OBJECTIVES: To investigate the correlation between bone mineral density (BMD) and bone metabolic markers in preschool children and the influencing factors for BMD, and to provide a clinical basis for promoting bone health in children. METHODS: A retrospective analysis was performed for the data of 127 preschool children who underwent physical examination in the Department of Child Health Care of the First Affiliated Hospital of Xinjiang Medical University, from June to December 2024. BMD and bone metabolic markers were measured, and physical examination was performed. A multiple linear regression analysis was used to investigate the effect of general information on BMD Z-score in preschool children. Spearman's rank correlation test was used to investigate the correlation of BMD Z-score with 25-hydroxyvitamin D (25-OHD), serum bone Gla protein (BGP), and parathyroid hormone (PTH). RESULTS: BMD Z-score significantly differed by ethnicity, weight category, and height category (all P<0.05). The multiple linear regression analysis indicated that weight and height significantly influenced BMD Z-score (P<0.05), whereas sex, age, ethnicity, and parental education level did not (P>0.05). In children, BMD Z-score was positively correlated with 25-OHD level (r_s=0.260, P<0.001) and BGP level (r_s=0.075, P=0.025) and was negatively correlated with PTH level (r_s=-0.043, P=0.032). CONCLUSIONS Weight, height, 25-OHD, BGP, and PTH are influencing factors for BMD in preschool children. In clinical practice, combined measurement of bone metabolic markers may provide a scientific basis for early identification of children with abnormal BMD and prevention of osteoporosis and osteomalacia.
Humans ; Bone Density ; Child, Preschool ; Female ; Male ; Retrospective Studies ; Vitamin D/blood* ; Parathyroid Hormone/blood* ; Biomarkers/blood* ; Osteocalcin/blood* ; Bone and Bones/metabolism* ; Calcium-Binding Proteins/blood* ; Linear Models ; Matrix Gla Protein ; Extracellular Matrix Proteins/blood* ; Body Weight ; Infant

Collagen, which widely exists in skin, bone, muscle and other tissues, is a major structural protein in mammalian extracellular matrix. It participates in cell proliferation, differentiation, migration and signal transmission, plays an important role in tissue support and repair and exerts a protective effect. Collagen is widely used in tissue engineering, clinical medicine, food industry, packaging materials, cosmetics and medical beauty due to its good biological characteristics. This paper reviews the biological characteristics of collagen and its application in bioengineering research and development in recent years. Finally, we prospect the future application of collagen as a biomimetic material.
Animals ; Collagen/analysis* ; Tissue Engineering/methods* ; Extracellular Matrix/metabolism* ; Biomimetic Materials/chemistry* ; Bone and Bones ; Tissue Scaffolds ; Mammals/metabolism*

OBJECTIVE: To measure the concentration of bone morphogenetic protein 2 (BMP-2) in demineralized bone matrix (DBM) prepared from different long bones and to evaluate the osteoinductivity of different DBM on MC3T3-E1 cells. METHODS: Different bones from the same cadaver donor were used as the initial materials for making DBM, which were divided into ulna group (uDBM), humerus group (hDBM), tibia group (tDBM), and femur group (fDBM) according to the origins, and boiled DBM (cDBM) was taken as the control group. The proteins of DBM were extracted by guanidine hydrochloride, and the concentrations of BMP-2 were determined by ELISA assay. Then the DBM were co-cultured with MC3T3-E1 cells, the proliferation of MC3T3-E1 cells was observed by cell counting kit 8 (CCK-8) assay. The osteogenic differentiation ability of MC3T3-E1 cells was qualitatively observed by alizarin red, alkaline phosphatase (ALP), and Van Gieson staining, and the osteogenic differentiation ability of MC3T3-E1 cells was quantitatively analyzed by ALP content. Linear regression was used to analyze the effect of BMP-2 concentration in DBM on ALP synthesis. RESULTS: There were significant differences in the concentration of BMP-2 among the DBM groups (P<0.05). The concentrations of BMP-2 in the lower limb long bone were higher than those in the upper limb long bone, and the concentration of BMP-2 in the fDBM group was about 35.5 times that in the uDBM group. CCK-8 assay showed that the cells in each group continued to proliferate within 5 days of co-culture, and the absorbance (A) values at different time points were in the order of cDBM groupP<0.05). Linear regression analysis showed that y^=0.361+0.017x, the effect of BMP-2 concentration in DBM on cellular ALP content was significant (t=3.552, P=0.005); for every 1 ng/g increase in BMP-2 concentration, ALP content would increase by 0.017 [95%CI (0.006, 0.027)] U/100 mL. CONCLUSION The concentration of natural BMP-2 in different long bones varies greatly, and the lower limb long bone is higher than the upper limb long bone. The harvested location of bone material was an important factor affecting the osteoinductivity of DBM.
Alkaline Phosphatase ; Bone Matrix ; Bone Morphogenetic Protein 2 ; Cell Count ; Coloring Agents ; Osteogenesis ; Animals ; Mice

OBJECTIVE: To investigate the relationship between serum matrix metalloproteinase-1(MMP-1) and matrix metalloproteinase-2(MMP-2) and the formation of deep venous thrombosis(LDVT) in lower extremity patients after surgery for lower extremity fracture, and to analyze the value of MMP-1 and MMP-2 in predicting the occurrence of LDVT after lower extremity fracture. METHODS: From June 2018 to December 2021, 352 patients who planned to receive surgical treatment of lower limb fracture in our hospital were selected as the research objects. Venous blood was collected at 1, 2 and 3 days after surgery, respectively, and serum MMP-1 and MMP-2 levels were detected. The incidence of LDVT during hospitalization was analyzed, and the risk factors of postoperative LDVT in patients with lower limb fracture surgery and the predictive value of MMP-1 and MMP-2 for LDVT were analyzed. RESULTS: LDVT occurred in 40 patients (LDVT group), the incidence of LDVT was 11.36%, and 312 patients did not occurred(no occurred group). The serum levels of MMP-1 and MMP-2 in LDVT group increased gradually after surgery; the serum levels of MMP-1 and MMP-2 in the no occurred group increased slightly after surgery at 2 days and then decreased at 3 days after surgery (P<0.01);the serum levels of MMP-1 and MMP-2 in LDVT group were higher than those in the no occurred group at 2 days and 3 days after surgery (P<0.05). Serum levels of MMP-1 and MMP-2 were positively correlated with serum levels of interleukin-6 (IL-6), IL-8 and tumor necrosis factor -α (TNF-α) in LDVT patients at 2 days and 3 days postoperatively (P<0.05). Operative time, MMP-1 and MMP-2 postoperative 3 days were related to the occurrence of LDVT after lower limb fracture (P<0.01). The area under the curve(AUC) predicted by MMP-1 and MMP-2 postoperative 3 days for LDVT after lower limb fracture was 0.738 and 0.744 respectively, and the AUC predicted by combined MMP-1 and MMP-2 was 0.910, which was higher than that predicted by single indicator(Z=2.819 and 2.025, P<0.05). CONCLUSION High levels of MMP-1 and MMP-2 after lower extremity fracture are closely related to the occurrence of LDVT, and 3 d mMP-1 and MMP-2 after surgery maybe used as evaluation indexes for LDVT risk prediction.
Humans ; Lower Extremity/surgery* ; Matrix Metalloproteinase 1/blood* ; Matrix Metalloproteinase 2/blood* ; Risk Factors ; Venous Thrombosis/etiology* ; Fractures, Bone/surgery*

Objective: To investigate the effects of non-muscle myosin Ⅱ (NMⅡ) gene silenced bone marrow-derived mesenchymal stem cells (BMMSCs) on pulmonary extracellular matrix (ECM) and fibrosis in rats with acute lung injury (ALI) induced by endotoxin/lipopolysaccharide (LPS). Methods: The experimental research methods were adopted. Cells from femur and tibial bone marrow cavity of four one-week-old male Sprague-Dawley rats were identified as BMMSCs by flow cytometry, and the third passage of BMMSCs were used in the following experiments. The cells were divided into NMⅡ silenced group transfected with pHBLV-U6-ZsGreen-Puro plasmid containing small interference RNA sequence of NMⅡ gene, vector group transfected with empty plasmid, and blank control group without any treatment, and the protein expression of NMⅡ at 72 h after intervention was detected by Western blotting (n=3). The morphology of cells was observed by an inverted phase contrast microscope and cells labeled with chloromethylbenzoine (CM-DiⅠ) in vitro were observed by an inverted fluorescence microscope. Twenty 4-week-old male Sprague-Dawley rats were divided into blank control group, ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group according to the random number table, with 5 rats in each group. Rats in blank control group were not treated, and rats in the other 3 groups were given LPS to induce ALI. Immediately after modeling, rats in ALI alone group were injected with 1 mL normal saline via tail vein, rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were injected with 1×10⁷/mL BMMSCs and NMⅡ gene silenced BMMSCs of 1 mL labelled with CM-DiⅠ via tail vein, and rats in blank control group were injected with 1 mL normal saline via tail vein at the same time point, respectively. At 24 h after intervention, the lung tissue was collected to observe intrapulmonary homing of the BMMSCs by an inverted fluorescence microscope. Lung tissue was collected at 24 h, in 1 week, and in 2 weeks after intervention to observe pulmonary inflammation by hematoxylin eosin staining and to observe pulmonary fibrosis by Masson staining, and the pulmonary fibrosis in 2 weeks after intervention was scored by modified Ashcroft score (n=5). The content of α-smooth muscle actin (α-SMA), matrix metalloproteinase 2 (MMP-2), and MMP-9 was detected by immunohistochemistry in 2 weeks after intervention (n=3), the activity of superoxide dismutase (SOD), malondialdehyde, myeloperoxidase (MPO) was detected by enzyme-linked immunosorbent assay at 24 h after intervention (n=3), and the protein expressions of CD11b and epidermal growth factor like module containing mucin like hormone receptor 1 (EMR1) in 1 week after intervention were detected by immunofluorescence staining (n=3). Data were statistically analyzed with one-way analysis of variance, Bonferroni method, and Kruskal-Wallis H test. Results: At 72 h after intervention, the NMⅡprotein expression of cells in NMⅡ silenced group was significantly lower than those in blank control group and vector group (with P values <0.01). BMMSCs were in long spindle shape and grew in cluster shaped like vortexes, which were labelled with CM-DiⅠ successfully in vitro. At 24 h after intervention, cell homing in lung of rats in ALI+NMⅡ silenced BMMSC group was more pronounced than that in ALI+BMMSC group, while no CM-DiⅠ-labelled BMMSCs were observed in lung of rats in blank control group and ALI alone group. There was no obvious inflammatory cell infiltration in lung tissue of rats in blank control group at all time points, while inflammatory cell infiltration in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly less than that in ALI alone group at 24 h after intervention, and alveolar wall turned to be thinner and a small amount of congestion in local lung tissue appeared in rats of the two groups in 1 week and 2 weeks after intervention. In 1 week and 2 weeks after intervention, collagen fiber deposition in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group was significantly aggravated compared with that in blank control group, while collagen fiber deposition in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly improved compared with that in ALI alone group. In 2 weeks after intervention, modified Ashcroft scores for pulmonary fibrosis of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were 2.36±0.22, 1.62±0.16, 1.06±0.26, respectively, significantly higher than 0.30±0.21 in blank control group (P<0.01). Modified Ashcroft scores for pulmonary fibrosis of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly lower than that in ALI alone group (P<0.01), and modified Ashcroft score for pulmonary fibrosis of rats in ALI+NMⅡ silenced BMMSC group was significantly lower than that in ALI+BMMSC group (P<0.01). In 2 weeks after intervention, the content of α-SMA in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly decreased compared with that in ALI alone group (P<0.05 or P<0.01). The content of MMP-2 in lung tissue of rats in the 4 groups was similar (P>0.05). The content of MMP-9 in lung tissue of rats in ALI alone group was significantly increased compared with that in blank control group (P<0.01), and the content of MMP-9 in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01). At 24 h after intervention, the activity of malondialdehyde, SOD, and MPO in lung tissue of rats in ALI alone group, ALI+BMMSC group, and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in blank control group (P<0.01), the activity of malondialdehyde in lung tissue of rats in ALI+NMⅡ silenced BMMSC group and the activity of SOD in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group were significantly increased compared with that in ALI alone group (P<0.05 or P<0.01), and the activity of SOD in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). The activity of MPO in lung tissue of rats in ALI+BMMSC group and ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI alone group (P<0.01), and the activity of MPO in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly decreased compared with that in ALI+BMMSC group (P<0.01). In 1 week after intervention, the protein expression of CD11b in lung tissue of rats in ALI+NMⅡ silenced BMMSC group was significantly increased compared with those in the other three groups (P<0.05 or P<0.01), while the protein expressions of EMR1 in lung tissue of rats in the four groups were similar (P>0.05). Conclusions: Transplantation of NMⅡ gene silenced BMMSCs can significantly improve the activity of ECM components in the lung tissue in LPS-induced ALI rats, remodel its integrity, and enhance its antioxidant capacity, and alleviate lung injury and pulmonary fibrosis.
Acute Lung Injury/therapy* ; Animals ; Bone Marrow ; Collagen/metabolism* ; Endotoxins ; Extracellular Matrix ; Lipopolysaccharides/adverse effects* ; Lung ; Male ; Malondialdehyde/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Mesenchymal Stem Cells/metabolism* ; Myosin Type II/metabolism* ; Pulmonary Fibrosis ; Rats ; Rats, Sprague-Dawley ; Saline Solution/metabolism* ; Superoxide Dismutase/metabolism*

Apoptosis ; Bone Neoplasms/drug therapy* ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Humans ; Matrix Metalloproteinase 2 ; Osteosarcoma ; Ropivacaine/pharmacology*

We assessed the efficacy of frozen-thawed gelatin-induced osteogenic cell sheet (FT-GCS) compared to that of fresh gelatin-induced osteogenic cell sheet (F-GCS) with adipose-derived mesenchymal stromal cells (Ad-MSCs) used as the control. The bone differentiation capacity of GCS has already been studied. On that basis, the experiment was conducted to determine ease of use of GCS in the clinic. In vitro evaluation of F-GCS showed 3–4 layers with an abundant extracellular matrix (ECM) formation; however, cryopreservation resulted in a reduction of FT-GCS layers to 2–3 layers. Cellular viabilities of F-GCS and FT-GCS did not vary significantly. Moreover, there was no significant difference in mRNA expressions of Runx2, β-catenin, OPN, and BMP-7 between F-GCS and FT-GCS. In an in vivo experiment, both legs of six dogs with transverse radial fractures were randomly assigned to one of three groups: F-GCS, FT-GCS, or control. Fracture sites were wrapped with the respective cell sheets and fixed with 2.7 mm locking plates and six screws. At 8 weeks after the operations, bone samples were collected and subjected to micro computed tomography and histopathological examination. External volumes of callus as a portion of the total bone volume in control, F-GCS, and FT-GCS groups were 49.6%, 45.3%, and 41.9%, respectively. The histopathological assessment showed that both F-GCS and FT-GCS groups exhibited significantly (p < 0.05) well-organized, mature bone with peripheral cartilage at the fracture site compared to that of the control group. Based on our results, we infer that the cryopreservation process did not significantly affect the osteogenic ability of gelatin-induced cell sheets.
Animals ; Bone Morphogenetic Protein 7 ; Bony Callus ; Cartilage ; Cryopreservation ; Dogs ; Extracellular Matrix ; Fracture Healing ; In Vitro Techniques ; Leg ; Mesenchymal Stromal Cells ; RNA, Messenger

BACKGROUND: Articular cartilage damage is still a troublesome problem. Hence, several researches have been performed for cartilage repair. The aim of this study was to evaluate the chondrogenicity of demineralized bone matrix (DBM) scaffolds under cyclic hydrostatic pressure (CHP) in vitro. METHODS: In this study, CHP was applied to human bone marrow mesenchymal stem cells (hBMSCs) seeded on DBM scaffolds at a pressure of 5 MPa with a frequency of 0.5 Hz and 4 h per day for 1 week. Changes in chondrogenic and osteogenic gene expressions were analyzed by quantifying mRNA signal level of Sox9, collagen type I, collagen type II, aggrecan (ACAN), Osteocalcin, and Runx2. Histological analysis was carried out by hematoxylin and eosin, and Alcian blue staining. Moreover, DMMB and immunofluorescence staining were used for glycosaminoglycan (GAG) and collagen type II detection, respectively. RESULTS: Real-time PCR demonstrated that applying CHP to hBMSCs in DBM scaffolds increased mRNA levels by 1.3-fold, 1.2-fold, and 1.7-fold (p < 0.005) for Sox9, Col2, and ACAN, respectively by day 21, whereas it decreased mRNA levels by 0.7-fold and 0.8-fold (p < 0.05) for Runx2 and osteocalcin, respectively. Additionally, in the presence of TGF-β1 growth factor (10 ng/ml), CHP further increased mRNA levels for the mentioned genes (Sox9, Col2, and ACAN) by 1.4-fold, 1.3-fold and 2.5-fold (p < 0.005), respectively. Furthermore, in histological assessment, it was observed that the extracellular matrix contained GAG and type II collagen in scaffolds under CHP and CHP with TGF-β1, respectively. CONCLUSION: The osteo-inductive DBM scaffolds showed chondrogenic characteristics under hydrostatic pressure. Our study can be a fundamental study for the use of DBM in articular cartilage defects in vivo and lead to production of novel scaffolds with two different characteristics to regenerate both bone and cartilage simultaneously.
Aggrecans ; Alcian Blue ; Bone Marrow ; Bone Matrix ; Cartilage ; Cartilage, Articular ; Collagen Type I ; Collagen Type II ; Eosine Yellowish-(YS) ; Extracellular Matrix ; Fluorescent Antibody Technique ; Gene Expression ; Hematoxylin ; Humans ; Hydrostatic Pressure ; In Vitro Techniques ; Mesenchymal Stromal Cells ; Osteocalcin ; Real-Time Polymerase Chain Reaction ; RNA, Messenger

BACKGROUND: Enhancement and maintenance of the stemness of mesenchymal stem cells (MSCs) is one of the most important factors contributing to the successful in vivo therapeutic application of these cells. In this regard, three-dimensional (3D) spheroid formation has been developed as reliable method for increasing the pluripotency of MSCs. Moreover, using a new protocol, we have previously shown that dental tissues of extracted wisdom teeth can be effectively cryopreserved for subsequent use as a source of autologous stem cells. The main purpose of this study is to analyze the stemness and in vitro osteogenic differentiation potential of 3D spheroid dental MSCs compared with conventional monolayer cultured MSCs. METHODS: In this study, MSC-characterized stem cells were isolated and cultured from long-term cryopreserved dental follicles (hDFSCs), and then 2D hDFSCs were cultured under 3D spheroid-forming conditions using a newly designed microchip dish. The spheroids (3D hDFSCs) thus produced were investigated and characterized with respect to stemness, MSC marker expression, apoptosis, cell cycle analysis, extracellular matrix (ECM) production, and osteogenic and adipogenic differentiation properties. RESULTS: In terms of MSC and senescence markers, spheroid cells showed no difference when compared with 2D hDFSCs; however, 3D hDFSCs were observed to have a higher proportion of cell cycle arrest and a larger number of apoptotic cells. Moreover, spheroids showed substantially increased levels of pluripotency marker (early transcription factors) and ECM protein expression. Compared with 2D hDFSCs, there was also a notable enhancement in the osteogenic induction potential of spheroids, although no differences were observed with respect to in vitro adipogenesis. CONCLUSION: To the best of our knowledge, this is the first study to demonstrate the application of a spheroid culture system for dental follicle-derived stem cells using a microchip dish. Although further studies are needed, including in vivo transplantation, the results obtained in this study indicate that spheroid hDFSCs derived from cryopreserved dental follicle tissues could be used as a valuable source of autologous stem cells for bone tissue regeneration.
Adipogenesis ; Aging ; Apoptosis ; Bone and Bones ; Cell Cycle ; Cell Cycle Checkpoints ; Dental Sac ; Extracellular Matrix ; Humans ; In Vitro Techniques ; Mesenchymal Stromal Cells ; Methods ; Molar, Third ; Osteogenesis ; Regeneration ; Stem Cells

STUDY DESIGN: A retrospective cohort study. PURPOSE: To compare the clinical and radiological outcomes of patients who underwent anterior cervical discectomy and fusion (ACDF) supplemented with plate fixation using allograft with those who underwent ACDF using tricortical iliac autograft. OVERVIEW OF LITERATURE: As plate fixation is becoming popular, it is reported that ACDF using allograft may have similar outcomes compared with ACDF using autograft. METHODS: Forty-one patients who underwent ACDF supplemented with plate fixation were included in this study. We evaluated 24 patients who used cortical ring allograft filled with demineralized bone matrix (DBM) (group A) and 17 patients who used tricortical iliac autograft (group B). In radiological evaluations, fusion rate, subsidence of grafted material, cervical lordosis, fused segmental lordosis, and radiological adjacent segment degeneration (ASD) were observed and analyzed with preoperative and postoperative plain radiographs. Clinical outcomes were evaluated using the Neck Disability Index score, Odom criteria, and Visual Analog Scale score of neck and upper extremity pain. Radiological union was determined by dynamic radiographs using cutoff values of 1 mm of interspinous motion as the indication of pseudarthrosis. RESULTS: There was no significant difference in the fusion rate, graft subsidence, cervical lordosis, fused segmental lordosis, and ASD incidence between the groups. Operative time was shorter in group A (136 min) than in group B (141 min), but it was not significant (p>0.05). Blood loss was greater in group B (325 mL) than in group A (210 mL, p=0.013). There was no difference in the clinical outcomes before and after surgery. CONCLUSIONS: In ACDF with plate fixation, cortical ring allograft filled with DBM group showed similar radiological and clinical outcomes compared with those of the autograft group. If the metal plate is reinforced, using cortical ring allograft could be a viable alternative to autograft.
Allografts ; Animals ; Autografts ; Bone Matrix ; Cohort Studies ; Diskectomy ; Humans ; Incidence ; Lordosis ; Neck ; Operative Time ; Pseudarthrosis ; Retrospective Studies ; Transplants ; Upper Extremity ; Visual Analog Scale