可生物降解聚合物载体微球口服防龋疫苗免疫效果

【目的】以PAc多肽(301～319)作为抗原,PBLG-PEG-PBLG做载体制备防龋微球疫苗,口服免疫SD大鼠,观察其对变链菌在大鼠牙面的黏附及对龋病发生的影响效果。【方法】28只出生30d的雄性SD大鼠随机分成4组建立龋模型,对各组大鼠口腔中变链菌的黏附菌落计数,根据Keyes评分标准做龋齿记分。【结果】PAc多肽抗原微球疫苗口服组的变形链球菌数为(13.2±8.16)×104CFU/ml;磨牙龋齿Keyes计分为31.8±6.77,均显著低于对照组(P<0.01)。【结论】口服PAc多肽抗原微球防龋疫苗均能减少龋模型大鼠龋齿的发生,以光滑面龋的减少更显著

大鼠牙囊细胞培养方法的探讨

【目的】探讨大鼠牙囊细胞体外培养的方法。【方法】分离出大鼠牙囊组织,分别采用组织块培养法、细胞消化分散法、及改良组织块法进行牙囊细胞原代及传代培养,倒置相差显微镜下进行细胞形态学观察,透射电镜观察细胞超微结构。【结果】培养至第3天,倒置相差显微镜观察发现,采用组织块培养法,见少数细胞从组织块爬出;而细胞消化分散法则可获得数量多的牙囊细胞,但与杂质细胞混杂生长;改良组织块法见量多、相对纯的牙囊细胞。电镜下牙囊细胞无桥粒,胞浆中含有高密度电子颗粒和大量粗面内质网。组织块法、细胞消化分散法和改良组织块法牙囊细胞培养成功率分别为80%、60%和100%;分别于10 d、7 d和6 d左右进行第一次传代。【结论】改良组织块法是一种良好的大鼠牙囊细胞培养方法

几种热塑牙胶根管充填方法根尖封闭性能的实验

【目的】比较并分析侧压根管充填术和4 种热塑牙胶根管充填术的根尖封闭性能。【方法】收集新鲜 拔除的54 颗牙, 预备后随机分为5 组。分别采用侧压根管充填术、热牙胶侧压根管充填术、Thermafil 根管充填 术、热牙胶垂直加压根管充填术和注射式热牙胶根管充填术, 进行牙胶根管充填。使用染料渗入法检测根尖微 渗漏的发生情况, 染色后在立体显微镜下测量染料自根尖渗入的长度并分析其结果。【结果】根尖微渗漏渗入 长度的中位数依次为冷侧压根管充填组1.55 mm 、热牙胶侧压根管充填术组为0.85 mm、热牙胶垂直加压根 管充填术组0.65 mm 、Thermafil 根管充填组0.50 mm、注射式热牙胶根管充填组0.40 mm; 两两比较发现冷、 热牙胶根管充填术后的根尖微渗漏发生差异有显著性意义( P< 0.05) ; 各组热牙胶根管充填术后的根尖微渗 漏发生情况差异没有显著性意义( P >0.05) ; 只有注射式热牙胶根管充填组与Thermafil 根管充填组之间的根 尖微渗漏差异有显著性意义( P< 0.05) 。【结论】热塑牙胶根管充填术的根尖封闭能力优于冷牙胶侧压根管充填 术; 4 种热塑压胶根管充填术之间, 以注射式热牙胶根管充填术的根尖封闭能力较好

表面改性聚合物左旋聚乳酸-多聚赖氨酸可促进骨髓基质细胞的初始黏附

BACKGROUND: It is an effective strategy that integrating the activated ligands into the surface of biomaterial scaffolds to enhance and regulate the material affinity for cells and cell compatibility. OBJECTIVE: To develop poly (L-lactic acid)-poly (L-lysine) (PLLA-PLL) to enhance cell initial adhesion on the polymer surface. METHODS: Different composition polymer films (PLLA-PLL, PLLA77-PLL72, PLLA45-PLL246) were synthesized through ring-opening metathesis polymerization. BMSCs were seeded onto these different composition polymer surfaces (PLLA and TCP served as the control), and detected the best composition of PLLA-PLL polymer film for cell adhesion and proliferation. RESULTS AND CONCLUSION: PLLA-PLL films increased the number of initially attached BMSCs in both serum and serum free conditions compared with PLLA. Increased PLL content in the PLLA-PLL co-polymer led to increase cell attachment, significant difference changes were detected on copolymer PLLA77-PLL72 (P< 0.05). Continued culture confirmed that PLLA77-PLL72 enhanced cell proliferation. BMSCs cultured on the PLLA-PLL had a clear and well organized F-actin fibre expression