Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defect...Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.展开更多
Objective： A new therapeutic strategy using nanocomposite scaffolds of grafted hydroxyapaUte （g-HA）/ poly（lactide-co-glycolide） （PLGA） carried with autologous mesenchymal stem cells （MSCs） and bone morphogene...Objective： A new therapeutic strategy using nanocomposite scaffolds of grafted hydroxyapaUte （g-HA）/ poly（lactide-co-glycolide） （PLGA） carried with autologous mesenchymal stem cells （MSCs） and bone morphogenetic protein-2 （BMP-2） was assessed for the therapy of critical bone defects. At the same time, tissue response and in vivo mineralization of tissue-engineered implants were investigated. Methods： A composite scaffold of PLGA and g-HA was fabricated by the solvent casting and particulate-leaching method. The tissue-engineered implants were prepared by seeding the scaffolds with autologous bone marrow MSCs in vitro. Then, mineralization and osteogenesis were ob- served by intramuscular implantation, as well as the repair of the critical radius defects in rabbits. Results： After eight weeks post-surgery, scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） revealed that g-HNPLGA had a better interface of tissue response and higher mineralization than PLGA. Apatite particles were formed and varied both in macropores and micropores of g-HNPLGA. Computer radiographs and histological analysis revealed that there were more and more quickly formed new bone formations and better fusion in the bone defect areas of g-HNPLGA at 2-8 weeks post-surgery. Typical bone synostosis between the implant and bone tissue was found in g-HNPLGA, while only fibrous tissues formed in PLGA. Conclusions： The incorporation of g-HA mainly im- proved mineralization and bone formation compared with PLGA. The application of MSCs can enhance bone for- mation and mineralization in PLGA scaffolds compared with cell-free scaffolds. Furthermore, it can accelerate the absorption of scaffolds compared with composite scaffolds.展开更多
BACKGROUND： Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological r...BACKGROUND： Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological rejections. Cells that do not induce immunological rejections and that are relatively easy to acquire are urgently needed for transplantation. OBJECTIVE： To bridge sciatic nerve defects using tissue engineered nerves constructed with neural tissue-committed stem cells （NTCSCs） derived from bone marrow; to observe morphology and function of rat nerves following bridging; to determine the effect of autologous nerve transplantation, which serves as the gold standard for evaluating efficacy of tissue-engineered nerves. DESIGN, TIME AND SETTING： This randomized, controlled, animal experiment was performed in the Anatomical Laboratory and Biomedical Institute of the Second Military Medical University of Chinese PLA between September 2004 and April 2006. MATERIALS： Five Sprague Dawley rats, aged 1 month and weighing 100-150 g, were used for cell culture. Sixty Sprague Dawley rats aged 3 months and weighing 220-250 g, were used to establish neurological defect models. Nestin, neuron-specific enolase （NSE）, glial fibrillary acidic protein （GFAP）, and S-100 antibodies were provided by Santa Cruz Biotechnology, Inc., USA. Acellular nerve grafts were derived from dogs. METHODS： All rats, each with 1-cm gap created in the right sciatic nerve, were randomly assigned to three groups. Each group comprised 20 rats. Autograft nerve transplantation group： the severed 1-cm length nerve segment was reverted, but with the two ends exchanged; the proximal segment was sutured to the distal sciatic nerve stump and the distal segment to the proximal stump. Blank nerve scaffold transplantation group： a 1-cm length acellular nerve graft was used to bridge the sciatic nerve gap. NTCSC engineered nerve transplantation group： a 1-cm length acellular nerve graft, in which NTCSCs were inoculated, was used to bridge the sciatic nerve gap. MAIN OUTCOME MEASURES： Following surgery, sciatic nerve functional index and electrophysiology functions were evaluated for nerve conduction function, including conduction latency, conduction velocity, and action potential peak. Horseradish peroxidase （HRP, 20%） was injected into the gastrocnemius muscle to retrogradely label the 1-4 and L5 nerve ganglions, as well as neurons in the anterior horn of the spinal cord, in the three groups. Positive expression of nestin, NSE, GFAP, and S-100 were determined using an immunofluorescence double-labeling method. RESULTS： NTCSCs differentiated into neuronal-like cells and glial-like cells within 12 weeks after NTCSC engineered nerve transplantation. HRP retrograde tracing displayed a large amount of HRP-labeled neurons in I-45 nerve ganglions, as well as the anterior horn of the spinal cord, in both the autograft nerve transplantation and the NTCSC engineered nerve transplantation groups. However, few HRP-labeled neurons were detected in the blank nerve scaffold transplantation group. Nerve bridges in the autograft nerve transplantation and NTCSC engineered nerve transplantation groups exhibited similar morphology to normal nerves. Neither fractures or broken nerve bridges nor neuromas were found after bridging the sciatic nerve gap with NTCSCs-inoculated acellular nerve graft, indicating repair. Conduction latency, action potential, and conduction velocity in the NTCSC engineered nerve transplantation group were identical to the autograft nerve transplantation group （P 〉 0.05）, but significantly different from the blank nerve scaffold transplantation group （P 〈 0.05）. CONCLUSION＂ NTCSC tissue-engineered nerves were able to repair injured nerves and facilitated restoration of nerve conduction function, similar to autograft nerve transplantation. ＂展开更多
目的探讨双能量CT Bone Marrow Edema(骨髓水肿)定量评估肋骨骨折演变时间节点的价值。方法收集60例双能量CT扫描的胸部外伤患者,利用CT Bone Marrow Edema技术,标准化定量肋骨骨折处骨髓水肿区域及骨折两侧1 cm处正常区域骨髓CT值,得...目的探讨双能量CT Bone Marrow Edema(骨髓水肿)定量评估肋骨骨折演变时间节点的价值。方法收集60例双能量CT扫描的胸部外伤患者,利用CT Bone Marrow Edema技术,标准化定量肋骨骨折处骨髓水肿区域及骨折两侧1 cm处正常区域骨髓CT值,得到三期骨髓水肿标准化CT值增量与VNCa标准化CT值增量。对数值变量行统计学描述,并对三期骨髓水肿标准化CT值增量、VNCa标准化CT值增量进行各自组间比较及两两间比较,对有差异的组别行诊断效能比较,由接受者工作特征(ROC)曲线下面积(AUC)进行评估,并计算Cut-off值。结果三期骨髓水肿标准化CT值增量及VNCa标准化CT值增量组间均有统计学意义(H=10.788,p=0.005;F=115.787,p=0.000),其中,软骨痂期(纤维性骨痂期)与硬骨痂-重塑期骨髓水肿标准化CT值增量有统计学意义(H=54.958,p=0.003),其余两两间无统计学意义(分别为H=-25.603,p=0.183;H=29.354,p=0.113)。而三期VNCa标准化CT值增量两两间均有统计学意义(P均为0.000)。ROC曲线鉴别软骨痂期(纤维性骨痂期)与硬骨痂-重塑期骨髓水肿标准化CT值增量曲线下面积为0.652,Cut-off值为81.575 Hu,鉴别血肿炎症机化期与软骨痂期(纤维性骨痂期)VNCa标准化CT值增量曲线下面积为0.668,Cut-off值为55.700 Hu,鉴别软骨痂期(纤维性骨痂期)与硬骨痂-重塑期VNCa标准化CT值增量曲线下面积为0.905,Cut-off值为37.625 Hu。结论通过双能量CT Bone Marrow Edema可定量评估肋骨骨折演变时间节点,骨折时间演变的标准化CT值增量差异性可为法医鉴定骨折处于不同时间段提供理论依据。通过标准化CT值增量Cut-off值可一定程度上预测骨折所处时间阶段,为法医在鉴定肋骨骨折方面提供定量依据。展开更多
Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from p...Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from piglets and cultured in different mediums including either vascular endothelial growth factor(VEGF)or platelet derived growth factor BB(PDGF-BB)to observe their expansion and differentiation.The aortas harvested from canines were processed by a multi-step decellularizing technique to erase.The bone marrow mononuclear cells cultured in the mediums without any growth factors were seeded to the acellular matrix.The cells-seeded grafts were incubated in vitro for 6 d and then implanted to the cells-donated piglets to substitute parts of their native pulmonary arteries.Results After 4 d culturing,the cells incubated in the medium including VEGF showed morphological feature of endothelial cells(ECs)and were positive to ECs-specific monoclonal antibodies of CD31,FLK-1,VE-Cadherin and vWF.The cells incubated in the medium including PDGF-BB showed morphological feature of smooth muscle cells(SMCs)and were positive to SMCs-specific monoclonal antibodies of α-SMA and Calponin.One hundred days after implantation of seeded grafts,the inner surfaces of explants were smooth without thrombosis,calcification and aneurysm.Under the microscopy,plenty of growing cells could be seen and elastic and collagen fibers were abundant.Conclusion Mesenchymal stem cells might exist in mononuclear cells isolated from bone marrow.They would differentiate into endothelial cells or smooth muscle cells in proper in vitro or in vivo environments.The bone marrow mononuclear cells might be a choice of seeding cells in constructing tissue-engineered graft.展开更多
Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relat...Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relatively ideal solution to these problems. Methods Bone marrow was aspirated from sternum of lamb goats to isolate BMCs. Cells were identified by flow cytometry and its capacity of differentiation. Cellular viability was assessed with Rhdomine 123 staining. 1 × 10^7cells were seeded on a patch of PGA sheet. After two-day in vitro culture, autologous cell/ scaffold sheets were used to replace the right posterior pulmonary valve leaflets under cardiopulmonary bypass. The leaflets were explanted at 2 days, 2, 6, 8 and 10 weeks after implantation. The samples were examined macroscopically, histologically, immunohistochemically, and by Scanning Electron Microscope （SEM）. Two goats were implanted with acellular sheets and established as a control group. Results BMCs exhibited fibroblastoid morphology with good viability. Flow cytometry showed negative CD14 and CD45 expression. In vitro cultured BMCs demonstrated the potential to differentiate into adipocytes. The explanted leaflets resembled the characteristics of native extracellular matrix was leaflets macroscopicaIly in the cellular group. Histology showed synthesized and cells were distributed in the single-layered leaflets.Immunohistochemistry revealed positive staining for yon Willebrand factor, α-SMA, vimentin. A confluent cell surface was formed on the explanted TEHLs. No calcium deposited on the leaflets. In control group, the acellular scaffolds were completely degraded, without leaflet remained at 8 weeks. Conclusions It is possible to create tissue-engineered heart valves in vivo using autologous bone marrow-derived cells.展开更多
The incidence of neurodegenerative diseases is increasing due to changing age demographics and the incidence of sports-related traumatic brain injury is tending to increase over time.Currently approved medicines for n...The incidence of neurodegenerative diseases is increasing due to changing age demographics and the incidence of sports-related traumatic brain injury is tending to increase over time.Currently approved medicines for neurodegenerative diseases only temporarily reduce the symptoms but cannot cure or delay disease progression.Cell transplantation strategies offer an alternative approach to facilitating central nervous system repair,but efficacy is limited by low in vivo survival rates of cells that are injected in suspension.Transplanting cells that are attached to or encapsulated within a suitable biomaterial construct has the advantage of enhancing cell survival in vivo.A variety of biomaterials have been used to make constructs in different types that included nanoparticles,nanotubes,microspheres,microscale fibrous scaffolds,as well as scaffolds made of gels and in the form of micro-columns.Among these,Tween 80-methoxy poly(ethylene glycol)-poly(lactic-co-glycolic acid)nanoparticles loaded with rhynchophylline had higher transport across a blood-brain barrier model and decreased cell death in an in vitro model of Alzheimer’s disease than rhynchophylline or untreated nanoparticles with rhynchophylline.In an in vitro model of Parkinson’s disease,trans-activating transcriptor bioconjugated with zwitterionic polymer poly(2-methacryoyloxyethyl phosphorylcholine)and protein-based nanoparticles loaded with non-Fe hemin had a similar protective ability as free non-Fe hemin.A positive effect on neuron survival in several in vivo models of Parkinson’s disease was associated with the use of biomaterial constructs such as trans-activating transcriptor bioconjugated with zwitterionic polymer poly(2-methacryoyloxyethyl phosphorylcholine)and protein-based nanoparticles loaded with non-Fe hemin,carbon nanotubes with olfactory bulb stem cells,poly(lactic-co-glycolic acid)microspheres with attached DI-MIAMI cells,ventral midbrain neurons mixed with short fibers of poly-(L-lactic acid)scaffolds and reacted with xyloglucan with/without glial-derived neurotrophic factor,ventral midbrain neurons mixed with Fmoc-DIKVAV hydrogel with/without glial-derived neurotrophic factor.Further studies with in vivo models of Alzheimer’s disease and Parkinson’s disease are warranted especially using transplantation of cells in agarose micro-columns with an inner lumen filled with an appropriate extracellular matrix material.展开更多
Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to impr...Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.展开更多
As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially ...As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.展开更多
Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,ha...Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,has garnered attention for cartilage repair in OA.While the iliac crest is the traditional site for bone marrow harvesting(BMH),associated morbidity has prompted the exploration of alternative sites such as the proximal tibia,distal femur,and proximal humerus.This paper reviews the impact of different harvesting sites on mesenchymal stem cell(MSC)yield,viability,and regenerative potential,emphasizing their relevance in knee OA treatment.The iliac crest consistently offers the highest MSC yield,but alternative sites within the surgical field of knee procedures offer comparable MSC characteristics with reduced morbidity.The integration of harvesting techniques into existing knee surgeries,such as total knee arthroplasty,provides a less invasive approach while maintaining thera-peutic efficacy.However,variability in MSC yield from these alternative sites underscores the need for further research to standardize techniques and optimize clinical outcomes.Future directions include large-scale comparative studies,advanced characterization of MSCs,and the development of personalized harvesting strategies.Ultimately,the findings suggest that optimizing the site of BMH can significantly influence the quality of MSC-based therapies for knee OA,enhancing their clinical utility and patient outcomes.展开更多
Following the discovery of bone as an endocrine organ with systemic influence,bone-brain interaction has emerged as a research hotspot,unveiling complex bidirectional communication between bone and brain.Studies indic...Following the discovery of bone as an endocrine organ with systemic influence,bone-brain interaction has emerged as a research hotspot,unveiling complex bidirectional communication between bone and brain.Studies indicate that bone and brain can influence each other’s homeostasis via multiple pathways,yet there is a dearth of systematic reviews in this area.This review comprehensively examines interactions across three key areas:the influence of bone-derived factors on brain function,the effects of brain-related diseases or injuries(BRDI)on bone health,and the concept of skeletal interoception.Additionally,the review discusses innovative approaches in biomaterial design inspired by bone-brain interaction mechanisms,aiming to facilitate bonebrain interactions through materiobiological effects to aid in the treatment of neurodegenerative and bone-related diseases.Notably,the integration of artificial intelligence(AI)in biomaterial design is highlighted,showcasing AI’s role in expediting the formulation of effective and targeted treatment strategies.In conclusion,this review offers vital insights into the mechanisms of bone-brain interaction and suggests advanced approaches to harness these interactions in clinical practice.These insights offer promising avenues for preventing and treating complex diseases impacting the skeleton and brain,underscoring the potential of interdisciplinary approaches in enhancing human health.展开更多
The delicate balance between bone formation by osteoblasts and bone resorption by osteoclasts maintains bone homeostasis.Nuclear receptors(NRs)are now understood to be crucial in bone physiology and pathology.However,...The delicate balance between bone formation by osteoblasts and bone resorption by osteoclasts maintains bone homeostasis.Nuclear receptors(NRs)are now understood to be crucial in bone physiology and pathology.However,the function of the Farnesoid X receptor(FXR),a member of the NR family,in regulating bone homeostasis remains incompletely understood.In this study,in vitro and in vivo models revealed delayed bone development and an osteoporosis phenotype in mice lacking FXR in bone marrow mesenchymal stem cells(BMSCs)and osteoblasts due to impaired osteoblast differentiation.Mechanistically,FXR could stabilize RUNX2 by inhibiting Thoc6-mediated ubiquitination,thereby promoting osteogenic activity in BMSCs.Moreover,activated FXR could directly bind to the Thoc6 promoter,suppressing its expression.The interaction between RUNX2 and Thoc6 was mediated by the Runt domain of RUNX2 and the WD repeat of Thoc6.Additionally,Obeticholic acid(OCA),an orally available FXR agonist,could ameliorate bone loss in an ovariectomy(OVX)-induced osteoporotic mouse model.Taken together,our findings suggest that FXR plays pivotal roles in osteoblast differentiation by regulating RUNX2 stability and that targeting FXR may be a promising therapeutic approach for osteoporosis.展开更多
The incidence of large bone defects caused by traumatic injury is increasing worldwide,and the tissue regeneration process requires a long recovery time due to limited self-healing capability.Endogenous bioelectrical ...The incidence of large bone defects caused by traumatic injury is increasing worldwide,and the tissue regeneration process requires a long recovery time due to limited self-healing capability.Endogenous bioelectrical phenomena have been well recognized as critical biophysical factors in bone remodeling and regeneration.Inspired by bioelectricity,electrical stimulation has been widely considered an external intervention to induce the osteogenic lineage of cells and enhance the synthesis of the extracellular matrix,thereby accelerating bone regeneration.With ongoing advances in biomaterials and energy-harvesting techniques,electroactive biomaterials and self-powered systems have been considered biomimetic approaches to ensure functional recovery by recapitulating the natural electrophysiological microenvironment of healthy bone tissue.In this review,we first introduce the role of bioelectricity and the endogenous electric field in bone tissue and summarize different techniques to electrically stimulate cells and tissue.Next,we highlight the latest progress in exploring electroactive hybrid biomaterials as well as self-powered systems such as triboelectric and piezoelectric-based nanogenerators and photovoltaic cell-based devices and their implementation in bone tissue engineering.Finally,we emphasize the significance of simulating the target tissue’s electrophysiological microenvironment and propose the opportunities and challenges faced by electroactive hybrid biomaterials and self-powered bioelectronics for bone repair strategies.展开更多
Neural EGFL-like 2(NELL2)is a secreted protein known for its regulatory functions in the nervous and reproductive systems,yet its role in bone biology remains unexplored.In this study,we observed that NELL2 was dimini...Neural EGFL-like 2(NELL2)is a secreted protein known for its regulatory functions in the nervous and reproductive systems,yet its role in bone biology remains unexplored.In this study,we observed that NELL2 was diminished in the bone of aged and ovariectomized(OVX)mice,as well as in the serum of osteopenia and osteoporosis patients.In vitro loss-of-function and gain-offunction studies revealed that NELL2 facilitated osteoblast differentiation and impeded adipocyte differentiation from stromal progenitor cells.In vivo studies further demonstrated that the deletion of NELL2 in preosteoblasts resulted in decreased cancellous bone mass in mice.Mechanistically,NELL2 interacted with the FNI-type domain located at the C-terminus of Fibronectin 1(Fn1).Moreover,we found that NELL2 activated the focal adhesion kinase(FAK)/AKT signaling pathway through Fn1/integrinβ1(ITGB1),leading to the promotion of osteogenesis and the inhibition of adipogenesis.Notably,administration of NELL2-AAV was found to ameliorate bone loss in OVX mice.These findings underscore the significant role of NELL2 in osteoblast differentiation and bone homeostasis,suggesting its potential as a therapeutic target for managing osteoporosis.展开更多
Bone age assessment(BAA)aims to determine whether a child’s growth and development are normal concerning their chronological age.To predict bone age more accurately based on radiographs,and for the left-hand X-ray im...Bone age assessment(BAA)aims to determine whether a child’s growth and development are normal concerning their chronological age.To predict bone age more accurately based on radiographs,and for the left-hand X-ray images of different races model can have better adaptability,we propose a neural network in parallel with the quantitative features from the left-hand bone measurements for BAA.In this study,a lightweight feature extractor(LFE)is designed to obtain the featuremaps fromradiographs,and amodule called attention erasermodule(AEM)is proposed to capture the fine-grained features.Meanwhile,the dimensional information of the metacarpal parts in the radiographs is measured to enhance the model’s generalization capability across images fromdifferent races.Ourmodel is trained and validated on the RSNA,RHPE,and digital hand atlas datasets,which include images from various racial groups.The model achieves a mean absolute error(MAE)of 4.42 months on the RSNA dataset and 15.98 months on the RHPE dataset.Compared to ResNet50,InceptionV3,and several state-of-the-art methods,our proposed method shows statistically significant improvements(p<0.05),with a reduction in MAE by 0.2±0.02 years across different racial datasets.Furthermore,t-tests on the features also confirm the statistical significance of our approach(p<0.05).展开更多
BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of th...BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of the radius associated with a 9 cm bone defect,which was filled with a large allogeneic cortical bone graft from a bone bank.Complete bony union was achieved after 14 months of follow-up.Previous studies have used autogenous bone as the primary bone source for the Masquelet technique;in our case,the exclusive use of allografts is as successful as the use of autologous bone grafts.With the advent of bone banks,it is possible to obtain an unlimited amount of allograft,and the Masquelet technique may be further improved based on this new way of bone grafting.CASE SUMMARY In this study,we reported a case of repair of a long bone defect in a 40-year-old male patient,which was characterized by the utilization of allograft cortical bone combined with the Masquelet technique for the treatment of the patient's long bone defect in the forearm.The patient's results of functional recovery of the forearm were surprising,which further deepens the scope of application of Masquelet technique and helps to strengthen the efficacy of Masquelet technique in the treatment of long bones indeed.CONCLUSION Allograft cortical bone combined with the Masquelet technique provides a new method of treatment to large bone defect.展开更多
The skeleton is innervated by different types of nerves and receives signaling from the nervous system to maintain homeostasis and facilitate regeneration or repair.Although the role of peripheral nerves and signals i...The skeleton is innervated by different types of nerves and receives signaling from the nervous system to maintain homeostasis and facilitate regeneration or repair.Although the role of peripheral nerves and signals in regulating bone homeostasis has been extensively investigated,the intimate relationship between the central nervous system and bone remains less understood,yet it has emerged as a hot topic in the bone field.In this review,we discussed clinical observations and animal studies that elucidate the connection between the nervous system and bone metabolism,either intact or after injury.First,we explored mechanistic studies linking specific brain nuclei with bone homeostasis,including the ventromedial hypothalamus,arcuate nucleus,paraventricular hypothalamic nucleus,amygdala,and locus coeruleus.We then focused on the characteristics of bone innervation and nerve subtypes,such as sensory,sympathetic,and parasympathetic nerves.Moreover,we summarized the molecular features and regulatory functions of these nerves.Finally,we included available translational approaches that utilize nerve function to improve bone homeostasis and promote bone regeneration.Therefore,considering the nervous system within the context of neuromusculoskeletal interactions can deepen our understanding of skeletal homeostasis and repair process,ultimately benefiting future clinical translation.展开更多
Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive mol...Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo.Hydrogels have emerged as ideal carriers to address these challenges,offering the potential to prolong retention times at lesion sites,extend half-lives in vivo and mitigate side effects,avoid burst release,and promote adsorption under physiological conditions.This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration,encompassing applications in cranial defect repair,femoral defect repair,periodontal bone regeneration,and bone regeneration with underlying diseases.Additionally,this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery,carrier-assisted delivery,and sequential delivery.Finally,this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.展开更多
基金This project was supported by national high technology re search and development program of China ( 863 Program,2001AA216031), key technologies research and developmentprogram of Beijing (H020920050031).
文摘Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.
基金Project supported by the National Natural Science Foundation of China(Nos.51473164 and 51273195)the Joint Research Project of Chinese Academy of Sciences and Japan Society for the Promotion of Science(CAS-JSPS+1 种基金No.GJHZ1519)the International Science and Technology Cooperation Program of China(No.2014DFG52510)
文摘Objective： A new therapeutic strategy using nanocomposite scaffolds of grafted hydroxyapaUte （g-HA）/ poly（lactide-co-glycolide） （PLGA） carried with autologous mesenchymal stem cells （MSCs） and bone morphogenetic protein-2 （BMP-2） was assessed for the therapy of critical bone defects. At the same time, tissue response and in vivo mineralization of tissue-engineered implants were investigated. Methods： A composite scaffold of PLGA and g-HA was fabricated by the solvent casting and particulate-leaching method. The tissue-engineered implants were prepared by seeding the scaffolds with autologous bone marrow MSCs in vitro. Then, mineralization and osteogenesis were ob- served by intramuscular implantation, as well as the repair of the critical radius defects in rabbits. Results： After eight weeks post-surgery, scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） revealed that g-HNPLGA had a better interface of tissue response and higher mineralization than PLGA. Apatite particles were formed and varied both in macropores and micropores of g-HNPLGA. Computer radiographs and histological analysis revealed that there were more and more quickly formed new bone formations and better fusion in the bone defect areas of g-HNPLGA at 2-8 weeks post-surgery. Typical bone synostosis between the implant and bone tissue was found in g-HNPLGA, while only fibrous tissues formed in PLGA. Conclusions： The incorporation of g-HA mainly im- proved mineralization and bone formation compared with PLGA. The application of MSCs can enhance bone for- mation and mineralization in PLGA scaffolds compared with cell-free scaffolds. Furthermore, it can accelerate the absorption of scaffolds compared with composite scaffolds.
基金Shanghai Municipal Natural Science Foundation,No.06ZR14108
文摘BACKGROUND： Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological rejections. Cells that do not induce immunological rejections and that are relatively easy to acquire are urgently needed for transplantation. OBJECTIVE： To bridge sciatic nerve defects using tissue engineered nerves constructed with neural tissue-committed stem cells （NTCSCs） derived from bone marrow; to observe morphology and function of rat nerves following bridging; to determine the effect of autologous nerve transplantation, which serves as the gold standard for evaluating efficacy of tissue-engineered nerves. DESIGN, TIME AND SETTING： This randomized, controlled, animal experiment was performed in the Anatomical Laboratory and Biomedical Institute of the Second Military Medical University of Chinese PLA between September 2004 and April 2006. MATERIALS： Five Sprague Dawley rats, aged 1 month and weighing 100-150 g, were used for cell culture. Sixty Sprague Dawley rats aged 3 months and weighing 220-250 g, were used to establish neurological defect models. Nestin, neuron-specific enolase （NSE）, glial fibrillary acidic protein （GFAP）, and S-100 antibodies were provided by Santa Cruz Biotechnology, Inc., USA. Acellular nerve grafts were derived from dogs. METHODS： All rats, each with 1-cm gap created in the right sciatic nerve, were randomly assigned to three groups. Each group comprised 20 rats. Autograft nerve transplantation group： the severed 1-cm length nerve segment was reverted, but with the two ends exchanged; the proximal segment was sutured to the distal sciatic nerve stump and the distal segment to the proximal stump. Blank nerve scaffold transplantation group： a 1-cm length acellular nerve graft was used to bridge the sciatic nerve gap. NTCSC engineered nerve transplantation group： a 1-cm length acellular nerve graft, in which NTCSCs were inoculated, was used to bridge the sciatic nerve gap. MAIN OUTCOME MEASURES： Following surgery, sciatic nerve functional index and electrophysiology functions were evaluated for nerve conduction function, including conduction latency, conduction velocity, and action potential peak. Horseradish peroxidase （HRP, 20%） was injected into the gastrocnemius muscle to retrogradely label the 1-4 and L5 nerve ganglions, as well as neurons in the anterior horn of the spinal cord, in the three groups. Positive expression of nestin, NSE, GFAP, and S-100 were determined using an immunofluorescence double-labeling method. RESULTS： NTCSCs differentiated into neuronal-like cells and glial-like cells within 12 weeks after NTCSC engineered nerve transplantation. HRP retrograde tracing displayed a large amount of HRP-labeled neurons in I-45 nerve ganglions, as well as the anterior horn of the spinal cord, in both the autograft nerve transplantation and the NTCSC engineered nerve transplantation groups. However, few HRP-labeled neurons were detected in the blank nerve scaffold transplantation group. Nerve bridges in the autograft nerve transplantation and NTCSC engineered nerve transplantation groups exhibited similar morphology to normal nerves. Neither fractures or broken nerve bridges nor neuromas were found after bridging the sciatic nerve gap with NTCSCs-inoculated acellular nerve graft, indicating repair. Conduction latency, action potential, and conduction velocity in the NTCSC engineered nerve transplantation group were identical to the autograft nerve transplantation group （P 〉 0.05）, but significantly different from the blank nerve scaffold transplantation group （P 〈 0.05）. CONCLUSION＂ NTCSC tissue-engineered nerves were able to repair injured nerves and facilitated restoration of nerve conduction function, similar to autograft nerve transplantation. ＂
文摘目的探讨双能量CT Bone Marrow Edema(骨髓水肿)定量评估肋骨骨折演变时间节点的价值。方法收集60例双能量CT扫描的胸部外伤患者,利用CT Bone Marrow Edema技术,标准化定量肋骨骨折处骨髓水肿区域及骨折两侧1 cm处正常区域骨髓CT值,得到三期骨髓水肿标准化CT值增量与VNCa标准化CT值增量。对数值变量行统计学描述,并对三期骨髓水肿标准化CT值增量、VNCa标准化CT值增量进行各自组间比较及两两间比较,对有差异的组别行诊断效能比较,由接受者工作特征(ROC)曲线下面积(AUC)进行评估,并计算Cut-off值。结果三期骨髓水肿标准化CT值增量及VNCa标准化CT值增量组间均有统计学意义(H=10.788,p=0.005;F=115.787,p=0.000),其中,软骨痂期(纤维性骨痂期)与硬骨痂-重塑期骨髓水肿标准化CT值增量有统计学意义(H=54.958,p=0.003),其余两两间无统计学意义(分别为H=-25.603,p=0.183;H=29.354,p=0.113)。而三期VNCa标准化CT值增量两两间均有统计学意义(P均为0.000)。ROC曲线鉴别软骨痂期(纤维性骨痂期)与硬骨痂-重塑期骨髓水肿标准化CT值增量曲线下面积为0.652,Cut-off值为81.575 Hu,鉴别血肿炎症机化期与软骨痂期(纤维性骨痂期)VNCa标准化CT值增量曲线下面积为0.668,Cut-off值为55.700 Hu,鉴别软骨痂期(纤维性骨痂期)与硬骨痂-重塑期VNCa标准化CT值增量曲线下面积为0.905,Cut-off值为37.625 Hu。结论通过双能量CT Bone Marrow Edema可定量评估肋骨骨折演变时间节点,骨折时间演变的标准化CT值增量差异性可为法医鉴定骨折处于不同时间段提供理论依据。通过标准化CT值增量Cut-off值可一定程度上预测骨折所处时间阶段,为法医在鉴定肋骨骨折方面提供定量依据。
基金Supported by Shanghai Nature Science Foundation,China(99ZB14018)
文摘Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from piglets and cultured in different mediums including either vascular endothelial growth factor(VEGF)or platelet derived growth factor BB(PDGF-BB)to observe their expansion and differentiation.The aortas harvested from canines were processed by a multi-step decellularizing technique to erase.The bone marrow mononuclear cells cultured in the mediums without any growth factors were seeded to the acellular matrix.The cells-seeded grafts were incubated in vitro for 6 d and then implanted to the cells-donated piglets to substitute parts of their native pulmonary arteries.Results After 4 d culturing,the cells incubated in the medium including VEGF showed morphological feature of endothelial cells(ECs)and were positive to ECs-specific monoclonal antibodies of CD31,FLK-1,VE-Cadherin and vWF.The cells incubated in the medium including PDGF-BB showed morphological feature of smooth muscle cells(SMCs)and were positive to SMCs-specific monoclonal antibodies of α-SMA and Calponin.One hundred days after implantation of seeded grafts,the inner surfaces of explants were smooth without thrombosis,calcification and aneurysm.Under the microscopy,plenty of growing cells could be seen and elastic and collagen fibers were abundant.Conclusion Mesenchymal stem cells might exist in mononuclear cells isolated from bone marrow.They would differentiate into endothelial cells or smooth muscle cells in proper in vitro or in vivo environments.The bone marrow mononuclear cells might be a choice of seeding cells in constructing tissue-engineered graft.
基金supported by the grant from Guangdong Nature Science Foundation(7001117)
文摘Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relatively ideal solution to these problems. Methods Bone marrow was aspirated from sternum of lamb goats to isolate BMCs. Cells were identified by flow cytometry and its capacity of differentiation. Cellular viability was assessed with Rhdomine 123 staining. 1 × 10^7cells were seeded on a patch of PGA sheet. After two-day in vitro culture, autologous cell/ scaffold sheets were used to replace the right posterior pulmonary valve leaflets under cardiopulmonary bypass. The leaflets were explanted at 2 days, 2, 6, 8 and 10 weeks after implantation. The samples were examined macroscopically, histologically, immunohistochemically, and by Scanning Electron Microscope （SEM）. Two goats were implanted with acellular sheets and established as a control group. Results BMCs exhibited fibroblastoid morphology with good viability. Flow cytometry showed negative CD14 and CD45 expression. In vitro cultured BMCs demonstrated the potential to differentiate into adipocytes. The explanted leaflets resembled the characteristics of native extracellular matrix was leaflets macroscopicaIly in the cellular group. Histology showed synthesized and cells were distributed in the single-layered leaflets.Immunohistochemistry revealed positive staining for yon Willebrand factor, α-SMA, vimentin. A confluent cell surface was formed on the explanted TEHLs. No calcium deposited on the leaflets. In control group, the acellular scaffolds were completely degraded, without leaflet remained at 8 weeks. Conclusions It is possible to create tissue-engineered heart valves in vivo using autologous bone marrow-derived cells.
文摘The incidence of neurodegenerative diseases is increasing due to changing age demographics and the incidence of sports-related traumatic brain injury is tending to increase over time.Currently approved medicines for neurodegenerative diseases only temporarily reduce the symptoms but cannot cure or delay disease progression.Cell transplantation strategies offer an alternative approach to facilitating central nervous system repair,but efficacy is limited by low in vivo survival rates of cells that are injected in suspension.Transplanting cells that are attached to or encapsulated within a suitable biomaterial construct has the advantage of enhancing cell survival in vivo.A variety of biomaterials have been used to make constructs in different types that included nanoparticles,nanotubes,microspheres,microscale fibrous scaffolds,as well as scaffolds made of gels and in the form of micro-columns.Among these,Tween 80-methoxy poly(ethylene glycol)-poly(lactic-co-glycolic acid)nanoparticles loaded with rhynchophylline had higher transport across a blood-brain barrier model and decreased cell death in an in vitro model of Alzheimer’s disease than rhynchophylline or untreated nanoparticles with rhynchophylline.In an in vitro model of Parkinson’s disease,trans-activating transcriptor bioconjugated with zwitterionic polymer poly(2-methacryoyloxyethyl phosphorylcholine)and protein-based nanoparticles loaded with non-Fe hemin had a similar protective ability as free non-Fe hemin.A positive effect on neuron survival in several in vivo models of Parkinson’s disease was associated with the use of biomaterial constructs such as trans-activating transcriptor bioconjugated with zwitterionic polymer poly(2-methacryoyloxyethyl phosphorylcholine)and protein-based nanoparticles loaded with non-Fe hemin,carbon nanotubes with olfactory bulb stem cells,poly(lactic-co-glycolic acid)microspheres with attached DI-MIAMI cells,ventral midbrain neurons mixed with short fibers of poly-(L-lactic acid)scaffolds and reacted with xyloglucan with/without glial-derived neurotrophic factor,ventral midbrain neurons mixed with Fmoc-DIKVAV hydrogel with/without glial-derived neurotrophic factor.Further studies with in vivo models of Alzheimer’s disease and Parkinson’s disease are warranted especially using transplantation of cells in agarose micro-columns with an inner lumen filled with an appropriate extracellular matrix material.
基金supported by the Natural Science Fund of Fujian Province,No.2020J011058(to JK)the Project of Fujian Provincial Hospital for High-level Hospital Construction,No.2020HSJJ12(to JK)+1 种基金the Fujian Provincial Finance Department Special Fund,No.(2021)848(to FC)the Fujian Provincial Major Scientific and Technological Special Projects on Health,No.2022ZD01008(to FC).
文摘Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.
基金supported by the National Natural Science Foundation of China(Nos.82160419 and 82302772)Guizhou Basic Research Project(No.ZK[2023]General 201)。
文摘As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.
文摘Knee osteoarthritis(OA)is a debilitating condition with limited long-term treatment options.The therapeutic potential of mesenchymal stem cells(MSCs),particularly those derived from bone marrow aspirate concentrate,has garnered attention for cartilage repair in OA.While the iliac crest is the traditional site for bone marrow harvesting(BMH),associated morbidity has prompted the exploration of alternative sites such as the proximal tibia,distal femur,and proximal humerus.This paper reviews the impact of different harvesting sites on mesenchymal stem cell(MSC)yield,viability,and regenerative potential,emphasizing their relevance in knee OA treatment.The iliac crest consistently offers the highest MSC yield,but alternative sites within the surgical field of knee procedures offer comparable MSC characteristics with reduced morbidity.The integration of harvesting techniques into existing knee surgeries,such as total knee arthroplasty,provides a less invasive approach while maintaining thera-peutic efficacy.However,variability in MSC yield from these alternative sites underscores the need for further research to standardize techniques and optimize clinical outcomes.Future directions include large-scale comparative studies,advanced characterization of MSCs,and the development of personalized harvesting strategies.Ultimately,the findings suggest that optimizing the site of BMH can significantly influence the quality of MSC-based therapies for knee OA,enhancing their clinical utility and patient outcomes.
基金financially supported by the Basic Science Center Program(T2288102)the Key Program of the National Natural Science Foundation of China(32230059)+3 种基金the Foundation of Frontiers Science Center for Materiobiology and Dynamic Chemistry(JKVD1211002)the Project supported by the Young Scientists Fund of the National Natural Science Foundation of China(32401128)Postdoctoral Fellowship Program of CPSF(GZC20230793)Shanghai Post-doctoral Excellence Program(2023251).
文摘Following the discovery of bone as an endocrine organ with systemic influence,bone-brain interaction has emerged as a research hotspot,unveiling complex bidirectional communication between bone and brain.Studies indicate that bone and brain can influence each other’s homeostasis via multiple pathways,yet there is a dearth of systematic reviews in this area.This review comprehensively examines interactions across three key areas:the influence of bone-derived factors on brain function,the effects of brain-related diseases or injuries(BRDI)on bone health,and the concept of skeletal interoception.Additionally,the review discusses innovative approaches in biomaterial design inspired by bone-brain interaction mechanisms,aiming to facilitate bonebrain interactions through materiobiological effects to aid in the treatment of neurodegenerative and bone-related diseases.Notably,the integration of artificial intelligence(AI)in biomaterial design is highlighted,showcasing AI’s role in expediting the formulation of effective and targeted treatment strategies.In conclusion,this review offers vital insights into the mechanisms of bone-brain interaction and suggests advanced approaches to harness these interactions in clinical practice.These insights offer promising avenues for preventing and treating complex diseases impacting the skeleton and brain,underscoring the potential of interdisciplinary approaches in enhancing human health.
基金supported by National Natural Science Foundation of China(grant numbers 82072523 to Zhiyong Hou)Postdoctoral program of Clinical medicine of Hebei Medical University(grant numbers PD2023012 to Sujuan Xu)+2 种基金Excellent postdoctoral research funding project of Hebei Province(grant numbers B2023005011 to Sujuan Xu)The 16th special grant of China Postdoctoral Science Foundation(grant numbers 2023T160182 to Sujuan Xu)Natural Science Foundation of Hebei Province,China(grant numbers H2023206230 to Yingchao Yin,H2024206186 to Sujuan Xu).
文摘The delicate balance between bone formation by osteoblasts and bone resorption by osteoclasts maintains bone homeostasis.Nuclear receptors(NRs)are now understood to be crucial in bone physiology and pathology.However,the function of the Farnesoid X receptor(FXR),a member of the NR family,in regulating bone homeostasis remains incompletely understood.In this study,in vitro and in vivo models revealed delayed bone development and an osteoporosis phenotype in mice lacking FXR in bone marrow mesenchymal stem cells(BMSCs)and osteoblasts due to impaired osteoblast differentiation.Mechanistically,FXR could stabilize RUNX2 by inhibiting Thoc6-mediated ubiquitination,thereby promoting osteogenic activity in BMSCs.Moreover,activated FXR could directly bind to the Thoc6 promoter,suppressing its expression.The interaction between RUNX2 and Thoc6 was mediated by the Runt domain of RUNX2 and the WD repeat of Thoc6.Additionally,Obeticholic acid(OCA),an orally available FXR agonist,could ameliorate bone loss in an ovariectomy(OVX)-induced osteoporotic mouse model.Taken together,our findings suggest that FXR plays pivotal roles in osteoblast differentiation by regulating RUNX2 stability and that targeting FXR may be a promising therapeutic approach for osteoporosis.
基金support of the National Natural Science Foundation of China(Grant No.52205593)Shaanxi Natural Science Foundation Project(2024JC-YBMS-711).
文摘The incidence of large bone defects caused by traumatic injury is increasing worldwide,and the tissue regeneration process requires a long recovery time due to limited self-healing capability.Endogenous bioelectrical phenomena have been well recognized as critical biophysical factors in bone remodeling and regeneration.Inspired by bioelectricity,electrical stimulation has been widely considered an external intervention to induce the osteogenic lineage of cells and enhance the synthesis of the extracellular matrix,thereby accelerating bone regeneration.With ongoing advances in biomaterials and energy-harvesting techniques,electroactive biomaterials and self-powered systems have been considered biomimetic approaches to ensure functional recovery by recapitulating the natural electrophysiological microenvironment of healthy bone tissue.In this review,we first introduce the role of bioelectricity and the endogenous electric field in bone tissue and summarize different techniques to electrically stimulate cells and tissue.Next,we highlight the latest progress in exploring electroactive hybrid biomaterials as well as self-powered systems such as triboelectric and piezoelectric-based nanogenerators and photovoltaic cell-based devices and their implementation in bone tissue engineering.Finally,we emphasize the significance of simulating the target tissue’s electrophysiological microenvironment and propose the opportunities and challenges faced by electroactive hybrid biomaterials and self-powered bioelectronics for bone repair strategies.
基金supported by grants from National Natural Science Foundation of China(82272444,81972031,81972033)China Postdoctoral Science Foundation(2022M722382)Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-032A)。
文摘Neural EGFL-like 2(NELL2)is a secreted protein known for its regulatory functions in the nervous and reproductive systems,yet its role in bone biology remains unexplored.In this study,we observed that NELL2 was diminished in the bone of aged and ovariectomized(OVX)mice,as well as in the serum of osteopenia and osteoporosis patients.In vitro loss-of-function and gain-offunction studies revealed that NELL2 facilitated osteoblast differentiation and impeded adipocyte differentiation from stromal progenitor cells.In vivo studies further demonstrated that the deletion of NELL2 in preosteoblasts resulted in decreased cancellous bone mass in mice.Mechanistically,NELL2 interacted with the FNI-type domain located at the C-terminus of Fibronectin 1(Fn1).Moreover,we found that NELL2 activated the focal adhesion kinase(FAK)/AKT signaling pathway through Fn1/integrinβ1(ITGB1),leading to the promotion of osteogenesis and the inhibition of adipogenesis.Notably,administration of NELL2-AAV was found to ameliorate bone loss in OVX mice.These findings underscore the significant role of NELL2 in osteoblast differentiation and bone homeostasis,suggesting its potential as a therapeutic target for managing osteoporosis.
基金supported by the grant from the National Natural Science Foundation of China(No.72071019)grant from the Natural Science Foundation of Chongqing(No.cstc2021jcyj-msxmX0185).
文摘Bone age assessment(BAA)aims to determine whether a child’s growth and development are normal concerning their chronological age.To predict bone age more accurately based on radiographs,and for the left-hand X-ray images of different races model can have better adaptability,we propose a neural network in parallel with the quantitative features from the left-hand bone measurements for BAA.In this study,a lightweight feature extractor(LFE)is designed to obtain the featuremaps fromradiographs,and amodule called attention erasermodule(AEM)is proposed to capture the fine-grained features.Meanwhile,the dimensional information of the metacarpal parts in the radiographs is measured to enhance the model’s generalization capability across images fromdifferent races.Ourmodel is trained and validated on the RSNA,RHPE,and digital hand atlas datasets,which include images from various racial groups.The model achieves a mean absolute error(MAE)of 4.42 months on the RSNA dataset and 15.98 months on the RHPE dataset.Compared to ResNet50,InceptionV3,and several state-of-the-art methods,our proposed method shows statistically significant improvements(p<0.05),with a reduction in MAE by 0.2±0.02 years across different racial datasets.Furthermore,t-tests on the features also confirm the statistical significance of our approach(p<0.05).
文摘BACKGROUND The induced-membrane technique was initially described by Masquelet as an effective treatment for large bone defects,especially those caused by infection.Here,we report a case of chronic osteomyelitis of the radius associated with a 9 cm bone defect,which was filled with a large allogeneic cortical bone graft from a bone bank.Complete bony union was achieved after 14 months of follow-up.Previous studies have used autogenous bone as the primary bone source for the Masquelet technique;in our case,the exclusive use of allografts is as successful as the use of autologous bone grafts.With the advent of bone banks,it is possible to obtain an unlimited amount of allograft,and the Masquelet technique may be further improved based on this new way of bone grafting.CASE SUMMARY In this study,we reported a case of repair of a long bone defect in a 40-year-old male patient,which was characterized by the utilization of allograft cortical bone combined with the Masquelet technique for the treatment of the patient's long bone defect in the forearm.The patient's results of functional recovery of the forearm were surprising,which further deepens the scope of application of Masquelet technique and helps to strengthen the efficacy of Masquelet technique in the treatment of long bones indeed.CONCLUSION Allograft cortical bone combined with the Masquelet technique provides a new method of treatment to large bone defect.
基金supported by the Health&Medical Research Fund(18190481)the General Research Fund(14120520).
文摘The skeleton is innervated by different types of nerves and receives signaling from the nervous system to maintain homeostasis and facilitate regeneration or repair.Although the role of peripheral nerves and signals in regulating bone homeostasis has been extensively investigated,the intimate relationship between the central nervous system and bone remains less understood,yet it has emerged as a hot topic in the bone field.In this review,we discussed clinical observations and animal studies that elucidate the connection between the nervous system and bone metabolism,either intact or after injury.First,we explored mechanistic studies linking specific brain nuclei with bone homeostasis,including the ventromedial hypothalamus,arcuate nucleus,paraventricular hypothalamic nucleus,amygdala,and locus coeruleus.We then focused on the characteristics of bone innervation and nerve subtypes,such as sensory,sympathetic,and parasympathetic nerves.Moreover,we summarized the molecular features and regulatory functions of these nerves.Finally,we included available translational approaches that utilize nerve function to improve bone homeostasis and promote bone regeneration.Therefore,considering the nervous system within the context of neuromusculoskeletal interactions can deepen our understanding of skeletal homeostasis and repair process,ultimately benefiting future clinical translation.
基金supported by the National Natural Science Foundation of China(51925304)Natural Science Foundation of Sichuan Province(2024NSFSC1023)Medical Research Program of Sichuan Province(Q23015).
文摘Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo.Hydrogels have emerged as ideal carriers to address these challenges,offering the potential to prolong retention times at lesion sites,extend half-lives in vivo and mitigate side effects,avoid burst release,and promote adsorption under physiological conditions.This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration,encompassing applications in cranial defect repair,femoral defect repair,periodontal bone regeneration,and bone regeneration with underlying diseases.Additionally,this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery,carrier-assisted delivery,and sequential delivery.Finally,this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.
