Paracrine Effects of Recombinant Human Adiponectin Promote Bone Regeneration

Bone regeneration is a delicate physiological process. Non-union and delayed fracture healing remains a great challenge in clinical practice nowadays. Bone and fat hold a close relationship to remain balanced through hormones and cytokines. Adiponectin is a well-known protein to maintain the hemostasis, which may be an interesting target for fracture healing. Herein, we provided a facile and efficient method to obtain high-purity and high-yield recombinant human adiponectin (ADPN). The biocompatibility and the pharmaceutical behaviors were evaluated in Sprague–Dawley rats. The paracrine effects of adiponectin on bone fracture healing were investigated with a rat tibia fracture model via intrabone injection. Significantly accelerated bone healing was observed in the medulla injection group, indicating the paracrine effects of adiponectin could be potentially utilized for clinical treatments. The underlying mechanism was primarily assessed, and the expression of osteogenic markers, including bone morphogenic protein 2, alkaline phosphatase, and osteocalcin, along with adiponectin receptor 1 (AdipoR1), was markedly increased at the fracture site. The increased bone healing of ADPN treatment may result from both enhanced osteogenic proliferation as well as differentiation. Cell experiments confirmed that the expression of osteogenesis markers increased significantly in ADPN treatment groups, while it decreased when the expression of AdipoR1 was knocked down by siRNA. Our study provided a feasible and efficacious way for bone fracture treatment with local administration of ADPN, which could be rapidly translated into the clinics.

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Wnt Pathway Inhibitor Delays Fracture Healing by Targeting Ephrin B1 (EFNB1) in Osteoprogenitor Cells

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2021.2813 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2427-2434

Author(s):

Zexue Zhao ◽

Pengfei Wu ◽

Jiwei Tian ◽

Yifan Yu

Keyword(s):

Endothelial Cells ◽

Fracture Healing ◽

Immunohistochemical Staining ◽

Underlying Mechanism ◽

Fracture Site ◽

Cartilage Tissue ◽

Control Group ◽

Sprague Dawley ◽

Osteoprogenitor Cells ◽

And Control

Our study assessed the role of Wnt signaling inhibitor (SM04690) in fracture healing and the underlying mechanism. Sprague Dawley (SD) rats were used to establish a fracture model which was then separated into SM04690 group which received SM04690 (50 mg/kg) by intraperitoneal injection once a day for one week, and control group which received saline once a day. After rats were sacrificed, the fractured femurs were harvested to measure femoral strength by stress testing, bone density and volume by CT. Femurs were sliced for immunohistochemical staining. Mesenchymal stem cells (MSCs), endothelial cells, osteoprogenitor cells and osteoblasts were detected by flow cytometer and EFNB1 expression was detected by immunoblotting and PCR. In addition, MSCs were treated with SM04690 (5 uM), followed by detection of EFNB1 expression. SM04690 treatment significantly inhibited EFNB1 expression and reduced bone volume and callus volume as well as decreased ultimate load of bones. Immunohistochemical staining and flow cytometry analysis showed no difference of osteoclast numbers at the fracture site between two groups, but proportion of osteoclasts in the cartilage tissue of SM04690 group was significantly decreased. In addition, the number of osteoblasts, osteoprogenitor cells and endothelial cells was significantly decreased after treatment. Under the conditions favoring osteogenic differentiation, the production of minerals by osteogenic cells was significantly decreased along with upregulated TAZ phosphorylation and downregulated Osterix in SM04690 group. In conclusion, SM04690 delays fracture healing by inhibiting EpRunB1 in osteoprogenitor cells.

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Dynamic protein corona influences immune-modulating osteogenesis in magnetic nanoparticle (MNP)-infiltrated bone regeneration scaffoldsin vivo

Nanoscale ◽

10.1039/c8nr08614a ◽

2019 ◽

Vol 11 (14) ◽

pp. 6817-6827 ◽

Cited By ~ 6

Author(s):

Yue Zhu ◽

Peipei Jiang ◽

Bin Luo ◽

Fang Lan ◽

Jing He ◽

...

Keyword(s):

Fracture Healing ◽

Bone Regeneration ◽

Inflammatory Reaction ◽

Magnetic Nanoparticle ◽

Protein Corona ◽

Underlying Mechanism

An inflammatory reaction initiates fracture healing and directly influences the osteoinductive effect of the magnetic hydroxyapatite (MHA) scaffold, but the underlying mechanism is yet to be elucidated.

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A novel MRI compatible mouse fracture model to characterize and monitor bone regeneration and tissue composition

Scientific Reports ◽

10.1038/s41598-020-73301-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Nina Schmitz ◽

Melanie Timmen ◽

Katharina Kostka ◽

Verena Hoerr ◽

Christian Schwarz ◽

...

Keyword(s):

Fracture Healing ◽

Bone Regeneration ◽

Cell Attachment ◽

Healing Process ◽

Living Organism ◽

Fracture Site ◽

Tissue Composition ◽

Metal Implants ◽

Callus Tissues

Abstract Over the last years, murine in vivo magnetic resonance imaging (MRI) contributed to a new understanding of tissue composition, regeneration and diseases. Due to artefacts generated by the currently used metal implants, MRI is limited in fracture healing research so far. In this study, we investigated a novel MRI-compatible, ceramic intramedullary fracture implant during bone regeneration in mice. Three-point-bending revealed a higher stiffness of the ceramic material compared to the metal implants. Electron microscopy displayed a rough surface of the ceramic implant that was comparable to standard metal devices and allowed cell attachment and growth of osteoblastic cells. MicroCT-imaging illustrated the development of the callus around the fracture site indicating a regular progressing healing process when using the novel implant. In MRI, different callus tissues and the implant could clearly be distinguished from each other without any artefacts. Monitoring fracture healing using MRI-compatible implants will improve our knowledge of callus tissue regeneration by 3D insights longitudinal in the same living organism, which might also help to reduce the consumption of animals for future fracture healing studies, significantly. Finally, this study may be translated into clinical application to improve our knowledge about human bone regeneration.

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Radiographic Long Bone Fracture Healing Scores: Can they predict non-union?

Injury ◽

10.1016/j.injury.2020.07.024 ◽

2020 ◽

Vol 51 (8) ◽

pp. 1693-1695

Author(s):

George D. Chloros ◽

Anthony Howard ◽

Vincenzo Giordano ◽

Peter V. Giannoudis

Keyword(s):

Fracture Healing ◽

Bone Fracture ◽

Long Bone ◽

Bone Fracture Healing ◽

Non Union ◽

Long Bone Fracture

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Analysis of low-dose estrogen on callus BMD as measured by pQCT in postmenopausal women

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03713-4 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

K. Jäckle ◽

J. P. Kolb ◽

A. F. Schilling ◽

C. Schlickewei ◽

M. Amling ◽

...

Keyword(s):

Bone Density ◽

Beneficial Effect ◽

Fracture Healing ◽

Postmenopausal Women ◽

Bone Healing ◽

Bone Fracture ◽

Low Dose ◽

Callus Formation ◽

Trial Registration ◽

Bone Fracture Healing

Abstract Background Osteoporosis affects elderly patients of both sexes. It is characterized by an increased fracture risk due to defective remodeling of the bone microarchitecture. It affects in particular postmenopausal women due to their decreased levels of estrogen. Preclinical studies with animals demonstrated that loss of estrogen had a negative effect on bone healing and that increasing the estrogen level led to a better bone healing. We asked whether increasing the estrogen level in menopausal patients has a beneficial effect on bone mineral density (BMD) during callus formation after a bone fracture. Methods To investigate whether estrogen has a beneficial effect on callus BMD of postmenopausal patients, we performed a prospective double-blinded randomized study with 76 patients suffering from distal radius fractures. A total of 31 patients (71.13 years ±11.99) were treated with estrogen and 45 patients (75.62 years ±10.47) served as untreated controls. Calculated bone density as well as cortical bone density were determined by peripheral quantitative computed tomography (pQCT) prior to and 6 weeks after the surgery. Comparative measurements were performed at the fractured site and at the corresponding position of the non-fractured arm. Results We found that unlike with preclinical models, bone fracture healing of human patients was not improved in response to estrogen treatment. Furthermore, we observed no dependence between age-dependent bone tissue loss and constant callus formation in the patients. Conclusions Transdermally applied estrogen to postmenopausal women, which results in estrogen levels similar to the systemic level of premenopausal women, has no significant beneficial effect on callus BMD as measured by pQCT, as recently shown in preclinical animal models. Trial registration Low dose estrogen has no significant effect on bone fracture healing measured by pQCT in postmenopausal women, DRKS00019858. Registered 25th November 2019 - Retrospectively registered. Trial registration number DRKS00019858.

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Knockdown of SERPINB2 enhances the osteogenic differentiation of human bone marrow mesenchymal stem cells via activation of the Wnt/β-catenin signalling pathway

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02581-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Kai Hang ◽

Li Ying ◽

Jinwu Bai ◽

Yibo Wang ◽

Zhihui Kuang ◽

...

Keyword(s):

Fracture Healing ◽

Osteogenic Differentiation ◽

Bone Fracture ◽

Osteoblast Differentiation ◽

Tibial Fracture ◽

Bone Fractures ◽

Bone Fracture Healing ◽

Non Union

Abstract Background Globally, bone fractures are the most common musculoskeletal trauma, and approximately 8–10% of cases that fall into the categories of delayed or non-union healing. To date, there are no efficient pharmacological agents to accelerate the healing of bone fractures. Thus, it is necessary to find new strategies that accelerate bone healing and reduce the incidence of non-union or delayed fracture healing. Previous studies have revealed that the plasminogen activation system has been demonstrated to play an important role in bone metabolism. However, the function of SERPINB2 in the osteogenesis of hBMSCs remains unclear. Therefore, in this study, we investigated the effects and mechanism of SERPINB2 on osteogenic differentiation. Methods We investigated the osteogenesis effects of hBMSCs by both exogenous SerpinB2 protein and SERPINB2 gene silencing in vitro. Cell proliferation assay was used to assess the effect of exogenous SerpinB2 or SERPINB2 silencing on proliferation of hBMSCs. qPCR and Western blotting analysis detected the expression of target genes and proteins respectively. ALP staining was used to evaluated ALP activity and Alizarin Red staining (ARS) was used to evaluate mineral deposition. In vivo, a murie tibial fracture model was established, histological evaluation and radiographic analysis was used to confirm the therapeutic effects of SERPINB2 silencing in fracture healing. Statistical significance between two groups was determined by Student’s t test, one-way ANOVA or Bonferroni’s post-hoc test according to the distribution of the tested population. Results The addition of exogenous SerpinB2 protein inhibted osteoblast differentiation of hBMSCs in vitro, while SERPINB2 gene silencing significant promote osteoblast differentiation of hBMSCs in vitro. And silenced SERPINB2 gene also increased mineral deposits. Moreover, β-catenin levels were up-regulated by SERPINB2 gene depletion. And the enhancement of osteogenic differentiation induced by SERPINB2 silencing was almost inhibited by specific Wnt/β-catenin signaling pathway inhibitor. In a murine tibial fracture model, local injection of SERPINB2 siRNA improved bone fracture healing. Conclusions Taken together, these findings indicate that SERPINB2 silencing promoted osteogenic differentiation of BMSCs via the Wnt/β-catenin signaling pathway, and silenced SERPINB2 in vivo effectively promotes fracture healing, suggesting that SERPINB2 may be a novel target for bone fracture healing.

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Management of impaired fracture healing: Historical aspects

Medicinski pregled ◽

10.2298/mpns0510507g ◽

2005 ◽

Vol 58 (9-10) ◽

pp. 507-512

Author(s):

Djordje Gajdobranski ◽

Ivan Micic ◽

Milorad Mitkovic ◽

Desimir Mladenovic ◽

Miroslav Milankov

Keyword(s):

Fracture Healing ◽

Bone Healing ◽

Bone Fracture ◽

Human Life ◽

Historical Review ◽

Treatment Modalities ◽

Bone Fracture Healing ◽

Ancient Medicine ◽

Adequate Treatment ◽

Orthopedic Surgeons

Introduction Establishing continuity of long bones in cases of impaired bone healing and pseudo-arthrosis is one of the most complex problems in orthopedics. Impaired bone healing The problem of impaired fracture healing is not new. As in other areas of human life, the roots of modern treatment of impaired bone healing lie in ancient medicine. A relatively high percentage of impaired bone healing, as well as unsatisfactory results of standard therapies of impaired bone healing and pseudoarthrosis demonstrate the actuality of this problem. This paper represents an attempt to pay respect to some of those who have dedicated their work to this problem in orthopedic surgery, and it is a historical review on impaired bone fracture healing. At the same time it should be an additional stimulus and challenge for orthopedic surgeons to further study impaired bone fracture healing, improve the existing and find new methods for their adequate treatment. Conclusion The authors are certain that the number of researchers throughout the world who have contributed to treatment modalities of impaired bone healing, is much higher, but not all are mentioned in this paper. However, it does not lessen their contributions to orthopedics.

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Influence of high-frequency cyclical stimulation on the bone fracture-healing process: mathematical and experimental models

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2011.0153 ◽

2011 ◽

Vol 369 (1954) ◽

pp. 4278-4294 ◽

Cited By ~ 16

Author(s):

María José Gómez-Benito ◽

Libardo Andrés González-Torres ◽

Esther Reina-Romo ◽

Jorge Grasa ◽

Belén Seral ◽

...

Keyword(s):

Fracture Healing ◽

Bone Healing ◽

Mechanical Stimulation ◽

Bone Fracture ◽

High Frequency ◽

Endochondral Ossification ◽

Healing Process ◽

Bone Fracture Healing ◽

Bone Healing Process ◽

Low Magnitude

Mechanical stimulation affects the evolution of healthy and fractured bone. However, the effect of applying cyclical mechanical stimuli on bone healing has not yet been fully clarified. The aim of the present study was to determine the influence of a high-frequency and low-magnitude cyclical displacement of the fractured fragments on the bone-healing process. This subject is studied experimentally and computationally for a sheep long bone. On the one hand, the mathematical computational study indicates that mechanical stimulation at high frequencies can stimulate and accelerate the process of chondrogenesis and endochondral ossification and consequently the bony union of the fracture. This is probably achieved by the interstitial fluid flow, which can move nutrients and waste from one place to another in the callus. This movement of fluid modifies the mechanical stimulus on the cells attached to the extracellular matrix. On the other hand, the experimental study was carried out using two sheep groups. In the first group, static fixators were implanted, while, in the second one, identical devices were used, but with an additional vibrator. This vibrator allowed a cyclic displacement with low magnitude and high frequency (LMHF) to be applied to the fractured zone every day; the frequency of stimulation was chosen from mechano-biological model predictions. Analysing the results obtained for the control and stimulated groups, we observed improvements in the bone-healing process in the stimulated group. Therefore, in this study, we show the potential of computer mechano-biological models to guide and define better mechanical conditions for experiments in order to improve bone fracture healing. In fact, both experimental and computational studies indicated improvements in the healing process in the LMHF mechanically stimulated fractures. In both studies, these improvements could be associated with the promotion of endochondral ossification and an increase in the rate of cell proliferation and tissue synthesis.

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BMP-2 delivered from a self-cross-linkable CaP/hydrogel construct promotes bone regeneration in a critical-size segmental defect model of non-union in dogs

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-14-03-0036 ◽

2014 ◽

Vol 27 (06) ◽

pp. 411-421 ◽

Cited By ~ 14

Author(s):

A. Touré ◽

M. Fusellier ◽

B. Fellah ◽

B. Bouvy ◽

P. Weiss ◽

...

Keyword(s):

Bone Regeneration ◽

Cancellous Bone ◽

Bone Healing ◽

Critical Size ◽

Bone Ingrowth ◽

Heterotopic Bone ◽

Segmental Defect ◽

Heterotopic Bone Formation ◽

Defect Model ◽

Non Union

SummaryObjectives: To determine whether the addition of recombinant human bone morphogenetic protein (rhBMP-2) to a self-crosslinkable cellulosic hydrogel/biphasic calcium phosphate (BCP) granules construct promotes bone healing in critical-size ulnar defects in dogs.Methods: A standardized 2 cm long ulnar ostectomy was performed bilaterally in five dogs to compare bone healing with hydrogel/BCP constructs associated with or without rhBMP-2. Cancellous-bone autografts were used as positive controls in unilateral ulnar defects in five additional dogs. Radiographically, bone healing was evaluated at four, eight, 12, 16 and 20 weeks postoperatively. Histological qualitative analysis with microCT imaging and light and scanning electron microscopy were performed 20 weeks after implantation.Results: All rhBMP-2-loaded constructs induced the formation of well-differentiated mineralized lamellar bone surrounding the BCP granules and bridging bone/implant interfaces as early as eight weeks after surgery. Bone regeneration appeared to develop earlier with the rhBMP-2 constructs than with the cancellous-bone autografts while similar results were obtained at 20 weeks. Constructs without any rhBMP-2 showed osteoconductive properties limited to the bone junctions and a lack of osteoinduction without bone ingrowth within the implantation site. In one dog, the leakage of the hydrogel loaded with rhBMP-2 induced an extensive heterotopic bone formation.Clinical significance: The addition of rhBMP-2 to a self-crosslinkable hydrogel/BCP construct could promote bone regeneration in a critical-size-defect model with similar performance to autologous bone grafts.

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Prospective study of managing long bone fracture nonunion: is bone graft needed in every case?

International Journal of Research in Orthopaedics ◽

10.18203/issn.2455-4510.intjresorthop20182035 ◽

2018 ◽

Vol 4 (4) ◽

pp. 556

Author(s):

Srinivas Balagani

Keyword(s):

Prospective Study ◽

Bone Graft ◽

Bone Fracture ◽

Fracture Site ◽

Long Bone ◽

Segmental Defect ◽

Long Bones ◽

Non Union ◽

Number Of Patients ◽

Long Bone Fracture

Background: Increased road traffic accidents lead to increased incidence of fracture of long bones. It has a tendency of non-union. Infection is very common in these cases which are an important cause of nonunion of long bone fractures. The objective of the study was to study the incidence and patterns of non-union of long bone fracture.Methods: Hospital based prospective study was carried out at Department of Orthopedics, from June 2017 to March 2018. Patients admitted to wards of Department of Orthopedics with nonunion of long bones were included. During the study period a total of 20 cases were eligible for the present study as per the inclusion and exclusion criteria.Results: Males were more affected than females. Most commonly affected age group was 41-50 years and 61-70 years (25% each). Most commonly affected long bone was femur in 35% of the cases. Most common type of non-union was hypertrophic (50%). Most common cause of non-union was broken implant in 35% of the cases. Maximum number of patients had union in 4-6 months in 60% of the cases after surgery of previous non-union of long bones. Only four patients developed complications like shortening of the limb or persistent non-union.Conclusions: Hypertrophic non unions doesn’t require bone graft, they require only stable fixation. For removal of broken implant in hypertrophic non-union if we open the fracture site, then even the gap after debridement of fracture site shows partial segmental defect it doesn’t require bone grafting.

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