جستجوی مقالات مرتبط با کلیدواژه « osteogenesis » در نشریات گروه « پزشکی »

Spheno-occipital synchondrosis is a growth center that is involved in craniofacial development. Since osteogenesis of this synchondrosis occurs relatively later than other synchondroses, it has been taken into account for age estimation in forensics. This study aimed to evaluate spheno-occipital synchondrosis using Cone-Beam Computed Tomography (CBCT) in an Iranian population.  In this cross-sectional study, 148 CBCT images (76 women and 72 men) of patients aged 7-25 years, with a mean age of 19.92±6.3 years, were assessed by two radiologists to analyze the spheno-occipital synchondrosis fusion degree using a four-stage system. In addition, the third molar development degree (Demirjian index) was assessed in panoramic and cross-sectional views of CBCT images. The correlation between spheno-occipital synchondrosis fusion degree and age was obtained. Multiple regression analysis was used for age estimation using spheno-occipital synchondrosis fusion degree and third molar development degree (Demirjian index). Intra-observer and inter-observer coefficients of agreements were also measured. IBM SPSS Statistics 20.0 was used.  There was a positive correlation between spheno-occipital synchondrosis fusion degree and age (r=0.75, p<0.001). The multiple regression model provides a more robust model than when each age marker is utilized individually. The kappa coefficient was 0.53 for inter-observer agreement and 0.77-0.92 for intra-observer agreement.  Assessing the four-stage spheno-occipital synchondrosis fusion degree was not a robust method; however, combined with the third molar development (Demirjian index), it could be considered as an appropriate marker for age estimation in 7-25-year-old Iranian population.

Bone tissue engineering is considered a new method in the treatment of bone defects and can be an effective alternative to surgery and bone grafting. The use of adipose tissue mesenchymal stem cells (ADMSCs) on synthetic polymer scaffolds is one of the new approaches in bone tissue engineering. In this study, we aimed to investigate the effect of laminin coating on biocompatibility and osteogenic differentiation of ADMSCs seeded on polycaprolactone (PCL) scaffolds.

The morphology of the electrospun scaffold was evaluated using a scanning electron microscope (SEM). Cell proliferation and cytotoxicity were determined by MTT assay. The adipogenic and osteogenic differentiation potential of the cells was evaluated. The osteogenic differentiation of ADMSCs cultured on the PCL scaffold coated with laminin was assessed by evaluating the level of alkaline phosphatase (ALP) activity, intracellular calcium content, and expression of bone-specific genes.

The results showed that the ADMSCs cultured on PCL/laminin showed enhanced osteogenic differentiation compared to those cultured on non-coated PCL or control medium (P<0.05).

It seems that laminin enhances the physicochemical properties and biocompatibility of PCL nanofiber scaffolds; and by modifying the surface of the scaffold, improves the differentiation of ADMSCs into osteogenic cells.

Statement of the Problem: 

Using plate and screws as the conventional bone fixation method in maxillofacial fractures leads to many complications as plate exposure, infection or unpleasant feeling on touching. Finding a substitute fixation method has been a far desire for many years.

This study compared the new bone formation using an experimental bone adhesive containing a functional monomer (benzophenone tetracarboxylic di-methacrylate, BTDMA) and the conventional plate and screw in fractured mandibles of rabbit.

This is an experimental animal study. The artificial fractures were induced at the mandibular angles of three male New Zealand rabbits. Screw and plate were used as control and titanium mesh with the resin-based bone adhesive containing 15 wt. % BTDMA monomer were applied as treatment. The mandible radiography were obtained and the density of the fracture line was compared to the control. The newly formed bone was assessed by a microscope.

The results obtained from the MTT cytotoxicity assay showed that 70% of cells were able to grow in the presence of the adhesive. The radiographic density of mesh-adhesive specimens was 119.88±76.29, while conventional plate specimens’ density was 120.38±73.89. The average new bone formation score in the mesh specimens and plate specimens was 3.67±4.62 and 7±4.36, respectively. There was no significant difference between the two groups. The application of bone adhesive containing 15% BTDMA monomer in a group of the rabbits showed lamellar bone formation.

Using bone adhesives containing BTDMA could lead to a new bone formation with high density in the case of adequate bonding to the fractured area.

Stem cells are used to treat numerous diseases; however, their lifespan is rather short. Factors such as probiotics affect and improve various cell lineage efficacies. The aim of this study was to investigate the effects of probiotics-conditioned media on dental pulp stem cell potentials in osteogenesis.

The experiment was initiated by culturing Lactobacillus casei and Lactobacillus acidophilus probiotics as well as DPS-7 cells. Bacterial supernatants were separated and concentrated as the conditioned media. The DPS-7 cells were treated with various concentrations of the conditioned media. Furthermore, MTT assay and alkaline phosphatase activity were used. The mRNA expression of three genes (bFGF, EGF-β and BMP-2) involved in osteogenesis was analyzed using a real-time polymerase chain reaction.

The response of dental pulp stem cells to probiotics preconditioning promoted cell proliferation, increased alkaline phosphatase activity and upregulated bFGF and BMP-2 gene expression. Increased expression was significant for BMP-2 and moderate for bFGF; however, it was non-significant for EGF-β. The use of the two probiotics was the most effective.

In general, synergism of the combined probiotics preconditioning induces differentiation of DPS-7 cells into osteoblasts most effectively.

Osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is an essential stage in bone formation. Autophagy plays a pivotal role in the self-renewal potential and pluripotency of stem cells. This study aimed to explore the function of autophagy-related genes during osteogenic differentiation of BMSCs.

The differentially expressed autophagy-related genes (ARGs) were obtained from the GEO and HADb databases. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using R software. The PPI and hub gene mining networks were constructed using the STRING database and Cytoscape. Finally, the RT-qPCR was conducted to validate the expression level of ARGs in BMSCs.

Thirty-seven differentially expressed ARGs were finally obtained, including 12 upregulated and 25 downregulated genes. GO and KEGG enrichment analysis showed that most of these genes were enriched in apoptosis and autophagy. The PPI network revealed strong interactions between differentially expressed ARGs. The expression level of differentially expressed ARGs tested by RT-qPCR showed 6 upregulated ARGs, including FOXO1, MAP1LC3C, CTSB, FOXO3, CALCOCO2, FKBP1A, and 4 downregulated  ARGs, including MAPK8IP1, NRG1, VEGFA, and ITGA6 were consistent with the expression of high-throughput sequencing data.

We identified 37 ARGs during osteogenic differentiation using bioinformatics analysis. FOXO1, MAP1LC3C, CTSB, FOXO3, CALCOCO2, FKBP1A, MAPK8IP1, NRG1, VEGFA, and ITGA6 may regulate osteogenic differentiation of hBMSCs by involving autophagy pathway. This study provides new insight into the osteogenic differentiation of hBMSCs and may be available in developing therapeutic strategies for maxillofacial bone defects.

Statement of the Problem: 

Predictable bone regeneration is an objective in implant and periodontal treatments and barrier membranes may play a significant role in osteogenic reconstruction and differentiation.

We compared the osteoblastic differentiation level of bone marrow stem cells in the vicinity of different barrier membranes.

In this experimental in vitro study, human collagen membrane (HCM; Regen), xenogeneic collagen membrane (XCM; Jason), human acellular dermal matrix (HADM; Regen), and xenogeneic acellular dermal matrix (XADM) were used in 4 groups. No membranes were used in the control group (5th group). Bone marrow stem cells with 150,000 cells/well density were added to the culture medium. Cellular differentiation was assessed through real-time quantitative reverse transcription polymerase chain reaction (QRT-PCR) for alkaline phosphatase (ALP) and osteopontin (OPN) gene expression, and Alizarin Red staining after 21 days. Data were analyzed using Kruskal- Wallis and Mann–Whitney statistical tests on SPSS 20 software (p Value< 0.05).

ALP gene expression was significantly higher in HCM group compared to other four groups (p< 0.009) followed by XADM, control, HADM and XCM groups, respectively (p< 0.001). OPN gene expression was significantly more prominent in HCM group compared to other groups (p< 0.01) followed by XADM group in which OPN gene was expressed significantly more than XCM group. OPN gene expression was not significantly different in HADM and control groups (p= 0.52). Light absorption rate was higher in HCM group compared with other groups (p< 0.012). Light absorption rate was not significantly different among HADM, XADM, and control groups (p> 0.05), though it was higher in XCM group (p= 0.009).

Bone marrow stem cells show different levels of differentiation in the vicinity of different membranes. Generally, cell differentiation was more prominent in the vicinity of human collagen membrane.

This study aimed to evaluate the amount of bone regeneration in critical defects of rabbit calvaria filled with magnesium‑ and strontium‑doped bioactive glasses.

In this rabbit critical‑size calvarial defects study, 12 male New Zealand white rabbits were randomly divided into two groups. On the calvaria of each rabbit, four lesions (two lesions in the frontal bone and two lesions in the peritoneal bone) were created with a diameter of 8 mm spaced apart. Each lesion was filled in with (1) strontium‑doped bioactive glass,(2) magnesium‑doped bioactive glass,(3) 45S5 bioactive glass, and (4) empty lesion (control). Six rabbits were sacrificed at the end of 4 weeks, and six rabbits were randomly sacrificed at the end of 8 weeks. Bone sections with a 5‑µ thickness of rabbit calvary bone were prepared, and the percentage of new bone, connective tissue, and residual material were calculated in microscopic images. Statistical analysis was performed by two‑way ANOVA and Bonferroni additional tests, and the level of significance was set at P < 0.05 in all categories.

At 4 weeks, magnesium‑doped bioactive glass showed the highest new bone formation with a mean of 11.66 ± 2.64, followed by the strontium‑doped bioactive glass with the mean of 11.10 ± 1.69 (P = 0.0001). While at week 8, the highest amount of new bone observed in the strontium‑doped group with a mean of 28.22 ± 3.19, and then, the magnesium‑doped bioactive glass with a mean of 22.55 ± 3.43 (P = 0.0001).

Doping strontium and magnesium in the structure of bioactive glasses increases new bone regeneration in comparison with 45S5 bioactive glass.

Recently, bone tissue engineering as a new strategy is used to repair and replace bone defects due to limitations in allograft and autograft methods. In this regard, we prepared nanofibrous scaffolds composed of polycaprolactone and magnesium oxide nanoparticles using the electrospinning technique for possible bone tissue engineering applications.

The fabricated composites were characterized via scanning electron microscopy imaging of scaffolds and seeded cells, water contact angle, DAPI staining, and MTT assay. Then osteogenic differentiation of adipose-derived mesenchymal stem cells cultured on this composite scaffold was determined by standard osteogenic marker tests, including alkaline phosphatase activity, calcium deposition, and expression of osteogenic differentiation genes in the laboratory conditions.

The Scanning electron microscopy analysis demonstrated that the diameter of nanofibers significantly decreased from 1029.25±209.349 µm to 537.83+0.140 nm, with the increase of MgO concentration to 2% (p<0.05). Initial adhesion and proliferation of the adipose-derived mesenchymal stem cells on magnesium oxide/polycaprolactone scaffolds were significantly enhanced with the increasing of magnesium oxide concentration (p<0.05). The 2% magnesium oxide/polycaprolactone nanofibrous scaffold showed significant increase in ALP activity (p<0.05) and osteogenic-related gene expressions (Col1a1 and OPN) (p<0.05) in compared to pure polycaprolactone and (0, 0.5 and 1%) magnesium oxide/polycaprolactone scaffolds.

According to the results, it was demonstrated that magnesium oxide/polycaprolactone composite nanofibers have considerable osteoinductive potential, and taking together adipose-derived mesenchymal stem cells-magnesium oxide/polycaprolactone composite nanofibers can be a proper bio-implant to usage for bone regenerative medicine applications. Future in vivo studies are needed to determine this composite therapeutic potential.

The collagen membrane which obtained from bovine pericardium and human skin in Guided Bone Regeneration (GBR) is costly and may even cause transmission of diseases. Replacing conventional collagen membranes with a more easily accessible and cheaper ones will have economic benefits. The aim was to determine the osteogenic effect of collagen‑membrane derived from Rutilus kutum swim bladder on rat calvaria.

The study was experimental. Thirty‑six male albino rats of the Wistar strain were included in the study. The 5 mm surgical defects were created on calvarias and filled with allograft bone material and covered by R. kutum swim bladder (Group I), bovine derived pericardial membrane (Group II) and without membrane cover(Group III).The specimen were euthanized after 3, 5 and 8 weeks. The surrounding connective tissue was evaluated in term of osseous formation. Kruskal–Wallis, Univariant analysis of variance, and post hoc tests were used for statistical analysis. The P < 0.05 was considered statistically significant.

A significant differences between groups in terms of osseous formation (P = 0.001) was noted. The difference of osseous formation was significantly higher in 5 and 8 weeks than 3 weeks after operation in all groups (P = 0.03 and P = 0.006, respectively). The osseous formation in Group I and II were significantly higher than Group III (P = 0.023 and P = 0.001).

The R.kutum swim bladder had osteogenic effect on rat calvaria. R.kutum swim bladder can be a new source in natural derived collagen membrane in GBR.

Platelet-rich plasma (PRP) is paid attention for regenerative therapy because it clinically improves neoangiogenesis and periodontal regeneration. PRP can be made in form of homologous PRP (HPRP) from healthy, screened, and habitual blood donors and freezedried to increase stored time of HPRP and maintain growth factors. The purpose of this study is to evaluate freeze-dried homologous plateletrich plasma (FD HPRP) on osteogenesis.

HPRP was taken from the blood bank and then a freeze-drying and gradiation process was carried out with doses of 20 and 25 KGy, respectively, for the sterilization. Blood was collected as much as 10 mL and then centrifuged at 700 rpm for 3 minutes to produce injectable platelet-rich fibrin (iPRF) as a positive control. Cell line MG63 were cultured to confluent, and then treated with FD HPRP 20 kGy, FD HPRP 25 kGy, iPRF, and one group non treated as a negative control. Osteocytes were determined based on morphology after hematoxylin staining to see the differentiation process. The data were analyzed using one-way analysis of variance (ANOVA).

There was a significant difference in the number of osteocytes between FD HPRP and negative control (P < 0.05). The number of osteocytes FD HPRP 25 was higher than FD HPRP 20.

The present results indicate that FD HPRP could support the bone regeneration and used without any preparation like fresh PRP.

The ability of simultaneous treatment of critical-sized femoral defects (CSFDs) with photobiomodulation (PBM) and demineralized bone matrix (DBM) with or without seeded adipose-derived stem cells (ASCs) to induce bone reconstruction in ovariectomized induced osteoporotic (OVX) rats was investigated.

The OVX rats with CSFD were arbitrarily separated into 6 groups: control, scaffold (S, DBM), S + PBM, S + alendronate (ALN), S + ASCs, and S + PBM + ASCs. Each group was assessed by cone beam computed tomography (CBCT) and histological examinations.

In the fourth week, CBCT and histological analyses revealed that the largest volume of new bone formed in the S + PBM and S + PBM + ASC groups. The S + PBM treatment relative to the S and S + ALN treatments remarkably reduced the CSFD (Mann-Whitney test, P = 0.009 and P = 0.01). Furthermore, S + PBM + ASCs treatment compared to the S and S + ALN treatments significantly decreased CSFD (Mann Whitney test, P = 0.01). In the eighth week, CBCT analysis showed that extremely enhanced bone regeneration occurred in the CSFD of the S + PBM group. Moreover, the CSFD in the S + PBM group was substantially smaller than S, S + ALN and S + ASCs groups (Mann Whitney test, P = 0.01, P = 0.02 and P = 0.009). Histological observations showed more new bone formation in the treated CSFD of S + PBM + ASCs and S + PBM groups.

The PBM plus DBM with or without ASCs significantly enhanced bone healing in the CSFD in OVX rats compared to control, DBM alone, and ALN plus DBM groups. The PBM plus DBM with or without ASCs significantly decreased the CSFD area compared to either the solo DBM or ALN plus DBM treatments.

Stem cells have gained great attention in tissue engineering and curcumin is a natural phenolic product that had showed some positive effects on these cells. The aim of this study was to evaluate the effect of curcumin on the differentiation of human dental pulp stem cells (hDPSCs).

In this experimental study, hDPSCs were isolated from human third molars and treated without and with different concentrations (5, 10 and 15 µM) of curcumin and dimethyl sulfoxide (DMSO) as solvent for curcumin. Proliferation of the cells was measured by methyl-thiazol-tetrazolium (MTT) assay. Osteo/odntogenesis were assessed by alkaline phosphatase (ALP) assay and alizarin red staining. The collected data were subjected to statistical analysis (two-way ANOVA and Bonferroni correction) at a significant level of 0.05 by using SPSS software version 21.

MTT assay showed that addition of curcumin at 5μM concentration to the medium had no significant effect on cell proliferation compared with control group. Higher concentrations significantly inhibited cell proliferation at days 2 and 14. ALP showed reduced cell activity at all concentrations compared with control group. However, curcumin at 5μm concentration increased the ALP activity compared with DMSO group. Alizarin red staining showed that curcumin had no effect on mineralization.

Curcumin did not induce osteo/odontogenic differentiation of hDPSCs. However, low concentration of curcumin was not toxic and increased the ALP activity of the cells compared with the DMSO group.

We investigated the role of various biomaterials on cell viability and in healing of an experimentally induced femoral bone hole model in rats. Cell viability and cytotoxicity of gelatin (Gel; 50 µg/µl), chitosan (Chi; 20 µg/µl), hydroxyapatite (HA; 50 µg/µl), nanohydroxyapatite (nHA; 10 µg/µl), three-calcium phosphate (TCP; 50 µg/µl) and strontium carbonate (Sr; 10 µg/µl) were evaluated on hADSCs via MTT assay. In vivo femoral drill-bone hole model was produced in rats that were either left untreated or treated with autograft, Gel, Chi, HA, nHA, TCP and Sr, respectively. The animals were euthanized after 30 days. Their bone holes were evaluated by gross-pathology, histopathology, SEM and radiography. Also, their dry matter, bone ash and mineral density were measured. Both the Gel and Chi showed cytotoxicity, while nHA had no role on cytotoxicity and cell-viability. All the HA, TCP and Sr significantly improved cell viability when compared to controls (p <0.05). Both the Gel and Chi had no role on osteoconduction and osteoinduction. Compared to HA, nHA showed superior role in increasing new bone formation, mineral density and ash (p <0.05). In contrast to HA and nHA, both the TCP and Sr showed superior morphological, radiographical and biochemical properties on bone healing (p <0.05). TCP and Sr showed the most effective osteoconduction and osteoinduction, respectively. In the Sr group, the most mature type of osteons formed. Various biomaterials have different in vivo efficacy during bone regeneration. TCP was found to be the best material for osteoconduction and Sr for osteoinduction.

 Small molecules are active substances which are used in bone tissue engineering. They present great characteristics including induction of developmental genes, bioavailability and easy metabolism. Purmorphamine is a small molecule which has been demonstrated to exert osteogenic effects. In the present study we aimed to review present literature regarding the osteogenic effect of purmorphamine.

 The MEDLINE (NCBI PubMed and PMC), Google Scholar and Scopus were searched by the following keywords “purmorphamine” AND “osteogenesis” OR “osteogenic differentiation” OR “bone formation”. According to PRISMA statement, all in vivo and in vitro studies conducted on osteogenic effect of purmorphamine were included. Search was limited to English-language studies up to February 2020.

 Finally, 16 studies were included and the data were extracted. Data were categorized by the studied cell type, purmorphamine dosage and treatment groups, scaffolds and results.

 It is demonstrated that purmorphamine may be effective in osteogenic differentiation of various cells but this effect may vary by applied dosage and duration.

The enhancement of osteogenesis by tissue engineering is a challenge in periodontal therapy. Several graft materials in conjunction with carriers, such as blood or saline, are used for this purpose. This study aimed to assess the effect of phosphate buffered saline (PBS), Hank's balanced salt solution (HBSS) and saline on the activity of MG-63 osteoblast-like cells in the presence and absence of beta-tricalcium phosphate (β-TCP).

In this in vitro experimental study, MG-63 osteoblast-like cells were cultured in 10% PBS, HBSS and saline (10%) with and without β-TCP granules for 24 and 72 h and five days. At 24 and 72 h, cell viability and proliferation were assessed. Alkaline phosphatase (ALP) activity test was used to assess bone activity. The data were analyzed using SPSS version 20 (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp) via one-way and two-way ANOVA (P<0.05).

Pairwise comparisons showed no significant difference in the viability of MG-63 cells at 24 h in the three solutions (with equal β-TCP content) or with the negative control group (complete culture). At 72 h, significant differences were only observed in the reduction of cell proliferation between 10% saline without β-TCP and 10% saline with β-TCP , and also between HBSS without β-TCP and HBSS with β-TCP (P<0.05).

The three solutions did not induce ALP activity at 24 or 72 h and did not cause the formation of any calcified nodule at three or five days in MG-63 cells.