OBJECTIVE: To explore effects of isopsoralen (ISO) with different doses on fracture and vascular healing in mice. METHODS: Sixty 2-month-old male C57BL/6 mices with body mass of (20±2) g were selected and divided into 4 groups by random number table method:model group (model), low dose group (isopsoralen-low dose, ISO-L), medium dose group (isopsoralen-medium dose, ISO-M) and high dose group (isopsoralen-high dose, ISO-H), with 15 animals in each group. The right tibial fracture model was established. After operation, ISO-L group, ISO-M group and ISO-H group were given ISO concentration of 10 mg·kg^-1, 20 mg·kg^-1 and 40 mg·kg^-1, respectively. Model group was given same volume of normal saline once a day for 28 days. Weighed once a week. X-ray was performed on 7, 14, 21 and 28 days, respectively, and modified I.R. Garrett scoring method was used to evaluate callus growth. After 28 days, the main organs were stripped and weighed, and organ coefficients were calculated. Hematoxylin eosin staining (HE staining) was performed on the organs to observe whether there were pathological structural changes. Micro-computed tomography (Micro-CT) was used to scan fracture area and conduct three-dimensional reconstruction to obtain the effect map, and quantify bone volume fraction (bone volume/total volume, BV/TV). After decalcification, the tibia was embedded in paraffin wax and sectioned. The healing and shape of fracture end were observed by HE staining and ferruxin solid green staining. The right tibia was removed and decalcified after intravascular infusion of Microfil contrast agent. Micro-CT was used to scan the callus microvessels in the fracture area, and the vascular volume fraction and vessel diameter were quantified. RESULTS: After 28 days of administration, there was no significant difference in body mass and organ coefficient among all groups (P>0.05), and no significant pathological changes were found in HE staining of organs. The results of X-ray and improved I.R. Garrett score showed that ISO-M group was higher than that of Model group at 28 days (P<0.05). Scores of ISO-H group at 14, 21 and 28 days were higher than those of the other 3 groups (P<0.05). Micro-CT results showed intracavitary callus in ISO-M group was significantly reduced, which was lower than that in Model group (P<0.05), most of the callus in ISO-H group were subsided, and BV/TV in ISO-H group was lower than that in the other 3 groups (P<0.05). The results of HE staining and ferrubens solid green staining showed fracture area of ISO-H group was closed, continuous laminar bone had appeared, and the fracture healing process was higher than that of other groups. Angiographic results showed vascular volume fraction in ISO-H and ISO-M groups was higher than that in Model and ISO-L groups (P<0.05), and the vascular diameter in ISO-H and ISO-M groups was higher than that in Model and ISO-L groups (P<0.05). CONCLUSION In the concentration range of 10-40 mg·kg^-1, ISO has no obvious toxic and side effects, and could improve bone microstructure, promote formation of callus microvessels, and accelerate healing of fracture ends in a concentration-dependent manner.
Mice ; Male ; Animals ; X-Ray Microtomography ; Mice, Inbred C57BL ; Bony Callus ; Fracture Healing ; Tibial Fractures/surgery*

Recent studies have suggested that long-term application of anti-angiogenic drugs may impair oral mucosal wound healing. This study investigated the effect of sunitinib on oral mucosal healing impairment in mice and the therapeutic potential of Bifidobacterium breve (B. breve). A mouse hard palate mucosal defect model was used to investigate the influence of sunitinib and/or zoledronate on wound healing. The volume and density of the bone under the mucosal defect were assessed by micro-computed tomography (micro-CT). Inflammatory factors were detected by protein microarray analysis and enzyme-linked immunosorbent assay (ELISA). The senescence and biological functions were tested in oral mucosal stem cells (OMSCs) treated with sunitinib. Ligated loop experiments were used to investigate the effect of oral B. breve. Neutralizing antibody for interleukin-10 (IL-10) was used to prove the critical role of IL-10 in the pro-healing process derived from B. breve. Results showed that sunitinib caused oral mucosal wound healing impairment in mice. In vitro, sunitinib induced cellular senescence in OMSCs and affected biological functions such as proliferation, migration, and differentiation. Oral administration of B. breve reduced oral mucosal inflammation and promoted wound healing via intestinal dendritic cells (DCs)-derived IL-10. IL-10 reversed cellular senescence caused by sunitinib in OMSCs, and IL-10 neutralizing antibody blocked the ameliorative effect of B. breve on oral mucosal wound healing under sunitinib treatment conditions. In conclusion, sunitinib induces cellular senescence in OMSCs and causes oral mucosal wound healing impairment and oral administration of B. breve could improve wound healing impairment via intestinal DCs-derived IL-10.
Animals ; Mice ; Interleukin-10 ; Bifidobacterium breve ; Up-Regulation ; Angiogenesis Inhibitors ; Sunitinib ; X-Ray Microtomography ; Administration, Oral ; Wound Healing ; Antibodies, Neutralizing

This study compared the effects on bone metabolism and morphology of pathological obesity induced by excessive fat intake in a non-hibernator (mice) versus healthy obesity due to pre-hibernation fattening in a hibernator (ground squirrels). Kunming mice were fed a high-fat diet to provide a model of pathological obesity (OB group). Daurian ground squirrels fattened naturally in their pre-hibernation season (PRE group) were used as a healthy obesity model. Micro-computed tomography (micro-CT) and three-point bending tests were used to determine the microstructure and mechanical properties of bone. Western blots were used to analyze protein expression levels related to bone metabolism (Runt-related transcription factor 2 (RunX2), osteocalcin (OCN), alkaline phosphatase (ALP), osteoprotegerin (OPG), receptor activator of nuclear factor-‍κB ligand (RANKL), cathepsin K, matrix metallopeptidase 9 (MMP9), patched protein homolog 1 (Ptch1), phosphorylated β‍-‍catenin (P‍-‍β‍-‍catenin), and glycogen synthase kinase-3β (GSK-3β)). Compared with controls, there was no obvious bone loss in the OB mice, and the stiffness of the femur was increased significantly. Compared with summer active squirrels, bone formation was enhanced but the mechanical properties did not change in the PRE group squirrels. In OB mice, western blots showed significantly increased expression levels of all proteins except RunX2, OPG, and Ptch1. PRE ground squirrels showed significantly increased expression of most proteins except OCN and Ptch1, which decreased significantly, and P‍-‍β‍-‍catenin and OPG, which did not change. In conclusion, for non-hibernating mice, moderate obesity had a certain protective effect on bones, demonstrating two-way regulation, increasing both bone loss and bone formation. For pre-hibernating ground squirrels, the healthy obesity acquired before hibernation had a positive effect on the microstructure of bones, and also enhanced the expression levels of proteins related to bone formation, bone resorption, and Wnt signaling.
Mice ; Animals ; Hibernation ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Glycogen Synthase Kinase 3 beta/metabolism* ; Diet, High-Fat ; X-Ray Microtomography ; Sciuridae/metabolism* ; Obesity

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. It is known that aucubin (AU) exerts anti-inflammatory activity, but its effects and mechanisms in RA are unclear. This study investigated the anti-inflammatory effects and mechanisms of AU in vivo and in vitro. Human fibroblast-like synoviocyte cells from patients with RA (HFLS-RA), RAW264.7 cells, and MC3T3-E1 cells were used to evaluate the effects of AU on migration, invasion, apoptosis, osteoclast differentiation and production. Immunofluorescence was used to observe nuclear translocation of nuclear factor (NF)-κB, the double luciferase reporter gene method was used to observe NF-κB-p65 activity in AU-treated MC3T3-E1 cells. RT-qPCR was used to measure expression of bone metabolism and inflammation-related genes, and western blot was used to measure bone metabolism and NF-κB protein expression levels. Collagen-induced arthritis (CIA) rat model was used for pharmacodynamics study. Arthritis indexes were measured in the ankle and knee, histological staining and Micro-computed tomography were performed on the ankle joints. Also, inflammatory factor gene expression and the levels of NF-κB-related proteins were detected as in vitro. AU effectively inhibited HFLS-RA cell migration and invasion, promoted apoptosis, and inhibited RAW264.7 cell differentiation into osteoclasts, as well as inhibited NF-κB-p65 activity in MC3T3-E1 cells. Notably, AU significantly reduced the gene expression levels of three cell-related inflammatory factors and bone metabolism factors, effectively inhibited the expression of p-Iκκα β, p-IκBα, and p-p65 proteins. In vivo, AU relieved joint inflammation, reduced related inflammatory factors, and inhibited NF-κB signaling. It could be used to treat RA-related synovial inflammation and bone destruction through the NF-κB pathway.
Animals ; Anti-Inflammatory Agents/therapeutic use* ; Arthritis, Experimental ; Arthritis, Rheumatoid/drug therapy* ; Cells, Cultured ; Humans ; Inflammation/pathology* ; Iridoid Glucosides ; NF-kappa B/metabolism* ; Rats ; X-Ray Microtomography

Objective: To investigate the effects of straight-line minimally invasive access cavity on the mechanical properties of endodontically treated maxillary first premolars using finite element analysis. Methods: Micro-CT data of twenty maxillary first premolars were collected for three-dimensional reconstruction. Three access cavities, including the conventional access cavity (ConvAC), the truss access cavity (TrussAC) and the straight-line minimally invasive access cavity (SMIAC), as well as the root canal treatment procedure, were simulated in all the 20 reconstruction samples of three-dimensional models, respectively. The peak von Mises stress on the cervical area of each model, as well as the stress distribution under vertical and oblique loading circumstances, were subsequently determined by using finite element analysis. Results: In comparison to the stresses of ConvAC [buccal cervical (BC): (188.7±13.4) MPa, palatal cervical (PC): (200.9±25.7) MPa], the stresses of TrussAC [BC: (146.0±12.9) MPa, PC: (167.6±15.9) MPa] (t=9.01, P<0.001; t=4.59, P<0.001) and SMIAC [BC: (142.6±13.7) MPa, PC: (168.1±17.4) MPa] (t=9.64, P<0.001; t=3.76, P=0.004) significantly reduced the peak von Mises stress on the cervical area of the maxillary first premolars after root canal treatment. Under vertical loading conditions, SMIAC also reduced the central tendency of stresses on the occlusal surface, cervical area and root. In the case of oblique loading conditions, similar results were observed. Under both loading conditions, there was no significant difference in the peak von Mises stress on the cervical area of the maxillary first premolar between TrussAC and SMIAC groups. Conclusions: The design of SMIAC could preserve the mechanical properties of the maxillary first premolar following root canal treatment, which might have certain clinical feasibility.
Bicuspid ; Dental Stress Analysis ; Finite Element Analysis ; Root Canal Therapy ; Stress, Mechanical ; X-Ray Microtomography

OBJECTIVE: To observe the effects of Taohong Siwu Decoction(, THSWD) on the mesenchymal stem cells(MSCs) migration, homing number and cytokine expression in callus during the early process of fracture healing, and to explore the mechanism of THSWD on accelerationg fracture healing by regulating the homing of MSCs in rats. METHODS: A rat model of right femoral shaft open fracture was established. Thirty-two 5-week-old male Sprague-Dawley rats, weighting 110 to 130 g, were divided into control group, low-dose group, medium-dose group and high-dose group by using random number table. Distilled water was given to the control group, and the other groups were given Taohong Siwu Decoction. The rats were gavaged twice a day for 5 consecutive days after surgery. Bone volume/tissue volume(BV/TV) and bone mineral density(BMD) were observed using micro-computed tomography (micro-CT) at 21 days after surgery. At 5 days post-fracture, peripheral blood MSCs from THSWD treated and untreated rats were cultured in vitro. Subsequently, the migration ability of MSCs was observed by cell migration assay. The number of MSCs homing to the callus at the early stage of fracture (5 d) was detected by Immunohistochemistry (IHC). Protein chip was used to detect the expression of cytokines in callus. RESULTS: Micro-CT results showed that BV/TV was higher in the high-dose group than in the medium-dose group (P=0.032), and higher in the medium-dose group than in the low-dose group(P=0.041), with no difference between the control and low-dose group (P=0.651). In addition, there was no difference in BMD between low-dose group and the model group (P=0.671), and lower in the low-dose group than in the medium-dose group(P=0.018), and the medium-dose group was lower than the high-dose group(P=0.008). Cell migration assay showed that THSWD promotes enhanced the migration ability of peripheral blood MSCs. IHC assay revealed that CD45^-, CD90⁺, CD29⁺ MSCs significantly increased in bone callus after THSWD intervention compared with the control group. Protein chip showed that THSWD promoted the upregulation of CINC-1(×2.91), CINC-3(×1.59), LIX(×1.5), Thymus Chemokine (×2.55), VEGF (×1.22) and the down-regulation of TIMP-1 (×2.98). CONCLUSION THSWD, a representative formula of "promoting blood circulation and removing blood stasis", can significantly accelerate fracture healing, and its mechanism may be related to enhancing the migration ability of peripheral blood MSCs and up-regulating CINC-1, CINC-3, LIX, Thymus Chemokine, VEGF and down-regulating TIMP-1 in bone callus, which promotes the peripheral blood MSCs homing in the early stage of fracture.
Animals ; Drugs, Chinese Herbal ; Fracture Healing ; Fractures, Bone/drug therapy* ; Humans ; Male ; Mesenchymal Stem Cells ; Rats ; Rats, Sprague-Dawley ; Tissue Inhibitor of Metalloproteinase-1/pharmacology* ; Vascular Endothelial Growth Factor A ; X-Ray Microtomography

OBJECTIVES: To compare the effects of different irradiators on the establishment of osteoradionecrosis of jaw model (ORNJ) to explore an ideal modeling method. METHODS: A total of 33 adult SD rats were included and randomly divided into three groups according to the radiation equipment, namely, the blank control (CN, 3 rats), group A (linear accelerator irradiation, 15 rats), and group B (small-animal irradiator irradiation, 15 rats). Groups A and B were irradiated with daily fractions of 7, 8, and 9 Gy for 5 days and further divided into three subgroups as follows: group A RESULTS: At 3 weeks after dental extractions, complete gingival healing was found in the regions of dental extractions in groups A CONCLUSIONS Small-animal irradiator irradiation is an ideal device for establishing ORNJ model.
Animals ; Mandible ; Molar ; Osteoradionecrosis/etiology* ; Rats ; Rats, Sprague-Dawley ; X-Ray Microtomography

OBJECTIVE: To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model. METHODS: The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group. RESULTS: The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05). CONCLUSION mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.
Animals ; Bone Regeneration ; Bone Substitutes ; Cattle ; Dogs ; Membranes, Artificial ; Minerals ; Tooth Extraction ; Tooth Socket/surgery* ; X-Ray Microtomography

In recent years, developing new methods to accelerate orthodontic tooth movement (OTM) has attracted extensive attention in the field of orthodontic clinical and scientific research. It reduces orthodontic treatment time and risks. Over the past, various approaches have been done to accelerate orthodontic tooth movement. Several forms of corticotomy techniques have been effective in inducing rapid tooth movement. These techniques activate regional acceleratory phenomenon and create a favorable microenvironment for accelerating tooth movement. Root resorption is one of most common side effects of orthodontic treatment. It affects the long-term viability and health of teeth. However, the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption still remains unclear. Accelerating tooth movement may have two-side effects on root resorption. Through shortening the treatment period and removing the hyalinized tissues, the acceleration of orthodontic tooth movement could reduce root resorption. The increase of root resorption might be due to the local inflammation and function of cementoclasts/odontoclasts. In this paper, we reviewed the effects of different corticotomy techniques accelerating orthodontic tooth movement on root resorption. Corticotomy techniques deal with mucoperio-steal flaps and bone tissues differently and develop towards minimally invasive. Previous studies on root resorption use two-dimensional images, including apical films and panoramic tomography, to evaluate the degree of root resorption. In recent years, researches measure the volume of root resorption accurately using cone-beam computed tomography (CBCT) and micro-CT. Most studies suggest that the root resorption during acceleration of orthodontic tooth movement through corticotomy techniques is not statistically different from that of traditional orthodontic treatment. Some studies using micro-CT have shown that the root resorption in the groups of corticotomy techniques increases compared with the control group without surgery. Because of the short duration of these studies, the clinical significance is controversial on the overall impact of corticotomy techniques on orthodontic treatment. Accelerating orthodontic tooth movement is still at its emerging phase and need further research in the form of clinical trials to illustrate the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption.
Cone-Beam Computed Tomography ; Humans ; Osteoclasts ; Root Resorption/etiology* ; Tooth Movement Techniques ; Tooth Root ; X-Ray Microtomography

OBJECTIVE: To establish an animal model with malignant tumor in the skull base-infratemporal region, and to explore the role of iodine staining technique in identifying tumor tissues with Micro-CT data. METHODS: Sedation anesthesia was carried out on 12 BABL/c nude mice using inhaled isoflurane, and then WSU-HN6 cells that cultured and immortalized from human tongue squamous cell carcinoma were injected into the right infratemporal fossa via the submandibular area. The procedure was carried out under ultrasonographic guidance. The nude mice were sacrificed after 3 weeks observation. The head specimens were fixed and scanned by Micro-CT, and repeated scans were performed after staining with 3.75% compound iodine solution. Following decalcification in 20% EDTA for 2-4 weeks, the head specimens were embedded and sectioned. Hematoxylin and eosin staining and Pan-Keratin immunohistochemical staining were carried out. Bright-field microscopy and stereomicroscopy were used to visualize. The Micro-CT data were analyzed using iPlan software (Brainlab). RESULTS: Non-traumatic ultrasonography was used to guide HN-6 cells injection and confirm skull-base tumor formation in all the animals. Ultrasonographic guidance reduced the risk of cervical vessel injury when transferring tumor cells into the skull base space. An obvious asymmetrical appearance was detected via ultrasonography 3 weeks after tumor cell injection. The Micro-CT analysis showed that the bone was obviously damaged on the right side of the skull base, but the soft tissue image was unrecognizable. After four days staining with compound iodine solution, the morphology of the tumor and surrounding soft tissue could be clearly identified. Hematoxylin and eosin staining showed the tumor formation of the right infratemporal fossa region accompanied by bone destruction. Human keratin immunohistochemical staining showed that the tumor tissue originated from human squamous cell carcinoma, and the polynuclear osteoclasts could be seen at the margin of the skull base bone resorption. CONCLUSION The animal model with malignant tumor in the skull base-infratemporal region could be successfully established via submandibular injection under ultrasound-guidance. Bone changes of the skull were easily observed on Micro-CT, but the tumor counter was not able to be distinguished from surrounding soft tissue. The 3.75% compound iodine staining of the head specimen could help discern the tumor and surrounding soft tissue in more details.
Animals ; Carcinoma, Squamous Cell/diagnostic imaging* ; Infratemporal Fossa ; Iodine ; Mice ; Mice, Nude ; Skull Base ; Staining and Labeling ; Tongue Neoplasms ; X-Ray Microtomography