钛种植体表面矿化胶原涂层的生物学性能研究

目的钛种植体表面应用电化学沉积技术制备的矿化胶原涂层的生物学性能研究。方法本研究应用电化学沉积技术在钛金属表面制备了矿化胶原涂层,应用模拟体液(SBF)浸泡表征其诱导羟基磷灰石骨性结合能力,利用MTS法检测涂层的细胞粘附及增殖性能。结果制备的矿化胶原涂层能在SBF中稳定存在并继续矿化,能促进植入成骨前体细胞在其表面的粘附、增殖和分化。结论钛种植体表面进行矿化胶原涂层修饰可以有效促进其生物活性。     

人牙周膜细胞在透明质酸/胶原支架上的黏附与生长

目的研究人牙周膜细胞（PDLC）在胶原、透明质酸及透明质酸/胶原支架上的黏附、生长情况,以初步探讨透明质酸/胶原支架应用于牙周组织工程的可行性。方法将体外培养的人牙周膜细胞接种到碳化二亚胺交联的胶原、透明质酸及透明质酸/胶原支架上;MTT法检测支架对人牙周膜细胞黏附、生长的影响;并用倒置相差显微镜和扫描电镜观察形态变化。结果MTT结果显示胶原、透明质酸及透明质酸/胶原支架上人PDLC的黏附、生长情况,在第1、2、4天组间比较差异具有统计学意义（P<0.05）,第7天组间差异无统计学意义（P>0.05）,且人牙周膜细胞数量透明质酸/胶原组均高于对照组;人牙周膜细胞在支架上生长良好。结论相对于胶原支架和透明质酸支架,透明质酸/胶原支架更有利于人牙周膜细胞的黏附,提示该材料具备成为牙周组织工程理想支架材料的潜力。     

纯钛超声微弧氧化-壳聚糖/海藻酸钠自组装种植体的动物实验研究

目的: 采用层层自组装技术(Layer-by-Layer self-assembly technique)在纯钛(TA2)微弧氧化表面制备壳聚糖(CS)/海藻酸钠(ALG)复合涂层,研究对骨结合的影响。方法: 选取24只新西兰大白兔建立双侧下颌骨种植模型,分别植入A、B、C组,TA2-MAO为A组,TA2-MAO-NAOH-CS为B组,TA2-MAO-NAOH-CS-ALG为C组。术后分别于2、4、6周取材,采用锥形束CT(cone beam,CBCT)和种植体骨扭出力测试的方法,观察种植体植入后骨结合的情况。选扭出6周的种植体做扫描电镜(SEM), 观察种植体涂层表面形貌。结果: CBCT观察:在2、4、6周,C组骨缺损区的愈合情况明显优于A、B组,B组骨缺损区的愈合情况稍好于A组,在6周时,观察到C组骨愈合良好,种植体骨界面无明显阴影区域,骨密度与正常骨密度一致。种植体骨扭出力测试中观察:在第2周时,A、B、C组的扭出力差异不明显,第4周时,B、C组扭力值高于A组,第6周时,C组的扭出力明显大于A、B组。在6周时,扫描电镜可以观察到c组对骨结合有促进作用。结论: TA2-MAO-NAOH-CS涂层和TA2-MAO-NAOH-CS-ALG涂层对骨结合都有促进作用,而TA2-MAO-NAOH-CS-ALG复合涂层对骨结合效果更好,双侧建立动物模型的方法可行。     

纯钛表面聚吡咯涂层的表面性能研究

目的：纯钛表面电化学聚合聚吡咯涂层并研究其表面性能。方法：采用恒电流法以0.25mA/cm^3、1mA/cm^2、4mA/cm^2的电流密度制备两种支撑电解质Cl^-和ToS^-的纯钛表面聚吡咯涂层。利用SEM、表面粗糙度仪以及接触角测量仪检测涂层表面性能。结果：随聚合电流密度增大，表面粗糙度（Ra、Rz值）和表面接触角逐渐增大，而表面自由能逐渐减小。在相同的聚合密度电流下，ToS^-搀杂组的表面粗糙度（Ra、Rz值）、表面接触角均大于Cl^-搀杂组；而表面自由能则小于Cl^-搀杂组。结论：聚吡咯的表面性质，如表面形貌、润湿性、表面自由能，可以通过改变搀杂离子种类和聚合电流密度来进行调整。     

热触发自组装型羟基磷灰石/胶原复合材料的基础研究

目的：本文研制热触发自组装型羟基磷灰石（hydroxyapatite,HA）／胶原复合材料并测定了其理化特性。方法：采用相交融合法（Interdigitation--Fusion,IF）制备载Ca2＋或Pi脂质体,考察其包封率及相变温度。提取Ⅰ型鼠尾胶原,与脂质体混合成前驱液,观察前驱液37℃时的显微结构及矿物质形成情况。结果：发现脂质体平均包封率为68％,前驱液34～35℃时开始形成HA／胶原复合体。因此提示前驱液在体温下可形成HA／胶原复合凝胶,可为新的根尖屏障材料提供方向。     

实验性牙龈炎Ⅰ型胶原的变化

目的观察实验性牙龈炎早期炎症牙龈组织Ⅰ型胶原的变化。方法以正畸钢丝拴结豚鼠切牙牙颈部，取临床牙周炎患者牙周袋内菌斑种入豚鼠受试牙龈沟，连续5天，受试牙龈局部红肿、龈沟加深，形成实验性牙龈炎动物模型。取其切牙连同周围牙同组织，常规石蜡切片，免疫组化PAP法检查牙龈Ⅰ型胶原，同时HE染色。结果炎性牙龈Ⅰ型胶原较正常着色明显减弱，着色缺乏连续性。结论早期炎症已有胶原受损，其损伤可能主要由炎症反应所致。     

釉基质蛋白对人牙周膜细胞形成Ⅰ型胶原、Ⅲ型胶原的影响

目的:观察釉基质蛋白对体外培养的人牙周膜细胞形成Ⅰ型胶原、Ⅲ型胶原的影响.方法:改良组织块法培养人牙周膜细胞,免疫细胞化学方法和图像分析方法观察细胞形成Ⅰ型胶原、Ⅲ型胶原的能力.结果:50、100、200 mg/L的釉基质蛋白可以促进牙周膜细胞合成Ⅰ、Ⅲ型胶原,其中,以100 mg/L釉基质蛋白的促Ⅰ型胶原合成作用最明显,50 mg/L釉基质蛋白的促Ⅲ型胶原合成作用最明显.但是,这种促进作用有一定的时间性.结论:一定浓度的釉基质蛋白可以促进牙周膜细胞形成Ⅰ型胶原、Ⅲ型胶原.     

壳聚糖-Ⅰ型胶原复合膜的制备及其生物相容性实验研究

目的 了解制备的壳聚糖-Ⅰ型胶原复合膜的理化性能及其与MG63成骨样细胞的生物相容性,以初步探讨其作为引导骨再生屏障膜的可行性.方法 采用提纯的牛肌腱Ⅰ型胶原和壳聚糖,经冷冻干燥,使用热交联、化学交联技术制成壳聚糖-Ⅰ型胶原复合膜(实验组)和Ⅰ型胶原膜(对照组).采用氨基酸含量检测、差示量热扫描法分析牛肌腱Ⅰ型胶原性质和表征,红外光谱、扫描电镜分析2种膜的理化性能.将MG63成骨样细胞接种于2种膜上,MTS法检测细胞1d、3d、5d、7d的增殖情况.结果 牛肌腱Ⅰ型胶原的胶原3股螺旋结构保持较完整,其热变性温度为99.04℃,提热吸收峰为53.54℃,与标准品指标接近,其成分比例及性质表征符合Ⅰ型胶原特征.红外光谱结果表明实验组具备胶原和壳聚糖特征峰表现,并且2种材料之间形成大量氢键,分子间结合良好.扫描电镜显示实验组和对照组膜表面和横切面为多孔结构,实验组膜孔径较大,为10～ 100 μm.MG63成骨样细胞在2组膜上呈明显的增殖趋势,具有较好的细胞相容性.结论 制备的壳聚糖-Ⅰ型胶原复合膜具有优良的结构及生物学性能,可应用于下一步引导骨再生膜材料的研究.     

钛表面儿茶酚化聚电解质多层膜对蛋白质的吸附研究

目的探讨钛表面儿茶酚化聚电解质多层膜对蛋白质的吸附行为,为钛种植体表面改性提供参考。 方法根据本课题组前期建立的方法,采用脂多糖胺纳米囊泡（NPs）和3,4-二羟苯基丙酸反应制备儿茶酚接枝率为40%的儿茶酚化NPs（cNPs）;采用透明质酸（HA）和多巴胺反应制备儿茶酚接枝率为10%的儿茶酚化透明质酸（cHA）。利用层层自组装技术,以cNPs为引发层、cHA/NPs为阴、阳离子聚电解质,在钛或石英表面构建含3个（cHA/NPs）双层的儿茶酚化聚电解质膜[（基底-cNPs-（cHA/NPs）₃],记为cPEM。同时以NPs为引发层,构建含（HA/NPs）₃的未儿茶酚化聚电解质膜（PEM）。采用红外光谱分析膜表面化学组成、激光扫描共聚焦显微镜（LSCM）检测膜表面粗糙度,Zeta电位分析仪记录膜表面Zeta电位。选取4种等电点（pI）分别小于、等于、大于生理pH 7.4的蛋白质：牛血清白蛋白（BSA,pI = 4.7）、纤连蛋白（Fn,pI = 5.8）、牛血红蛋白（BHb,pI = 6.8 ~ 7.0）、多聚赖氨酸（PLL,pI = 9.74）,以其为模型蛋白,用0.15 mol/L的NaCl配制成1 mg/mL的水溶液。采用石英晶体微天平（QCM）实时动态监测膜表面蛋白吸附情况、原子力显微镜观察样品蛋白吸附前后形貌,LSCM、荧光酶标仪分别分析荧光标记蛋白在膜表面吸附情况,并测试荧光标记蛋白的吸附量。使用SPSS 20.0对数据进行单因素方差分析、SNK和LSD法进行比较,P<0.05认为差异有统计学意义。 结果LSCM结果表明,石英表面粗糙度为（301 ± 12）nm,组装cPEM、PEM后,表面粗糙度增加,分别为（656 ± 88）、（446 ± 25）nm,组间差异具有统计学意义（F = 66.974,P<0.001）。cPEM组的红外谱图中出现儿茶酚中的苯环（ν_{C = C}）、PEM组的胺基和烷基、多糖中的糖醛酸环等特征峰,证实钛表面引入cPEM和PEM。组装过程中Zeta电位呈锯齿状交替上升,cPEM组表面电位为+22.53 mV,PEM组的表面电位为+17.36 mV。QCM结果表明,生理pH下,所有表面均基本不吸附PLL。在不同表面,BSA和BHb的吸附量cPEM组>PEM组>Ti组。原子力显微镜下可见cPEM、PEM组表面为分布均匀的水滴形海岛状结构,吸附BSA后,表面可见圆盘状结构,且cPEM组量大于PEM组,说明可能BSA在cPEM组表面的吸附量大于PEM组。采用LSCM和荧光酶标仪分析绿色荧光标记蛋白在不同表面的吸附情况,发现在不同种膜表面,同一蛋白吸附量cPEM组>PEM组>Ti组;在同一种膜表面,不同蛋白吸附量BSA>Fn>BHb。 结论本实验研发的聚电解质多层膜对钛表面进行改性后,能提高蛋白在表面的吸附,儿茶酚化改性则进一步促进这种吸附。蛋白吸附的驱动力可能主要源于静电相互作用和儿茶酚基团对蛋白偶联捕捉作用。     

Influences of hyaluronic acid on the anticandidal activities of lysozyme and the peroxidase system

Oral Diseases (2011) 17 , 577–583 Objective: To investigate the fungistatic and fungicidal activity of hyaluronic acid (HA) and the influences of HA on the anticandidal activities of lysozyme and the peroxidase system. Materials and Methods: HA, hen egg‐white lysozyme, and the bovine lactoperoxidase system were used. Candida albicans ATCC 10231, 18804, and 11006 strains were used in the experiments. The fungistatic activity of HA was determined by measuring the optical densities of the cultures. The candidacidal activity of HA and the influences of HA on the candidacidal activities of lysozyme and the peroxidase system were determined by comparing the numbers of colony‐forming units. Results: Hyaluronic acid displayed inhibitory effects on the growth of C. albicans, and the inhibitory effects were proportional to HA concentration. HA did not have any measurable candidacidal activity. HA showed inhibitory effects on the candidacidal activities of lysozyme, and the peroxidase system that was proportional to HA concentration. HA at 1.0–2.0 mg ml^?1 almost completely inhibited the candidacidal activities of lysozyme and the peroxidase system. Conclusions: Hyaluronic acid possesses fungistatic activity but no candidacidal activity. HA showed inhibitory effects on the candidacidal activities of lysozyme and the peroxidase system.     

The efficacy of topical hyaluronic acid in the management of oral lichen planus

Background:  The aim of this study was to evaluate the efficacy of a topical hyaluronic acid (HA) gel preparation (0.2%) in the management of oral lichen planus (OLP).
Methods:  A total of 124 patients with erosive OLP participated in a randomized, placebo-controlled, double-blind trial to evaluate the efficacy of a topical HA preparation. Outcome measures included soreness relief following immediate application, oral function and size of erosive/ulcerative area. Patients were medicated for 28 days and completed a log diary recording oral function and soreness scores.
Results:  Application of topical HA produced a significant reduction ( P  < 0.05) in soreness scores when compared with placebo for up to 4 h post-application. There was no difference between treatment groups ( P  > 0.05) with respect to oral function. Patients treated with 0.2% HA showed a significant reduction ( P  < 0.05) in the size of the erosive/ulcerated area after 28 days of treatment when compared with baseline. There was no significant difference in changes in ulcerative areas between treatment groups.
Conclusions:  Topical HA (0.2%) does appear to be of some benefit in the management of erosive lichen planus providing efficacy for up to 4 h after administration. Very frequent applications should be considered to obtain a more significant clinical benefit. Topical HA gel may be a useful addition to the treatment option for OLP.     

The efficacy of topical hyaluronic acid in the management of recurrent aphthous ulceration

BACKGROUND: The aim of this study was to evaluate the efficacy of a topical hyaluronic acid (HA) preparation (0.2%) in the management of recurrent aphthous ulceration (RAU). METHODS: One hundred and twenty patients with RAU participated in a randomized, placebo controlled, double-blind trial to evaluate the efficacy of the topical HA and preparation. Outcome measures include soreness relief on immediate application (recorded over 60 min). Thereafter, patients completed a log diary recording soreness from the ulcers, occurrence of new ulcers and ulcer duration. RESULTS: Both topical HA and placebo resulted in a significant reduction in ulcer soreness following immediate application (P = 0.0004). Throughout the rest of the investigation period, there was no significant differences (P > 0.05) between the treatments for reducing soreness. Patients treated with topical HA recorded few ulcers on day 5 of the investigation than those treated with placebo (P < 0.001). Likewise, the occurrence of new ulcers was lower in the HA treated group on day 4 when compared with placebo (P = 0.047). CONCLUSION: Topical HA (0.2%) may be of benefit in the management of RAU. Immediate reduction of symptoms appears to be a barrier effect.