OBJECTIVE: To investigate the effects of the Arg-Gly-Asp polypeptedes (RGD) peptides-modified porous tantalum surface on osteoblasts morphology and expressions of osteogenesis factors, and to evaluate RGD peptides promotes junctura ossium of tantalum-bone interface in vivo. METHODS: RGD peptides of different concentrations (1 g/L, 5 g/L, and 10 g/L) were loaded to porous tantalum slices with a diameter of 10 mm and a thickness of 3 mm by physical absorption. The 3rd generation of MG63 cells were co-cultured with tantalum and divided into 4 groups: Ta-cells (control) group, 1 g/L cells/Ta/RGD group, 5 g/L cells/Ta/RGD group, and 10 g/L cells/Ta/RGD group. Porous tantalum compo-sites and osteoblasts-tantalum interface were observed by scanning electron microscopy. The adhesion rate of osteoblasts was detected and immunocytochemistry was used to detect the expressions of filamentous actin (F-actin), osteocalcin (OC) and fibronectin (FN). RESULTS: The scanning electron microscope (SEM) revealed that osteoblasts distributed on the surface of porous tantalum and secreted extracellular matrix on outside and inner of micro-pores. The osteoblasts adhesion rate on porous tantalum modified with RGD was higher than that in the unmodified porous tantalum at the end of 24, 48, and 72 hours. The best adhesion effect was got in 5 g/L cells/Ta/RGD group at hour 48 [(68.07±3.80) vs. (23.40±4.39), P<0.05]. The results of immunocytochemistry showed that the expressions intensity of F-actin, OC and FN in osteoblasts on porous tantalum modified groups with RGD were stronger than that in the unmodified groups, and the expressions of 5 g/L cells/Ta/RGD group were significantly higher than those in the 10 g/L group and 1 g/L group [OC: (18.08±0.08) vs. (15.14±0.19), P<0.05; (18.08±0.08) vs. (14.04±0.61), P<0.05. FN: (24.60±0.98) vs. (15.90±0.53), P<0.05; (24.60±0.98) vs. (15.30±0.42), P<0.05. F-actin: (29.20±1.31) vs. (24.50±1.51), P<0.05; (29.20±1.31) vs. (16.92±0.40), P<0.05]. Correspondingly F-actin in osteoblasts was showed in longitudinal arrangement, and the expressions intensity was stronger than those OC and FN. CONCLUSION The RGD peptides is beneficial to enhance adhesion of osteoblast, spreading and reorganization of cytoskeleton on porous tantalum surface and improve the interface morphology, further promoting osteoblasts-tantalum conjunctive interface osseointegration.
Cell Adhesion ; Oligopeptides ; Osteoblasts/physiology* ; Osteogenesis ; Tantalum

Distraction osteogenesis (DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.
Bone Regeneration/physiology* ; Bone and Bones ; Osteogenesis/physiology* ; Osteogenesis, Distraction/methods* ; Tissue Engineering

With additional functions of osteocytes being identified, the concept that osteocytes are just "static lacunar-dwelling cells" is no longer accepted. We reviewed most of the relevant literature on osteocyte's function in the direct remodeling of the perilucunar matrix, discussing the advantages and disadvantages. Special attention was paid to how the negative researchers argue about the "osteocytic osteolysis" principle, and how the positive side addressed the arguments. We also discussed the newly found data of osteocytic remodeling function from our group. With more biotechnology in hand, there is increased excitement in the prospect of now being able to answer the two important questions: do osteocytes have the capability to remove mineral from the perilacunar matrix and if so what are the molecular and cellular mechanisms? do osteocytes have the capability to deposit new mineral on the perilacunar matrix and if so what are the cellular and molecular mechanisms?
Animals ; Bone Matrix ; physiology ; Bone Remodeling ; physiology ; Humans ; Osteocytes ; physiology ; Osteogenesis ; physiology ; Osteolysis ; physiopathology

The performance and the characteristics of various sensors are analyzed to meet the requirement of measuring the bone force-electromechanical potentials. The strain sensor that is suitable small signal and bone force-electromechanical potential measure is developed and the curved structural form of the strain sensor is chosen. The strain sensor has the advantage of small volume, large linear range, convenient installation and high sensitivity. The relationship between the strain and force-electromechanical potential of bone specimen is determined in the experiment on the bone of femur and bone of teeth using this type of sensor which provides the valuable data for clinical use.
Biomechanical Phenomena ; Biosensing Techniques ; Electrophysiology ; Equipment Design ; Femur ; physiology ; Humans ; Mandible ; physiology ; Maxilla ; physiology ; Osteogenesis ; physiology

The effects of electromagnetic field on distraction osteogenesis and new bony tissue were investigated. Twenty-five New Zealand rabbits were divided into an experimental (12 rabbits) and a control (13 rabbits) group. An osteotomy was performed on the right tibia in the diaphyseal region in both groups. The experimental group was exposed to a magnetic field of 50 Hz 1.0 mT for 3 hours a day for 13 weeks. The control group was kept in a similar environment but with no electromagnetic field. The distraction was continued until an increase of 10 mm was achieved. At weeks 4, 8, and 13, radiography, scintigraphy, and a biopsy were performed in both groups, and the results were statistically analyzed. The X-ray results were similar in both groups at all times. On the other hand while the scintigraphic and histopathological results were similar at weeks 4 and 13 in both groups, the osteoblastic activity was significantly greater in the experimental group at week 8 (p < 0.01). In conclusion an electromagnetic field increases the osteoblastic activity and osteogenesis, but has little effect during the remodeling phase.
Animals ; *Electromagnetic Fields ; Osteoblasts/physiology/radiation effects ; Osteogenesis/radiation effects ; *Osteogenesis, Distraction ; Osteotomy ; Rabbits

OBJECTIVEThe purpose of this experimental study was to investigate the histomorphological changes of tubular bone following widening distraction osteogenesis.

METHODSTwelve Chinese mountain goats were subjected to the study. After the procedure of vertical and horizontal osteotomy, two widening distraction osteogenesis devices were put in each goat's left tibiae. After an 8-day latency period, nine tibiae were widening distracted; another three tibiae served as sham control group. Every three animals from the experimental group were sacrificed in different consolidated periods including 1-month, 2-month, and 3-month. Radiography, tetracycline double labeling, histomorphology, as well as biomechanics were used to evaluate the quality and quantity of new generated bone in different consolidated period after distraction osteogenesis.

RESULTSAfter a distraction period, the average width of the tibiae is increased 7.83mm. From the end of distraction to 3-month after the consolidation period, radiography demonstrated that the distraction gaps gradually became vague. Tetracycline double labeling showed that the double labeling brands were rarely seen in normal cortex bone, but strongly increased in the distracted callus. Mineralization rates (MR) has a significant difference (P < 0.05) within distracted callus region compared with control cortex bone. Histomorphological study shows that there was a different result in two sides of vertical distracted gaps. The non-exposure side had a good bone formation, while a non-union of bone occurred at the exposure side. Three months after consolidation period, part of the gap in exposure side was filled with dense connection tissue, whereas the distracted callus had been remodeled and become lamellar bone in non-exposure side. The control group showed normal fracture healing procedure.

CONCLUSIONSThere was a different outcome in two sides distraction gaps of tubular bone following widening distraction osteogenesis. A viable and well-perfused soft-tissue envelope in the area of distraction osteogenesis is important for creation of sufficient amount of new bone during distraction osteogenesis.

Animals ; Biomechanical Phenomena ; Bone Regeneration ; Goats ; Osteogenesis ; Osteogenesis, Distraction ; methods ; Radiography ; Tibia ; diagnostic imaging ; physiology

OBJECTIVETo review the recent developments in the mechanisms of epithelium sodium channels (ENaCs) induced bone formation and regulation.

DATA SOURCESStudies written in English or Chinese were searched using Medline, PubMed and the index of Chinese-language literature with time restriction from 2005 to 2014. Keywords included ENaC, bone, bone formation, osteonecrosis, estrogen, and osteoporosis. Data from published articles about the structure of ENaC, mechanism of ENaC in bone formation in recent domestic and foreign literature were selected.

STUDY SELECTIONAbstract and full text of all studies were required to obtain. Studies those were not accessible and those did not focus on the keywords were excluded.

RESULTSENaCs are tripolymer ion channels which are assembled from homologous α, β, and γ subunits. Crystal structure of ENaCs suggests that ENaC has a central ion-channel located in the central symmetry axis of the three subunits. ENaCs are protease sensitive channels whose iron-channel activity is regulated by the proteolytic reaction. Channel opening probability of ENaCs is regulated by proteinases, mechanical force, and shear stress. Several molecules are involved in regulation of ENaCs in bone formation, including nitride oxide synthases, voltage-sensitive calcium channels, and cyclooxygenase-2.

CONCLUSIONThe pathway of ENaC involved in shear stress has an effect on stimulating osteoblasts even bone formation by estrogen interference.

Calcium Channels ; physiology ; Epithelial Sodium Channels ; chemistry ; physiology ; Estrogens ; pharmacology ; Humans ; Osteogenesis ; physiology

Cell Differentiation ; Nicotine/pharmacology* ; Osteogenesis/physiology* ; Periodontal Ligament ; Stem Cells

OBJECTIVETo observe the effect of the platelet-rich plasma (PRP) on osteogenesis during bone distraction.

METHODSThe osteoblasts were cultured in vitro. The rabbits were used as the animal model of distraction osteogenesis. The proliferation of osteoblasts was analysed through MTT methods. The osteogenesis was observed by histochemical and histoimmunochemical methods.

RESULTSPRP stimulated the proliferation of osteoblasts and facilitated distraction osteogenesis.

CONCLUSIONSPRP could accelerate the osteogenesis during bone distraction. The application of PRP in clinical practice might shorten the period of distraction osteogenesis.

Animals ; Blood Platelets ; physiology ; Cells, Cultured ; Immunohistochemistry ; Male ; Osteoblasts ; cytology ; metabolism ; Osteogenesis ; physiology ; Osteogenesis, Distraction ; Platelet Count ; Rabbits

Osteogenesis and angiogenesis are two closely correlated processes during bone growth, development, remodelling and repair.Vascular endothelial growth factor (VEGF) is an essential mediator during the process of angiogenesis. Based on an extensive literature search, which was carried out using the PubMed database and the keywords of osteogenesis, VEGF, endochondral ossification and intramembranous ossification, this manuscript reviews the role of VEGF in ossification, with emphasis on its effect in endochondral and intramembranous ossification. Osteogenesis and angiogenesis are closely correlated processes. VEGF acts as an essential mediator during these processes. It not only functions in bone angiogenesis but also in various aspects of bone development.
Animals ; Bone Remodeling ; physiology ; Bone and Bones ; cytology ; physiology ; Calcification, Physiologic ; physiology ; Cartilage ; cytology ; physiology ; Humans ; Neovascularization, Physiologic ; physiology ; Osteoclasts ; physiology ; Osteogenesis ; physiology ; Vascular Endothelial Growth Factor A ; physiology