scholarly journals In Vivo Efficacy of Neutrophil-Mediated Bone Regeneration Using a Rabbit Calvarial Defect Model

2021 ◽  
Vol 22 (23) ◽  
pp. 13016
Author(s):  
Thanuja D. K. Herath ◽  
Leonardo Saigo ◽  
Benoit Schaller ◽  
Anis Larbi ◽  
Swee Hin Teoh ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Volume Fraction ◽  
Bone Defects ◽  
Bone Volume ◽  
Surgical Removal ◽  
Calvarial Defect ◽  
Bone Area ◽  
Defect Model ◽  
In Vivo Efficacy

Reconstruction of bone due to surgical removal or disease-related bony defects is a clinical challenge. It is known that the immune system exerts positive immunomodulatory effects on tissue repair and regeneration. In this study, we evaluated the in vivo efficacy of autologous neutrophils on bone regeneration using a rabbit calvarial defect model. Methods: Twelve rabbits, each with two surgically created calvarial bone defects (10 mm diameter), were randomly divided into two groups; (i) single application of neutrophils (SA-NP) vs. SA-NP control, and (ii) repetitive application of neutrophils (RA-NP) vs. RA-NP control. The animals were euthanized at 4 and 8 weeks post-operatively and the treatment outcomes were evaluated by micro-computed tomography, histology, and histomorphometric analyses. Results: The micro-CT analysis showed a significantly higher bone volume fraction (bone volume/total volume) in the neutrophil-treated groups, i.e., median interquartile range (IQR) SA-NP (18) and RA-NP (24), compared with the untreated controls, i.e., SA-NP (7) and RA-NP (14) at 4 weeks (p < 0.05). Similarly, new bone area fraction (bone area/total area) was significantly higher in neutrophil-treated groups at 4 weeks (p < 0.05). Both SA-NP and RA-NP had a considerably higher bone volume and bone area at 8 weeks, although the difference was not statistically significant. In addition, immunohistochemical analysis at 8 weeks revealed a higher expression of osteocalcin in both SA-NP and RA-NP groups. Conclusions: The present study provides first hand evidence that autologous neutrophils may have a positive effect on promoting new bone formation. Future studies should be performed with a larger sample size in non-human primate models. If proven feasible, this new promising strategy could bring clinical benefits for bone defects to the field of oral and maxillofacial surgery.

Melatonin decorated 3D-printed beta-tricalcium phosphate scaffolds promoting bone regeneration in a rat calvarial defect model

2019 ◽  
Vol 7 (20) ◽  
pp. 3250-3259 ◽  
Author(s):  
Yali Miao ◽  
Yunhua Chen ◽  
Xiao Liu ◽  
Jingjing Diao ◽  
Naru Zhao ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Tricalcium Phosphate ◽  
Calvarial Defect ◽  
Defect Model ◽  
Beta Tricalcium Phosphate ◽  
3D Printed ◽  
Rat Calvarial Defect

3D-printed β-TCP scaffolds decorated with melatonin via dopamine mussel-inspired chemistry enhance the osteogenesis and in vivo bone regeneration.

Ultraviolet-Crosslinkable and Injectable Chitosan/Hydroxyapatite Hybrid Hydrogel for Critical Size Calvarial Defect Repair In Vivo

2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Baoqiang Li ◽  
Lei Wang ◽  
Yu Hao ◽  
Daqing Wei ◽  
Ying Li ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Critical Size ◽  
Rabbit Model ◽  
Single Step ◽  
Calvarial Defect ◽  
Defect Model ◽  
Calvarial Bone ◽  
Hybrid Hydrogel ◽  
Defect Site

To promote bone regeneration in vivo using critical-size calvarial defect model, hybrid hydrogel was prepared by mixing chitosan with hydroxyapatite (HA) and ultraviolet (UV) irradiation in situ. The hydrosoluble, UV-crosslinkable and injectable N-methacryloyl chitosan (N-MAC) was synthesized via single-step N-acylation reaction. The chemical structure was confirmed by 1H-NMR and FTIR spectroscopy. N-MAC hydrogel presented a microporous structure with pore sizes ranging from 10 to 60 μm. Approximately 80% cell viability of N-MAC hydrogel against encapsulated 3T3 cell indicated that N-MAC is an emerging candidate for mimicking native extracellular matrix (ECM). N-MAC hydrogel hybridized with HA was used to accelerate regeneration of calvarial bone using rabbit model. The effects of hybrid hydrogels to promote bone regeneration were evaluated using critical size calvarial bone defect model. The healing effects of injectable hydrogels with/without HA for bone regeneration were investigated by analyzing X-ray image after 4 or 6 weeks. The results showed that the regenerated new bone for N-MAC 100 was significantly greater than N-MAC without HA and untreated controls. The higher HA content in N-MAC/HA hybrid hydrogel benefited the acceleration of bone regeneration. About 50% closure of defect site after 6 weeks postimplantation demonstrated potent osteoinductivity of N-MAC 100 UV-crosslinkable and injectable N-MAC/HA hybrid hydrogel would allow serving as a promising biomaterial for bone regeneration using the critical-size calvarial defect.

scholarly journals In Vitro and In Vivo Evaluation of Commercially Available Fibrin Gel as a Carrier of Alendronate for Bone Tissue Engineering

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Beom Su Kim ◽  
Feride Shkembi ◽  
Jun Lee
Keyword(s):  
Bone Regeneration ◽  
Osteogenic Differentiation ◽  
Release Kinetics ◽  
Human Mesenchymal Stem Cells ◽  
Calvarial Defect ◽  
Defect Model ◽  
Fibrin Gel ◽  
In Vivo Evaluation

Alendronate (ALN) is a bisphosphonate drug that is widely used for the treatment of osteoporosis. Furthermore, local delivery of ALN has the potential to improve the bone regeneration. This study was designed to investigate an ALN-containing fibrin (fibrin/ALN) gel and evaluate the effect of this gel on both in vitro cellular behavior using human mesenchymal stem cells (hMSCs) and in vivo bone regenerative capacity. Fibrin hydrogels were fabricated using various ALN concentrations (10−7–10−4 M) with fibrin glue and the morphology, mechanical properties, and ALN release kinetics were characterized. Proliferation and osteogenic differentiation of and cytotoxicity in fibrin/ALN gel-embedded hMSCs were examined. In vivo bone formation was evaluated using a rabbit calvarial defect model. The fabricated fibrin/ALN gel was transparent with Young’s modulus of ~13 kPa, and these properties were not affected by ALN concentration. The in vitro studies showed sustained release of ALN from the fibrin gel and revealed that hMSCs cultured in fibrin/ALN gel showed significantly increased proliferation and osteogenic differentiation. In addition, microcomputed tomography and histological analysis revealed that the newly formed bone was significantly enhanced by implantation of fibrin/ALN gel in a calvarial defect model. These results suggest that fibrin/ALN has the potential to improve bone regeneration.

scholarly journals The Release of the Bromodomain Ligand N,N-Dimethylacetamide Adds Bioactivity to a Resorbable Guided Bone Regeneration Membrane in a Rabbit Calvarial Defect Model

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 501 ◽  
Author(s):  
Barbara Siegenthaler ◽  
Chafik Ghayor ◽  
Nisarat Ruangsawasdi ◽  
Franz E. Weber
Keyword(s):  
Drug Delivery ◽  
Bone Regeneration ◽  
Guided Bone Regeneration ◽  
Good Combination ◽  
Calvarial Defect ◽  
Delivery Vehicle ◽  
Defect Model ◽  
Therapeutic Benefits ◽  
Biodegradable Poly

N,N-Dimethylacetamide (DMA) is FDA approved as an excipient and is used as drug-delivery vehicle. Due to its amphipathic nature and diverse bioactivities, it appears to be a good combination of biodegradable poly-lactide-co-glycolide (PLGA)-based guided bone regeneration membranes. Here we show that the solvent DMA can be loaded to PLGA membranes by different regimes, leading to distinct release profiles, and enhancing the bone regeneration in vivo. Our results highlight the potential therapeutic benefits of DMA in guided bone regeneration procedures, in combination with biodegradable PLGA membranes.

scholarly journals Temporal induction of Lhx8 by optogenetic control system for efficient bone regeneration

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Delan Huang ◽  
Runze Li ◽  
Jianhan Ren ◽  
Haotian Luo ◽  
Weicai Wang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Control System ◽  
Bone Regeneration ◽  
Osteogenic Differentiation ◽  
Blue Light ◽  
Calvarial Defect ◽  
Defect Model ◽  
Alizarin Red ◽  
Optogenetic Control

Abstract Background The spatiotemporal regulation of essential genes is crucial for controlling the growth and differentiation of cells in a precise manner during regeneration. Recently, optogenetics was considered as a potent technology for sophisticated regulation of target genes, which might be a promising tool for regenerative medicine. In this study, we used an optogenetic control system to precisely regulate the expression of Lhx8 to promote efficient bone regeneration. Methods Quantitative real-time PCR and western blotting were used to detect the expression of Lhx8 and osteogenic marker genes. Alkaline phosphatase staining and alizarin red staining were used to detect alkaline phosphatase activity and calcium nodules. A customized optogenetic expression system was constructed to regulate Lhx8, of which the expression was activated in blue light but not in dark. We also used a critical calvarial defect model for the analysis of bone regeneration in vivo. Moreover, micro-computed tomography (micro-CT), three-dimensional reconstruction, quantitative bone measurement, and histological and immunohistochemistry analysis were performed to investigate the formation of new bone in vivo. Results During the osteogenic differentiation of BMSCs, the expression levels of Lhx8 increased initially but then decreased thereafter. Lhx8 promoted the early proliferation of BMSCs but inhibited subsequent osteogenic differentiation. The optogenetic activation of Lhx8 in BMSCs in the early stages of differentiation by blue light stimulation led to a significant increase in cell proliferation, thus allowing a sufficient number of differentiating BMSCs to enter the later osteogenic differentiation stage. Analysis of the critical calvarial defect model revealed that the pulsed optogenetic activation of Lhx8 in transplanted BMSCs over a 5-day period led to a significant increase in the generation of bone in vivo. Conclusions Lhx8 plays a critical role in balancing proliferation and osteogenic differentiation in BMSCs. The optogenetic activation of Lhx8 expression at early stage of BMSCs differentiation led to better osteogenesis, which would be a promising strategy for precise bone regeneration.

scholarly journals Cathelicidin LL37 Promotes Osteogenic Differentiation in vitro and Bone Regeneration in vivo

2021 ◽  
Vol 9 ◽  
Author(s):  
Lunhao Li ◽  
Yiyu Peng ◽  
Qingyue Yuan ◽  
Jing Sun ◽  
Ai Zhuang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Osteogenic Differentiation ◽  
Antibacterial Properties ◽  
Bone Defects ◽  
Optimum Concentration ◽  
Calvarial Defect ◽  
Defect Model ◽  
Calvarial Bone ◽  
Rat Calvarial Defect

Different types of biomaterials have been used to repair the defect of bony orbit. However, exposure and infections are still critical risks in clinical application. Biomaterials with characteristics of osteogenesis and antibiosis are needed for bone regeneration. In this study, we aimed to characterize the antimicrobial effects of cathelicidin-LL37 and to assess any impacts on osteogenic activity. Furthermore, we attempted to demonstrate the feasibility of LL37 as a potential strategy in the reconstruction of clinical bone defects. Human adipose-derived mesenchyme stem cells (hADSCs) were cultured with different concentrations of LL37 and the optimum concentration for osteogenesis was selected for further in vitro studies. We then evaluated the antibiotic properties of LL37 at the optimum osteogenic concentration. Finally, we estimated the efficiency of a PSeD/hADSCs/LL37 combined scaffold on reconstructing bone defects in the rat calvarial defect model. The osteogenic ability on hADSCs in vitro was shown to be dependent on the concentration of LL37 and reached a peak at 4 μg/ml. The optimum concentration of LL37 showed good antimicrobial properties against Escherichia coli and Staphylococcus anurans. The combination scaffold of PSeD/hADSCs/LL37 showed superior osteogenic properties compared to the PSeD/hADSCs, PSeD, and control groups scaffolds, indicating a strong bone reconstruction effect in the rat calvarial bone defect model. In Conclusion, LL37 was shown to promote osteogenic differentiation in vitro as well as antibacterial properties. The combination of PSeD/hADSCs/LL37 was advantageous in the rat calvarial defect reconstruction model, showing high potential in clinical bone regeneration.

scholarly journals Bone Regeneration by Dedifferentiated Fat Cells Using Composite Sponge of Alfa-Tricalcium Phosphate and Gelatin in a Rat Calvarial Defect Model

2021 ◽  
Vol 11 (24) ◽  
pp. 11941
Author(s):  
Nobuhito Tsumano ◽  
Hirohito Kubo ◽  
Rie Imataki ◽  
Yoshitomo Honda ◽  
Yoshiya Hashimoto ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Tricalcium Phosphate ◽  
Electrostatic Interactions ◽  
Bone Defects ◽  
Gelatin Sponge ◽  
Calvarial Defect ◽  
Micro Computed Tomography ◽  
Defect Model ◽  
Rat Calvarial Defect ◽  
Dfat Cells

Mechanical and resorbable scaffolds are in high demand for stem cell-based regenerative medicine, to treat refractory bone defects in craniofacial abnormalities and injuries. Multipotent progenitor cells, such as dedifferentiated fat (DFAT) cells, are prospective sources for regenerative therapies. Herein, we aimed to demonstrate that a composite gelatin sponge (α-TCP/GS) of alfa-tricalcium phosphate (α-TCP) mixed with gelatin scaffolds (GS), with/without DFATs, induced bone regeneration in a rat calvarial defect model in vivo. α-TCP/GS was prepared by mixing α-TCP and 2% GS using vacuum-heated methods. α-TCP/GS samples with/without DFATs were transplanted into the model. After 4 weeks of implantation, the samples were subjected to micro-computed tomography (μ-CT) and histological analysis. α-TCP/GS possessed adequate mechanical strength; α-TCP did not convert to hydroxyapatite upon contact with water, as determined by X-ray diffraction. Moreover, stable α-TCP/GS was formed by electrostatic interactions, and verified based on the infrared peak shifts. μ-CT analyses showed that bone formation was higher in the α-TCP/GS+ DFAT group than in the α-TCP/GS group. Therefore, the implantation of α-TCP/GS comprising DFAT cells enhanced bone regeneration and vascularization, demonstrating the potential for healing critical-sized bone defects.

scholarly journals Surface Modification of Pure Magnesium Mesh for Guided Bone Regeneration: In Vivo Evaluation of Rat Calvarial Defect

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2684 ◽  
Author(s):  
Shuang Wu ◽  
Yong-Seok Jang ◽  
Yu-Kyoung Kim ◽  
Seo-Young Kim ◽  
Seung-O Ko ◽  
...  
Keyword(s):  
Surface Modification ◽  
Bone Regeneration ◽  
Protective Layer ◽  
Guided Bone Regeneration ◽  
Bone Volume ◽  
Pure Magnesium ◽  
Calvarial Defect ◽  
Barrier Membrane ◽  
Rat Calvarial Defect

Guided bone regeneration is a therapeutic method that uses a barrier membrane to provide space available for new bone formation at sites with insufficient bone volume. Magnesium with excellent biocompatibility and mechanical properties has been considered as a promising biodegradable material for guided bone regeneration; however, the rapid degradation rate in the physiological environment is a problem to be solved. In this study, surface modification of pure magnesium mesh was conducted by plasma electrolytic oxidation and hydrothermal treatment to form a densely protective layer on the Mg substrate. The protective layer mainly consisted of Mg(OH)2 with the amorphous calcium phosphate. Then, weight loss measurement and Micro-CT imaging were performed after an immersion test in a simulated body fluid. The effect of surface modification of the magnesium mesh on the guided bone regeneration was evaluated through an in vivo test using the rat calvarial defect model. The biodegradation of the magnesium mesh was identified to be significantly retarded. Additionally, the surface modification of Mg also can improve the bone volume and bone density of calvarial defect in comparison with that of the pristine Mg mesh.

scholarly journals Canine Mesenchymal Stromal Cell-Mediated Bone Regeneration is Enhanced in the Presence of Sub-Therapeutic Concentrations of BMP-2 in a Murine Calvarial Defect Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Lauren K. Dobson ◽  
Suzanne Zeitouni ◽  
Eoin P. McNeill ◽  
Robert N. Bearden ◽  
Carl A. Gregory ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Bone Healing ◽  
Human Mscs ◽  
Calvarial Defect ◽  
Defect Model ◽  
Alp Activity ◽  
Calvarial Defects ◽  
Species Specific

Novel bone regeneration strategies often show promise in rodent models yet are unable to successfully translate to clinical therapy. Sheep, goats, and dogs are used as translational models in preparation for human clinical trials. While human MSCs (hMSCs) undergo osteogenesis in response to well-defined protocols, canine MSCs (cMSCs) are more incompletely characterized. Prior work suggests that cMSCs require additional agonists such as IGF-1, NELL-1, or BMP-2 to undergo robust osteogenic differentiation in vitro. When compared directly to hMSCs, cMSCs perform poorly in vivo. Thus, from both mechanistic and clinical perspectives, cMSC and hMSC-mediated bone regeneration may differ. The objectives of this study were twofold. The first was to determine if previous in vitro findings regarding cMSC osteogenesis were substantiated in vivo using an established murine calvarial defect model. The second was to assess in vitro ALP activity and endogenous BMP-2 gene expression in both canine and human MSCs. Calvarial defects (4 mm) were treated with cMSCs, sub-therapeutic BMP-2, or the combination of cMSCs and sub-therapeutic BMP-2. At 28 days, while there was increased healing in defects treated with cMSCs, defects treated with cMSCs and BMP-2 exhibited the greatest degree of bone healing as determined by quantitative μCT and histology. Using species-specific qPCR, cMSCs were not detected in relevant numbers 10 days after implantation, suggesting that bone healing was mediated by anabolic cMSC or ECM-driven cues and not via engraftment of cMSCs. In support of this finding, defects treated with cMSC + BMP-2 exhibited robust deposition of Collagens I, III, and VI using immunofluorescence. Importantly, cMSCs exhibited minimal ALP activity unless cultured in the presence of BMP-2 and did not express endogenous canine BMP-2 under any condition. In contrast, human MSCs exhibited robust ALP activity in all conditions and expressed human BMP-2 when cultured in control and osteoinduction media. This is the first in vivo study in support of previous in vitro findings regarding cMSC osteogenesis, namely that cMSCs require additional agonists to initiate robust osteogenesis. These findings are highly relevant to translational cell-based bone healing studies and represent an important finding for the field of canine MSC-mediated bone regeneration.

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