Injectable nano/chitosan/bone morphogenetic protein-2 induces periodontal tissue regeneration / 中国组织工程研究

BACKGROUND:Chitosan hydrogel has good biocompatibility, biodegradability and antibacterial property, which can promote tissue healing and induce bone formation. As a scaffold carrying growth factors, it can ensure the efficient and slow release of exogenous growth factors. OBJECTIVE: To observe the effect of injectable nano/chitosan/bone morphogenetic protein-2 composite to promote periodontal tissue regeneration in rats. METHODS:Fifty-four Wistar rats were randomized into three groups, and then chronic periodontitis model of the second molar was established. After modeling, injectable nano/chitosan/bone morphogenetic protein-2 composite was implanted into the periodontal tissue of the second molar in the experimental group; injectable nano/chitosan hydrogel was implanted in the control grouop; and nothing was implanted in the blank group. At 3, 6, 9 weeks after surgery, gingival bleeding index, probing depth, and tooth mobility were detected. X-ray and histopathological observations were carried out. RESULTS AND CONCLUSION:At 9 weeks after surgery, the probing depth and tooth mobility were both lower in the experimental group than the other two groups (P < 0.05). In the experimental group, the alveolar bone height was restored at the root bifurcations, bone trabeculae were arranged densely and evenly, the newly formed periodontal ligament and alveolar bone tissues were dense and equaly distributed in the bone defect area at 9 weeks after surgery, indicating a better restoration effect than the control and blank groups. These findings suggest that the injectable nano/chitosan/bone morphogenetic protein-2 composite has an anti-inflammatory role and can guide periodontal tissue regeneration.

The potential role of COX-2 in cancer stem cell-mediated canine mammary tumor initiation: an immunohistochemical study

Increasing evidence suggests that cancer stem cells (CSCs) are responsible for tumor initiation and maintenance. Additionally, it is becoming apparent that cyclooxygenase (COX) signaling is associated with canine mammary tumor development. The goals of the present study were to investigate COX-2 expression patterns and their effect on CSC-mediated tumor initiation in primary canine mammary tissues and tumorsphere models using immunohistochemistry. Patterns of COX-2, CD44, octamer-binding transcription factor (Oct)-3/4, and epidermal growth factor receptor (EGFR) expression were examined in malignant mammary tumor (MMT) samples and analyzed in terms of clinicopathological characteristics. COX-2 and Oct-3/4 expression was higher in MMTs compared to other histological samples with heterogeneous patterns. In MMTs, COX-2 expression correlated with tumor malignancy features. Significant associations between COX-2, CD44, and EGFR were observed in low-differentiated MMTs. Comparative analysis showed that the levels of COX-2, CD44, and Oct-3/4 expression varied significantly among TSs of three histological grades. Enhanced COX-2 staining was consistently observed in TSs. Similar levels of staining intensity were found for CD44 and Oct-3/4, but EGFR expression was weak. Our findings indicate the potential role of COX-2 in CSC-mediated tumor initiation, and suggest that COX-2 inhibition may help treat canine mammary tumors by targeting CSCs.

Nano-chitosan/bone morphogenetic protein gel prevents absorption of rat’s alveolar ridge / 中国组织工程研究

BACKGROUND:Absorption and atrophy of the alveolar ridge always happen after tooth extraction. There are stil a lot of difficulties to be worked out to prevent the atrophy of the alveolar ridge. OBJECTIVE:To investigate the effect of the nano-chitosan/bone morphogenetic protein hydrogel on preventing absorption of the residual alveolar ridge of the rats. METHODS:Total y 54 Sprague-Dawley rats were divided randomly and equal y into three groups. A model of residual alveolar ridge was made by extraction of the left central incisor. Nano-chitosan bone morphogenetic protein hydrogel was implanted into the rat’s alveolar fossa of the experimental group;the alveolar fossa of the control group was implanted with nano-chitosan hydrogel;the alveolar fossa of the blank group was implanted with nothing. Rat’s mandible was ful y dissected after 3, 6, 9 weeks, respectively. Molybdenum target X-ray examination and pathological observation were evaluated. RESULTS AND CONCLUSION:At weeks 3, 6, 9 postoperation, the residual alveolar ridge was absorbed to different degrees, which was milder in the experimental group than the cotrol group and blank group (P<0.05). After 3 weeks, in the blank group, less new bone formed, but bleeding and a large amount of inflammatory cells were visible; in the control group, a few of osteoid tissues and lymphocytes were found; in the experimental group,new bone formed and a small amount of inflammatory cells were observed. After 6 weeks, new bone formed obviously in the experimental group, a little new bone formed in the control group, but less new bone formed in the blank group. After 9 weeks, a large amount of new bone formed in the experimental group with good osteogenic ability; only a few of new bone formed in the control and blank groups. Nano-chitosan/bone morphogenetic protein hydrogel can be used to prevent the absorption of the residual alveolar ridge after tooth extraction.

The effects of nano-chitosan/bone morphogenetic protein gel on the repair of mandibular defect / 实用口腔医学杂志

Objective:To investigate the effects of Nano-chitosan rhBMP-2 Gel(NCS/BMP-2 Gel)on the repair of mandibular de-fect.Methods:NCS/BMP-2 Gel and NCS Gel were prepared and respectively injected into the subcutaneous space on both sides of dorsum of 9 rats.3 rats were respectively sacrificed 10,20 and 30 d after injection.The subcutaneous nodules were histologicaly ex-amined.Mandibular defect was made in 54 SD rats and the rats were divided randomly and into 3 groups(n=18):NCS/BMP-2 Gel was implanted into the defects in group 1,NCS Gel in group 2,no injection in group 3.Animals were sacrificed 3,6 and 9 weeks after transplantation.X-ray examination,pathologic observation were conducted.Results:Subcutaneous nodules were found in both sides of the rat dorsum.The residual mandibular defect area in study group 1 was apparently smaller than that in group 2 and 3(P<0.05). More new bone formation was observed in the gel injected area in group 1 than in group 2 and 3.Conclusion:Nano-CS/BMP-2 Gel is biocompatible and can accelerate the healing of mandibular defect.

Analysis of reconstruction using non-vascularized iliac bone graft for patients with mandibular defects / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To make a clinical retrospective analysis of reconstruction using autogenous non-vascularized iliac bone graft for patients with mandibular defects, and then to evaluate the treatment effectiveness and operation announcements of this method.</p><p><b>METHODS</b>34 patients who were suffered from discontinued mandibule because of tumor or trauma, were treated with autogenous non-vascularized iliac bone graft. The surgery technique, postoperative outcomes and complications were analyzed.</p><p><b>RESULTS</b>In 34 patients adopted non-vascularized iliac bone graft, 31 patients adopted rigid internal fixation with titanium mini plate, 3 patients with bridging titanium plate. 27 bone grafts survived completely, the overall success rate was 79.41%. 3(8.82%) of the bone grafts healed after infection, 4(11.76%) bone grafts lost because of infection.</p><p><b>CONCLUSION</b>The autogenous non-vascularized iliac bone graft is one of the most important way for the reconstruction of mandibular defects. The methods of internal fixation includes titanium mini pate and bridging titanium plate.</p>

A study on the compound bone morphogenetic protein with chitosan and cyanoacrylate on preventive absorption of rat's alveolar ridge / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effectiveness and feasibility of compound bone morphogenetic protein (BMP) with chitosan and cyanoacrylate on preventive absorption of rat's alveolar ridge.</p><p><b>METHODS</b>Fifty-four Wistar rats were divided randomly into three groups: Experimental group (compound BMP with chitosan and cyanoacrylate group), control group (chitosan composite group) and blank group. After rat lower incisors were extracted, compound BMP with chitosan and cyanoacrylate were implanted into experimental group rat's residual alveolar fossa, control group implanted with chitosan, blank group left empty. Animals were sacrificed after 3, 6, 9 weeks. X-ray examination, Image-Pro Plus analysis and pathologic observation were evaluated.</p><p><b>RESULTS</b>The relative length values of residual alveolar ridge and optical density test in experimental group were all greater than those of control group and blank group at 3, 6, 9 weeks after operation (P < 0.05). Light microscopy showed that new bone formations in experimental group were better than those in control group and blank group at 3, 6, 9 weeks after implantation.</p><p><b>CONCLUSION</b>Compound BMP with chitosan and cyanoacrylate can be used to prevent the absorption of residual alveolar ridge and have more clinical predications. [</p>

Clinical application of light cure Dyract flow in early caries of molar pits and fissures / 实用口腔医学杂志

0.05),24 .49 and 12.25 (P