Gelatamp胶质银明胶海绵在前牙区Ⅱ型种植位点的临床应用研究

目的:观察Gelatamp胶质银明胶海绵在前牙区Ⅱ型种植位点的临床应用效果。方法:选择40例前牙区拔牙拟作Ⅱ型种植的病人,随机分层分为Gelatamp胶质银明胶海绵填塞止血组(试验组)及棉球压迫止血组(对照组)。拔牙后,试验组在牙槽窝置入Gelatamp胶质银明胶海绵,对照组常规紧咬棉球30分钟后取出,观察比较两组的止血效果和4周后行Ⅱ型种植手术前拔牙位点软组织愈合的情况。结果:试验组拔牙创出血很快停止,出血平均时间为0.67分,试验组、对照组止血效果有效率分别为100%,80%,差异有统计学意义(P<0.05)。在4周后Ⅱ型种植手术前试验组、对照组的软组织愈合良好率分别为70%和40%,差异有统计学意义(P<0.05)。结论:Gelatamp胶质银明胶海绵,能显著缩短出血时间,有效增强止血效果,具有止血和持久杀菌的双重效果,有利于形成良好的软组织,有利于早期种植体植入后封闭创面,具有一定的临床应用价值。     

Silver oxide‐containing hydroxyapatite coating has in vivo antibacterial activity in the rat tibia

Bacterial infection is a serious postoperative complication of joint replacement. To prevent infections related to implantation, we have developed a novel antibacterial coating with Ag‐containing hydroxyapatite (Ag‐HA). In the present study, we examined the antibacterial activity of Ag‐HA implant coatings in the medullary cavity of rat tibiae. Forty 10‐week‐old rats received implantation of Ag‐HA‐ or HA‐coated titanium rods, then were inoculated with ～1.0 × 10² colony‐forming units of methicillin‐resistant Staphylococcus aureus. Bacterial counts were calculated for rats euthanized at 24, 48, and 72 h postoperatively. Serum levels of Ag (in the Ag‐HA group only) were calculated for rats euthanized at 24, 48, 72 h and 4 weeks. Radiographic evaluations of bone infection were also performed at 4 weeks. Tibiae from both groups showing infection were evaluated histologically. Significant differences in bacterial counts were seen at 24, 48, and 72 h. Mean concentrations of Ag in serum peaked about 48 h after implantation, then gradually decreased. Mean radiographic scores for infection were significantly lower with Ag‐HA implants than with HA implants. Histological examination showed better results for abscesses, bone resorption, and destruction of cortical bone around Ag‐HA‐coated implants. These results indicate that Ag‐HA coatings may help prevent surgical‐site infections associated with joint replacement. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1195–1200, 2013     

Clinical evaluation of diamine silver fluoride/potassium iodide as a dentine desensitizing agent. A pilot study

Background: The aim of the present study was to compare the efficacy of an experimental diamine silver fluoride/potassium iodide product with an oxalic acid‐based preparation in reducing dentine hypersensitivity. Methods: The study was conducted as a double‐blind, randomized clinical trial. A total of 19 subjects with dentine hypersensitivity on both sides of their upper arch were selected. The most sensitive tooth in each quadrant was identified and received a cold stimulus. The response was recorded on a visual analogue scale (VAS). The tooth thus selected was treated with one of the treatment agents. One week later the level of dentine sensitivity was assessed. Participants were also asked for their subjective assessment of treatment effects. Results: The mean difference between VAS at baseline and seven days for teeth treated with diamine silver fluoride/potassium iodide was greater than that for teeth treated with the oxalic acid‐based preparation (p = 0.0134). The subjects’ subjective assessment of changes in dentine hypersensitivity indicated that more obtained relief with the diamine silver fluoride/potassium iodide treatment (p = 0.0129). Conclusions: It was concluded that an experimental diamine silver fluoride/potassium iodide product has potential as a treatment for dentine hypersensitivity.     

可吸收修复胶原联合银离子敷料治疗供皮区创面的疗效

 目的 观察可吸收修复胶原联合银离子敷料治疗供皮区创面的临床效果。方法 选取2016-07至2018-12医院收治的100例自体皮移植患者,随机分为治疗组和对照组,每组50例,治疗组采用可吸收修复胶原联合银离子敷料治疗供皮区创面,对照组采用传统凡士林纱布治疗。观察供皮区创面换药时疼痛程度、创面感染率、愈合时间,以及创面愈合后瘢痕指标评定。结果 治疗组供皮区创面换药时疼痛分数在术后3、6、9 d分别为6.24±2.23,4.13±2.37,1.49±1.31,显著低于对照组的7.73±2.14,5.24±1.59,2.43±1.66(P<0.05);治疗组供皮区创面感染率为2%,较对照组14%显著降低(P<0.05);治疗组创面愈合时间明显短于对照组(P<0.05);治疗组创面愈合后3、6、9个月温哥华瘢痕量表评分较对照组显著降低,差异均有统计学意义(P<0.05)。结论 可吸收修复胶原联合银离子敷料治疗供皮区创面相比于传统凡士林纱布治疗是一种更优越的方式,适合临床推广使用。     

基于金磁微粒标记技术的可目视化蛋白质芯片检测方法的建立

目的：应用金磁微粒标记蛋白质技术,建立可目视化蛋白质芯片检测体系,比较金磁微粒和胶体金标记蛋白质技术应用于蛋白质芯片检测效果的优劣。方法：将人IgG点制于环氧基修饰的玻片上,分别与金磁微粒和胶体金标记的羊抗人IgG温育,银染显色,肉眼观察并用普通扫描仪记录结果。结果：基于金磁微粒的蛋白质芯片人IgG最佳点样浓度为0．2mg／ml,37℃温育2h,银染10～15min,检测结果信噪比高;基于胶体金的蛋白质芯片人IgG最佳点样浓度为0．1mg／ml,37℃温育1h,银染15～20min．检测结果信噪比高。结论：金磁微粒标记蛋白质技术应用于蛋白质芯片的检测,具有和胶体金一致的可目视化检测效果。且其标记技术简单,标记的蛋白质可定量。     

石头鱼毒素胶体金检测试纸条的研制

目的：研制石头鱼毒素（neoverrucotoxin,stonefish toxin,neoVTX）的胶体金检测试纸条,建立一种该毒素的快速检测方法。方法采用柠檬酸三钠还原法制备胶体金溶液,以neoVTX马血清抗体用于胶体金标记,并将该抗体固定于硝酸纤维素膜作为捕获抗体,利用双抗体夹心法原理制备胶体金检测试纸条。结果制备的检测试纸条对该毒素检测灵敏度为50 ng／ml,该试纸与牛血清白蛋白、卵清蛋白及水母毒素等蛋白无反应,具有较好的特异性。结论成功研制了石头鱼毒素胶体金检测试纸,该试纸条灵敏度高,特异性好,可用于该毒素的快速检测。     

Immunomodulatory effect of gelatin-coated silver nanoparticles in mice: Ultrastructural evaluation

Silver nanoparticles (SNP) are used in many pharmaceutical, cosmetic, and industrial products already available in the market. Although they are considered relatively safe, many toxic and pathological alterations in different organs including immune organs were reported after SNP administration. In this study, 10-week-old male mice (n = 20) were divided into two groups. Ten mice received greenly synthesized gelatin-coated silver nanoparticles in a dose of 10 mg/kg body weight for five consecutive days while the other 10 received 0.5 ml of distilled water daily for 5 days and kept as control. At the sixth day, all mice were sacrificed; blood and tissue samples were collected and prepared for pathological analysis. Liver and kidney lesions were in the form of degenerative and inflammatory changes. Interestingly, the immune organs were drastically affected by SNP treatment. Severe hyperplasia of the Peyer’s patches was noticed in the intestines of intoxicated animals both in gross and microscopic examination. Spleen was enlarged and showed large number of megakaryocytes. The particles were encountered in membrane-bound phagosomes inside macrophages in different organs like lungs and spleen. Blood picture complied to morphological findings with an increase in monocytes and eosinophils accompanied by drop in the platelets count in the intoxicated animals.     

Ultrastructural hepatocytic alterations induced by silver nanoparticle toxicity

Silver nanoparticles (SNPs) are widely used in nanomedicine and consuming products with potential risk to human health. While considerable work was carried out on the molecular, biochemical, and physiological alterations induced by these particles, little is known of the ultrastructural pathological alterations that might be induced by nanosilver materials. The aim of the present work is to investigate the hepatocyte ultrastructural alterations that might be induced by SNP exposure. Male rats were subjected to a daily single dose (2 mg/kg) of SNPs (15–35 nm diameter) for 21 days. Liver biopsies from all rats under study were processed for transmission electron microscopy examination. The following hepatic ultrastructural alterations were demonstrated: mitochondria swelling and crystolysis, endoplasmic reticulum disruption, cytoplasmic vacuolization, lipid droplets accumulation, glycogen depletion, karyopyknosis, apoptosis, sinusoidal dilatation, Kupffer cells activation, and myelin figures formation. The current findings may indicate that SNPs can induce hepatocyte organelles alteration, leading to cellular damage that may affect the function of the liver. These findings might indicate that SNPs potentially trigger heptocyte ultrastructural alterations that may affect the function of the liver with potential risk on human health in relation to numerous applications of these particles. More work is needed to elucidate probable ultrastructural alterations in the vital organs that might result from nanosilver toxicity.     

Synthesis,characterization, and biological activity of cross-linked chitosan biguanidine loaded with silver nanoparticles

Chitosan biguanidine hydrochloride (ChG) and glutaraldehyde cross-linked chitosan biguanidine (CChG) were synthesized and characterized by Fourier transform infrared spectroscopy, ¹H NMR and ¹³C NMR, X-ray diffraction, scanning electron microscopy (SEM) and thermal analyses (TGA and DTA). The results showed that ChG and CChG had a more amorphous structure than that of chitosan, and their thermal stability were slightly lower than that of chitosan. Colloidal silver nanoparticles (AgNPs) were prepared using borohydride reduction method and then investigated as fillers in partially cross-linked chitosan biguanidine. The obtained nanoparticles were uniform and spherical with average size of 9.6 ± 0.5 nm. The prepared CChG/AgNPs composites were characterized for their morphology, thermal properties, cytotoxicity and antimicrobial activity. The SEM images showed that the AgNPs are well imbedded in the CChG matrix. The thermal stability of CChG was improved with incorporation of AgNPs. The CChG and CChG/AgNPs showed less cytotoxicity to breast cancer cells (MCF-7). Compared with chitosan and CChG, the ChG and CChG/AgNPs showed better antimicrobial activity against Streptococcus pneumoniae and Bacillus subtilis as Gram-positive bacteria, Escherichia coli as Gram-negative bacteria and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum as fungi.     

Hydrolytic stability of composite repair bond

The hydrolytic stability of composite repairs is a desirable property. In the present study, the composite repair microtensile bond strength, failure mode distribution, and nanoleakage occurrence before and after thermocycling were evaluated. Standardized, 1-month-old composite substrates were roughened, cleaned, and randomly assigned to seven groups according to the intermediate agent applied. Resin-based, silane-based, and combined silane/adhesive coupling agents were investigated. The same resin composite as the substrate was used for repair. For each group, repaired samples were wet stored for 24 h (37 degrees C) or thermocycled (5,000 cycles, 5-55 degrees C). Failure mode and silver nitrate penetration were examined by stereomicroscopy. Intermediate agent, experimental condition, and their interaction were significant factors. Hydrophobic flowable composites resulted in statistically higher repair strengths, lower occurrence of adhesive failures, and good quality interfacial coupling without any silver uptake in both conditions. Light-curing, hydrophilic resin monomer-based intermediate agents, although not affected by thermocycling, showed a more pronounced silver penetration. The composite repair strength of a self-curing silane/adhesive agent was significantly affected by thermal stresses, despite the absence of silver uptake. A prehydrolized silane agent recorded the lowest repair strength, with minimal or no evidence of interfacial silver impregnation after thermocycling. In conclusion, flowability and hydrophobic nature can be considered important properties when selecting intermediate agents for composite repair.