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Resumen Antecedentes: Respecto a la distracción osteogénica (generación ósea inducida), con mayor o menor éxito han sido descritos diversos protocolos para el manejo del período de latencia, velocidad de distracción y período de consolidación. Objetivo: Entender mejor el proceso de la distracción mandibular y establecer los factores determinantes y sus tiempos óptimos. Material y métodos: Se estudiaron 27 perros sometidos a distracción osteogénica unidireccional, bilateral de la mandíbula. Los procesos de distracción se aplicaron con seis variantes, dos por cada factor (período de latencia, período de distracción y velocidad de distracción). Se estudiaron los cambios mediante biopsias del hueso y radiografías de la zona a los 0, 7, 14, 21, 45 y 55 días del proceso. Resultados: Los parámetros de distracción osteogénica más eficientes fueron período de latencia de cinco días, período de consolidación de seis semanas, 1 mm diario de velocidad de distracción para distancias menores a 20 mm y 3 mm diarios para distancias mayores. Conclusiones: El estudio histológico secuencial permitió observar la aparición de los elementos celulares (osteocitos, osteoclastos, matriz osteoide, trabeculado, etcétera) y su participación en el tejido de granulación, el hueso neoformado y el hueso maduro compacto.
Abstract Background: Distraction osteogenesis is a process of induced bone generation. Various protocols have been described for the management of the latency period, distraction speed and consolidation period, with greater or lesser success. Objective: To better understand the process of mandibular distraction and establish the determining factors and their optimal times. Material and methods: Twenty-seven dogs were studied, which had 54 distractors placed and that underwent unidirectional, bilateral mandibular distraction osteogenesis. The distraction processes were applied using six variants, two for each factor: latency period, distraction period and distraction speed. The changes were examined by means of bone biopsies and X-rays of the area at 0, 7, 14, 21, 45 and 55 days of the process. Results: The most efficient osteogenic distraction parameters were a latency period of five days, a consolidation period of six weeks, distraction speed of 1 mm/day for distances of less than 20 mm, and 3 mm/day for longer distances. Conclusions: The sequential histological study allowed to observe the appearance of cellular elements (osteocytes, osteoclasts, osteoid matrix, trabeculate, etc.) and their participation in granulation tissue, newly-formed bone and compact mature bone.
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Osteogenesis imperfecta（OI）is a hereditary connective tissue disease，and roughly 85% of the patients are caused by heterozygous mutations in COL1A1 and COL1A2，the coding genes of type Ⅰcollagen. Primary symptomatic manifestations of OI are low bone mass，frequent fractures and skeletal deformity，and other symptoms include blue sclera，dentinogenesis imperfecta，hyperlaxity of joint and ligaments，short stature and hearing impairment. Some patients may have muscle weakness，obesity and other symptoms，and the systemic low-grade inflammation and changes in bone microenvironment caused by obesity may have more negative effects on OI bones. The occurrence of obesity in OI patients may be related to energy metabolism abnormalities caused by multiple factors such as reduced activity，abnormal muscle fat metabolism，and diverse genotypes. Currently，there is a lack of large sample data on the incidence of obesity，and exploring the mechanism of skeletal-muscle interaction and energy metabolism regulation is of great significance for OI related obesity prevention and treatment.
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Objective·To evaluate the effects of anterior maxillary segmental distraction osteogenesis(AMSDO)in treating sagittal maxillary hypoplasia in cleft lip and palate(CLP)patients and to report a 3D-printed surgical guide to facilitate the osteotomy.Methods·Twelve patients with CLP who underwent AMSDO were included in this study.Virtual osteotomy was performed in a 3-dimensional model and the osteotomy line were fabricated into a tooth-borne surgical guide by using 3D-printing technique.Lateral cephalograms taken before surgery(T0),at the end of consolidation(T1)and six months after consolidation(T2)were used to evaluate the effects of AMSDO.The accuracy of the osteotomy guide was measured by superimposing the postoperative CT data to virtual planning.Results·All the patients went through surgery without serious complications.SNA and overjet changed significantly both from T0 to T1 and from T0 to T2.ANB,facial convexity,and palatal length changed without significance from T0 to T1 and from T0 to T2.SNB remained stable.All the variables remained relatively stable from T1 to T2.The anteroposterior linear root-mean-square deviation(RMSD)between planning and actual results was 0.90 mm,while the angular RMSD in the sagittal plane was 5.07°.Conclusion·AMSDO is an effective treatment for maxillary hypoplasia secondary to CLP.The accuracy of this 3D-printed osteotomy guide is clinically acceptable,and this can simplify the surgery with fewer complications.
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Objective:To establish an animal model of trans-sutural distraction osteogenesis in SD rats.Methods:A self-designed V-shaped distraction device(distractor)was fabricated with the traction force(N)of 0,1.3,2.2,3.0,4.3 and 5.0 corresponding to the distraction length(mm)of 5,4,3,2,1 and 0 respectively,meeting the trans-sutural distraction osteogenesis requirements in skull of 5-week-old SD rats.The distractor was plased into the sagittal suture of 12 SD rats.Continuous sampling was conducted 1,3,5 and 7 days respectively(n=3)after operation.The tissue changes in the trans-sutural distraction area were observed by HE and Masson's trichrome staining.Inflammation levels were determined using Arg-1 immunofluorescence staining.The early angiogenesis was clarified through co-staining with CD31 and EMCN.Results:A stable trans-sutural distraction osteogenesis model was estab-lished,5 mm distraction osteogenesis width was observed completely within 7 days of distraction.Significant new bone formation was observed at 7 days after operation.Arg-1 expression increased and was concentrated at the bone margins,overlapping with the areas of new bone formation.EMCN expression gradually decreased,and by day 7 CD31 was predominant,indicating the basic maturation of blood vessels.Conclusion:This study successfully constructed a stable and effective trans-sutural distraction osteogenesis animal model,and provides an experimental basis for the investigation of its early continuous histological changes.
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Objective To explore the healing pattern of condylar neck fractures by using mathematical models to simulate the dynamic changes of osteogenesis and chondrogenesis in the process of rat condylar neck fracture healing.Methods A math-ematical model was constructed to simulate the healing process of rat condylar neck fractures.The values of various parameters(mb,mc,cb and cc)generated by the model at different time points within 28 days were statistically analyzed.Subsequently,den-sity maps and growth curves of bone,cartilage,osteoblasts,and chondrocytes were fitted and the osteogenesis mode was de-duced.Results The bone area ratio simulated by the mathematical model was similar to that measured in rat fracture experi-ments(P＞0.05).The simulated density maps showed that osteogenesis was concentrated around the periosteum from day 3 to day 7 after fracture,and then concentrated in the cartilage region and gradually replaced cartilage from day 7 to day 21.The bone growth curve and cartilage growth curve were positively correlated from day 5 to day 8 and from day 21 to day 28.However,the curves were negatively correlated from day 8 to day 14 after fracture.The growth curves of osteoblasts and chondrocytes both showed an increasing trend before decreasing,with chondrocyte density peaking at day 6 and osteoblast density peaking at day 13.Conclusion The mathematical model can effectively simulate the healing process of rat condylar neck fractures and display the dynamic changes of osteogenesis and chondrogenesis during the whole process.This provides a new idea for studying healing methods of condylar neck fractures.
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Fracture is a common orthopedic disease in clinical practice,and the resulting nonunion or delayed union of frac-tures is a major challenge in clinical treatment.In the process of fracture healing,there is a complex interaction between angio-genesis and osteogenesis,which is called the"angiogenesis-osteogenesis coupling"mechanism.In recent years,a new capillary subtype characterized by high expression of platelet endothelial cell adhesion molecule-1(PECAM-1/CD31)and salivary glyco-protein(EMCN),namely type H blood vessel,has been identified and found to play an important role in regulation of the angio-genesis-osteogenesis coupling.In this review,the mechanism of type H blood vessels promoting angiogenesis-osteogenesis cou-pling,the related molecules and signal pathways regulating type H blood vessels regeneration were discussed,in order to provide new ideas and methods for promoting fracture healing.
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BACKGROUND:Previous studies have shown that human dental pulp stem cells have good osteogenic differentiation potential and are potential seed cells in bone tissue engineering,and the effect of recombinant human growth hormone on the proliferative osteogenic differentiation of human dental pulp stem cells is still unclear. OBJECTIVE:To explore the effect of recombinant human growth hormone on the proliferation and osteogenic differentiation of human dental pulp stem cells. METHODS:Human dental pulp stem cells were isolated and cultured by tissue block culture method.After screening according to the drug concentration gradient,recombinant human growth hormone containing 10,100,250,500,1 000 μg/L was selected as the experimental group,and 0 μg/L without recombinant human growth hormone was selected as the control group.CCK-8 detection reagents were used on days 1,3,5,and 7 after the drug intervention to detect the proliferation of human dental pulp stem cells.Different concentrations(10,100,250,500,and 1 000 μg/L)of recombinant human growth hormone were added to the osteogenesis induction solution to intervene in human dental pulp stem cells.Alkaline phosphatase activity was detected by alkaline phosphatase staining and semi-quantitative analysis on day 7 of mineralization induction.The mRNA expression levels of osteogenic gene type I collagen,osteocalcin and Runt-related transcription factor 2 were detected by fluorescence quantitative RT-qPCR.Alizarin red staining was performed on day 14 of mineralization induction to detect osteogenic mineralized nodules. RESULTS AND CONCLUSION:(1)CCK-8 assay results showed that from the third day of intervention,the 100,250,500,1 000 μg/L recombinant human growth hormone group could promote the proliferation of human dental pulp stem cells compared with the control group(P<0.01).(2)The alkaline phosphatase activity of human dental pulp stem cells in the 100,250,and 500 μg/L recombinant human growth hormone group was significantly increased compared with the control group(P<0.01).The number of alizarin-stained mineralized nodules in human dental pulp stem cells in the 100,250 μg/L recombinant human growth hormone group was significantly increased compared with the control group(P<0.01).Compared with the control group,the mRNA expression of type I collagen and osteocalcin increased in the 250 μg/L recombinant human growth hormone group(P<0.05,P<0.01).mRNA expression of Runt-associated transcription factor 2 increased in the 100 and 250 μg/L recombinant human growth hormone groups(P<0.01).(3)According to the above results,recombinant human growth hormone at a concentration of 250 μg/L is a more suitable concentration to promote the proliferation and osteogenic differentiation of human dental pulp stem cells.
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BACKGROUND:Compound Shengmai Chenggu capsule has good therapeutic effects on early steroid-induced osteonecrosis of the femoral head,but the exact mechanism of treatment is not fully understood. OBJECTIVE:To observe the effect of compound Shengmai Chenggu capsule on fucosyltransferase 8,osteogenic gene and Wnt/β-catenin in bone tissue of rats with steroid-induced osteonecrosis of the femoral head. METHODS:Sixty Sprague-Dawley rats were randomized into blank group,model group,low-,middle-,and high-dose drug groups(n=12 per group).In the latter four groups,animal models of steroid-induced osteonecrosis of the femoral head were established by subcutaneous injection of imiquimod(once every 2 weeks,2 times in total)and gluteal muscle injection of methylprednisolone(once a week,4 times in total).The low-,middle-and high-dose drug groups were given 1.89,3.78 and 7.56 g/kg per day compound Shengmai Chenggu capsule solution by gavage respectively on the second day after the last modeling.The same amount of saline was given by gavage to the model group.Administration lasted 8 weeks.After the administration,micro-CT scan,histological staining,compression test,RT-qPCR and western blot were performed on the femoral head. RESULTS AND CONCLUSION:Micro-CT scan results showed that compared with the blank group,trabecular volume fraction,trabecular number and trabecular thickness were significantly decreased(P<0.05),while trabecular separation was increased in the model group(P<0.05).Compared with the model group,the compound Shengmai Chenggu capsule could increase trabecular volume fraction,trabecular number and trabecular thickness(P<0.05),and decrease trabecular separation(P<0.05)in a dose-dependent manner.Hematoxylin-eosin staining results showed that compared with the model group,the rate of empty bone lacunae was reduced in a dose-dependent group in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups(P<0.05).Immunohistochemical staining results showed that compared with the blank group,the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 was reduced in the model group(P<0.05);compared with the model group,the compound Shengmai Chenggu capsule increased the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 in a dose-dependent manner(P<0.05).Results from the compression test showed that there was a dose-dependent increase in the maximum load and elastic modulus of the femoral head in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).RT-qPCR and western blot results showed that the mRNA and protein expressions of fucosyltransferase 8,Runx2,alkaline phosphatase,osteocalcin,osteoblast-specific transcription factor and bone morphogenetic protein 2 were decreased in the model group compared with the blank group(P<0.05);compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of the above indicators in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).Compared with the blank group,the mRNA and protein expression of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin were decreased(P<0.05)and the mRNA and protein expressions of glycogen synthase kinase 3β were increased(P<0.05)in the model group;compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin(P<0.05)but a dose-dependent decrease in the mRNA and protein expressions of lycogen synthase kinase 3β(P<0.05)in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups.To conclude,the mechanism by which the compound Shengmai Chenggu capsule treats steroid-induced osteonecrosis of the femoral head may activate the Wnt/β-catenin signaling pathway through the up-regulation of fucosyltransferase 8,thereby promoting bone formation.
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BACKGROUND:At present,it is found that both Chinese medicine for activating blood circulation and removing blood stasis and platelet-rich plasma technology can repair damaged blood vessels,promote vascular regeneration,rebuild blood supply in the femoral head,restore normal blood supply,and further promote osteogenesis.Both of them have certain advantages in early intervention of steroid-induced necrosis of femoral head.It can also further understand the mechanism of blood activating and stasis removing herbs and platelet-rich plasma technology in improving steroid-induced necrosis of the femoral head,and provide new ideas for future treatment. OBJECTIVE:To review the research progress of the mechanism of the combination of blood activating and blood stasis removing herbs and platelet-rich plasma technology on steroid-induced necrosis of the femoral head according to the related literature at home and abroad. METHODS:PubMed,Web of Science,Metstr,CNKI and WanFang databases were searched for relevant articles."Traditional Chinese medicine,signal pathways,steroid induced necrosis of femoral head,vascular endothelial growth factor,platelet rich plasma"were used as the Chinese and English search terms separately.The time limit for searching the literature was from January 2000 to July 2022,and 75 related articles were finally included. RESULTS AND CONCLUSION:Both Chinese medicine for activating blood circulation and removing blood stasis and platelet-rich plasma technology have certain advantages in intervening the early stage of steroid-induced necrosis of femoral head.For traditional Chinese medicine,both single and compound drugs can effectively alleviate the further development of steroid-induced necrosis of the femoral head.The specific mechanism is as follows:(1)The traditional Chinese medicine for activating blood circulation and removing blood stasis has a significant anticoagulation effect,which can antagonize the abnormal(hypercoagulable)state of blood caused by hormone drugs,and further restore the normal blood supply in the femoral head.(2)Traditional Chinese medicine for activating blood circulation and removing blood stasis can repair damaged vascular endothelium,regenerate blood vessels and remodel blood supply in the femoral head by activating vascular endothelial growth factor.(3)The traditional Chinese medicine of promoting blood circulation and removing blood stasis has the obvious effect of removing blood stasis,which can reduce the accumulation of fat cells in the bone marrow cavity and relieve the pressure in the femoral head.(4)Traditional Chinese medicine for promoting blood circulation and removing blood stasis can regulate relevant signal pathways,maintain bone metabolism,promote the differentiation and balance of osteoblasts and osteoclasts,and effectively reduce steroid-induced necrosis of the femoral head.In addition,platelet-rich plasma contains a large amount of high concentration of cell growth factor,which plays a positive role in osteogenesis and vascular regeneration,and can also improve the abnormal state of the blood.Traditional Chinese medicine for activating blood circulation and removing blood stasis combined with platelet-rich plasma technology can play their biological roles,and the intervention effect is more significant.
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BACKGROUND:Bone defects are caused by many factors,such as inflammation,tumor,trauma or bone diseases.Erythropoietin can promote the differentiation of mesenchymal stem cells into osteoblasts and osteoclasts and act on vascular endothelial cells to induce angiogenesis and accelerate the repair of bone and cartilage defects.Erythropoietin is a growth factor with potential application in bone tissue engineering construction. OBJECTIVE:To expound the application and potential mechanism of erythropoietin in bone tissue engineering. METHODS:The first author searched the related articles published in CNKI,WanFang,VIP,and PubMed databases from 2004 to 2022 by computer.Search terms were"erythropoietin,bone defect,bone regeneration,angiogenesis,osteogenesis,osteoblast,osteoclast,bone tissue engineering"in Chinese and English.Finally,64 articles were included for review. RESULTS AND CONCLUSION:(1)Erythropoietin can directly act on osteoblasts and osteoclasts in the bone marrow microenvironment by promoting the differentiation of mesenchymal stem cells into osteoblasts,osteoclasts,adipocytes,nerve cells and stromal cells.The activation of Wnt/β-catenin,hypoxia-inducible factor 1α/vascular endothelial growth factor,p38 MAPK and EphrinB2/EphB4 signaling pathways mediates the osteogenic differentiation of mesenchymal stem cells.(2)Erythropoietin can not only regulate the production of erythrocytes to alter the oxygen-carrying capacity of blood but also stimulate vascular endothelial cells to promote angiogenesis.The new blood vessels can carry oxygen,nutrients,growth factors,and bone progenitor cells necessary for osteogenesis to the osteogenic site,thereby promoting bone formation and fracture healing.(3)Currently,erythropoietin is being used as a growth factor with osteogenic and angiogenic effects in various types of scaffold materials such as chitosan,polycaprolactone,bioceramics,and nanofibers through various drug delivery methods.Erythropoietin,along with other growth factors such as bone morphogenetic protein-2 and bone morphogenetic protein-9,has been applied to the surface of scaffold materials to participate in the repair of bone defects.Erythropoietin has demonstrated excellent practicality in the construction of new tissue-engineered bone and has potential clinical application value.
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BACKGROUND:Peripheral nerves play an important role in bone metabolism.In clinical practice,the specific impact of nerve injury on bone transport technology needs further study. OBJECTIVE:To investigate the effect of tibial nerve injury on the treatment of tibial slip by single-plane osteotomy. METHODS:Thirty-two patients with tibial bone defects admitted to Tangshan Second Hospital from May 2011 to June 2022 were selected.According to the presence or absence of tibial nerve injury,patients were divided into the tibial nerve injury group(n=16)and the non-tibial nerve injury group(n=16).Both groups were treated with single-plane osteotomy and bone slip.After treatment,the patients were followed up to collect the mineralization zone healing index,external fixation index,docking point healing and needle infection.After the removal of external fixation,the bone healing and functional evaluation were evaluated by a classification of the Association for the Study and Application of the Method of Ilizarov(ASAMI). RESULTS AND CONCLUSION:(1)All 32 patients were followed up for(25.28±4.79)months.There were no significant differences in bone healing time,external fixation time,healing index and external fixation index between the two groups(P＞0.05).Needle infection occurred in two cases of the tibial nerve injury group and one case of the non-tibial nerve injury group,all of which were PALEY I,and there was no significant difference between the two groups(P＞0.05).The non-union rate of the occlusal end of the tibial nerve injury group was 31%,and that of the non-tibial nerve injury group was 13%;there was no statistical difference between the two groups(P＞0.05).The excellent and good rate of ASAMI bone healing score in the two groups was 100%;the excellent and good rate of limb score was 81%in the tibial nerve injury group and 94%in the non-tibial nerve injury group;there was no statistical difference between the two groups(P＞0.05).(2)Our research shows that tibial nerve injury has no significant effect on the mineralization speed,external fixation time,union of the occlusal end,infection of the needle tract,and the quality of bone formation in the mineralized area of the single-plane osteotomy.
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BACKGROUND:Shikonin contributes to the promotion of bone defect repair and the treatment of osteoporosis. OBJECTIVE:To summarize the application potential of shikonin and its derivatives in oral soft and hard tissue regeneration. METHODS:A literature review was conducted in databases such as PubMed,Web of Science,Wanfang,China National Knowledge Infrastructure(CNKI),and VIP,spanning articles from 2002 to 2023.The search terms were"shikonin,oral cavity,periodontitis,antibacterial,bone formation,osteoclast,osteoporosis,toxicology"in Chinese and English. RESULTS AND CONCLUSION:Shikonin and its derivatives possess anti-inflammatory effects,inhibit periodontal pathogens such as Porphyromonas gingivalis,promote periodontal wound healing,and regenerate alveolar bone tissue.Shikonin formulations can be used to treat oral diseases such as aphthous ulcers and oral candidiasis.These findings suggest a promising future for shikonin and its derivatives in treating periodontal diseases,preventing oral ailments,and promoting the regeneration of both soft and hard periodontal tissues.Further research is needed to explore how to combine shikonin with tissue engineering to achieve quicker healing of oral soft and hard tissues.
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BACKGROUND:Deferoxamine mesylate is a potential anti-osteoporosis drug with iron chelation,vascular regeneration,and antioxidant effects.Recent studies have shown that the application of deferoxamine mesylate can be extended to the field of tissue regeneration engineering. OBJECTIVE:To investigate whether deferoxamine mesylate can promote the repair effect of iron overload osteoporotic rats after bone grafting for mandibular bone defects by simulating the state of iron accumulation in patients with postmenopausal osteoporosis with high iron intervention in osteoporotic rats. METHODS:An iron accumulation ovariectomized osteoporosis model was firstly constructed.The model group underwent bilateral ovariectomy,and the intraperitoneal injection of ferric ammonium citrate(90 mg/kg,twice a week,for 11 weeks)was started in the 2nd week,while the sham-operated group had some fat around the ovaries removed and was given an equal amount of saline for 11 weeks.After the successful modeling,the experimental rats were divided into sham-operated group(n=6),high iron ovariectomtized group(n=6)and high iron ovariectomized deferoxamine mesylate treatment group(deferoxamine mesylate group,n=6).Bone defects of 5 mm in diameter were established in the rat's bilateral mandibles and implanted with Bio-Oss bone powder.Intraperitoneal injection of deferoxamine mesylate(100 mg/kg,3 times a week)was started on postoperative day 4 in the deferoxamine mesylate group,and equal volume of saline was given in the sham-operated and high iron ovariectomized groups.The bone samples of the mandible,liver and blood were taken at 2 and 12 weeks after bone grafting for Prussian blue staining of the jaw and liver and ELISA detection of serum ferritin to detect iron levels in various body tissues;hematoxylin-eosin staining and Masson staining were performed to observe inflammatory cell infiltration and early osteogenesis in the bone defect area;tartrate resistant acid phosphatase staining was performed to observe osteoclast differentiation;ELISA was performed to detect serum calcitonin and type I collagen C-terminal peptide levels;and Micro-CT and hematoxylin-eosin staining were performed to observe osteogenesis in the middle and late stages. RESULTS AND CONCLUSION:The number of tibial trabeculae was reduced and the trabeculae were sparsely arranged in the high iron ovariectomized group.Iron levels in the liver,jaw bone and serum were significantly higher in the high iron ovariectomized group than the sham-operated group at 2 weeks after bone grafting,while the iron levels were significantly decreased after deferoxamine mesylate intervention(P＜0.05).In the early stage of bone defect repair,more inflammatory cell infiltration,less new bone matrix and less type I collagen fiber production were observed in the high iron ovariectomized group than in the sham-operated group(P＜0.05);after deferoxamine mesylate treatment,inflammatory cell infiltration was reduced,a small amount of new bone matrix was produced and collagen fibers increased significantly(P＜0.05).In the middle and late stages of bone defect repair,Micro-CT results showed a reduction in new bone production in the high iron ovariectomized group compared with the sham-operated group and increased new bone matrix after deferoxamine mesylate treatment(P＜0.05).Compared with the sham-operated group,the osteoclast number,serum calcitonin level,and serum type I collagen C-terminal peptide level were increased in the high-iron ovariectomized group,while the osteoclast number was decreased and bone metabolic indexes were improved after treatment with deferoxamine mesylate.To conclude,in ovariectomized rats with high iron intervention,elevated iron levels can be seen in multiple tissues,accompanied by reduced new bone production in the mandibular bone defect area.Deferoxamine mesylate can improve bone metabolism and inhibit osteoclast activity by removing iron deposits in tissues,improve bone formation in iron-accumulated osteoporotic rats,and promote bone healing in the mandibular bone defect area.
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BACKGROUND:Titanium and its alloys are widely used in orthopedic implants due to their excellent biocompatibility,corrosion resistance,and mechanical properties.However,it has biological inertia itself,cannot provide a good growth environment for osteoblasts,and it is difficult to form good osseointegration. OBJECTIVE:To construct a composite hydrogel material of gelatin methacryloyl and polyacrylamide on the surface of titanium alloy scaffold,and analyze its osteogenic ability in vitro. METHODS:Gelatin methacryloyl was mixed with acrylamide.Crosslinking agent and catalyst were added to synthesize gelatin methacryloyl and acrylamide(Gelma-PAAM)composite hydrogel.The titanium alloy scaffold modified by affinity silane was mixed with the Gelma hydrogel and Gelma-PAAM composite hydrogel to complete the loading(recorded as Ti-Gelma and Ti-Gelma-PAAM,respectively).The swelling ratio and degradation rate of the two hydrogels on the surface of the scaffold were compared.The bonding state between hydrogels and titanium alloy was observed by scanning electron microscope.Rat bone marrow mesenchymal stem cells were inoculated into Ti,Ti-Gelma and Ti-Gelma-PAAM scaffolds,separately.Cell proliferation,adhesion,and osteogenic differentiation were detected. RESULTS AND CONCLUSION:(1)Compared with Gelma hydrogel,Gelma-PAAM hydrogel had higher swelling rate and lower degradation rate.(2)Scanning electron microscope showed that the surface of the two kinds of hydrogels was honeycomb structure.After being combined with porous titanium alloy scaffold,the film was wrapped on the surface of scaffold and filled with pores.Among them,the Gelma-PAAM composite hydrogel coated the scaffold more fully.(3)CCK-8 assay and live/dead fluorescence staining showed that bone marrow mesenchymal stem cells proliferated well after coculture with Ti-Gelma and Ti-Gelma-PAAM scaffolds and maintained high activity.After osteogenic induction culture,alkaline phosphatase activity,calcium deposition,and osteogenic gene expression of cells of titanium alloy scaffold group were the lowest,and alkaline phosphatase activity,calcium deposition,and osteogenic gene expression of cells of Ti-Gelma-PAAM scaffold group were the highest.(4)Phalloidin cytoskeletal staining exhibited that the cells of pure titanium alloy scaffold group and Ti-Gelma scaffold group were sparse and insufficiently extended,while the cells of Ti-Gelatin-PAAM group had the most adequate stretching and the densest filamentous actin.(5)The results show that Gelma-PAAM hydrogel has good biocompatibility and osteogenic ability,and is more suitable for osteogenic modification on the surface of titanium alloy than Gelma hydrogel.
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BACKGROUND:The dura mater and skull are physically and functionally related,although there have been few investigations on primary extraction of dura mater and cranial cells,as well as co-culture of the two.The use of primary cells to investigate the influence of the dura mater on the skull is novel,and it is hoped that it may give a theoretical foundation for therapeutic therapy. OBJECTIVE:Rat dura mater and cranial bone cells were retrieved in situ to observe the influence of dura mater on cranial bone proliferation and differentiation,as well as to get a basic knowledge of the involvement of Twist1 in this process. METHODS:The enzyme digestion method was used in conjunction with the tissue block method to extract dural cells and cranial osteoblasts from rats within three days of birth.Immunofluorescence staining was used to identify the extracted cells,and alizarin red staining was used to identify and evaluate cranial osteoblasts and their mineralization ability.After co-culturing dural cells and cranial osteoblasts,real-time PCR was utilized to identify the expression of genes associated to cranial osteoblast proliferation and osteogenesis,as well as Twist1. RESULTS AND CONCLUSION:(1)Morphology:The retrieved dural cells had morphological traits similar to fibroblasts,while the osteoblasts were spindle-shaped.(2)Cell identification:immunofluorescence staining revealed that extracted dural cells expressed high levels of vimentin and cranial osteoblasts expressed high levels of alkaline phosphatase;cranial osteoblasts were stained with alizarin red 28 days after osteogenic induction,and obvious mineralized nodules were observed.(3)Real time PCR detection showed that the co-culture group had higher levels of PCNA,alkaline phosphatase,and RUNX2 mRNA expression than the control group(P＜0.01);however,Twist1 mRNA expression was lower(P＜0.01).(4)The findings showed that the primary extracted cranial osteoblasts had a high mineralization capacity,and that the dura mater was a key factor in promoting cranial growth and development and osteogenic differentiation,with Twist1 playing a key role in this process.
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BACKGROUND:Our previous studies found that adding barium sulfate could improve the mechanical and radiopaque properties of calcium phosphate cement.However,with the degradation of calcium phosphate,the remaining radiopaque agent is difficult to degrade,and the space-occupying and osteoclast effects at the implantation site affect the bone repair process.Therefore,it is necessary to develop a new biodegradable radiopaque material. OBJECTIVE:To discuss the radiopaque ability of bioactive degradable material strontium polyphosphate(SrPP)and its impact on the physicochemical properties and osteogenic effect of calcium phosphate cement. METHODS:(1)Calcium phosphate cement(CPC),starch modified calcium phosphate cement(CPS)and starch modified calcium phosphate cement(20%SrPP-CPN)containing SrPP(20%mass fraction of bone cement powder)were prepared respectively,and the physicochemical properties of the three groups of bone cements were characterized.(2)The three groups of bone cement extracts were co-cultured with rat bone marrow mesenchymal stem cells,respectively,to detect cell proliferation,energy metabolism,and osteogenic differentiation.(3)Bone defects with a diameter of 5 mm were made on each side of the top of the skull of 24 SD rats,and they were randomly divided into control group(without any intervention),CPC group,CPS group,and 20%SrPP-CPN group for intervention,with 6 rats in each group.Relevant tests were performed after 4 and 12 weeks of intervention. RESULTS AND CONCLUSION:(1)Compared with the other two groups of bone cement,20%SrPP-CPN had enhanced radiopaque ability,increased compressive strength and degradation rate,and prolonged curing time,and 20%SrPP-CPN could release Sr2+ stably during degradation.(2)CCK-8 assay showed that 20%SrPP-CPN did not affect the proliferation of bone marrow mesenchymal stem cells.Cell starvation test(serum-free culture)showed that 20%SrPP-CPN could promote the proliferation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.Compared with the other two groups of bone cements,20%SrPP-CPN increased adenosine triphosphate concentration in bone marrow mesenchymal stem cells.Alkaline phosphatase and alizarin red staining showed that 20%SrPP-CPN could promote osteogenic differentiation of bone marrow mesenchymal stem cells compared with the other two groups of bone cement.(3)In the rat skull defect experiment,Micro-CT scanning and histological observation(hematoxylin-eosin and Masson stainings)showed that bone cement in 20%SrPP-CPN group was significantly degraded compared with that in CPC and CPS groups,and a large number of new bone tissues were dispersed in degraded bone cement.Immunohistochemical staining showed that Runx2 protein expression was increased in 20%SrPP-CPN group compared with CPC group and CPS group(P＜0.01).(4)These results show that 20%SrPP-CPN has good radiopaque ability and osteogenic properties.
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BACKGROUND:Some studies have found that local application of alendronate can promote osteogenesis,but less is reported on the process of distraction osteogenesis. OBJECTIVE:To observe the promoting effect of alendronate on rapid mandibular distraction in a rabbit model and explore its possible mechanism. METHODS:Thirty-six male New Zealand white rabbits were randomly divided into groups A,B and C(n=12 per group)after operation and rapid distraction(3-day delay period followed by 3-day distraction at 1.5 mm/12 hours).At the 1st,3rd and 7th days of the consolidation period,animal were injected with 200 μg/kg alendronate in group A and 100 μg/kg alendronate in group B,while those in group C were treated as controls.CT scanning and dual energy X-ray bone mineral density measurement were performed at 4 and 8 weeks of the consolidation period.After the radionuclide scanning was completed at the 4th week,several animals were sacrificed and the samples were collected for western blot assay and tartrate resistant acid phosphatase staining.A three-point bending test was performed after the animals were sacrificed at the 8th week. RESULTS AND CONCLUSION:CT results showed that bone formation in the distraction space of group B was significantly better than that in groups A and C.At the 4th week,the bone mineral density in group B was(0.092±0.010)g/cm2,which was 1.26 times higher than that in group A(P＜0.001)and 1.28 times higher than that in group C(P＜0.001).At the 8th week,the bone mineral density in group B was(0.175±0.029)g/cm2,which was 1.38 times higher than that in group A(P＜0.001)and 1.45 times higher than that in group C(P＜0.001).Tartrate resistant acid phosphatase staining showed that the number of osteoclast-like cells in group C were 2.83 times more than that in group A(P＜0.001)and 2.21 times more than that in group B(P＜0.001).The radionuclide intensity was higher in group C than in groups A and B.Western blot assay results showed that the expression of Runx2 was significantly stronger in group B than in groups A and C.The maximum biomechanical load in group B was(158.48±23.21)N,which was 1.26 times higher than that in group A(P=0.007)and 1.31 times higher than that in group C(P=0.003).To conclude,the low concentration of alendronate may promote rapid distraction osteogenesis of the rabbit mandible by inhibiting osteoclast signals.
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Objective To evaluate the efficacy,safety and economy of teriparatide in the treatment of osteoporosis.Methods PubMed,Embase,Cochrane Library,Web of Science,CNKI,WanFang Data,VIP databases and websites related to health technology evaluation were systematically searched to collect high-quality clinical evidence and economic evaluation literature of teriparatide in the treatment of osteoporosis from the inception to January 20,2023.Two researchers independently identified studies,extracted data,assessed the quality of included studies,and descriptive analyzed and summarised the results.Results A total of 25 literatures were included,involving 3 HTA reports,15 systematic review/Meta-analyses and 7 economic studies were included.In terms of effectiveness,the evaluation results showed that teriparatide could improve bone mineral density in patients with osteoporosis,reduce the incidence of vertebral/non-vertebral fractures in primary and secondary osteoporosis and prevent the fractures in postmenopausal osteoporosis compared to bisphosphonates and placebos.In terms of safety,teriparatide was proven to be safe with no elevated risk of adverse drug reactions.In terms of economic cost,teriparatide has a higher cost and economic disadvantage compared with bisphosphonates,however,for people with severe postmenopausal osteoporosis and high risk of fracture,teriparatide can be considered as a potential cost-effect treatment option.Conclusion Teriparatide is effective and safe in the treatment of osteoporosis,but it is not cost-effective advantages compared with the existing other anti-osteoporosis medications.
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@#Graphene family nanomaterials (GFNs) are highly popular in the field of bone tissue engineering because of their excellent mechanical properties, biocompatibility, and ability to promote the osteogenic differentiation of stem cells. GFNs play a multifaceted role in promoting the bone regeneration microenvironment. First, GFNs activate the adhesion kinase/extracellularly regulated protein kinase (FAK/ERK) signaling pathway through their own micromorphology and promote the expression of osteogenesis-related genes. Second, GFNs adapt to the mechanical strength of bone tissue, which helps to maintain osseointegration; by adjusting the stiffness of the extracellular matrix, they transmit the mechanical signals of the matrix to the intracellular space with the help of focal adhesions (FAs), thus creating a favorable physiochemical microenvironment. Moreover, they regulate the immune microenvironment at the site of bone defects, thus directing the polarization of macrophages to the M2 type and influencing the secretion of relevant cytokines. GFNs also act as slow-release carriers of bioactive molecules with both angiogenic and antibacterial abilities, thus accelerating the repair process of bone defects. Multiple types of GFNs regulate the bone regeneration microenvironment, including scaffold materials, hydrogels, biofilms, and implantable coatings. Although GFNs have attracted much attention in the field of bone tissue engineering, their application in bone tissue regeneration is still in the basic experimental stage. To promote the clinical application of GFNs, there is a need to provide more sufficient evidence of their biocompatibility, elucidate the mechanism by which they induce the osteogenic differentiation of stem cells, and develop more effective form of applications.
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@#Adjunctive interventions for accelerating orthodontic tooth movement have been a hot topic of interest in orthodontics. Prolonged orthodontic treatment is often associated with multiple potential complications, such as decalcification, caries, root resorption, and gingival inflammation. Therefore, applying adjunctive interventions that accelerate orthodontic tooth movement and reduce the duration of orthodontic treatment can provide patients with numerous benefits that are of profound clinical significance. Currently, adjunctive interventions for accelerating orthodontic tooth movement can be divided into two main categories: surgical and nonsurgical. Surgical interventions, represented by corticotomy and modified corticotomy procedures, are the most common in clinical practice and can minimize the treatment duration, augment alveolar bone, and expand the range of orthodontic tooth movement. However, these procedures are inevitably traumatic and have many risks and limitations that prevent them from being widely used in clinical practice. In recent years, multiple modified corticotomy techniques, such as corticision, piezocision, micro-osteoperforation, and discision, have been proposed; these techniques can reduce soft and hard tissue damage and the incidence of postoperative complications and are relatively easy to perform in the clinic. Corticotomy and other improved surgical techniques can shorten the duration of orthodontic treatment to a certain extent and promote the recovery of periodontal health with no adverse effects on periodontal, dental, or pulp tissues. However, in clinical application, several potential side effects (such as periodontal tissue damage, root resorption, loss of pulp vitality, etc) and shortcomings need further research with long-term follow-up.