Exosomes derived from human adipose-derived stem cells (hADSCs-Exos) have shown potential as an effectivetherapeutic tool for repairing bone defects. Although metal-organic framework (MOF) scaffolds are promisingstrat...Exosomes derived from human adipose-derived stem cells (hADSCs-Exos) have shown potential as an effectivetherapeutic tool for repairing bone defects. Although metal-organic framework (MOF) scaffolds are promisingstrategies for bone tissue regeneration, their potential use for exosome loading remains unexplored. In this study,motivated by the potential advantages of hADSCs-Exos and Mg-GA MOF, we designed and synthesized anexosome-functionalized cell-free PLGA/Mg-GA MOF (PLGA/Exo-Mg-GA MOF) scaffold, taking using of thebenefits of hADSCs-Exos, Mg2+, and gallic acid (GA) to construct unique nanostructural interfaces to enhanceosteogenic, angiogenic and anti-inflammatory capabilities simultaneously. Our in vitro work demonstrated thebeneficial effects of PLGA/Exo-Mg-GA MOF composite scaffolds on the osteogenic effects in human bonemarrow-derived mesenchymal stem cells (hBMSCs) and angiogenic effects in human umbilical endothelial cells(HUVECs). Slowly released hADSCs-Exos from composite scaffolds were phagocytosed by co-cultured cells,stabilized the bone graft environment, ensured blood supply, promoted osteogenic differentiation, and acceleratedbone reconstruction. Furthermore, our in vivo experiments with rat calvarial defect model showed thatPLGA/Exo-Mg-GA MOF scaffolds promoted new bone formation and satisfactory osseointegration. Overall, weprovide valuable new insights for designing exosome-coated nanocomposite scaffolds with enhanced osteogenesisproperty.展开更多
Calvarial bones are connected by fibrous sutures. These sutures provide a niche environment that includes mesenchymal stem cells(MSCs), osteoblasts, and osteoclasts, which help maintain calvarial bone homeostasis and ...Calvarial bones are connected by fibrous sutures. These sutures provide a niche environment that includes mesenchymal stem cells(MSCs), osteoblasts, and osteoclasts, which help maintain calvarial bone homeostasis and repair. Abnormal function of osteogenic cells or diminished MSCs within the cranial suture can lead to skull defects, such as craniosynostosis. Despite the important function of each of these cell types within the cranial suture, we have limited knowledge about the role that crosstalk between them may play in regulating calvarial bone homeostasis and injury repair. Here we show that suture MSCs give rise to osteoprogenitors that show active bone morphogenetic protein(BMP) signalling and depend on BMP-mediated Indian hedgehog(IHH) signalling to balance osteogenesis and osteoclastogenesis activity. IHH signalling and receptor activator of nuclear factor kappa-Β ligand(RANKL) may function synergistically to promote the differentiation and resorption activity of osteoclasts. Loss of Bmpr1a in MSCs leads to downregulation of hedgehog(Hh) signalling and diminished cranial sutures. Significantly, activation of Hh signalling partially restores suture morphology in Bmpr1a mutant mice, suggesting the functional importance of BMP-mediated Hh signalling in regulating suture tissue homeostasis. Furthermore, there is an increased number of CD200+ cells in Bmpr1a mutant mice, which may also contribute to the inhibited osteoclast activity in the sutures of mutant mice. Finally, suture MSCs require BMPmediated Hh signalling during the repair of calvarial bone defects after injury. Collectively, our studies reveal the molecular and cellular mechanisms governing cell–cell interactions within the cranial suture that regulate calvarial bone homeostasis and repair.展开更多
Background:Bone microarchitecture is affected by multiple genes,each having a small effect on the external appearance.It is thus challenging to characterize the genes and their specific effect on bone thickness and po...Background:Bone microarchitecture is affected by multiple genes,each having a small effect on the external appearance.It is thus challenging to characterize the genes and their specific effect on bone thickness and porosity.The purpose of this study was to assess the heritability and the genetic variation effect,as well as the sex effect on the calvarial bone thickness(Ca.Th)and calvarial porosity(%PoV)using the Collaborative Cross(CC)mouse population.Methods:In the study we examined the parietal bones of 56 mice from 9 lines of CC mice.Morphometric parameters were evaluated using microcomputed tomography(μCT)and included Ca.Th and%PoV.We then evaluated heritability,genetic versus environmental variance and the sex effect for these parameters.Results:Our morphometric analysis showed that Ca.Th and%PoV are both significantly different among the CC lines with a broad sense heritability of 0.78 and 0.90,respectively.The sex effect within the lines was significant in line IL111 and showed higher values of Ca.Th and%PoV in females compared to males.In line IL19 there was a borderline sex effect in Ca.Th in which males showed higher values than females.Conclusions:These results stress the complexity of sex and genotype interactions controlling Ca.Th and%PoV,as the skeletal sexual dimorphism was dependent on the genetic background.This study also shows that the CC population is a powerful tool for establishing the genetic effect on these traits.展开更多
Background: Skull vault lesions are rare and represent 1% - 2% of all bone masses. Most cerebral metastases are the intra axial tumors, whereas extra-axial masses mimicking meningioma are extremely rare. Case presenta...Background: Skull vault lesions are rare and represent 1% - 2% of all bone masses. Most cerebral metastases are the intra axial tumors, whereas extra-axial masses mimicking meningioma are extremely rare. Case presentation: A 35-year-old woman with a history of mastectomy left breast cancer 5 years below radiotherapy was referred to the neurosurgery department with a parietal extra-axial mass parietal evolving for one year. CT scan with Magnetic resonance imaging revealed an extra-axial tumor with lysis bone. A craniotomy was performed to remove the mass that was located extra-axial. Histopathological examination revealed metastasis. Conclusions: Lesion skull vaults are rare but they should be considered in the differential diagnosis of intraosseous meningioma lesions. In this report, we discuss the clinical aspects of cases we observed, in which the metastasis bone was found thanks to the histological examination of a calvarial mass after surgery.展开更多
Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone...Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone wound healing. The findings of recent studies suggest that the use of selective serotonin reuptake inhibitors(SSRIs) can reduce bone mass, precipitate osteoporotic fractures and increase the rate of dental implant failure. With 10% of Americans prescribed antidepressants, the potential of SSRIs to impair bone healing may adversely affect millions of patients’ ability to heal after sustaining trauma. Here, we investigate the effect of the SSRI sertraline on bone healing through pre-treatment with(10 mg·kg-1sertraline in drinking water, n = 26) or without(control, n = 30) SSRI followed by the creation of a 5-mm calvarial defect. Animals were randomized into three surgical groups:(a) empty/sham,(b) implanted with a DermaMatrix scaffold soak-loaded with sterile PBS or(c) DermaMatrix soak-loaded with542.5 ng BMP2. SSRI exposure continued until sacrifice in the exposed groups at 4 weeks after surgery. Sertraline exposure resulted in decreased bone healing with significant decreases in trabecular thickness, trabecular number and osteoclast dysfunction while significantly increasing mature collagen fiber formation. These findings indicate that sertraline exposure can impair bone wound healing through disruption of bone repair and regeneration while promoting or defaulting to scar formation within the defect site.展开更多
The potential of combining bioactive glass（MBG） and silk fibroin（SF） together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method...The potential of combining bioactive glass（MBG） and silk fibroin（SF） together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.展开更多
Covalent binding between bioactive substances and materials in different ways can significantly improve the bone inductivity and biological activity of bone repair materials.However,there is a lack of systematic under...Covalent binding between bioactive substances and materials in different ways can significantly improve the bone inductivity and biological activity of bone repair materials.However,there is a lack of systematic understanding of how these binding modes affect biological activities of the active substances.In this study,four kinds of functionalized Multi-walled carbon nanotubes(MWCNTs)were prepared,ensuring the same grafting rate of different functional groups.Subsequently,two kinds of osteogenic-related peptides,bone morphogenetic protein-2 mimicking peptides and osteogenic growth mimicking peptides,were covalently bound to functionalized MWCNTs,ensuring the same molar mass of peptides bound to different functionalized MWCNTs in this process.Then the same amount of functionalized MWC-NTs/Peptides composites were introduced into the scaffolds,and through the ectopic osteogenesis model in rats and calvarial defect model in rabbits,ectopic osteogenesis and bone repair ability of the composites were analyzed.Furthermore,the effects of different covalent binding modes on peptide-induced osteogenesis and bone repair were studied.The results showed that the negative influencing trend of different covalent binding modes of osteogenic-related peptides with artificial carriers on their biological activities was in the order as follows:amide binding(carboxyl)>silane coupling>dopamine bind-ing>amide binding(amino),whose mechanism might be mainly that the covalent binding of peptides with different functional groups resulted in different charges.We believe that the results of this study have important guiding significance for the research and development of bone repair materials covalently bound with bioactive substances.展开更多
BACKGROUND Clopidogrel is a widely prescribed drug for prevention of myocardial infarction and stroke in patients at risk.It inhibits thrombus formation via inhibition of the P2Y12 purinergic receptor on platelets,whi...BACKGROUND Clopidogrel is a widely prescribed drug for prevention of myocardial infarction and stroke in patients at risk.It inhibits thrombus formation via inhibition of the P2Y12 purinergic receptor on platelets,which is important in their activation by ADP.However,the P2Y12 receptor has also been found to be expressed in both osteoblasts and osteoclasts.Accumulated evidence suggests that purinergic receptors regulate important functions of bone turnover.Previous studies on the effect of clopidogrel on bone metabolism indicated potential harmful effects,but their results remain conflicting.Thus,clopidogrel treatment may affect bone healing,but it has not yet been studied.AIM To evaluate if continuous perioperative clopidogrel treatment has any negative effect on bone healing in the rabbit calvarial defect model.METHODS Sixteen male white New Zealand rabbits were randomly assigned in two groups:One group received daily 3 mg/kg of clopidogrel per os and the other group received the vehicle alone for a week prior to the surgical procedures;the treatments were continued for another 6 wk postoperatively.The surgical procedures included generation of two circular calvarial defects 11 mm in diameter in every animal.After the 6-wk period of healing,postmortem radiographic and histomorphometric evaluation of the defects was performed.RESULTS Both the surgical procedures and the postoperative period were uneventful and well tolerated by all the animals,without any surgical wound dehiscence,signs of infection or other complication.New bone was formed either inwards from the defect margins or in the central portion of the defect as separated bony islets.While defect healing was still incomplete in both groups,the clopidogrel group had significantly improved radiographic healing scores.Moreover,the histomorphometric analysis showed that bone regeneration(%)was 28.07±7.7 for the clopidogrel group and 19.47±4.9 for the control group,showing a statistically significant difference between them(P=0.018).Statistically significa展开更多
Chitosan nanofiber membranes have been known to have a high degree of biocompatibility and support new bone formation with controllable biodegradation. The surface area of these membranes may allow them to serve as lo...Chitosan nanofiber membranes have been known to have a high degree of biocompatibility and support new bone formation with controllable biodegradation. The surface area of these membranes may allow them to serve as local delivery carriers for different biologic mediators. Simvastatin, a drug commonly used for lowering cholesterol, has demonstrated promising bone regenerative capability. The aim of this study was to evaluate simvastatin loaded chitosan nanofiber membranes for guided bone regeneration (GBR) applications and their ability to enhance bone formation in rat calvarial defects. Nanofibrous chitosan membranes with random fiber orientation were fabricated by electrospinning technique and loaded with 0.25 mg of simvastatin under sterile conditions. One membrane was implanted subperiosteally to cover an 8 mm diameter critical size calvarial defect. Two groups: 1) Control: non-loaded chitosan membranes;2) Experimental: chitosan membranes loaded with 0.25 mg of simvastatin were evaluated histologically and via micro-computed tomography (micro-CT) for bone formation at 4 and 8 weeks time points (n = 5/group per time point). Both groups exhibited good biocompatibility with only mild or moderate inflammatory response during the healing process. Histologic and micro-CT evaluations confirmed bone formation in calvarial defects as early as 4 weeks using control and experimental membranes. In addition, newly-formed bony bridges consolidating calvarial defects histologically along with partial radiographic defect coverage were observed at 8 weeks in both groups. Although control and experimental groups demonstrated no significant statistical differences in results of bone formation, biodegradable chitosan nanofiber membranes loaded with simvastatin showed a promising regenerative potential as a barrier material for guided bone regeneration applications.展开更多
Tobacco mosaic virus(TMV)has been studied as a multi-functional agent for bone tissue engineering.An osteo-inductive effect of wild-type TMV has been reported,as it can significantly enhance the bone differentiation p...Tobacco mosaic virus(TMV)has been studied as a multi-functional agent for bone tissue engineering.An osteo-inductive effect of wild-type TMV has been reported,as it can significantly enhance the bone differentiation potential of bone marrow stromal cells both on a two-dimensional substrate and in a three-dimensional(3D)hydrogel system.A TMV mutant(TMV-RGD1)was created which featured the adhesion peptide arginyl-glycyl-aspartic acid(RGD),the most common peptide motif responsible for cell adhesion to the extracellular matrix,on the surface of the virus particle to enhance the bio-functionality of the scaffold material.We hypothesised that the incorporation of either wild-type TMV or TMV-RGD1 in the 3D hydrogel scaffold would induce bone healing in critical size defects of the cranial segmental bone.We have previously tested the virus-functionalised scaffolds,in vitro,with a hyaluronic acid-based system as an in-situ hydrogel platform for 3D cell encapsulation,culture,and differentiation.The results of these experiments suggested the potential of the virus-functionalised hydrogel to promote in vitro stem cell differentiation.The hydrogel-forming system we employed was shown to be safe and biocompatible in vivo.Here,we further explored the physiological responses regarding bone regeneration of a calvarial defect in both normal and osteoporotic ovariectomized rat models.Our results,based on histological analysis in both animal models,suggested that both wild-type TMV and TMV-RGD1 functionalised hydrogels could accelerate bone regeneration,without systemic toxicity,evaluated by blood counts.New bone formation was intensified by the incorporation of the RGD-mutant viral particles.This finding increased the potential for use of the rodshaped plant virus as a platform for the addition of powerful biofunctionality for tissue engineering applications.This study was approved by the Ethics Committee on Animal Use of the Zhenjiang Affiliated First People’s Hospital affiliated to Jiangsu University.展开更多
β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen a...β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen as a main object. Northern blot analysis revealed up to two-fold increase in the steady statelevel of ALP mRNA after stimulation of rat osteoblast with 10 mM β-GP- Likewise, 10 mM β-GP induced a 10─30 % increase in ALP activity (P< 0. 01) of early passages (1 to 4), but not of later passages (5 to 6). The β-GP induced increase in ALP activity was totally inhibited by the protein synthesis inhibitor, cycloheximide (50 μM).β- GP stimulation was found to be without effect on cell proliferation measured as 3H-thymidine incorporation. It is concluded that β-GP has no effect on proliferation but induces an increase in both mRNA level and activity of ALP in the non-mineralization phase of cultures of fetal rat calvarial cells , which lasts for several passages but will disappear in older cultures.展开更多
Human stromal stem cells derived from endometrium (hESCs) are a type of multipotent stromal cells of the proven ability to differentiate into osteogenic lineage. Thus, it was suggested that these cells may be used to ...Human stromal stem cells derived from endometrium (hESCs) are a type of multipotent stromal cells of the proven ability to differentiate into osteogenic lineage. Thus, it was suggested that these cells may be used to repair skeletal defects. In this study, Human ESCs were extracted from female endometrium and harvested. Biomimetic gelatin/apatite (Gel/Ap) scaffolds with and without harvested cells were implanted in a Critical size calvarial defects in the cranial bone of adult male rat. To CT-Scan and Histological studies were performed to investigate the level of bone formation after 8 weeks of surgery. Results confirmed that the treated defects with the bare and hESCs grafted Gel/Ap scaffold showed significant bone formation and maturation in comparison with the control group.展开更多
Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- con...Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- continuity defect was produced approximately mid-way along left radius of young female rabbits using ro- tary diamond disc under continuous saline irrigation and stabilised with autoclaved steel miniplate and screws. The defect was then fitted with sterile bioresorbable coral implant loaded with homologous neonatal calvarial osteoblasts or control implants without osteoblasts. All animals underwent radiography immedi- ately post-operative, at weekly intervals for four weeks and at fortnightly intervals thereafter. Operated bones were histologically evaluated for osteogenesis at 12 weeks. Results: Findings demonstrate osteogenesis and complete repair of bioresorbable coral implant by homologous osteoblasts loaded on coral scaffold. Conclu- sions: Single stage surgery using this technique to induce osteogenesis and closure of discontinuity bone de- fects including palatal clefts and peripheral reduction of large craniofacial defects might prove better thera- peutic modality than autologous bone grafting or tissue distraction osteogenesis.展开更多
The regulation of cellular differentiation by progesterone in fetal rat calvarial osteoblasts was investigated. Our results showed that cells cultured in the presence of progesterone had a 7% increase in the alkaline ...The regulation of cellular differentiation by progesterone in fetal rat calvarial osteoblasts was investigated. Our results showed that cells cultured in the presence of progesterone had a 7% increase in the alkaline phosphatase activity when compared to untreated cells. The concentration of osteocalcin in the conditioned medium from progesterone treated osteoblasts was 28% higher than that of untreated controls. In addition,administration of progesterone significantly enhanced the number and area of bone nodules. In conclusion, progesterone stimulates the differentiation of fetal rat calvarial osteoblastic cells in vitro展开更多
Background:Neuronavigation is a very beneficial tool in modern neurosurgical practice.However,the neuronavigation is not available in most of the hospitals in our country raising the question about its importance in l...Background:Neuronavigation is a very beneficial tool in modern neurosurgical practice.However,the neuronavigation is not available in most of the hospitals in our country raising the question about its importance in localizing the calvarial extra-axial lesions and to what extent it is safe to operate without it.Methods:We studied twenty patients with calvarial extra-axial lesions who underwent surgical interventions.All lesions were preoperatively located with both neuronavigation and the usual linear measurements.Both methods were compared regarding the time consumed to localize the tumor and the accuracy of each method to anticipate the actual center of the tumor.Results:The mean error of distance between the planned center of the tumor and the actual was 6.50±1.762 mm in conventional method,whereas the error was 3.85±1.309 mm in IGS method.Much more time was consumed during the neuronavigation method including booting,registration,and positioning.A statistically significant difference was found between the mean time passed in the conventional method and IGS method(2.05±0.826,24.90±1.334,respectively),P-value<0.001.Conclusion:In the setting of limited resources,the linear measurement localization method seems to have an accepted accuracy in the localization of calvarial extra-axial lesions and it saves more time than neuronavigation method.展开更多
Critical-sized craniofacial defect repair represents a significant challenge to reconstructive surgeons.Many strategies have been employed in an effort to achieve both a functionally and cosmetically acceptable outcom...Critical-sized craniofacial defect repair represents a significant challenge to reconstructive surgeons.Many strategies have been employed in an effort to achieve both a functionally and cosmetically acceptable outcome.Bone morphogenetic proteins(BMPs)provide a robust osteoinductive cue to stimulate bony growth and remodeling.Previous studies have suggested that the BMP-9 isoform is particularly effective in promoting osteogenic differentiation of mesenchymal progenitor cells.The aim of this study is to characterize the osteogenic capacity of BMP-9 on calvarial mesenchymal progenitor cell differentiation.Reversibly immortalized murine calvarial progenitor cells(iCALs)were infected with adenoviral vectors encoding BMP-9 or GFP and assessed for early and late stages of osteogenic differentiation in vitro and for osteogenic differentiation via in vivo stem cell implantation studies.Significant elevations in alkaline phosphatase(ALP)activity,osteocalcin(OCN)mRNA transcription,osteopontin(OPN)protein expression,and matrix mineralization were detected in BMP-treated cells compared to control.Specifically,ALP activity was elevated on days 3,7,9,11,and 13 post-infection and OCN mRNA expression was elevated on days 8,10,and 14 in treated cells.Additionally,treatment groups demonstrated increased OPN protein expression on day 10 and matrix mineralization on day 14 post-infection relative to control groups.BMP-9 also facilitated the formation of new bone in vivo as detailed by gross,microcomputed tomography,and histological analyses.Therefore,we concluded that BMP-9 significantly stimulates osteogenic differentiation in iCALs,and should be considered an effective agent for calvarial tissue regeneration.展开更多
Neurofibromatosis type 1(NF1)is an autosomal dominant disorder in which the nerve tissue grows tumors that may be benign and may cause serious damage by compressing nerves and other tissues.The NF1 gene
A 45-year-old male was autopsied. He had fallen backwards from a two-stairs height to the ground and passed away. A skull fracture was detected in the left occipital area, extending up to the left side of the skul! ba...A 45-year-old male was autopsied. He had fallen backwards from a two-stairs height to the ground and passed away. A skull fracture was detected in the left occipital area, extending up to the left side of the skul! base. The patient＇s death occurred due to the very low thickness of the calvarial bones, which led to the aforementioned fracture, and in turn resulted in subarachnoid hemorrhage and death. The cortical thickness was measured and compared with average values at standardized points. Uniform bone thinning was confirmed rather than localized. Calvarial thinning may result from various conditions. In the present case study, however, the exact mechanism which led to the low thickness of the calvarial bones of the patient is undetermined. Death due to the susceptible structure and fracture of calvarial bones has rarely been reported throughout relevant literature.展开更多
The development of injectable bone substitutes(IBS)have obtained great importance in the bone re-generation field,as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to...The development of injectable bone substitutes(IBS)have obtained great importance in the bone re-generation field,as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to irregular topographies.In this scenario,the association of injectable hydrogels and bone graft granules is emerging as a well-established trend.Particularly,in situ forming hydrogels have arisen as a new IBS generation.An in situ forming and injectable dextrin-based hydrogel(HG)was developed,aiming to act as a carrier of granular bone substitutes and bioactive agents.In this work,the HG was associated to a granular bone substitute(Bonelike)and implanted in goat critical-sized calvarial defects(14mm)for 3,6 and 12weeks.The results showed that HG improved the han-dling properties of the Bonelike granules and did not affect its osteoconductive features,neither impairing the bone regener ation process.Human multipotent mesenchymal stromal cells from the umbilical cord,extracellular matrix hydrolysates and the pro-angiogenic peptide LLKKK18 were also combined with the IBS.These bioactive agents did not enhance the new bone formation significantly under the conditions tested,according to micro-computed tomography and histological analysis.展开更多
基金Natural science Foundation of Liaoning Province,China,grant number of 2020-ZLLH-40.
文摘Exosomes derived from human adipose-derived stem cells (hADSCs-Exos) have shown potential as an effectivetherapeutic tool for repairing bone defects. Although metal-organic framework (MOF) scaffolds are promisingstrategies for bone tissue regeneration, their potential use for exosome loading remains unexplored. In this study,motivated by the potential advantages of hADSCs-Exos and Mg-GA MOF, we designed and synthesized anexosome-functionalized cell-free PLGA/Mg-GA MOF (PLGA/Exo-Mg-GA MOF) scaffold, taking using of thebenefits of hADSCs-Exos, Mg2+, and gallic acid (GA) to construct unique nanostructural interfaces to enhanceosteogenic, angiogenic and anti-inflammatory capabilities simultaneously. Our in vitro work demonstrated thebeneficial effects of PLGA/Exo-Mg-GA MOF composite scaffolds on the osteogenic effects in human bonemarrow-derived mesenchymal stem cells (hBMSCs) and angiogenic effects in human umbilical endothelial cells(HUVECs). Slowly released hADSCs-Exos from composite scaffolds were phagocytosed by co-cultured cells,stabilized the bone graft environment, ensured blood supply, promoted osteogenic differentiation, and acceleratedbone reconstruction. Furthermore, our in vivo experiments with rat calvarial defect model showed thatPLGA/Exo-Mg-GA MOF scaffolds promoted new bone formation and satisfactory osseointegration. Overall, weprovide valuable new insights for designing exosome-coated nanocomposite scaffolds with enhanced osteogenesisproperty.
基金supported by grants from the National Institute of Dental and Craniofacial Research, NIH (supported by R01 DE026339)
文摘Calvarial bones are connected by fibrous sutures. These sutures provide a niche environment that includes mesenchymal stem cells(MSCs), osteoblasts, and osteoclasts, which help maintain calvarial bone homeostasis and repair. Abnormal function of osteogenic cells or diminished MSCs within the cranial suture can lead to skull defects, such as craniosynostosis. Despite the important function of each of these cell types within the cranial suture, we have limited knowledge about the role that crosstalk between them may play in regulating calvarial bone homeostasis and injury repair. Here we show that suture MSCs give rise to osteoprogenitors that show active bone morphogenetic protein(BMP) signalling and depend on BMP-mediated Indian hedgehog(IHH) signalling to balance osteogenesis and osteoclastogenesis activity. IHH signalling and receptor activator of nuclear factor kappa-Β ligand(RANKL) may function synergistically to promote the differentiation and resorption activity of osteoclasts. Loss of Bmpr1a in MSCs leads to downregulation of hedgehog(Hh) signalling and diminished cranial sutures. Significantly, activation of Hh signalling partially restores suture morphology in Bmpr1a mutant mice, suggesting the functional importance of BMP-mediated Hh signalling in regulating suture tissue homeostasis. Furthermore, there is an increased number of CD200+ cells in Bmpr1a mutant mice, which may also contribute to the inhibited osteoclast activity in the sutures of mutant mice. Finally, suture MSCs require BMPmediated Hh signalling during the repair of calvarial bone defects after injury. Collectively, our studies reveal the molecular and cellular mechanisms governing cell–cell interactions within the cranial suture that regulate calvarial bone homeostasis and repair.
文摘Background:Bone microarchitecture is affected by multiple genes,each having a small effect on the external appearance.It is thus challenging to characterize the genes and their specific effect on bone thickness and porosity.The purpose of this study was to assess the heritability and the genetic variation effect,as well as the sex effect on the calvarial bone thickness(Ca.Th)and calvarial porosity(%PoV)using the Collaborative Cross(CC)mouse population.Methods:In the study we examined the parietal bones of 56 mice from 9 lines of CC mice.Morphometric parameters were evaluated using microcomputed tomography(μCT)and included Ca.Th and%PoV.We then evaluated heritability,genetic versus environmental variance and the sex effect for these parameters.Results:Our morphometric analysis showed that Ca.Th and%PoV are both significantly different among the CC lines with a broad sense heritability of 0.78 and 0.90,respectively.The sex effect within the lines was significant in line IL111 and showed higher values of Ca.Th and%PoV in females compared to males.In line IL19 there was a borderline sex effect in Ca.Th in which males showed higher values than females.Conclusions:These results stress the complexity of sex and genotype interactions controlling Ca.Th and%PoV,as the skeletal sexual dimorphism was dependent on the genetic background.This study also shows that the CC population is a powerful tool for establishing the genetic effect on these traits.
文摘Background: Skull vault lesions are rare and represent 1% - 2% of all bone masses. Most cerebral metastases are the intra axial tumors, whereas extra-axial masses mimicking meningioma are extremely rare. Case presentation: A 35-year-old woman with a history of mastectomy left breast cancer 5 years below radiotherapy was referred to the neurosurgery department with a parietal extra-axial mass parietal evolving for one year. CT scan with Magnetic resonance imaging revealed an extra-axial tumor with lysis bone. A craniotomy was performed to remove the mass that was located extra-axial. Histopathological examination revealed metastasis. Conclusions: Lesion skull vaults are rare but they should be considered in the differential diagnosis of intraosseous meningioma lesions. In this report, we discuss the clinical aspects of cases we observed, in which the metastasis bone was found thanks to the histological examination of a calvarial mass after surgery.
基金supported by a grant from the Musculoskeletal Transplant Foundation (JC)the National Institute of Health, the National Institute of Aging [NIH-NIA PO1-AG036675] (ME, WDH)+4 种基金in part by the Department of Veterans Affairs (VA Merit Award BX000333, ACL 1I01CX000930-01, WDH)funded through a training grant from the National Institutes of Health National Institute of Dental and Craniofacial Research [5T32DE017551]S.H. is funded through a fellowship from the National Institutes of Health National Institute of Dental and Craniofacial Research [5F32DE02471202]supported by the National Institutes of Health National Institute of General Medicine [P30GM103331]
文摘Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone wound healing. The findings of recent studies suggest that the use of selective serotonin reuptake inhibitors(SSRIs) can reduce bone mass, precipitate osteoporotic fractures and increase the rate of dental implant failure. With 10% of Americans prescribed antidepressants, the potential of SSRIs to impair bone healing may adversely affect millions of patients’ ability to heal after sustaining trauma. Here, we investigate the effect of the SSRI sertraline on bone healing through pre-treatment with(10 mg·kg-1sertraline in drinking water, n = 26) or without(control, n = 30) SSRI followed by the creation of a 5-mm calvarial defect. Animals were randomized into three surgical groups:(a) empty/sham,(b) implanted with a DermaMatrix scaffold soak-loaded with sterile PBS or(c) DermaMatrix soak-loaded with542.5 ng BMP2. SSRI exposure continued until sacrifice in the exposed groups at 4 weeks after surgery. Sertraline exposure resulted in decreased bone healing with significant decreases in trabecular thickness, trabecular number and osteoclast dysfunction while significantly increasing mature collagen fiber formation. These findings indicate that sertraline exposure can impair bone wound healing through disruption of bone repair and regeneration while promoting or defaulting to scar formation within the defect site.
基金Funded by the National Natural Science Foundation of China(No.81170992)
文摘The potential of combining bioactive glass（MBG） and silk fibroin（SF） together as a new drug delivery system was evaluated. The three-dimensional porous scaffolds were selected as the form of SF, and sol-gel method was adopted to fabricate MBG in this study. The characteristic of the synthesized material was measured by transmission electron microscopy and scanning electron microscopy. In vitro evaluation of drug delivery was carried out in terms of drug loading and drug release. And aspirin was chosen as the drug for scaffolds to carry out in vitro tests and repair BALB/C mice calvarial defects. Bone formation was examined by microcomputed tomography. The experimental results show that MBG/silk scaffolds have better physiochemical properties compared with silk scaffolds. In comparison to pure silk scaffolds, MBG/silk scaffolds enhance the drug loading efficiency, release rate in vitro and promote bone regeneration in vivo. Thus we conclude that MBG/silk scaffold is a more efficient drug delivery system than pure silk scaffolds.
基金support from the National Natural Science Foundation of China(Nos.32171345 and 31771042)the Hebei Provincial Natural Science Foundation of China(No.C2022104003)+2 种基金the Fok Ying Tung Education Foundation(No.141039)the Fund of Key Laboratory of Advanced Materials of Ministry of Educationthe International Joint Research Center of Aerospace Biotechnology and Medical Engineering,Ministry of Science and Technology of China,and the 111 Project(No.B13003).
文摘Covalent binding between bioactive substances and materials in different ways can significantly improve the bone inductivity and biological activity of bone repair materials.However,there is a lack of systematic understanding of how these binding modes affect biological activities of the active substances.In this study,four kinds of functionalized Multi-walled carbon nanotubes(MWCNTs)were prepared,ensuring the same grafting rate of different functional groups.Subsequently,two kinds of osteogenic-related peptides,bone morphogenetic protein-2 mimicking peptides and osteogenic growth mimicking peptides,were covalently bound to functionalized MWCNTs,ensuring the same molar mass of peptides bound to different functionalized MWCNTs in this process.Then the same amount of functionalized MWC-NTs/Peptides composites were introduced into the scaffolds,and through the ectopic osteogenesis model in rats and calvarial defect model in rabbits,ectopic osteogenesis and bone repair ability of the composites were analyzed.Furthermore,the effects of different covalent binding modes on peptide-induced osteogenesis and bone repair were studied.The results showed that the negative influencing trend of different covalent binding modes of osteogenic-related peptides with artificial carriers on their biological activities was in the order as follows:amide binding(carboxyl)>silane coupling>dopamine bind-ing>amide binding(amino),whose mechanism might be mainly that the covalent binding of peptides with different functional groups resulted in different charges.We believe that the results of this study have important guiding significance for the research and development of bone repair materials covalently bound with bioactive substances.
文摘BACKGROUND Clopidogrel is a widely prescribed drug for prevention of myocardial infarction and stroke in patients at risk.It inhibits thrombus formation via inhibition of the P2Y12 purinergic receptor on platelets,which is important in their activation by ADP.However,the P2Y12 receptor has also been found to be expressed in both osteoblasts and osteoclasts.Accumulated evidence suggests that purinergic receptors regulate important functions of bone turnover.Previous studies on the effect of clopidogrel on bone metabolism indicated potential harmful effects,but their results remain conflicting.Thus,clopidogrel treatment may affect bone healing,but it has not yet been studied.AIM To evaluate if continuous perioperative clopidogrel treatment has any negative effect on bone healing in the rabbit calvarial defect model.METHODS Sixteen male white New Zealand rabbits were randomly assigned in two groups:One group received daily 3 mg/kg of clopidogrel per os and the other group received the vehicle alone for a week prior to the surgical procedures;the treatments were continued for another 6 wk postoperatively.The surgical procedures included generation of two circular calvarial defects 11 mm in diameter in every animal.After the 6-wk period of healing,postmortem radiographic and histomorphometric evaluation of the defects was performed.RESULTS Both the surgical procedures and the postoperative period were uneventful and well tolerated by all the animals,without any surgical wound dehiscence,signs of infection or other complication.New bone was formed either inwards from the defect margins or in the central portion of the defect as separated bony islets.While defect healing was still incomplete in both groups,the clopidogrel group had significantly improved radiographic healing scores.Moreover,the histomorphometric analysis showed that bone regeneration(%)was 28.07±7.7 for the clopidogrel group and 19.47±4.9 for the control group,showing a statistically significant difference between them(P=0.018).Statistically significa
文摘Chitosan nanofiber membranes have been known to have a high degree of biocompatibility and support new bone formation with controllable biodegradation. The surface area of these membranes may allow them to serve as local delivery carriers for different biologic mediators. Simvastatin, a drug commonly used for lowering cholesterol, has demonstrated promising bone regenerative capability. The aim of this study was to evaluate simvastatin loaded chitosan nanofiber membranes for guided bone regeneration (GBR) applications and their ability to enhance bone formation in rat calvarial defects. Nanofibrous chitosan membranes with random fiber orientation were fabricated by electrospinning technique and loaded with 0.25 mg of simvastatin under sterile conditions. One membrane was implanted subperiosteally to cover an 8 mm diameter critical size calvarial defect. Two groups: 1) Control: non-loaded chitosan membranes;2) Experimental: chitosan membranes loaded with 0.25 mg of simvastatin were evaluated histologically and via micro-computed tomography (micro-CT) for bone formation at 4 and 8 weeks time points (n = 5/group per time point). Both groups exhibited good biocompatibility with only mild or moderate inflammatory response during the healing process. Histologic and micro-CT evaluations confirmed bone formation in calvarial defects as early as 4 weeks using control and experimental membranes. In addition, newly-formed bony bridges consolidating calvarial defects histologically along with partial radiographic defect coverage were observed at 8 weeks in both groups. Although control and experimental groups demonstrated no significant statistical differences in results of bone formation, biodegradable chitosan nanofiber membranes loaded with simvastatin showed a promising regenerative potential as a barrier material for guided bone regeneration applications.
基金This research was supported by the Thailand Research Fund and Office of the Higher Education Commission(No.MRG6180264)Chulalongkorn University,and the National Natural Science Foundation of China(No.21750110445).
文摘Tobacco mosaic virus(TMV)has been studied as a multi-functional agent for bone tissue engineering.An osteo-inductive effect of wild-type TMV has been reported,as it can significantly enhance the bone differentiation potential of bone marrow stromal cells both on a two-dimensional substrate and in a three-dimensional(3D)hydrogel system.A TMV mutant(TMV-RGD1)was created which featured the adhesion peptide arginyl-glycyl-aspartic acid(RGD),the most common peptide motif responsible for cell adhesion to the extracellular matrix,on the surface of the virus particle to enhance the bio-functionality of the scaffold material.We hypothesised that the incorporation of either wild-type TMV or TMV-RGD1 in the 3D hydrogel scaffold would induce bone healing in critical size defects of the cranial segmental bone.We have previously tested the virus-functionalised scaffolds,in vitro,with a hyaluronic acid-based system as an in-situ hydrogel platform for 3D cell encapsulation,culture,and differentiation.The results of these experiments suggested the potential of the virus-functionalised hydrogel to promote in vitro stem cell differentiation.The hydrogel-forming system we employed was shown to be safe and biocompatible in vivo.Here,we further explored the physiological responses regarding bone regeneration of a calvarial defect in both normal and osteoporotic ovariectomized rat models.Our results,based on histological analysis in both animal models,suggested that both wild-type TMV and TMV-RGD1 functionalised hydrogels could accelerate bone regeneration,without systemic toxicity,evaluated by blood counts.New bone formation was intensified by the incorporation of the RGD-mutant viral particles.This finding increased the potential for use of the rodshaped plant virus as a platform for the addition of powerful biofunctionality for tissue engineering applications.This study was approved by the Ethics Committee on Animal Use of the Zhenjiang Affiliated First People’s Hospital affiliated to Jiangsu University.
文摘β-GP influences on rat osteoblast development at the early period of culture i.e , the non-mineralization phase, and changes with the different cell passages were investigated. Alkaline phosphatase (ALP) was chosen as a main object. Northern blot analysis revealed up to two-fold increase in the steady statelevel of ALP mRNA after stimulation of rat osteoblast with 10 mM β-GP- Likewise, 10 mM β-GP induced a 10─30 % increase in ALP activity (P< 0. 01) of early passages (1 to 4), but not of later passages (5 to 6). The β-GP induced increase in ALP activity was totally inhibited by the protein synthesis inhibitor, cycloheximide (50 μM).β- GP stimulation was found to be without effect on cell proliferation measured as 3H-thymidine incorporation. It is concluded that β-GP has no effect on proliferation but induces an increase in both mRNA level and activity of ALP in the non-mineralization phase of cultures of fetal rat calvarial cells , which lasts for several passages but will disappear in older cultures.
文摘Human stromal stem cells derived from endometrium (hESCs) are a type of multipotent stromal cells of the proven ability to differentiate into osteogenic lineage. Thus, it was suggested that these cells may be used to repair skeletal defects. In this study, Human ESCs were extracted from female endometrium and harvested. Biomimetic gelatin/apatite (Gel/Ap) scaffolds with and without harvested cells were implanted in a Critical size calvarial defects in the cranial bone of adult male rat. To CT-Scan and Histological studies were performed to investigate the level of bone formation after 8 weeks of surgery. Results confirmed that the treated defects with the bare and hESCs grafted Gel/Ap scaffold showed significant bone formation and maturation in comparison with the control group.
文摘Objectives: This study explores feasibility of tissue-engineered osteogenesis using sterile coral implants loaded with homologous osteoblasts to repair bone defects. Study Design: A unilateral 4 mm transverse dis- continuity defect was produced approximately mid-way along left radius of young female rabbits using ro- tary diamond disc under continuous saline irrigation and stabilised with autoclaved steel miniplate and screws. The defect was then fitted with sterile bioresorbable coral implant loaded with homologous neonatal calvarial osteoblasts or control implants without osteoblasts. All animals underwent radiography immedi- ately post-operative, at weekly intervals for four weeks and at fortnightly intervals thereafter. Operated bones were histologically evaluated for osteogenesis at 12 weeks. Results: Findings demonstrate osteogenesis and complete repair of bioresorbable coral implant by homologous osteoblasts loaded on coral scaffold. Conclu- sions: Single stage surgery using this technique to induce osteogenesis and closure of discontinuity bone de- fects including palatal clefts and peripheral reduction of large craniofacial defects might prove better thera- peutic modality than autologous bone grafting or tissue distraction osteogenesis.
文摘The regulation of cellular differentiation by progesterone in fetal rat calvarial osteoblasts was investigated. Our results showed that cells cultured in the presence of progesterone had a 7% increase in the alkaline phosphatase activity when compared to untreated cells. The concentration of osteocalcin in the conditioned medium from progesterone treated osteoblasts was 28% higher than that of untreated controls. In addition,administration of progesterone significantly enhanced the number and area of bone nodules. In conclusion, progesterone stimulates the differentiation of fetal rat calvarial osteoblastic cells in vitro
文摘Background:Neuronavigation is a very beneficial tool in modern neurosurgical practice.However,the neuronavigation is not available in most of the hospitals in our country raising the question about its importance in localizing the calvarial extra-axial lesions and to what extent it is safe to operate without it.Methods:We studied twenty patients with calvarial extra-axial lesions who underwent surgical interventions.All lesions were preoperatively located with both neuronavigation and the usual linear measurements.Both methods were compared regarding the time consumed to localize the tumor and the accuracy of each method to anticipate the actual center of the tumor.Results:The mean error of distance between the planned center of the tumor and the actual was 6.50±1.762 mm in conventional method,whereas the error was 3.85±1.309 mm in IGS method.Much more time was consumed during the neuronavigation method including booting,registration,and positioning.A statistically significant difference was found between the mean time passed in the conventional method and IGS method(2.05±0.826,24.90±1.334,respectively),P-value<0.001.Conclusion:In the setting of limited resources,the linear measurement localization method seems to have an accepted accuracy in the localization of calvarial extra-axial lesions and it saves more time than neuronavigation method.
基金This work was funded by the Chicago Biomedical Consortium with support from the Searle Funds at The Chicago Community TrustThe reported work was also supported in part by an NIH/NIDCK K08 Career Development Award(#1K08DE020140-01,RRR)This work was also supported in part by The University of Chicago Core Facility Subsidy grant from the National Center for Advancing Translational Sciences(NCATS)of the National Institutes of Health through Grant UL1 TR000430(RRR).
文摘Critical-sized craniofacial defect repair represents a significant challenge to reconstructive surgeons.Many strategies have been employed in an effort to achieve both a functionally and cosmetically acceptable outcome.Bone morphogenetic proteins(BMPs)provide a robust osteoinductive cue to stimulate bony growth and remodeling.Previous studies have suggested that the BMP-9 isoform is particularly effective in promoting osteogenic differentiation of mesenchymal progenitor cells.The aim of this study is to characterize the osteogenic capacity of BMP-9 on calvarial mesenchymal progenitor cell differentiation.Reversibly immortalized murine calvarial progenitor cells(iCALs)were infected with adenoviral vectors encoding BMP-9 or GFP and assessed for early and late stages of osteogenic differentiation in vitro and for osteogenic differentiation via in vivo stem cell implantation studies.Significant elevations in alkaline phosphatase(ALP)activity,osteocalcin(OCN)mRNA transcription,osteopontin(OPN)protein expression,and matrix mineralization were detected in BMP-treated cells compared to control.Specifically,ALP activity was elevated on days 3,7,9,11,and 13 post-infection and OCN mRNA expression was elevated on days 8,10,and 14 in treated cells.Additionally,treatment groups demonstrated increased OPN protein expression on day 10 and matrix mineralization on day 14 post-infection relative to control groups.BMP-9 also facilitated the formation of new bone in vivo as detailed by gross,microcomputed tomography,and histological analyses.Therefore,we concluded that BMP-9 significantly stimulates osteogenic differentiation in iCALs,and should be considered an effective agent for calvarial tissue regeneration.
基金This study was supported by grants from National Natural Science Foundation of China （No. 81071215）, Natural Science Foundation of Heilongjiang Province of China （No. D201062）, Foreign Collaboration Project of Heilongjiang Province （No. WB10B104）, and Science Foundation of the First Affiliated Hospital of Harbin Medical University （No. 2011BS13 ）.
文摘Neurofibromatosis type 1(NF1)is an autosomal dominant disorder in which the nerve tissue grows tumors that may be benign and may cause serious damage by compressing nerves and other tissues.The NF1 gene
文摘A 45-year-old male was autopsied. He had fallen backwards from a two-stairs height to the ground and passed away. A skull fracture was detected in the left occipital area, extending up to the left side of the skul! base. The patient＇s death occurred due to the very low thickness of the calvarial bones, which led to the aforementioned fracture, and in turn resulted in subarachnoid hemorrhage and death. The cortical thickness was measured and compared with average values at standardized points. Uniform bone thinning was confirmed rather than localized. Calvarial thinning may result from various conditions. In the present case study, however, the exact mechanism which led to the low thickness of the calvarial bones of the patient is undetermined. Death due to the susceptible structure and fracture of calvarial bones has rarely been reported throughout relevant literature.
基金This work was funded by the project‘DEXGELERATION-Advanced solu-tions for bone regeneration based on dextrin hydrogels’(Norte-07-0202-FEDER-038853).It was also funded by FCT under the scope of the strategic funding of UID/BIO/04469/2013 and UID/BIM/04293/2013 units and COMPETE 2020(POCI-01-0145-FEDER-006684),BioTecNorte operation(NORTE-01-0145-FEDER-000004)and NORTE-01-0145-FEDER-000012 funded by FEDER under the scope of Norte2020-Programa Operacional Regional do Norte.Isabel Pereira and Ana Rita Caseiro were supported by the grants SFRH/BD90066/2012 and SFRH/BD/101174/2014,respectively,from FCT,Portugal.
文摘The development of injectable bone substitutes(IBS)have obtained great importance in the bone re-generation field,as a strategy to reach hardly accessible defects using minimally invasive techniques and able to fit to irregular topographies.In this scenario,the association of injectable hydrogels and bone graft granules is emerging as a well-established trend.Particularly,in situ forming hydrogels have arisen as a new IBS generation.An in situ forming and injectable dextrin-based hydrogel(HG)was developed,aiming to act as a carrier of granular bone substitutes and bioactive agents.In this work,the HG was associated to a granular bone substitute(Bonelike)and implanted in goat critical-sized calvarial defects(14mm)for 3,6 and 12weeks.The results showed that HG improved the han-dling properties of the Bonelike granules and did not affect its osteoconductive features,neither impairing the bone regener ation process.Human multipotent mesenchymal stromal cells from the umbilical cord,extracellular matrix hydrolysates and the pro-angiogenic peptide LLKKK18 were also combined with the IBS.These bioactive agents did not enhance the new bone formation significantly under the conditions tested,according to micro-computed tomography and histological analysis.
