scholarly journals Injectable Magnesium-Zinc Alloy Containing Hydrogel Complex for Bone Regeneration

2020 ◽  
Vol 8 ◽  
Author(s):  
Wei-Hua Wang ◽  
Fei Wang ◽  
Hai-Feng Zhao ◽  
Ke Yan ◽  
Cui-Ling Huang ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Zinc Alloy ◽  
Calvarial Defect ◽  
Alizarin Red ◽  
Capacity Limits ◽  
Growth Status ◽  
Defect Site ◽  
Calvarial Defects ◽  
Related Transcription Factor ◽  
Polymerase Chain

Gelatin methacryloyl (GelMA) has been widely used in bone engineering. It can also be filled into the calvarial defects with irregular shape. However, lack of osteoinductive capacity limits its potential as a candidate repair material for calvarial defects. In this study, we developed an injectable magnesium–zinc alloy containing hydrogel complex (Mg-IHC), in which the alloy was fabricated in an atomization process and had small sphere, regular shape, and good fluidity. Mg-IHC can be injected and plastically shaped. After cross-linking, it contents the elastic modulus similar to GelMA, and has inner holes suitable for nutrient transportation. Furthermore, Mg-IHC showed promising biocompatibility according to our evaluations of its cell adhesion, growth status, and proliferating activity. The results of alkaline phosphatase (ALP) activity, ALP staining, alizarin red staining, and real-time polymerase chain reaction (PCR) further indicated that Mg-IHC could significantly promote the osteogenic differentiation of MC3T3-E1 cells and upregulate the genetic expression of collagen I (COL-I), osteocalcin (OCN), and runt-related transcription factor 2 (RUNX2). Finally, after applied to a mouse model of critical-sized calvarial defect, Mg-IHC remarkably enhanced bone formation at the defect site. All of these results suggest that Mg-IHC can promote bone regeneration and can be potentially considered as a candidate for calvarial defect repairing.

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 Effects of Polylactide Copolymer Implants and Platelet-Rich Plasma on Bone Regeneration within a Large Calvarial Defect in Sheep

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Bartłomiej Błaszczyk ◽  
Wojciech Kaspera ◽  
Krzysztof Ficek ◽  
Maciej Kajor ◽  
Marcin Binkowski ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Regeneration ◽  
Bone Healing ◽  
Platelet Rich Plasma ◽  
Calvarial Defect ◽  
Proof Of Concept ◽  
Adult Sheep ◽  
The Future ◽  
Calvarial Defects

The aim of this study was to verify whether L-lactide/DL-lactide copolymer 80/20 (PLDLLA) and platelet-rich plasma (PRP) trigger bone formation within critical-sized calvarial defects in adult sheep (n=6). Two craniectomies, each ca. 3 cm in diameter, were created in each animal. The first craniectomy was protected with an inner polylactide membrane, filled with PRP-polylactide granules, and covered with outer polylactide membrane. The second control craniectomy was left untreated. The animals were euthanized at 6, 7, 17, 19, 33, and 34 weeks after surgery, and the quality and the rate of reossification were assessed histomorphometrically and microtomographically. The study demonstrated that application of implants made of PLDLLA 80/20 combined with an osteopromotive substance (e.g., PRP) may promote bone healing in large calvarial defect in sheep. These promising proof-of-concept studies need to be verified in the future on a larger cohort of animals and over a longer period of time in order to draw definitive conclusions.

scholarly journals Effects of collagen/β-tricalcium phosphate bone graft to regenerate bone in critically sized rabbit calvarial defects

2019 ◽  
Vol 17 (1) ◽  
pp. 228080001882049 ◽  
Author(s):  
Hamid Tebyanian ◽  
Mohammad Hadi Norahan ◽  
Hossein Eyni ◽  
Mansoureh Movahedin ◽  
SM Javad Mortazavi ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Bone Regeneration ◽  
Bone Repair ◽  
Bone Growth ◽  
Bone Defects ◽  
Histological Evaluation ◽  
Material Degradation ◽  
Alizarin Red ◽  
Calvarial Defects ◽  
Hematoxylin And Eosin

Bone defects remain a significant health issue and a major cause of morbidity in elderly patients. Composites based on collagen/calcium phosphate have been widely used for bone repair in clinical applications, owing to their comparability to bone extracellular matrix. This study aimed to evaluate the effects of a scaffold of collagen/calcium phosphate (COL/β-TCP) on bone formation to assess its potential use as a bone substitute to repair bone defects. Bilateral full-thickness critically sized calvarial defects (8 mm in diameter) were created in New Zealand white rabbits and treated with COL/β-TCP or COL scaffolds. One defect was also left unfilled as a control. Bone regeneration was assessed through histological evaluation using hematoxylin and eosin and Masson’s trichrome staining after 4 and 8 weeks. Alizarin Red staining was also utilized to observe the mineralization process. Our findings indicated that COL/β-TCP implantation could better enhance bone regeneration than COL and exhibited both new bone growth and scaffold material degradation.

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 Rhizoma Drynariae promotes the Osteogenic differentiation of Bone Mesenchymal Stem Cells by activating the Wnt/β-catenin Signaling Pathway

2021 ◽  
Author(s):  
Yi-Wei Shen ◽  
Yi Li ◽  
Zuo Li ◽  
Bing-you Yang ◽  
Xue Li
Keyword(s):  
Osteogenic Differentiation ◽  
Signaling Pathway ◽  
Biological Activities ◽  
Clinical Problem ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red ◽  
Age Related ◽  
Related Transcription Factor ◽  
Polymerase Chain ◽  
Rhizoma Drynariae

Abstract Background: Rhizoma Drynariae (RD), a traditional Chinese medicine with pleiotropic biological activities, exerts a protective effect against age-related osteoporosis. Osteoporosis is a serious clinical problem and characterized by the deterioration in bone volume and strength, mainly due to the dysfunction of bone marrow stromal cells (BMSCs). However, it remains unclear whether RD-containing serum regulates the osteogenic differentiation of BMSCs via Wnt/β-catenin signaling pathway. Methods: The effects of RD-containing serum on the osteogenesis of BMSCs were detected via quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), western blotting, alkaline phosphatase (ALP) activity assay and alizarin red staining. Using Dickkopf-related protein-1 (DKK1), an inhibitor of the Wnt/β-catenin signaling pathway, we examined whether RD-containing serum regulates osteoblast differentiation of BMSCs via the Wnt/b-catenin signalling pathway. Results: The results showed that RD-containing serum promoted the BMSC proliferation and ALP activities, as well as up-regulated the expression of osteogenic markers and Wnt/β-catenin pathway-related genes, i.e., runt-related transcription factor 2, Sp7, osteocalcin, β-catenin and Wnt3a, in BMSCs. Moreover, we found that RD-containing serum activated the Wnt/β-catenin pathway. Adding DKK1 to the RD-containing serum could decrease the promotion of osteogenic differentiation of RD-containing serum on BMSCs. Conclusions: Collectively, RD-containing serum could promote the osteogenic differentiation of BMSCs, and the potential mechanism may involve regulation of Wnt/β-catenin signaling.

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.

scholarly journals Evaluation of Open Hollow Hydroxyapatite Microsphere on Bone Regeneration in Rat Calvarial Defects

2019 ◽  
Author(s):  
Youqu Shen ◽  
Mohamed Rahaman ◽  
Yongxian Liu ◽  
Yue-Wern Huang
Keyword(s):  
Surface Roughness ◽  
Bone Formation ◽  
Bone Regeneration ◽  
Convex Surface ◽  
Total Surface Area ◽  
Calvarial Defect ◽  
New Bone Formation ◽  
Calvarial Defects ◽  
The Difference ◽  
Rat Calvarial Defect

AbstractHollow hydroxyapatite (HA) microspheres showed the ability to facilitate bone regeneration in rats with non-healing calvarial defects. However, new bone formation in the rat calvarial defect implanted with the closed HA microspheres was limited. The objective of this work is to evaluate size-, time, and structure-dependent bone regeneration between open and closed HA microspheres in an osseous model. Open HA microspheres were obtained by sectioning closed HA microspheres. The open HA microsphere had dense convex surface and rough and porous concave surface. For both size ranges (ϕ106-150 μm vs. ϕ212-250 μm), the open HA microsphere were more effective in facilitating bone regeneration than the closed HA microspheres in rat calvarial defects. Bone regeneration in the open HA microspheres (49 ± 7% for ϕ106-150 μm; 40 ± 8% for ϕ212-250 μm) were higher than the closed HA microsphere (26 ± 8% for ϕ106-150 μm; 30 ± 9% for ϕ212-250 μm) at 12 weeks. Furthermore, the open HA microspheres of smaller size showed a significant increase in bone regeneration than the open HA microspheres of larger size at both 6 weeks and 12 weeks. The difference in bone regeneration between these microspheres could be due to their differences in microstructures, namely curvature, concavity, porosity, surface roughness, and total surface area available for cells to attached to.

Targeting EZH2 Ameliorates the LPS-Inhibited PDLSC Osteogenesis via Wnt/β-Catenin Pathway

2021 ◽  
pp. 1-9
Author(s):  
Mosha Cheng ◽  
Qing Zhou
Keyword(s):  
Bone Morphogenetic Protein 2 ◽  
Periodontal Ligament Stem Cells ◽  
Alizarin Red ◽  
Protein Levels ◽  
Inflammatory Conditions ◽  
Morphogenetic Protein ◽  
Related Transcription Factor ◽  
Underlying Mechanisms ◽  
Factor Α ◽  
Osteoblast Maturation

As a histone methyltransferase, enhancer of zeste homolog 2 (EZH2), suppresses osteoblast maturation and is involved in inflammation. However, the role of EZH2 in human periodontal ligament stem cells (PDLSCs) under inflammation still needs to be further investigated. This study aimed to identify the underlying mechanisms and explore the function of EZH2 in PDLSC osteogenesis under inflammation. PDLSCs were treated with sh-EZH2, DZNep or DKK1 under inflammation. The alkaline phosphatase (ALP) activity, alizarin red staining, and osteogenesis-related protein levels were analyzed. Lipopolysaccharide (LPS)-induced inflammation restrained osteogenic differentiation. Under inflammation, the upregulation of EZH2 suppressed the expression of osteogenic markers, including osteocalcin, runt-related transcription factor 2, and bone morphogenetic protein-2, the activity of ALP, and the accumulation of mineralization through the Wnt/β-catenin pathway. EZH2 knockdown inhibited the levels of proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. These results suggested that LPS-induced overexpression of EZH2 suppressed PDLSC osteogenesis under inflammatory conditions through the Wnt/β-catenin pathway. These findings give new insights into the physiological differentiation and pathological inflammation of PDLSC osteogenesis, and provide an underlying therapeutic target for periodontitis.

scholarly journals Construction of hollow polydopamine nanoparticle based drug sustainable release system and its application in bone regeneration

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lu Wang ◽  
Shuwei Liu ◽  
Chunxia Ren ◽  
Siyuan Xiang ◽  
Daowei Li ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Bone Defect ◽  
Load Capacity ◽  
Good Prospect ◽  
Alizarin Red ◽  
Drug Load ◽  
Load Rate ◽  
Low Toxicity

AbstractNanomaterial-based drug sustainable release systems have been tentatively applied to bone regeneration. They, however, still face disadvantages of high toxicity, low biocompatibility, and low drug-load capacity. In view of the low toxicity and high biocompatibility of polymer nanomaterials and the excellent load capacity of hollow nanomaterials with high specific surface area, we evaluated the hollow polydopamine nanoparticles (HPDA NPs), in order to find an optimal system to effectively deliver the osteogenic drugs to improve treatment of bone defect. Data demonstrated that the HPDA NPs synthesized herein could efficiently load four types of osteogenic drugs and the drugs can effectively release from the HPDA NPs for a relatively longer time in vitro and in vivo with low toxicity and high biocompatibility. Results of qRT-PCR, ALP, and alizarin red S staining showed that drugs released from the HPDA NPs could promote osteogenic differentiation and proliferation of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. Image data from micro-CT and H&E staining showed that all four osteogenic drugs released from the HPDA NPs effectively promoted bone regeneration in the defect of tooth extraction fossa in vivo, especially tacrolimus. These results suggest that the HPDA NPs, the biodegradable hollow polymer nanoparticles with high drug load rate and sustainable release ability, have good prospect to treat the bone defect in future clinical practice.

scholarly journals Sinusoidal electromagnetic fields accelerate bone regeneration by boosting the multifunctionality of bone marrow mesenchymal stem cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weigang Li ◽  
Wenbin Liu ◽  
Wei Wang ◽  
Jiachen Wang ◽  
Tian Ma ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Bone Regeneration ◽  
Electromagnetic Fields ◽  
Bone Defects ◽  
Cell Scaffolds ◽  
Marrow Mesenchymal Stem Cells ◽  
Calvarial Defects

Abstract Background The repair of critical-sized bone defects is always a challenging problem. Electromagnetic fields (EMFs), used as a physiotherapy for bone defects, have been suspected to cause potential hazards to human health due to the long-term exposure. To optimize the application of EMF while avoiding its adverse effects, a combination of EMF and tissue engineering techniques is critical. Furthermore, a deeper understanding of the mechanism of action of EMF will lead to better applications in the future. Methods In this research, bone marrow mesenchymal stem cells (BMSCs) seeded on 3D-printed scaffolds were treated with sinusoidal EMFs in vitro. Then, 5.5 mm critical-sized calvarial defects were created in rats, and the cell scaffolds were implanted into the defects. In addition, the molecular and cellular mechanisms by which EMFs regulate BMSCs were explored with various approaches to gain deeper insight into the effects of EMFs. Results The cell scaffolds treated with EMF successfully accelerated the repair of critical-sized calvarial defects. Further studies revealed that EMF could not directly induce the differentiation of BMSCs but improved the sensitivity of BMSCs to BMP signals by upregulating the quantity of specific BMP (bone morphogenetic protein) receptors. Once these receptors receive BMP signals from the surrounding milieu, a cascade of reactions is initiated to promote osteogenic differentiation via the BMP/Smad signalling pathway. Moreover, the cytokines secreted by BMSCs treated with EMF can better facilitate angiogenesis and osteoimmunomodulation which play fundamental roles in bone regeneration. Conclusion In summary, EMF can promote the osteogenic potential of BMSCs and enhance the paracrine function of BMSCs to facilitate bone regeneration. These findings highlight the profound impact of EMF on tissue engineering and provide a new strategy for the clinical treatment of bone defects.

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