi-Yan Wu
- State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), LDS YYC R & D Centre for Chinese Medicine and School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei-Wei Su
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
| | - Pang-Chui Shaw
- State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), LDS YYC R & D Centre for Chinese Medicine and School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Pei-Bo Li
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Re-evaluation of Post-marketed TCM, Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
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30
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The effects of gelatin, fibrin-platelet glue and their combination on healing of the experimental critical bone defect in a rat model: radiological, histological, scanning ultrastructural and biomechanical evaluation. Cell Tissue Bank 2017; 19:341-356. [PMID: 29264693 DOI: 10.1007/s10561-017-9679-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 12/12/2017] [Indexed: 01/09/2023]
Abstract
Fibrin-platelet glue (FPG) is a blood derivative, in which platelets and fibrinogen are concentrated in a small plasma volume, by differential centrifugation and precipitation. It can form a three-dimensional and biocompatible fibrin scaffold with a myriad of growth factors and proteins that are released progressively to the local environment and contribute to the accelerated postoperative bone healing. Gelatin (Gel) is a derivative of collagen and can promote cell adhesion and proliferation due to its unique sequence of amino acids, so it is suitable for bone tissue applications. This study examined the effects of Gel, FPG and their combinations as bone scaffold on the healing of surgically created critical-size defects in rat radius. Fifty critical size defects of 5 mm long were bilaterally created in the radial diaphysis of 25 rats. The animals were randomly divided into five equal groups as empty defect, autograft, Gel, FPG and Gel-FPG groups (n = 10 in each group). Radiographs of each forelimb were taken postoperatively on the 1st day and then at the 28th and 56th days post injury to evaluate bone formation, union and remodeling of the defect. After 56 days, the rats were euthanized and their harvested healing bone samples were evaluated by histopathology, scanning electron microscopy (SEM) and biomechanical testing. The results of present study showed that the Gel alone did not significantly affect bone healing and regeneration; however, the Gel treated defects promoted healing more than those that were left untreated (negative control). Furthermore, the FPG-enhanced grafts provided a good scaffold containing numerous growth factors for proliferation of osteoinduction and was effective in improving the structural and functional properties of the newly formed bone more than that of the untreated and also the Gel treated groups. Incorporation of Gel into the FPG scaffold improved healing potential of the FPG scaffold; however, it was still inferior to the autograft (positive control). Although the Gel-FPG scaffolds had best effectiveness during bone regeneration, it still needs to be further enhanced by incorporation of the ceramic and osteoinductive biomaterials.
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Brady RD, Shultz SR, Sun M, Romano T, van der Poel C, Wright DK, Wark JD, O'Brien TJ, Grills BL, McDonald SJ. Experimental Traumatic Brain Injury Induces Bone Loss in Rats. J Neurotrauma 2016; 33:2154-2160. [PMID: 25686841 DOI: 10.1089/neu.2014.3836] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Few studies have investigated the influence of traumatic brain injury (TBI) on bone homeostasis; however, pathophysiological mechanisms involved in TBI have potential to be detrimental to bone. The current study assessed the effect of experimental TBI in rats on the quantity and quality of two different weight-bearing bones, the femur and humerus. Rats were randomly assigned into either sham or lateral fluid percussion injury (FPI) groups. Open-field testing to assess locomotion was conducted at 1, 4, and 12 weeks post-injury, with the rats killed at 1 and 12 weeks post-injury. Bones were analyzed using peripheral quantitative computed tomography (pQCT), histomorphometric analysis, and three-point bending. pQCT analysis revealed that at 1 and 12 weeks post-injury, the distal metaphyseal region of femora from FPI rats had reduced cortical content (10% decrease at 1 week, 8% decrease at 12 weeks; p < 0.01) and cortical thickness (10% decrease at 1 week, 11% decrease at 12 weeks p < 0.001). There was also a 23% reduction in trabecular bone volume ratio at 1 week post-injury and a 27% reduction at 12 weeks post-injury in FPI rats compared to sham (p < 0.001). There were no differences in bone quantity and mechanical properties of the femoral midshaft between sham and TBI animals. There were no differences in locomotor outcomes, which suggested that post-TBI changes in bone were not attributed to immobility. Taken together, these findings indicate that this rat model of TBI was detrimental to bone and suggests a link between TBI and altered bone remodeling.
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Affiliation(s)
- Rhys D Brady
- 1 Department of Physiology, Anatomy and Microbiology, La Trobe University , Bundoora, VIC, Australia
| | - Sandy R Shultz
- 2 Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne , Parkville, VIC, Australia
| | - Mujun Sun
- 2 Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne , Parkville, VIC, Australia
| | - Tania Romano
- 1 Department of Physiology, Anatomy and Microbiology, La Trobe University , Bundoora, VIC, Australia
| | - Chris van der Poel
- 1 Department of Physiology, Anatomy and Microbiology, La Trobe University , Bundoora, VIC, Australia
| | - David K Wright
- 3 Anatomy and Neuroscience, The University of Melbourne , Parkville, VIC, Australia .,4 The Florey Institute of Neuroscience and Mental Health, The University of Melbourne , Parkville, VIC, Australia
| | - John D Wark
- 2 Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne , Parkville, VIC, Australia
| | - Terence J O'Brien
- 2 Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne , Parkville, VIC, Australia
| | - Brian L Grills
- 1 Department of Physiology, Anatomy and Microbiology, La Trobe University , Bundoora, VIC, Australia
| | - Stuart J McDonald
- 1 Department of Physiology, Anatomy and Microbiology, La Trobe University , Bundoora, VIC, Australia
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Jokihaara J, Pörsti IH, Sievänen H, Kööbi P, Kannus P, Niemelä O, Turner RT, Iwaniec UT, Järvinen TLN. Phosphate Binding with Sevelamer Preserves Mechanical Competence of Bone Despite Acidosis in Advanced Experimental Renal Insufficiency. PLoS One 2016; 11:e0163022. [PMID: 27658028 PMCID: PMC5033583 DOI: 10.1371/journal.pone.0163022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 09/01/2016] [Indexed: 11/19/2022] Open
Abstract
Introduction Phosphate binding with sevelamer can ameliorate detrimental histomorphometric changes of bone in chronic renal insufficiency (CRI). Here we explored the effects of sevelamer-HCl treatment on bone strength and structure in experimental CRI. Methods Forty-eight 8-week-old rats were assigned to surgical 5/6 nephrectomy (CRI) or renal decapsulation (Sham). After 14 weeks of disease progression, the rats were allocated to untreated and sevelamer-treated (3% in chow) groups for 9 weeks. Then the animals were sacrificed, plasma samples collected, and femora excised for structural analysis (biomechanical testing, quantitative computed tomography). Results Sevelamer-HCl significantly reduced blood pH, and final creatinine clearance in the CRI groups ranged 30%-50% of that in the Sham group. Final plasma phosphate increased 2.4- to 2.9-fold, and parathyroid hormone 13- to 21-fold in CRI rats, with no difference between sevelamer-treated and untreated animals. In the femoral midshaft, CRI reduced cortical bone mineral density (-3%) and breaking load (-15%) (p<0.05 for all versus Sham), while sevelamer increased bone mineral density (+2%) and prevented the deleterious changes in bone. In the femoral neck, CRI reduced bone mineral density (-11%) and breaking load (-10%), while sevelamer prevented the decrease in bone mineral density (+6%) so that breaking load did not differ from controls. Conclusions In this model of stage 3–4 CRI, sevelamer-HCl treatment ameliorated the decreases in femoral midshaft and neck mineral density, and restored bone strength despite prevailing acidosis. Therefore, treatment with sevelamer can efficiently preserve mechanical competence of bone in CRI.
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Affiliation(s)
- Jarkko Jokihaara
- Department of Hand and Microsurgery, Tampere University Hospital, Tampere, Finland
- Center for Hip Health and Mobility, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
| | | | | | - Peeter Kööbi
- Medical School, University of Tampere, Tampere, Finland
| | - Pekka Kannus
- Bone Research Group, UKK-Institute, Tampere, Finland
| | - Onni Niemelä
- Medical School, University of Tampere, Tampere, Finland
- Department of Laboratory Medicine, Seinäjoki Central Hospital Laboratory, Seinäjoki, Finland
| | - Russell T. Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States of America
| | - Urszula T. Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR, United States of America
| | - Teppo L. N. Järvinen
- Center for Hip Health and Mobility, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada
- Department of Orthopaedics and Traumatology, University of Helsinki, Helsinki, Finland
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The effects of photobiomodulation and low-amplitude high-frequency vibration on bone healing process: a comparative study. Lasers Med Sci 2016; 31:1827-1836. [DOI: 10.1007/s10103-016-2058-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/17/2016] [Indexed: 10/21/2022]
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Çakir ZÜ, Demirel C, Kilciksiz SC, Gürgül S, Zincircioğlu SB, Erdal N. Melatonin can Ameliorate Radiation-Induced Oxidative Stress and Inflammation-Related Deterioration of Bone Quality in Rat Femur. Inflammation 2016; 39:1134-40. [PMID: 27052631 DOI: 10.1007/s10753-016-0347-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of the present study was to evaluate the radioprotective effects of melatonin on the biomechanical properties of bone in comparison to amifostine (WR-2721). Forty Sprague Dawley rats were divided equally into 5 groups namely; control (C), irradiation (R; single dose of 50 Gy), irradiation + WR-2721 (R + WR-2721; irradiation + 200 mg/kg WR-2721) radiation + melatonin 25 mg/kg (R + M25; irradiation + 25 mg/kg melatonin), and radiation + melatonin 50 mg/kg (R + M50; irradiation + 50 mg/kg melatonin). In order to measure extrinsic (organ-level mechanical properties of bone; the ultimate strength, deformation, stiffness, energy absorption capacity) and intrinsic (tissue-level mechanical properties of bone; ultimate stress, ultimate strain, elastic modulus, toughness) features of the bone, a three-point bending (TPB) test was performed for biomechanical evaluation. In addition, a bone mineral density (BMD) test was carried out. The BMD and extrinsic properties of the diaphyseal femur were found to be significantly higher in the R + M25 group than in group R (p < 0.05). A significant increase was observed in R + M50 (p < 0.05) in comparison to group R in the cross-sectional area of the femoral shaft and elastic modulus parameter. The protective effect of melatonin was similar to that of WR-2721. Thus, biomechanical quality of irradiated bone can be ameliorated by free radical scavenger melatonin.
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Affiliation(s)
- Zelal Ünlü Çakir
- Department of Biophysics, Faculty of Medicine, Gaziantep University, Gaziantep, TR-27310, Turkey
| | - Can Demirel
- Department of Biophysics, Faculty of Medicine, Gaziantep University, Gaziantep, TR-27310, Turkey.
| | | | - Serkan Gürgül
- Department of Biophysics, Faculty of Medicine, Gaziosmanpaşa University, Tokat, TR-60000, Turkey
| | | | - Nurten Erdal
- Department of Biophysics, Faculty of Medicine, Mersin University, Mersin, TR-33169, Turkey
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Oksztulska-Kolanek E, Znorko B, Michałowska M, Pawlak K. The Biomechanical Testing for the Assessment of Bone Quality in an Experimental Model of Chronic Kidney Disease. Nephron Clin Pract 2015; 132:51-8. [DOI: 10.1159/000442714] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 10/30/2015] [Indexed: 11/19/2022] Open
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Mataliotakis GI, Tsouknidas A, Panteliou S, Vekris MD, Mitsionis GI, Agathopoulos S, Beris AE. A new, low cost, locking plate for the long-term fixation of a critical size bone defect in the ratfemur: in vivo performance, biomechanical and finite element analysis. Biomed Mater Eng 2015; 25:335-46. [PMID: 26407196 DOI: 10.3233/bme-151540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The optimum fixation device for the critical size bone defect is not established yet. OBJECTIVE A reliable, feasible and low-cost fixation device for the long-term maintenance of a critical bone defect. METHODS A custom-made plate made of poly-methyl-methacrylate was used for the fixation of a critical defect of rats' femurs. The screws were securely fixing both on the plate and the bone. A three point bending test, aimed to resemble the in vivo loading pattern, a Finite Element Analysis and a 24-week in vivo monitoring of the integrity of the plate fixation were utilized. RESULTS The plate has linear and reproducible behavior. It presents no discontinuities in the stress field of the fixation. Its properties are attributed to the material and the locking principle. It fails beyond the level of magnitude of the normal ambulatory loads. In vivo, 100% of the plates maintained the bone defect intact up to 12 weeks and 85% of them at 24 weeks. CONCLUSION This novel locking plate shows optimal biomechanical performance and reliability with high long-term in vivo survival rate. It is fully implantable, inexpensive and easily manufactured. It can be qualified for long term critical defect fixation in bone regeneration studies.
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Affiliation(s)
| | - Alexander Tsouknidas
- Department of Mechanical Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Sofia Panteliou
- Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - Marios D Vekris
- Department of Orthopaedic Surgery, University of Ioannina, Ioannina, Greece
| | | | - Simeon Agathopoulos
- Department of Materials Science and Engineering, University of Ioannina, Ioannina, Greece
| | - Alexander E Beris
- Department of Orthopaedic Surgery, University of Ioannina, Ioannina, Greece
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Comparative study of two types of herbal capsules with different Epimedium species for the prevention of ovariectomised-induced osteoporosis in rats. J Orthop Translat 2015; 4:14-27. [PMID: 30035062 PMCID: PMC5987012 DOI: 10.1016/j.jot.2015.07.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 06/24/2015] [Accepted: 07/07/2015] [Indexed: 11/21/2022] Open
Abstract
Background/Objective Epimedii Folium is the most important osteogenic herb formulated for the traditional Chinese Medicine Xian Ling Gu Bao (XLGB) capsule. The present study compared XLGB capsules containing two different Epimedium species, i.e., either Epimedium pubescens (XEP) or Epimedium koreanum (XEK), with the focus being on the chemical constituents and antiosteoporotic efficacy. Methods Ultra performance liquid chromatography was used to demonstrate the different chemical constituents. Biomechanical tests, histological, and cytological evaluation were performed to characterise and compare the bone mineral density, bone strength, microstructure of bone tissue, and biological activity between XEP and XEK using an established ovariectomised (OVX) rat model. Results Six flavonoids with different contents between XEK and XEP were identified. As compared with the OVX group, significantly higher bone mineral density, elastic-modulus, and compressive strength were found in both the XEK group and XEP group (p < 0.05 for all, n = 8). Histomorphometric data presented significantly higher osteoblast surface ratio and osteoid area accompanied by significantly lower values of erosion surface and adiopocytes area in two treatment groups (p < 0.05, n = 6). XLGB Fufang with either XEK or XEP all showed significant preventive effects in OVX-induced osteoporosis and deterioration of bone mechanical properties. Conclusion The significance of the current preclinical experimental study was that these two Epimedium species used for formulating XLGB capsules were equally effective for the prevention of oestrogen-depletion induced osteoporosis.
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Xie D, Guo J, Mehdizadeh M, Tran RT, Chen R, Sun D, Qian G, Jin D, Bai X, Yang J. Development of Injectable Citrate-Based Bioadhesive Bone Implants. J Mater Chem B 2015; 3:387-398. [PMID: 25580247 PMCID: PMC4286886 DOI: 10.1039/c4tb01498g] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Injectable bone implants have been widely used in bone tissue repairs including the treatment of comminuted bone fractures (CBF). However, most injectable bone implants are not suitable for the treatment of CBF due to their weak tissue adhesion strengths and minimal osteoinduction. Citrate has been recently reported to promote bone formation through enhanced bioceramic integration and osteoinductivity. Herein, a novel injectable citrate-based mussel-inspired bioadhesive hydroxyapatite (iCMBA/HA) bone substitute was developed for CBF treatment. iCMBA/HA can be set within 2-4 minutes and the as-prepared (wet) iCMBA/HA possess low swelling ratios, compressive mechanical strengths of up to 3.2±0.27 MPa, complete degradation in 30 days, suitable biocompatibility, and osteoinductivity. This is also the first time to demonstrate that citrate supplementation in osteogenic medium and citrate released from iCMBA/HA degradation can promote the mineralization of osteoblastic committed human mesenchymal stem cells (hMSCs). In vivo evaluation of iCMBA/HA in a rabbit comminuted radial fracture model showed significantly increased bone formation with markedly enhanced three-point bending strength compared to the negative control. Neovascularization and bone ingrowth as well as highly organized bone formation were also observed showing the potential of iCMBA/HA in treating CBF.
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Affiliation(s)
- Denghui Xie
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China ; Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Jinshan Guo
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Mohammadreza Mehdizadeh
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Richard T Tran
- Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
| | - Ruisong Chen
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Dawei Sun
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Guoying Qian
- Department of Biology, College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
| | - Dadi Jin
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Xiaochun Bai
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China
| | - Jian Yang
- Department of Orthopedic Surgery, The Third Affiliated Hospital of Southern Medical University; Academy of Orthopedics, Guangdong Province; Biology Department, Southern Medical University, Guangzhou, 510515, China ; Department of Biomedical Engineering, Materials Research Institutes, The Huck Institutes of The Life Sciences, The Pennsylvania State University, University Park 16802, USA
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Lu Y, He B, Zhang X, Yang R, Li S, Song B, Zhang Y, Yun Y, Yan H, Chen P, Shen Z. Osteoprotective effect of geraniin against ovariectomy-induced bone loss in rats. Bioorg Med Chem Lett 2014; 25:673-9. [PMID: 25532904 DOI: 10.1016/j.bmcl.2014.11.081] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 11/26/2014] [Accepted: 11/28/2014] [Indexed: 11/16/2022]
Abstract
In the present study, we investigated the antiosteoporotic effect of geraniin on osteoporosis induced by OVX in rats. The analysis of biochemical parameters showed that geraniin could significantly increase serum calcium, estradiol and calcitonin levels, and decrease serum ALP, tartrate-resistant acid phosphatase, serum crosslinked C-terminal telopeptide of type I collagen, and urinary deoxypyridinoline/creatinine ratio levels, respectively. Geraniin was also found to prevent OVX-induced bone loss in bone mineral density and bone mineral content, to elevate femur weight and bone calcium content, and to enhance the bone mechanical properties as compared with OVX group. In addition, geraniin was demonstrated to improve the histomorphological parameters of OVX-induced bone loss, including bone trabecular number, thickness, and separation. These results indicated that geraniin have a protective effect against OVX-induced rat osteoporosis.
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Affiliation(s)
- Yiqin Lu
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China; Department of Obstetrics and Gynecology, First People's Hospital of Yunnan Province, Kunming 650032, PR China
| | - Bo He
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China; Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071, PR China
| | - Xiaochao Zhang
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China
| | - Renhua Yang
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China
| | - Shude Li
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China; Department of Biochemistry and Molecular Biology, Kunming Medical University, Kunming 650500, PR China
| | - Bo Song
- Department of Pharmacology, Yunnan University of Traditional Chinese Medicine, Kunming 650050, PR China
| | - Yue Zhang
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China
| | - Yu Yun
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China
| | - Hongli Yan
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China; Department of Pharmacology, Yunnan University of Traditional Chinese Medicine, Kunming 650050, PR China
| | - Peng Chen
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China.
| | - Zhiqiang Shen
- School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China.
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Hsu JT, Wang SP, Huang HL, Chen YJ, Wu J, Tsai MT. The assessment of trabecular bone parameters and cortical bone strength: A comparison of micro-CT and dental cone-beam CT. J Biomech 2013; 46:2611-8. [DOI: 10.1016/j.jbiomech.2013.08.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 11/26/2022]
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Abstract
OBJECTIVE The development of osteoarthritis after intra-articular fractures has been described for decades, although the exact mechanical and cellular changes that occur remain poorly understood. There are several animal models to study this phenomenon, but they are mechanistically different from physiologic fractures in several important ways. This article describes a novel model that recreates the kinematics present in high-energy trauma and intra-articular fractures. METHODS We designed a "drop tower" for the creation of intercondylar femoral fractures in rats and tested it on cadaveric rats to determine the optimal kinetic parameters. Intra-articular fractures were then created in live rats and the animals were killed at 0, 24, and 72 hours after the fracture. Cartilage samples were obtained for live/dead staining, and the relationships among fracture time, cartilage depth, and cell viability were evaluated. RESULTS The model reproduced intra-articular fractures very similar to those seen in high-energy trauma, although we required significantly higher energies (3600 mJ) than those reported in other fracture models (40-200 mJ). Cartilage viability decreased with time (68% immediately after the fracture and 46% at 72 hours, P = 0.02) and increased with depth from the articular surface (47% at the surface vs. 66% in the deepest layer, P = 0.001). CONCLUSIONS This model is a physiologically relevant reliable method for creating intra-articular fractures in rats and can produce meaningful data about the biologic changes occurring in cartilage after injury. Cell viability decreases with time postfracture and with proximity to the articular surface.
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Hsu JT, Chen YJ, Tsai MT, Lan HHC, Cheng FC, Chen MYC, Wang SP. Predicting cortical bone strength from DXA and dental cone-beam CT. PLoS One 2012; 7:e50008. [PMID: 23226234 PMCID: PMC3511426 DOI: 10.1371/journal.pone.0050008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/15/2012] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE This study compared the capabilities of dual-energy X-ray absorptiometry (DXA) and dental cone-beam computed tomography (CBCT) for predicting the cortical bone strength of rat femurs and tibias. MATERIALS AND METHODS Specimens of femurs and tibias obtained from 14 rats were first scanned with DXA to obtain the areal bone mineral density (BMD) of the midshaft cortical portion of the bones. The bones were then scanned using dental CBCT to measure the volumetric cortical bone mineral density (vCtBMD) and the cross-sectional moment of inertia (CSMI) for calculating the bone strength index (BSI). A three-point bending test was conducted to measure the fracture load of each femur and tibia. Bivariate linear Pearson analysis was used to calculate the correlation coefficients (r values) among the CBCT measurements, DXA measurements, and three-point bending parameters. RESULTS The correlation coefficients for the associations of the fracture load with areal BMD (measured using DXA), vCtBMD (measured using CBCT), CSMI (measured using CBCT), and BSI were 0.585 (p = 0.028) and 0.532 (p = 0.050) (for the femur and tibia, respectively), 0.638 (p = 0.014) and 0.762 (p = 0.002), 0.778 (p = 0.001) and 0.792 (p<0.001), and 0.822 (p<0.001) and 0.842 (p<0.001), respectively. CONCLUSIONS CBCT was found to be superior to DXA for predicting cortical bone fracture loads in rat femurs and tibias. The BSI, which is a combined index of densitometric and geometric parameters, was especially useful. Further clinical studies are needed to validate the predictive value of BSI obtained from CBCT and should include testing on human cadaver specimens.
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Affiliation(s)
- Jui-Ting Hsu
- School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan
| | - Ying-Ju Chen
- Stem Cell Center, Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Ming-Tzu Tsai
- Department of Biomedical Engineering, Hungkuang University, Taichung, Taiwan
| | - Howard Haw-Chang Lan
- Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan
- School of Radiological Technology, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Fu-Chou Cheng
- Stem Cell Center, Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Michael Y. C. Chen
- School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan
| | - Shun-Ping Wang
- Department of Orthopaedics, Taichung Veterans General Hospital, Taichung, Taiwan
- * E-mail:
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Lu Y, Thiagarajan G, Nicolella DP, Johnson ML. Load/strain distribution between ulna and radius in the mouse forearm compression loading model. Med Eng Phys 2011; 34:350-6. [PMID: 21903442 DOI: 10.1016/j.medengphy.2011.07.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 07/24/2011] [Accepted: 07/26/2011] [Indexed: 10/17/2022]
Abstract
Finite element analysis (FEA) of the mouse forearm compression loading model is used to relate strain distributions with downstream changes in bone formation and responses of bone cells. The objective of this study was to develop two FEA models - the first one with the traditional ulna only and the second one in which both the ulna and radius are included, in order to examine the effect of the inclusion of the radius on the strain distributions in the ulna. The entire mouse forearm was scanned using microCT and images were converted into FEA tetrahedral meshes using a suite of software programs. The performance of both linear and quadratic tetrahedral elements and coarse and fine meshes were studied. A load of 2N was applied to the ulna/radius model and a 1.3N load (based on previous investigations of load sharing between the ulna and radius in rats) was applied to the ulna only model for subsequent simulations. The results showed differences in the cross sectional strain distributions and magnitude within the ulna for the combined ulna/radius model versus the ulna only model. The maximal strain in the combined model occurred about 4mm toward the distal end from the ulna mid-shaft in both models. Results from the FEA model simulations were also compared to experimentally determined strain values. We conclude that inclusion of the radius in FE models to predict strains during in vivo forearm loading increases the magnitude of the estimated ulna strains compared to those predicted from a model of the ulna alone but the distribution was similar. This has important ramifications for future studies to understand strain thresholds needed to activate bone cell responses to mechanical loading.
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Affiliation(s)
- Yunkai Lu
- Department of Civil and Mechanical Engineering, University of Missouri-Kansas City, Kansas City, MO 64110, United States
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Leppänen OV, Sievänen H, Jokihaara J, Pajamäki I, Kannus P, Cooper DM, Järvinen TLN. The effects of loading and estrogen on rat bone growth. J Appl Physiol (1985) 2010; 108:1737-44. [DOI: 10.1152/japplphysiol.00989.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study evaluated the contributions of locomotive loading and estrogen to the development of diaphysis of rat femur. A randomized 2 × 2 study design was used. Altogether, 70 female Sprague-Dawley rats were used, of which 10 were euthanized at entry. Of the remaining rats, 16 served as controls, and the rest, 44, underwent a unilateral sciatic neurectomy. The effect of estrogen was removed by ovariectomizing one-half of the neurectomized rats. After 27 wk, the animals were euthanized, and the femora were excised. Irrespective of loading or estrogen, the femur length and mineral mass increased by 142 and 687%, respectively. Axial growth was not modulated either by locomotive loading or estrogen, but the loading resulted in direction-specific changes in the cross-sectional geometry. The estrogen-related gains were evident on the endocortical surface, while the loading-related gains occurred on the periosteal surface. The loading and estrogen were significantly associated with increased bone strength (21 and 15%, respectively) in the mediolateral direction, but not in the anteroposterior direction. Axial growth and accrual of bone mineral mass of the rat femur are largely independent of locomotive loading or estrogen, whereas these factors specifically account for the femur function, as either a mechanical lever or a mineral reservoir for reproduction, respectively.
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Affiliation(s)
- Olli V. Leppänen
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
| | - Harri Sievänen
- The Bone Research Group, UKK Institute, Tampere, Finland
| | - Jarkko Jokihaara
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia; and
| | - Ilari Pajamäki
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
| | - Pekka Kannus
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- The Bone Research Group, UKK Institute, Tampere, Finland
| | - David M. Cooper
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Teppo L. N. Järvinen
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia; and
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Sun LW, Fan YB, Li DY, Zhao F, Xie T, Yang X, Gu ZT. Evaluation of the mechanical properties of rat bone under simulated microgravity using nanoindentation. Acta Biomater 2009; 5:3506-11. [PMID: 19450712 DOI: 10.1016/j.actbio.2009.04.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 03/24/2009] [Accepted: 04/22/2009] [Indexed: 11/25/2022]
Abstract
Exposure to microgravity causes a decrease in bone mass and altered bone geometry due to the lack of weight-bearing forces on the skeleton. The mechanical properties of bone are due not only to the structure and geometry, but also to the tissue properties of the bone material itself. To study the effects of microgravity on bone tissue, the mechanical properties of tail suspension rat femurs were investigated. Twelve Sprague-Dawley rats were randomly divided into two groups, tail suspension (TS) and control (CON). On days 0 and 14, the bone mineral density (BMD) of the femurs was determined by Dual Energy X-ray Absorptiometry. After 14 days, three-point bending was used to test the mechanical properties of the whole femur and nanoindentation was used to measure the mechanical properties of the bone materials. The BMD of femurs in TS was significantly lower than that in CON. In the three-point bending testing, the breaking load, stiffness and energy absorption all decreased significantly in the TS group. In the nanoindentation tests, there was no significant difference between TS and CON in elastic modulus (E), while hardness (H) was significantly decreased and E/H significantly increased in TS. Weightlessness affects the intrinsic mechanical properties of bone at the bone material level. It is necessary to investigate further the effect of microgravity on the collagen bone matrix. Nanoindentation is a relatively new technique that is useful for investigating the above changes induced by microgravity and for assessing the efficacy of intervention.
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Yarrow JF, Conover CF, Purandare AV, Bhakta AM, Zheng N, Conrad B, Altman MK, Franz SE, Wronski TJ, Borst SE. Supraphysiological testosterone enanthate administration prevents bone loss and augments bone strength in gonadectomized male and female rats. Am J Physiol Endocrinol Metab 2008; 295:E1213-22. [PMID: 18780767 DOI: 10.1152/ajpendo.90640.2008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High-dose testosterone enanthate (TE) may prevent hypogonadism-induced osteopenia. For this study, 3-mo-old male and female Fisher SAS rats underwent sham surgery, gonadectomy (GX), or GX plus 28 days TE administration (7.0 mg/wk). GX reduced serum sex hormones (i.e., testosterone, dihydrotestosterone, and estradiol) (P < 0.05) in both sexes and bone concentrations of testosterone (males only), and estradiol (females only). GX also elevated urine deoxypyridinoline/creatinine in both sexes and serum osteocalcin (females only), findings that are consistent with high-turnover osteopenia. GX reduced cancellous bone volume (CBV) and increased osteoid surfaces in tibia of both sexes. GX males also experienced reduced trabecular number and width and increased trabecular separation, whereas GX females experienced increased osteoblast and osteoid surfaces. Bone biomechanical characteristics remained unaffected by GX, except that femoral stiffness was reduced in females. In contrast, TE administration to GX rats elevated serum and bone androgens to supraphysiological concentrations in both sexes but altered neither serum nor bone estradiol in males. Additionally, TE did not prevent GX-induced reductions in serum or bone estradiol in females. TE also reduced markers of high-turnover osteopenia in both sexes. In males, TE prevented GX-induced changes in trabecular number and separation, CBV, and osteoid surfaces while diminishing osteoblast and osteoclast surfaces; however, these changes were not fully prevented in females. In both sexes, TE increased femoral length and femoral maximal strength to above that of Sham and GX animals while preventing the loss of femoral stiffness in females. In conclusion, TE administration appears protective of cancellous bone in male rats and augments cortical bone strength in both sexes.
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Affiliation(s)
- Joshua F Yarrow
- Geriatric Research, Education and Clinical Center, Veterans Administration Medical Center, Gainesville, Florida, USA
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Pajamäki I, Sievänen H, Kannus P, Jokihaara J, Vuohelainen T, Järvinen TLN. Skeletal effects of estrogen and mechanical loading are structurally distinct. Bone 2008; 43:748-57. [PMID: 18620089 DOI: 10.1016/j.bone.2008.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 06/06/2008] [Accepted: 06/11/2008] [Indexed: 11/28/2022]
Abstract
Estrogen has been suggested to influence skeletal homeostasis by both increasing the sensitivity of the feedback control system for skeletal rigidity and acting directly on bone surfaces. The objective of the present study was to explore the proposed interaction between the skeletal effects of estrogen and locomotion. Thirty 3-week-old littermates of female Sprague-Dawley rats were first randomly assigned into bilateral sham (E(+)) or ovariectomy (E(-)) surgery after which, the left hindlimb each study animal was cast immobilized (L(-)) while the right limb served as locomotively loaded control (L(+)), a classic 2x2 factorial study design. After 8-week study period, femoral neck, femur midshaft and distal metaphysis were analyzed by peripheral quantitative computed tomography (pQCT), microcomputed tomography (microCT), and mechanical testing. The loading-induced effects were virtually identical in the estrogen-replete (E(+)) and estrogen-deplete (E(-)) groups (Femoral neck: +78% vs. +69% in the tCSA, +74% vs. +55% in the tBMC, -6.0% vs. -7.2% in the tBMD, and +33% vs. +58% in the F(max); Femoral midshaft: +6.9% vs. +3.9% in the cCSA, +13% vs. +13% in the tCSA, +23% vs. +16% in the cBMC, +5.2% vs. +5.1% in the cBMD, and +8.0% vs. +8.0% in the F(max), respectively. All comparisons, NS), challenging the alleged modulatory effect of estrogen on skeletal mechanosensitivity. Estrogen did not have an independent effect on the periosteal apposition at any of the evaluated bone regions. Instead, according to its primary reproductive function, the effects of estrogen were restricted to accrual of bone mass only, the stimulus being apparent at the endosteal surface of cortex and trabecular structure of the distal metaphysis. In conclusion, the present results indicate that that the actions of estrogen and loading on bone structure are independent and additive in nature.
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Affiliation(s)
- Ilari Pajamäki
- Department of Surgery and the Institute of Medical Technology, University of Tampere, Tampere, Finland
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Pathogenesis of age-related osteoporosis: impaired mechano-responsiveness of bone is not the culprit. PLoS One 2008; 3:e2540. [PMID: 18648530 PMCID: PMC2481275 DOI: 10.1371/journal.pone.0002540] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 05/21/2008] [Indexed: 11/21/2022] Open
Abstract
Background According to prevailing understanding, skeletal mechano-responsiveness declines with age and this apparent failure of the mechano-sensory feedback system has been attributed to the gradual bone loss with aging (age-related osteoporosis). The objective of this study was to evaluate whether the capacity of senescent skeleton to respond to increased loading is indeed reduced as compared to young mature skeleton. Methods and Findings 108 male and 101 female rats were randomly assigned into Exercise and Control groups. Exercise groups were subjected to treadmill training either at peak bone mass between 47–61 weeks of age (Mature) or at senescence between 75–102 weeks of age (Senescent). After the training intervention, femoral necks and diaphysis were evaluated with peripheral quantitative computed tomography (pQCT) and mechanical testing; the proximal tibia was assessed with microcomputed tomography (μCT). The μCT analysis revealed that the senescent bone tissue was structurally deteriorated compared to the mature bone tissue, confirming the existence of age-related osteoporosis. As regards the mechano-responsiveness, the used loading resulted in only marginal increases in the bones of the mature animals, while significant exercise-induced increases were observed virtually in all bone traits among the senescent rats. Conclusion The bones of senescent rats displayed a clear ability to respond to an exercise regimen that failed to initiate an adaptive response in mature animals. Thus, our observations suggest that the pathogenesis of age-related osteoporosis is not attributable to impaired mechano-responsiveness of aging skeleton. It also seems that strengthening of even senescent bones is possible – naturally provided that safe and efficient training methods can be developed for the oldest old.
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Jokihaara J, Pörsti IH, Kööbi P, Jolma PM, Mustonen JT, Saha HHT, Sievänen H, Kannus P, Iwaniec UT, Turner RT, Järvinen TLN. Treatment of experimental renal osteodystrophy with pamidronate. Kidney Int 2008; 74:319-27. [PMID: 18463610 DOI: 10.1038/ki.2008.180] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We evaluated the effects of the bisphosphonate pamidronate on bone histomorphometry, structure and strength in male rats with uninephrectomy or with chronic renal disease induced by 5/6 nephrectomy. In rats with chronic renal disease the plasma urea, phosphate and parathyroid hormone levels were significantly increased compared to rats with a uninephroctomy and none of these parameters was affected by pamidronate treatment. In the femoral midshaft, chronic renal disease reduced cortical bone mineral density and content. No difference was observed in the breaking load of the femoral midshaft. In the distal femur, a high-turnover renal osteodystrophy was found but pamidronate suppressed this bone turnover and increased bone mineral content. Treatment had no effect on chronic disease-induced augmentation of osteoid volume or fibroblast surface. These studies show that in this model of stage 3 renal disease, pamidronate increased mineral content in the femoral midshaft and distal metaphysis primarily by adding bone to endocortical and trabecular surfaces but did not reduce osteitis fibrosa.
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Affiliation(s)
- Jarkko Jokihaara
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
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Leppänen OV, Sievänen H, Järvinen TLN. Biomechanical testing in experimental bone interventions--May the power be with you. J Biomech 2008; 41:1623-31. [PMID: 18460409 DOI: 10.1016/j.jbiomech.2008.03.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 02/01/2008] [Accepted: 03/17/2008] [Indexed: 10/22/2022]
Abstract
Total variation in any measured variable, in conjunction with expected treatment effect, defines the minimum sample size (minSS) required to detect the expected effect with statistical confidence should the effect truly exist. A comprehensive literature survey of 3472 original studies was carried out to identify studies with biomechanical testing of whole bones. Total variation in common biomechanical traits and expected treatment effects in typical interventions were statistically determined. According to this survey, total variation in biomechanical traits between different species of experimental animals was similar, justifying the use of rat femur as a model in further analyses. Due to poorer precision, stiffness and energy absorption assessment require substantially larger sample size than breaking load. Due to same reason, minSS for femoral neck compression test is considerably larger than for femoral shaft three-point bending test. For the bending test, minSS to show a 10% treatment effect in the breaking load with 80% statistical power is 11rats/group, while corresponding minSS is 23 for the stiffness, and 53 for the energy absorption. For the femoral neck compression test, minSSs are 16, 51, and 134rats/group, respectively. Among the reviewed studies, the mean sample size was 11animals/group. This underscores the need for considerably larger sample sizes in experimental bone interventions which employ mechanical traits as primary outcome variables. In particular, poor precision and generally small expected treatment effects compromise the utility of stiffness and energy absorption assessments in experimental bone interventions.
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Affiliation(s)
- Olli V Leppänen
- Medical School and the Institute of Medical Technology, University of Tampere, 33 014 Tampere, Finland
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