Objective Astragalus polysaccharide (APS) has promoting angiogenesis function. To explore the effects of APS collagen sponge on enhancing angiogenesis and collagen synthesis so as to provide evidence for the future tissue engineering appl ication as a kind of angiogenic scaffold. Methods APS collagen sponges were prepared by covalent binding with collagen polypeptides by using of crossl inking agents at the ratio of 1 ∶ 1 (W/W). Twenty 10-week-old SpragueDawley rats (10 males and 10 females, and weighing 200-250 g) were selected. Longitudinal incision was made at both sides of the back to form subcutaneous pockets. APS collagen sponges of 5 mm × 5 mm × 5 mm at size were implanted into the left pockets as the experimental group, collagen sponges without APS of the same size into the right pockets as the control group. The general conditions were observed after operation. At 3, 7, 14，and 21 days, 5 rats were sacrificed and the samples were harvested to count the number of microvessels, to measure the contents of the hydroxyprol ine (Hyp), and to detect the mRNA expressions of angiopoetin 1 (Ang1), matrix metalloproteinases 9 (MMP-9), and tissue inhibitors of metalloproteinases 1 (TIMP-1). Results All rats were al ive during experiment period. The number of microvessels increased gradually, and reached the peak at 14 days in 2 groups; the expermental group was significantly higher than the control group (P lt; 0.05). The contents of Hyp increased gradually in 2 groups, and the experimental group was significantly higher than the control group (P lt; 0.05). The mRNA expressions of Ang1 and MMP-9 in the experimental group were significantly higher than those in the control group at 3, 7, and 14 days (P lt; 0.05); the mRNA expression of TIMP-1 in the experimental group was significantly lower than that in the control group at 3 days and was significantly higher at 14 and 21 days (P lt; 0.05). Conclusion The APS collagen sponges can improve angiogenesis and collagen synthesis in wound heal ing by regulating the expressions of Ang1, MMP-9, and TIMP-1.
Objective To investigate the effect of astragalus polysaccharides(AP) on chitosan／polylactic acid(AP／C／PLA)scaffolds and marrow stromal cells(MSCs)tissue engineering on periodontal regeneration of horizontal alveolar bone defects in dogs． Methods MSCs were isolatedfrom the bone marrow and then cultured in conditioned medium to be induced to become osteogenic．The MSCs were harvested and implanted into AP／C／PLA and C／PLA scaffolds．A horizontal alveolar bone defect(5 mm depth, 2 mm width)were produced surgically in the buccal side of the mandibular premolar 3 and 4 of 10 dogs．The defects were randomly divided into 4 groups(n=10)：Group A, root planning only(blank contro1); group B, AP／C／PLA with conditioned medium(medium contro1);group C, C／PLA with MSCs(scaffolds contro1); and group D, AP／C／PLA with MSCs(experimental group)．Eight weeks after surgery， block sections of the defects were collected for gross, histological and X-ray analysis. Results MSCs induced in vitro exhibited an osteogenic phenotype with expressingcollagen I and alkaline phosphatase． X-ray film observation showed that the bone density and height had no changes in group A; in group B, the bone density was increased to a certain extent and furcation area reached a few height, but no height was increased in interdental septum; in group C，the bone density was increased and furcation area nearly reached the native height,but interdental septum reached a few height;in group D,the bone density was increased significantly and furcation area and interdental septum reached the native height. Histological evaluation showed that there was greater tissue formation in group D than that in groups A, B and C, in which new alveolar bone, new cementum, periodontal ligament with Sharpey’s fibers, and new bone tissue was similar to native periodontal tissues. Ingroup A，B, C and D respectively, the amount of new alveolar bone regeneration was 0.83±0.30, 1.46±0.55, 2.67±0.26 and 2.90±0.41 mm; new cementum regeneration was 0.78±0.45，1.30±0.60，2.29±0.18 and 2.57±0.22 mm; the amount of connective tissue adhesion was 0.80±0.22，1.33±0.34，2.23±0.42 and 2.64±0.27 mm; all showing significant differenecs between group D and groups A, Band C (Plt;0.05)．Conclusion The technology of tissue engineering with AP／C／PLAscaffolds and induced MSCs may contribute to periodontal regeneration．
Objective To explore the protective effect and mechanism of Astragalus polysaccharides (APS) on liver injury in the state of brain death in New Zealand rabbits. Methods Twenty-four New Zealand rabbits were randomly divided into 3 groups (n=8): the blank control group, the brain death group, and the APS group. We obtained blood and liver tissue specimens from rabbits of three groups at 4 h and 8 h after treatment respectively (n=4). The rabbits of blank control group simulated the procedures of anesthesia and surgery of the brain death, without the Foley balloon catheter being pressurized, and maintained anesthesia. The brain death group: brain-dead models were established. The APS group: injection of APS (12 mg/kg) via the femoral vein bolus immediately after anesthesia, brain-dead models were established as same as rabbits of brain death group. The blood and liver tissue samples were taken at 4 h and 8 h after treatment to detect aminotrans-ferase (AST), alanine amino-transferase (ALT) and tumor necrosis factor α (TNF-α), and to observe the change of liver tissue by HE staining and immunohistochemical staining〔expression level of nuclear transcription factor p65 protein (NF-κB p65) could be detected by immunohistochemical staining〕. Results ① ALT and AST. Compare with the blank control group at the same time (4 h and 8 h), levels of ALT and AST in brain death group and APS group were significantly increased (P<0.05), and the levels of ALT and AST in brain death group were higher than those of APS group at each time point (P<0.05). In the same group, compared with 4 h, there was no significant difference in the levels of ALT and AST in blank control group at 8 h (P>0.05); the levels of ALT and AST in brain death group at 8 h were both higher than those of 4 h (P<0.05); the levels of ALT at 8 h in APS group was higher than that of 4 h, but there was no significant difference in the level of AST between 4 h and 8 h (P>0.05). ② TNF-α. Compare with the blank control groups at same time (4 h and 8 h), levels of TNF-α in brain death group and APS group were significantly increased(P<0.05), and level of TNF-α in brain death group was higher than that of APS group at 4 h and 8 h (P<0.05). ③ The HE results. The liver tissue structure of blank control group, brain death group, and APS group at 4 h had no obvious change. The liver tissue structure of brain death group at 8 h showed the evident tissue damage: liver cells showed the balloon samples, disordered arrangement, cytoplasmic loose light dye net-like, and inflammatory cells infiltrated in portal area. The liver tissue structure of APS group at 8 h showed that, liver cells showed mild edema, normal arrangement, and a small amount of inflammatory cells infiltrated in portal area. The liver tissue structure damage of APS group at 8 h was milder than that of brain death group. ④ Immunohistochemical staining results. There was no significant difference in expression levels of NF-κB p65 protein among blank control group, brain death group, and APS group at 4 h (P>0.05). But at 8 h, the expression levels of NF-κB p65 protein in brain death group and APS group were higher than that of blank control group (P<0.05), and the expression level of NF-κB p65 protein in brain death group was higher than that of APS group (P<0.05). The expression levels of NF-κB p65 protein in brain death group and APS group at 8 h was higher than that of 4 h in the same group (P<0.05), but there was no significant difference between 4 h and 8 h in blank control group (P>0.05). Conclusions Brain death will cause liver damage and the injury degree may be related to the continuous time. The damage at 8 h was more serious than that of 4 h. APS has a protective effect on liver of brain-dead rabbits' and its mechanism may be closely related to inhibit TNF-α and NF-κB by diverse ways to reduce the inflammation of the liver injury.