Osteoblast Density Research Articles

Development and characterization of MAO/PLA-nHA nanocomposite coatings on pure zinc for orthopedic applications

Zinc (Zn)-based medical alloys are considered to be a biodegradable material with great potential. Hydroxyapatite (HA) can improve the osteogenic properties of Zn alloys, but its adhesion strength needs improvement. In this study, a micro-arc oxidation (MAO) interlayer and polylactic acid (PLA) composite layers containing different contents of nano-HA (nHA) were successively prepared on the pure Zn surface by MAO and sol–gel impregnation methods. The adhesion results showed that PLA could enhance the adhesion of HA on the Zn surface, where the adhesion of the Zn/MAO/PLA-nHA (7:3) composite coating was close to that of the pure PLA layer. In addition, the degradation rate of the implant could be controlled by varying the content of nHA in the composite coating while significantly improving its bioactivity. Finally, the addition of nHA increased the roughness of the surface of the composite coating, which was favorable for cell adhesion and proliferation. The highest adhesion density of MC3T3-E1 osteoblasts was exhibited on the Zn/MAO/PLA-nHA (7:3) composite coating. The Zn/MAO/PLA-nHA (7:3) composite coatings showed good adhesion, wettability, corrosion resistance, and excellent cytocompatibility. Thus, this study provides a reasonable design guide for the modification of degradable Zn alloy surfaces in bone tissue engineering biomaterials.

Freeze-Dried human platelet-rich plasma effect on osteoblast number and collagen density in periodontitis treatment

Objective: This study aimed to determine the effect of FD-hPRP on the number of osteoblast and collagen density in periodontitis treatment by a histomorphometric study on oryctolagus cuniculus rabbits' alveolar bone and periodontal ligament. Material and Methods: Sixteen male rabbits were randomly divided into four groups: Normal; Periodontitis; FD-hPRP; DFDBA. After periodontal surgery by open flap debridement, FD-hPRP was applied in group 3, and DFDBA was applied in group 4. Then all rabbits were decapitated eight weeks after surgery. Histomorphometric analysis calculates the number of osteoblasts and collagen density using image J software. Data were analyzed using one-way ANOVA followed by Post Hoc Least Significant Difference (LSD) test. Results: The results showed a significant difference (p>0.05) between the periodontitis and FD-hPRP and also DFDBA group. Conclusion: The application of FD-hPRP effect increases the number of osteoblast and collagen density in periodontitis treatment histomorphometrically in rabbit’s alveolar bone and periodontal ligament.

Effect of alfacalcidol on bone regeneration in senile rats

Background. Among the drugs that have a pleiotropic effect on bone, attention is drawn to alfacalcidol – the precursor of the active form of D-hormone. There are studies that have revealed distinctive features of the effect of alfacalcidol on bone regeneration in osteoporosis and in young animals. The purpose was to study bone regeneration after treatment with alfacalcidol in senile animals. Materials and methods. A transcortical defect from the lateral to the medial femur was modeled in rats aged 24 months in the area of the metadiaphysis. A treatment with alfacalcidol was carried out from the 2-nd day and for 10 and 30 days before the animals was withdrawn from the experiment. Histological study of bone regeneration with morphometric analysis of tissues in the areas of callus had been performed. Results. On the 10-th day of the treatment with alfacalcidol in senile animals, connective tissue, osteoid and coarse-fibrous trabecular bone with a high density of osteoblasts were located in the defect area. On the 30-th day in treated animals, the bone tissue of the callus was mature; its area was larger than in untreated animals. In the area of cancellous bone there is a network of newly formed bone trabeculae. Destructive manifestations around the defect were reduced in animals treated with alfacalcidol. In untreated animals there was no dense bone fusion with cortex fragments; trabeculae of cancellous bone were intermittent. In the lateral part of the callus, the area of bone tissue was reduced compared to the medial part. Conclusions. Treatment of animals with alfacalcidol accelerates the formation of bone tissue in the defect and reduces destructive manifestations around the defect compared to untreated animals.

In Vivo Effects of Nanotechnologically Synthesized and Characterized Fluoridated Strontium Apatite Nanoparticles in the Surgical Treatment of Endodontic Bone Lesions

In this study, fluoridated strontium apatite (SAP) nanoparticles with different mole percentages (5%, 10%, 30%, and 50%) synthesized using a hydrothermal method were used as biomaterials. The in vivo biocompatibility of the synthesized nanoparticles was investigated by embedding them as biomaterials in bone defects created in rat tibiae. Through the hematoxylin-eosin staining method, a histopathological analysis was performed for new bone formation, osteoblast density, and fibrotic tissue formation. Fluorine (F) addition affected the structural and morphological properties of the nanoparticles. With the F doping, the shapes of the nanoparticles changed from nano-rods to almost spherical. The Sr/P ratios, with a stoichiometric value of 1.67, were 1.76, 1.53, 1.54, 1.68, and 1.79 in pure, 5%, 10%, 30%, and 50% F-doped nanoparticles, respectively. The F/Sr ratios of 5%, 10%, 30%, and 50% F-doped nanoparticles were 0.05, 0.13, 0.16, and 0.20, respectively. The highest values in terms of fibrotic tissue formation were obtained in the group containing pure SAP. The best results in terms of new bone formation and osteoblast density in bone defects were observed in the groups with higher F ratios (30% and 50% F-doped). Pure and F-doped strontium apatite nanoparticles showed good results for new bone formation and osteoblast levels compared to the control group. It was observed that an increase in the fluorine ratio resulted in better bone healing. The results showed that pure and F-doped SAP nanoparticles synthesized by a hydrothermal method can be used as biomaterials in orthopedics and dentistry, especially in the surgical treatment of endodontic lesions.

In Vivo Evaluation of the Effects of B-Doped Strontium Apatite Nanoparticles Produced by Hydrothermal Method on Bone Repair.

In the present study, the structural, morphological, and in vivo biocompatibility of un-doped and boron (B)-doped strontium apatite (SrAp) nanoparticles were investigated. Biomaterials were fabricated using the hydrothermal process. The structural and morphological characterizations of the fabricated nanoparticles were performed by XRD, FT-IR, FE-SEM, and EDX. Their biocompatibility was investigated by placing them in defects in rat tibiae in vivo. The un-doped and B-doped SrAp nanoparticles were successfully fabricated. The produced nanoparticles were in the shape of nano-rods, and the dimensions of the nano-rods decreased as the B ratio increased. It was observed that the structural and morphological properties of strontium apatite nanoparticles were affected by the contribution of B. A stoichiometric Sr/P ratio of 1.67 was reached in the 5% B-doped sample (1.68). The average crystallite sizes were 34.94 nm, 39.70 nm, 44.93 nm, and 48.23 nm in un-doped, 1% B-doped, 5% B-doped, and 10% B-doped samples, respectively. The results of the in vivo experiment revealed that the new bone formation and osteoblast density were higher in the groups with SrAp nanoparticles doped with different concentrations of B than in the control group, in which the open defects were untreated. It was observed that this biocompatibility and the new bone formation were especially elevated in the B groups, which added high levels of strontium were added. The osteoblast density was higher in the group in which the strontium element was placed in the opened bone defect compared with the control group. However, although new bone formation was slightly higher in the strontium group than in the control group, the difference was not statistically significant. Furthermore, the strontium group had the highest amount of fibrotic tissue formation. The produced nanoparticles can be used in dental and orthopedic applications as biomaterials.

The Impact of Hempseed Consumption on Bone Parameters and Body Composition in Growing Mice

ObjectivesThis study investigated the effect of a diet containing hempseeds (HS), which are rich in polyunsaturated fatty acids and polyphenols, on body composition, bone mineral measurements and epiphyseal plate osteoblast density. MethodsGroups (n = 8 each) of female C57BL/6 mice were fed one of three AIN-93G-based diets (15% HS by weight; 5% HS; 0% HS) from age 5 to 30 weeks. Diets contained ∼16, 18, and 60% total kcals from fat, protein and carbohydrate, respectively. In-vivo whole-body composition and bone mineral density and content were measured every 4 weeks using dual-energy x-ray absorptiometry. Ex-vivo humeri osteoblast density was determined by sectioning bone longitudinally, mounting the sections on slides and staining using alkaline phosphatase. Stain intensity at the epiphyseal plate was ranked independently by 5 evaluators. ANOVA was used to compare outcomes across groups. Linear regression was used to examine the relationship of end-point bone mineral measurements and osteoblast density. ResultsNo differences were seen in bone mineral measurements, lean mass or fat mass across diet groups. Body weight gain did not differ across groups yet mice fed the 15% HS diet consumed significantly more food than those fed the 0% and 5% HS diets (p = 0.0002). Humeri from both HS groups displayed significantly lower osteoblast densities compared to the control group (P < 0.0001). No relationship was seen between osteoblast density and body composition measurements. ConclusionsDiets enriched with 5% and 15% HS supported growth as well as the control diet without significant impacts on whole-body composition, including bone mineral density and content. At the cellular level, however, HS consumption resulted in reduced density of osteoblasts at the epiphyseal plate. These data invite closer examination of bone cell activity and microarchitecture to determine the effect of habitual HS consumption on bone integrity. Funding SourcesInstitute of Cannabis Research at Colorado State University, Pueblo; Idaho State University.

The Impact of Hempseed Consumption on Bone Parameters and Body Composition in Growing Female C57BL/6 Mice.

Optimizing peak bone mass is critical to healthy aging. Beyond the established roles of dietary minerals and protein on bone integrity, fatty acids and polyphenols modify bone structure. This study investigated the effect of a diet containing hempseeds (HS), which are rich in polyunsaturated fatty acids and polyphenols, on bone mineral density, bone cell populations and body composition. Groups (n = 8 each) of female C57BL/6 mice were fed one of three diets (15% HS by weight; 5% HS; 0% HS (control)) from age 5 to 30 weeks. In vivo whole-body composition and bone mineral density and content were measured every 4 weeks using dual-energy X-ray absorptiometry. Ex vivo humeri cell populations in the epiphyseal plate region were determined by sectioning the bone longitudinally, mounting the sections on slides and staining with tartrate-resistant acid phosphatase and alkaline phosphatase stain to identify osteoclasts and osteoblasts, respectively. Mixed models with repeated measures across experimental weeks showed that neither body weight nor body weight gain across weeks differed among groups yet mice fed the 15% HS diet consumed significantly more food and more kilocalories per g body weight gained than those fed the 5% HS and control diets (p < 0.0001). Across weeks, fat mass was significantly higher in the 5% HS versus the control group (p = 0.02). At the end point, whole-body bone mineral content was significantly higher in the control compared to the 5% HS group (p = 0.02). Humeri from both HS groups displayed significantly lower osteoblast densities compared to the control group (p < 0.0001). No relationship was seen between osteoblast density and body composition measurements. These data invite closer examination of bone cell activity and microarchitecture to determine the effect of habitual HS consumption on bone integrity.

Histopathologic and Spectrometric Evaluation of Bony Components of Synostotic Suture and Parietal Bone in Children with Sagittal Synostosis.

Sagittal synostosis, the premature fusion of sagittal suture, is the most common form of craniosynostosis. The premature suture line closure restricts bone growth in the direction perpendicular to the suture line with frontal bossing, bitemporal narrowing, and often a characteristic palpable ridge along the fused sagittal suture. This study aimed to understand the characterization of the ossification process both in the synostotic suture and adjacent parietal bone. The surgical procedure for the 28 patients diagnosed with sagittal synostosis consisted of removing the synostotic bone as a whole, if possible, "Barrel-Stave" relaxation osteotomies, and strip osteotomies to the parietal and temporal bones perpendicular to the synostotic suture. The synostotic (group I) and parietal (group II) bone segments are obtained during osteotomies. Atomic absorption spectrometry was used to determine the amount of calcium in both groups, which is an indicator of ossification. Scanning electron microscopy and immunohistochemistry were employed to assess trabecular bone formation, osteoblastic density, and osteopontin, which is one of the in vivo indicators of new bone formation. Histopathologically, trabecular bone formation scores did not indicate any significant difference between the groups. However, the osteoblastic density and calcium accumulation in group I were higher than those in group II, and the difference was significant. Osteopontin staining scores in cells showing membranous and cytoplasmic staining with osteopontin antibodies significantly increased in group II. In this study, we found reduced differentiation of osteoblasts despite their increase in number. Moreover, the osteoblastic maturation rate was low in synostotic sutures, bone resorption becomes slower than new bone formation, and the remodeling rate is low in sagittal synostosis.

A new non targeted bone remodeling model combined with an interpolation meshless method

Regardless of the bone remodeling type (i.e. targeted or non targeted), disturbances in this process can have serious repercussions in bone diseases’ progression. Therefore, research in this field has been continuous in recent decades, producing clinically relevant results. Regarding non targeted remodeling, distinct computational models were developed to describe the process. However, they only offer a time analysis, lacking mathematical models able to simulate the process in space. Thus, this work combines, for the first time, advanced numerical discretization techniques with non targeted remodeling models. The mathematical formulation used is based on Komarova’s model, correlating the remodeling activity of osteoclasts and osteoblasts with their autocrine and paracrine signaling pathways. For the numerical example, a two-dimensional bone patch was studied, allowing a spatio-temporal analysis of bone mass, cell density of osteoclasts and osteoblasts during an event of bone remodeling. A biological stimulus was applied to trigger remodeling and the obtained bone mass variation is consistent with the applied stimulus. Also, results are supported by the histomorphometric data available in the literature. The numerical methods used in this work are the Finite Element Method (FEM) and the Radial Point Interpolation Method (RPIM). The inclusion of the meshless method RPIM conveys a great advantage for future work since the model will be combined with medical images obtained with CT scans and MRI.

Brain-Derived Acetylcholine Maintains Peak Bone Mass in Adult Female Mice.

Preclinical and clinical data support a role of the sympathetic nervous system in the regulation of bone remodeling, but the contribution of parasympathetic arm of the autonomic nervous system to bone homeostasis remains less studied. In this study, we sought to determine whether acetylcholine (ACh) contributes to the regulation of bone remodeling after peak bone mass acquisition. We show that reduced central ACh synthesis in mice heterozygous for the choline transporter (ChT) leads to a decrease in bone mass in young female mice, thus independently confirming the previously reported beneficial effect of ACh signaling on bone mass accrual. Increasing brain ACh levels through the use of the blood brain barrier (BBB)-permeable acetylcholinesterase inhibitor (AChEI) galantamine increased trabecular bone mass in adult female mice, whereas a peripheral increase in ACh levels induced by the BBB-impermeable AChEI pyridostigmine caused trabecular bone loss. AChEIs did not alter skeletal norepinephrine level, and induced an overall increase in osteoblast and osteoclast densities, two findings that do not support a reduction in sympathetic outflow as the mechanism involved in the pro-anabolic effect of galantamine on the skeleton. In addition, we did not detect changes in the commitment of skeletal progenitor cells to the osteoblast lineage in vivo in AChEI-treated mice, nor a direct impact of these drugs in vitro on the survival and differentiation of osteoblast and osteoclast progenitors. Last, ChT heterozygosity and galantamine treatment triggered bone changes in female mice only, thus revealing the existence of a gender-specific skeletal response to brain ACh level. In conclusion, this study supports the stimulatory effect of central ACh on bone mass accrual, shows that it also promotes peak bone mass maintenance in adult mice, and suggests that central ACh regulates bone mass via different mechanisms in growing versus sexually mature mice. © 2020 American Society for Bone and Mineral Research.

Optimization, characterization and evaluation of ZnO/polyvinylidene fluoride nanocomposites for orthopedic applications: improved antibacterial ability and promoted osteoblast growth

Herein, electrospun zinc oxide nanoparticle/poly (vinylidene fluoride) (ZnONP/PVDF) composite fiber membranes were designed, fabricated, and tested for improved orthopedic applications. A single factor screening study was conducted to determine the optimal ZnONP/PVDF formulation based on osteoblast (bone forming cells) proliferation and antibacterial properties. Further, ZnONP/PVDF materials were characterized for their morphology, crystallinity, roughness, piezoelectric properties, and chemistry to understand such cell results. The optimal concentration of high molecular weight PVDF (18%, w/v) and a low concentration of ZnONPs (1 mg/ml) were identified for electrospinning at room temperature in order to inhibit bacterial colonization (without resorting to antibiotic use) and promote osteoblast proliferation. Compared to no ZnO/PVDF scaffold without Piezo-excited group,the study showed that on the 1 mg/ml ZnO/PVDF scaffolds with piezo-excitation, the density of SA and E.coli decreased by 68% and 56%.The density of osteoblasts doubled within three days(compared to the control). In summary, ZnONP/PVDF composite fiber membranes were formulated by electrospinning showing an exceptional ability to eliminate bacteria colonization while at the same time promote osteoblast functions and, thus, they should be further studied for a wide range of orthopedic applications.

Evaluation of the Effects of Low-Level Laser Therapy on Diabetic Bone Healing.

The aim of the present study was to evaluate the effects of low-level laser therapy (LLLT) and biphasic alloplastic bone graft material on diabetic bone healing. Induction of diabetes was performed in 14 male Sprague-Dawley rats by intraperitoneal injection of a 50 mg/kg dose of streptozotocin. Two bilaterally symmetrical non-critical-sized bone defects were created in the parietal bones in each rat. Right defects were filled with biphasic alloplastic bone graft. Rats were randomly divided into 2 groups, with 1 group receiving 10 sessions of LLLT (GaAlAs, 78.5 J/cm, 100mW, 0.028 cm beam). The LLLT was started immediately after surgery and once every 3 days during postoperative period. At the end of treatment period, new bone formation and osteoblast density were determined using histomorphometry. Empty (control), graft-filled, LLLT-treated and both graft-filled and LLLT-treated bone defects were compared. New bone formation was higher in the graft treatment samples compared with the control (P = 0.009) and laser samples (P = 0.029). In addition, graft-laser combination treatment samples revealed higher bone formation than control (P = 0.008) and laser (P = 0.026) samples. Osteoblast density was significantly higher in the laser treatment (P <0.001), graft treatment (P = 0.001) and graft-laser combination treatment (P <0.001) samples than control samples. In addition, significantly higher osteoblast density was observed in the graft-laser combination treatment samples compared to the graft treatment samples (P = 0.005). The LLLT was effective to stimulate osteoblastogenesis but failed to increase bone formation. Graft augmentation for treatment of bone defects seems essential for proper bone healing in diabetes, regeneration may be supported by the LLLT to enhance osteoblastogenesis.

Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization.

Additively manufactured selective laser melted titanium (SLM-Ti) opens the possibility of tailored medical implants for patients. Despite orthopedic implant advancements, significant problems remain with regard to suboptimal osseointegration at the interface between the implant and the surrounding tissue. Here, we show that applying a nanodiamond (ND) coating onto SLM-Ti scaffolds provides an improved surface for mammalian cell growth while inhibiting colonization of Staphylococcus aureus bacteria. Owing to the simplicity of our methodology, the approach is suitable for coating SLM-Ti geometries. The ND coating achieved 32 and 29% increases in cell density of human dermal fibroblasts and osteoblasts, respectively, after 3 days of incubation compared with the uncoated SLM-Ti substratum. This increase in cell density complements an 88% reduction in S. aureus detected on the ND-coated SLM-Ti substrata. This study paves a way to create facile antifouling SLM-Ti structures for biomedical implants.

An In Vitro Study of Osteoblast Response on Fused-Filament Fabrication 3D Printed PEEK for Dental and Cranio-Maxillofacial Implants.

Polyetheretherketone (PEEK) is a prime candidate to replace metallic implants and prostheses in orthopedic, spine and cranio-maxillofacial surgeries. Fused-filament fabrication (FFF) is an economical and efficient three-dimensional (3D) printing method to fabricate PEEK implants. However, studies pertaining to the bioactivity of FFF 3D printed PEEK are still lacking. In this study, FFF 3D printed PEEK samples were fabricated and modified with polishing and grit-blasting (three alumina sizes: 50, 120, and 250 µm) to achieve varying levels of surface roughness. In vitro cellular response of a human osteosarcoma cell line (SAOS-2 osteoblasts, cell adhesion, metabolic activity, and proliferation) on different sample surfaces of untreated, polished, and grit-blasted PEEK were evaluated. The results revealed that the initial cell adhesion on different sample surfaces was similar. However, after 5 days the untreated FFF 3D printed PEEK surfaces exhibited a significant increase in cell metabolic activity and proliferation with a higher density of osteoblasts compared with the polished and grit-blasted groups (p < 0.05). Therefore, untreated FFF 3D printed PEEK with high surface roughness and optimal printing structures might have great potential as an appropriate alloplastic biomaterial for reconstructive cranio-maxillofacial surgeries.

Greater osteoblast densities due to the addition of amphiphilic peptide nanoparticles to nano hydroxyapatite coatings.

BackgroundIn vitro and in vivo studies have shown that metallic implants coated with nano hydroxyapatite (HA) reduce the time needed for complete osseointegration compared to metallic implants coated with conventional or micron-sized HA. Moreover, due to their biologically inspired nanometer dimensions, amphiphilic peptide nanoparticles (APNPs) can also promote osteoblast attachment and enhance other cell functions if used as a coating material. Coatings made of HA and APNPs could improve osteoblast functions, but have never been tested.PurposeThe objective of this study was to prepare coatings of nanocrystalline HA and APNPs on poly(2-hydroxyethyl methacrylate) (pHEMA) coatings in order to improve osteoblast (bone-forming cells) adhesion and cell density.MethodsHA was synthesized by a wet chemical process. Coatings were synthesized with different conditions and components.ResultsX-ray diffraction infrared spectroscopy, transmission electron microscopy, and electron diffraction showed that nanocrystalline HA was synthesized with an expected nano size and shape distribution but with low impurities. pHEMA hydrogels with HA and APNPs increased osteoblast densities after 3 days compared to controls.ConclusionSince cell proliferation is a prerequisite function for bone formation, these results imply that the current materials should be tested for a wide range of orthopedic applications.

Different Types of Low-frequency Electromagnetic Fields Resist Bone Loss Caused by Weightlessness

Objective To compare the effects of 50-Hz 0.6-mT low-frequency pulsed electromagnetic fields(PEMFs) and 50-Hz 1.8-mT sinusoidal alternating electromagnetic fields(SEMFs) in preventing bone loss in tail-suspended rats,with an attempt to improve the prevention and treatment of bone loss caused by weightlessness.Methods Tail-suspension rat models were used to simulate microgravity on the ground. Forty rats were randomly divided into four groups[control group,hindlimb-suspended(HLS) group,HLS+PEMFs group,and HLS+SEMFs group],with 10 rats in each group. In the PEMFs treatment group and SEMFs treatment group,the intervention was 90 min per day. Rats were sacrificed after four weeks. Bone mineral density(BMD) of femur and vertebra was measured by dual-energy X-ray absorptiometry and biomechanical strength by AG-IS biomechanical instrument. Serum osteocalcin(OC),tartrate-resistant acid phosphatase 5b(Tracp 5b),parathyroid hormone(PTH),and cyclic adenosine monophosphate(cAMP) were detected by ELISA. The microstructure of bone tissue was observed by Micro-CT and HE staining.Results The BMD of the femur(P=0.000) and vertebrae(P=0.001) in the HLS group was significantly lower than in the control group;the BMD of the femurs(P=0.001) and vertebrae(P=0.039) in the HLS+PEMFs group was significantly higher than in the HLS group;the BMD of the femurs in the HLS+SEMFs group was significantly higher than in the HLS group(P=0.003),but the BMD of the vertebrae showed no significant difference(P=0.130). There was no significant difference in the BMD of the femur(P=0.818) and vertebrae(P=0.614) between the HLS+PEMFs group and the HLS+SEMFs group. The maximum load(P=0.000,P=0.009) and elastic modulus(P=0.015,P=0.009) of the femurs and vertebrae in the HLS group were significantly lower than those in the control group;the maximum load of the femur(P=0.038) and vertebrae(P=0.087) in the HLS+PEMFs group was significantly higher than that in the HLS group,but the elastic modulus was not significantly different from that in the HLS group(P=0.324,P=0.091). The maximum load(P=0.190,P=0.222) and elastic modulus(P=0.512,P=0.437) of femurs and vertebrae in the HLS+SEMFs group were not significantly different from those in the HLS group. There were no significant differences in the maximum load and elastic modulus of femurs(P=0.585,P=0.948) and vertebrae(P=0.668,P=0.349) between the HLS+PEMFs group and the HLS+SEMFs group. The serum OC level in the HLS group was significantly lower than that in the control group(P=0.000),and the OC level in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.006) were significantly higher than that in the HLS group. The serum Tracp 5b concentration in the HLS group was significantly higher than that in the control group(P=0.011). There was no significant difference between the HLS+PEMFs group(P=0.459) and the HLS+SEMFs group(P=0.469) compared with the control group.Serum Tracp 5b concentrations in the HLS+PEMFs group(P=0.056) and the HLS+SEMFs group(P=0.054) were not significantly different from those in the HLS group. The PTH(P=0.000) and cAMP concentrations(P=0.000) in the HLS group were significantly lower than those in the control group. The PTH(P=0.000,P=0.000) and cAMP concentrations(P=0.000,P=0.000) in the HLS+PEMFs group and the HLS+SEMFs group were significantly higher than in the HLS group. The femoral cancellous bone of the HLS group was very sparse and small compared with the control group. The density and volume of the cancellous bone were similar among the control group,HLS+PEMFs group,and HLS+SEMFs group. Compared with the control group,the HLS group had lower BMD(P=0.000),bone volume (BV)/tissue volume(TV)(P=0.000),number of trabecular bone (Tb.N)(P=0.000),and trabecular thickness(Tb.Th)(P=0.000) and higher trabecular bone dispersion(Tb.Sp)(P=0.000) and bone surface area(BS)/BV(P=0.000). Compared with the HLS group,the HLS+PEMFs group and the HLS+SEMFs group had significantly lower Tb.Sp(P=0.000,P=0.000) and BS/BV(P=0.000,P=0.000) and significantly increased BMD(P=0.000,P=0.000),BV/TV(P=0.001,P=0.004),Tb.Th(P=0.000,P=0.001),and Tb.N(P=0.000,P=0.001). The trabecular thickness significantly differed between the HLS+PEMFs group and the HLS+SEMFs group(P=0.024). The HLS group(P=0.000),HLS+PEMFs group(P=0.000),and HLS+SEMFs group(P=0.000) had the significantly lower osteoblast density on the trabecular bone surface than the control group;however,it was significantly higher in the HLS+SEMFs group(P=0.000) and the HLS+PEMFs group(P=0.000) than in the HLS group. The HLS group had significantly lower density of osteoblasts in the endothelium than the control group(P=0.000);however,the density of osteoblasts was significantly higher in HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than HLS group and was significantly higher in HLS+PEMFs group than in HLS+SEMFs group(P=0.041). Compared with the control group,a large number of fatty cavities were produced in the bone marrow cavity in the HLS group,but the fat globules remarkably decreased in the treatment groups,showing no significant difference from the control group. The number of adipose cells per mm 2 bone marrow in the HLS group was 4 times that of the control group(P=0.000);it was significantly smaller in the HLS+PEMFs group(P=0.000) and HLS+SEMFs group(P=0.000) than in the HLS group,whereas the difference between the HLS+PEMFs group and the HLS+SEMFs group was not statistically significant(P=0.086). Conclusions 50-Hz 0.6-mT PEMFs and 50-Hz 1.8-mT SEMFs can effectively increase bone mineral density and biomechanical values in tail-suspended rats,increase the concentration of bone formation markers in rat blood,activate the cAMP pathway by affecting PTH levels,and thus further increase the content of osteoblasts to prevent the deterioration of bone micro-structure. In particular,PEMFs can prevent the reduction of bone mineral density and maximum load value by about 50% and increase the bone mass of tail-suspended rats by promoting bone formation.

Effects of GPTMS concentration and powder to liquid ratio on the flowability and biodegradation behaviors of 45S5 bioglass/tragacanth bioactive composite pastes

ABSTRACTInjectable composite pastes were prepared using melt‐derived 45S5 bioactive glass and tragacanth crosslinked by (3‐glycidyloxypropyl)trimethoxysilane (GPTMS). The effect of powder to liquid ratio (P:L = 1.0:2.0–1.0:2.5) and GPTMS/tragacanth ratio (0.0–1.5) on the injectability, swelling behavior, rheology, bioactivity, and cellular behavior of the pastes was investigated. Based on the results, the apparent stability and consistency of the pastes increased upon crosslinking by GPTMS. Due to the increased interactions between tragacanth and glass, a hysteresis loop with larger area was formed in the presence of GPTMS. With increase of GPTMS:tragacanth ratio from 0 to 1.5, the swelling percent dropped from 24.65 to 16.25% after 24 h and the degradation percent also went down from 27.89 to 9.11% after 21 days in the simulated body fluid. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay showed a drop in the optical density of MG63 osteoblasts up to 30.07% after exposure to the GPTMS‐crosslinked composite pastes for 3 days. However, the number of viable cells gradually increased in the presence of the pastes and the cell morphology remained unchanged over time. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47604.

2. The Effect Of Sipatah-patah (Cissus quadrangularis Salisb) Extract On The Femur Bone Density of White Rat (Rattus norvegicus) with Model Ovariectomy

This research aimed to determine the effect of giving Sipatah-patah extract toward the histopathological and femur bone growth of white rat that was ovariectomized. The experimental animals that were used were 12 white rats divided into 4 treatment group with 3 repetitions. K0 was the ovariectomized rat without giving Sipatah-patah extract (ESP); K1, K2 and K3 were ovariectomized rats which were given Sipatah-patah extract with multilevel doses of 500 mg/kg BW, 700 mg/kg BW and 900 mg/kg BW for 30 days. On the 31st day, rats were euthanized using chloroform and os femur that was taken to being made into histological preparation. There was the decrease in the bones density of the K0 group which is characterized by thinning of trabecular structure, there were lots of osteoclast cells on the edge of the trabecular and lower density of active osteoblasts and passive osteoblasts. The rat of group K1 and K2 showed an improvement on the trabecular structure and lower osteoclast than group K0. The rat of group K3 had a visible improvement of the most congested trabecular structures, cohesive with the most density cell of active osteoblasts than the other groups. The result of this research concluded that the giving of Sipatah-patah extract doses 900 mg/kg BW showed a higher density of trabecular and active osteoblasts than the control group, K1 and K2 on the white rat bones that were ovariectomized.

Mandibular Invasion by Oral Squamous Cell Carcinoma: Clinicopathologic Features of 74 Cases.

(1) For patients with oral squamous cell carcinoma (OSCC) and mandibular invasion, to determine whether prior radiation to the head and neck region (PXRTHN) affects the density of osteoblasts, osteoclasts, or fibroblasts along the tumor interface invading the mandible and whether this is significantly associated with overall survival. (2) To identify clinicopathologic features that are associated with overall survival. Case series with chart review. University of Missouri hospital. Retrospective review of 74 cases with pathologically confirmed mandible invasion by OSCC and surgical treatment between January 1, 2005, and December 31, 2015. A board-certified anatomic pathologist reviewed the slides from all mandibulectomy cases. The mean density of osteoclasts was 2.0 per linear mm among the patients with PXRTHN and 7.1 among those without PXRTHN ( P < .001). Positive soft tissue frozen section margin was significantly associated with overall survival on univariate analysis ( P < .001; hazard ratio [HR], 0.34; 95% CI, 0.19-0.62) and multivariate analysis ( P = .026; HR, 0.41; 95% CI, 0.19-0.90). Maximum tumor dimension was significantly associated with overall survival on univariate analysis ( P = .021; HR, 1.19; 95% CI, 1.03-1.38) and multivariate analysis ( P = .002; HR, 1.49; 95% CI, 1.16-1.93). Osteoclast, osteoblast, and fibroblast density were not associated with overall survival. (1) Osteoclast density along the tumor front is significantly lower among patients with PXRTHN. Stromal cell density was not associated with overall survival. (2) Positive soft tissue frozen section margin and maximum tumor dimension are significantly associated with overall survival among patients with mandibular invasion by OSCC.

In vitro evaluvation of cytomechanics of osteoblast for enhanced peri‐implant bone regeneration

Background With the increasing application of dental implants in poor-quality bones, the need for implant surfaces ensuring accelerated osseointegration, by a number of biomaterials, therapeutic agents, but often these drugs are not specifically targeted to the site and, thus, lack an immediate directed therapeutic effect. The optimal drug delivery system should enhance Osteoconduction ,healthy bone growth with high specificity to the site of the implant. Aim/Hypothesis The aim of study was to build off this evidence and determine the potential applications of cytomechanics of osteoblast , that were upregulated in response to the attached nanoparticles and exposure to a magnetic force may also play a crucial role in improving cell-invasive cell-invasive ability and osteoconduction. Material and Methods The magnetic nanoparticles (MNs) coated with chitosan (CS) for enhancing cellular invasion using magnetic force. MNs were characterized by XRD, UV spectroscopy, SEM. The MNs where spherical shape with a diameter from 10 nm to 15 nm. MNs were further coated with CS, The coatings were conducted in the presence of CTAB, 0.25 g of MNs was dispersed in a CTAB (2grams of CTAB dissolved in 400 ml of water)(A). Then, 100 ml CS solution (0.02gram CS powders dissolved in 100 ml of 1% (w v) acetic acid solution) was dropped into (A), the obtained MNsCS were dried at 60°C. In vitro behavior CS-MNs and the effects of intracellular force on osteoblast cell (MG63) line were studied. We generated intracellular force on MG63 by magnetic fields using the cellular uptake of CS-MNs. Cell responses to intracellular force were observed using fluorescent microscopy. The cell viability of the groups was measured using the Cell-Counting Kit-8 reagent. Migration and invasion assay by Boyden Chamber Assays. Results Our results indicated that MNs were taken up by the MG63 cells. MNs inside the cell could be relocated by the application of a magnetic force. The intracellular magnetic force could also be used to accelerate cell migration by adjusting the magnetic fields and giving the cell free culture space. No cytotoxicity of nanoparticles was found in our experiments. By comparing intracellular relocalization with the migration of the whole osteoblast cell line. The cell number in the MNs-100% group significantly increased, compared with that in the other groups at 6, 12, and 24 hours (P < 0.05). In all the groups, the number of cells that passed through the membrane increased with time. Invasion assay - Cell-invasion efficiency was enhanced by introducing our novel MNs into cells and by the presence of magnetic force showed that CS MNs significantly promoted osteoblast density (that is, cells per well) after 5 and 8 days of culture compared to controls (no particles). Conclusions and Clinical Implications Established promising mechanical properties and low cytotoxicity of magnetic nanoparticles, their potential applications in cytomechanics can efficiently enhance osteoconduction , osteoblast seeding into the depth of the scaffold, increase subsequent cell–cell interactions and shorten the period of cell proliferation. This system is thought to be useful in the development of cell-based strategies for the repair or replacement of tissue and other novel therapies.