羧甲基壳聚糖铋盐在大鼠体内分布及排泄的初步研究

用羧甲基壳聚糖作为铋的载体合成了新型含铋化合物——羧甲基壳聚糖铋盐（CM-Chitosan-Bismuth,CM-ChBi）,用这种药剂对实验大鼠进行了灌胃观察,研究了它在大鼠体内的分布及排泄情况。实验结果表明：羧甲基壳聚糖铋盐组大鼠肝脏、肾脏、胃、脑、血液经酸水解产物中氨基葡萄糖含量均高于水对照组,粪便中含量最高;羧甲基壳聚糖铋盐组大鼠粪便、肝脏、肾脏、胃、脑、血液中铋的含量,以粪便中含量最高。实验结果提示：羧甲基壳聚糖铋盐主要经粪便排泄,少量被降解吸收。本研究为进一步的代谢动力学研究提供了参考数据。     

羧甲基壳聚糖和羧甲基甲壳素的生物学性质研究和比较

制备并纯化出了医用级羧化度为103．14％、脱乙酰度为97．18％的羧甲基壳聚糖和羧化度为96．37％的羧甲基甲壳素，对其对成纤维细胞生长作用和体内外可降解性、生物相容性进行了研究。结果表明，两种多糖均能不同程度地促进成纤维细胞的生长，其中以100μg／ml的羧甲基壳聚糖效果最好。体内外降解实验表明二者均具有良好的可降解性和生物相容性，其中羧甲基甲壳素降解的速度相对较快，而羧甲基壳聚糖的生物相容性更好，在体内降解7d后，已无明显炎症反应。     

羧甲基甲壳素及羧甲基壳聚糖特性粘数的测定

测定了在２５．０℃下，羧甲基壳素及羧甲基壳聚糖（ＣＭ－ＣＨＯ）在纯水溶液及ＮａＣｌ水溶液中的特性粘数。在纯水溶液中用Ｆｏｕｓｓ经验式关联实验数据得ＣＭ－ＣＨ及ＣＭ－ＣＨＯ的分别为１１９７ｍＬ／ｇ，１２６ｍＬ／ｇ；是出了０．０１ｍｏｌ／ＬＮａＣｌ溶液中ＣＭ－ＣＨ及ＣＭ－ＣＨＯ的的２３８ｍｌ／ｇ     

羧甲基壳聚糖基调湿材料的制备及性能

以羧甲基壳聚糖为原料添加无机盐,制得调湿材料.研究了实验因素,如无机盐的种类,无机盐的用量对调湿材料的调湿性能的影响.结果表明:无机盐选用KAc,用量占总量的50%时,调湿材料在相对湿度为30%、50%、70%下吸湿量分别可达26.2%、45.5%和86.0%,同时具有较好的放湿能力.     

苦参碱/羧甲基壳聚糖/磷酸化壳聚糖纳米粒子的制备及性能表征

为了克服壳聚糖只能溶于酸性水溶液的局限,对壳聚糖进行了化学修饰,通过引入磷酸基官能团,合成了可溶于中性水的磷酸化壳聚糖.以磷酸化壳聚糖和羧甲基壳聚糖为基材,采用聚电解质复合法制备了苦参碱/羧甲基壳聚糖/磷酸化壳聚糖纳米粒子水分散制剂.测试结果表明,纳米粒子的平均粒径为l00～200nm,纳米粒子对苦参碱的负载率最高可达66.2%.     

天然橡胶/羧甲基壳聚糖抗菌复合膜的力学性能研究

采用胶乳共混法制备得到了天然橡胶羧甲基壳聚糖(NR/CCS)复合胶膜,通过NMR交联密度仪、拉力测试机、动态热力学分析仪等对复合材料的性能进行了表征。结果表明,复合胶膜的交联密度略微增大(5.75×10-5mol/cm3),力学性能增强到11.25MPa,并且复合胶膜的弹性模量增大,刚性增强,并通过这些测试证明了NR与CCS分子存在氢键的作用。     

羧甲基壳聚糖在酸性溶液中对铝的缓蚀作用

羧甲基壳聚糖是一种环境友好的重要衍生物,采用失重及电化学方法（EIS）研究了羧甲基壳聚糖（CM—ehitosan）在1mol／LHCI溶液中对铝（2024）的缓蚀作用。失重和电化学测试均表明,当羧甲基壳聚糖浓度达到200mg／L时缓蚀效率最高,可达88．54％。进一步的拟合计算表明,羧甲基壳聚糖在铝表面的吸附基本遵循修正的Langmuir吸附等温式,并获得上述吸附过程的热力学参数△Go、△Ho和△So。     

羧甲基壳聚糖/苯甲酸金属盐的制备及其防污性能研究

无毒或低毒防污剂是环境友好型防污涂料开发的关键。以无毒或低毒的羧甲基壳聚糖、苯甲酸钠等为主要原料,制成了羧甲基壳聚糖/苯甲酸铜盐、羧甲基壳聚糖/苯甲酸锌盐、羧甲基壳聚糖/苯甲酸铋盐3种在环境友好型防污涂料中具有应用前景的高分子金属盐,通过红外谱对其进行结构表征;通过对新月菱形藻的半数致死浓度、生长抑制曲线及实海挂板试验研究了其防污性能,3种化合物的LC50分别为75.98、28.52、437.85mg/L;防污性能测试表明含有苯甲酸的羧甲基壳聚糖盐防污能力好于含同种金属离子但不含苯甲酸的羧甲基壳聚糖盐,防污性能表现为CMC-Cu-B>CMC-Zn-B>CMC-Bi-B。     

羧甲基壳聚糖/纳米银抗菌剂的制备及缓释性能研究

以羧甲基壳聚糖(CMCS)、银氨溶液为主要原料,采用微波辐射法合成具有缓释抗菌作用的羧甲基壳聚糖/纳米银(CMCS-Ag)抗菌剂。研究反应时间与温度对CMCS-Ag抗菌剂中纳米银生成量的影响,以较优条件制备抗菌剂并通过紫外-可见光谱、X射线衍射、透射电镜及红外光谱对抗菌剂进行结构表征,与商用纳米银进行对比测试,对CMCS-Ag抗菌剂的抗菌性能与Ag⁺缓释性能进行评价。结果表明：羧甲基壳聚糖与银氨溶液比例为100mg∶0.4mmol时,在70℃、40min条件下制备出CMCS-Ag抗菌剂的纳米银含量最高,纳米银浓度为(1250±2.8)mg/L;CMCS-Ag抗菌剂中纳米银晶型良好且粒径较小,平均粒径为(26±0.12)nm,能够均匀地负载于CMCS网状结构中;CMCS-Ag抗菌剂对大肠杆菌最小抑菌浓度为7.81mg/L、对金黄色葡萄球菌为15.63mg/L,抗菌效果优于商用纳米银;CMCS-Ag抗菌剂240h累计Ag⁺释放浓度为(26±0.5)μg/L,Ag⁺释放总量低于商用纳米银,Ag⁺缓释性能优...     

壳聚糖与羧甲基壳聚糖蛋白质印迹聚合物的制备及吸附性能

首先制备了壳聚糖的衍生物——羧甲基壳聚糖,再以壳聚糖与羧甲基壳聚糖的共混物为功能单体,牛血清白蛋白(BSA)为模板蛋白质,制备了一种壳聚糖与羧甲基壳聚糖共混物的蛋白质印迹聚合物。模板蛋白质吸附测试结果表明,该蛋白质印迹聚合物对BSA的吸附量是非印迹聚合物的30.8倍;对不同蛋白质的吸附测试结果表明,相比于其它对比蛋白质,该蛋白质印迹聚合物具有良好的选择性吸附模板蛋白质BSA的效果;并且该蛋白质印迹聚合物具有良好的可重复使用性能。     

体外建立幽门螺秆菌感染胃粘液细胞的实验模型

建立胃粘液细胞原代培养的方法,并在此基础上观察幽门螺秆菌(Hp)对它的损伤作用。取水囊引产的胎龄5个月以上胚胎的胃粘膜,采用组织块贴壁培养的方法进行培养,用倒置显微、电镜进行形态学鉴定,并用电镜观察其与Hp共培养后形态学变化。结果细胞为多边形,呈簇状或片状生长,排列紧密,电镜下见细胞表面有微绒毛,胞浆内有丰富的粗面内质网、高尔基体及粘液分泌颗粒,细胞同有紧密连接。加入Hp后,原代培养的胃粘液细胞出现空泡变性,有部分细胞发生凋亡,其核固缩。胚胎的胃粘液细胞原代培养不失为一种体外研究Hp相关胃部疾病的较理想模型。     

Preparation of epigallocatechin gallate-loaded nanoparticles and characterization of their inhibitory effects on Helicobacter pylori growth in vitro and in vivo

A variety of approaches have been proposed for overcoming the unpleasant side effects associated with antibiotics treatment of Helicobacter pylori (H. pylori) infections. Research has shown that epigallocatechin-3-gallate (EGCG), a major ingredient in green tea, has antibacterial activity for antiurease activity against H. pylori. Oral EGCG is not good because of its digestive instability and the fact that it often cannot reach the targeted site of antibacterial activity. To localize EGCG to H. pylori infection site, this study developed a fucose–chitosan/gelatin nanoparticle to encapsulate EGCG at the target and make direct contact with the region of microorganisms on the gastric epithelium. Analysis of a simulated gastrointestinal medium indicated that the proposed in vitro nanocarrier system effectively controls the release of EGCG, which interacts directly with the intercellular space at the site of H. pylori infection. Meanwhile, results of in vivo clearance assays indicated that our prepared fucose–chitosan/gelatin/EGCG nanoparticles had a significantly greater H. pylori clearance effect and more effectively reduced H. pylori-associated gastric inflammation in the gastric-infected mouse model than the EGCG solution alone.     

Phototherapy and Mechanism Exploration of Biofilm and Multidrug-Resistant Helicobacter pylori by Bacteria-Targeted NIR Photosensitizer

Helicobacter pylori (H. pylori) infection has been the leading cause of gastric cancer development. In recent years, the resistance of H. pylori against antibiotic treatment has been a great challenge for most countries worldwide. Since biofilm formation is one of the reasons for the antibiotic resistance of H. pylori, and phototherapy has emerged as a promisingly alternative antibacterial treatment, herein the bacteria-targeted near-infrared (NIR) photosensitizer (T780T-Gu) by combining positively-charged guanidinium (Gu) with an efficient phototherapeutic agent T780T is developed. The proposed molecule T780T-Gu exhibits synergistic photothermal therapy/photodynamic therapy effect against both H. pylori biofilms and multidrug-resistant (MDR) clinical strains. More importantly, the phototherapy mechanism of T780T-Gu acquired by the RNA-seq analysis indicates that structural deficiency as well as a decrease in metabolism and defense activity are the possible reasons for the efficient H. pylori phototherapy.     

The acidic complexation of tetracycline with sucralfate for its mucoadhesive preparation

The complex of antibiotics with sucralfate (SF) was prepared with acid. The mechanism of the complexation and some factors concerning the preparation, which influence the mucoadhering property, were studied. The complexation was confirmed by the change in color and instrumental analysis. The acidic complex appeared to be produced by reagglomeration of SF preliminary particles. It was suggested that the amide or amine groups of tetracycline (TC) and aluminum moieties of SF serve as the binding sites. The potential of multiple binding sites and a priority in them were suggested by the Scatchard plot analysis. The additional amounts of acid and the increase in the surface area increased the number of sites. The amount of the additional acid appeared to be the most important factor during the preparation of the acidic complex. The appropriate amount of acid added appeared to produce a complex rich in TC. However, an excess amount might cause the excess dissociation of aluminum moieties, which destroys the mucoadhesive paste-forming property.     

Preparation and Bioevaluation of [99mTc]Tricarbonyl Omeprazole for Gastric Ulcer Localization in Mice

Radiochemistry - [99mTc]Tricarbonyl Omeprazole was prepared using [99mTc]tricarbonyl core. The radiochemical conversion of 98.0% was reached under optimized reaction conditions: substrate amount...     

Design and Evaluation of a Two-Layer Floating Tablet for Gastric Retention Using Cisapride as a Model Drug

A new kind of two-layer floating tablet for gastric retention (TFTGR) with cisapride as a model drug was developed. The in vitro drug release was determined, and the resultant buoyancy and the time-buoyancy curve were plotted. Because of the sodium bicarbonate added to the floating layer, when immersed in simulated gastric fluid (SGF) the tablet expands and rises to the surface, where the drug is gradually released. The in vitro drug release of this kind of two-layer dosage was controlled by the amount of hydroxypropylmethylcellulose (HPMC) in the drug-loading layer. Generally, the more HPMC, the slower the drug releases. Because cisapride has greater solubility in SGF than simulated intestinal fluid (SIF), its in vitro drug dissolution in SGF is faster than in SIF. One of the distinguishing characteristics of this kind of tablet is the separate regulation of buoyancy and drug release. The idea developed in this experiment can be used as a general model for the design of other tablets for gastric retention.     

Design and Evaluation of a Two-Layer Floating Tablet for Gastric Retention Using Cisapride as a Model Drug

A new kind of two-layer floating tablet for gastric retention (TFTGR) with cisapride as a model drug was developed. The in vitro drug release was determined, and the resultant buoyancy and the time-buoyancy curve were plotted. Because of the sodium bicarbonate added to the floating layer, when immersed in simulated gastric fluid (SGF) the tablet expands and rises to the surface, where the drug is gradually released. The in vitro drug release of this kind of two-layer dosage was controlled by the amount of hydroxypropylmethylcellulose (HPMC) in the drug-loading layer. Generally, the more HPMC, the slower the drug releases. Because cisapride has greater solubility in SGF than simulated intestinal fluid (SIF), its in vitro drug dissolution in SGF is faster than in SIF. One of the distinguishing characteristics of this kind of tablet is the separate regulation of buoyancy and drug release. The idea developed in this experiment can be used as a general model for the design of other tablets for gastric retention.     

超高压处理对鸡全蛋液杀菌效果和品质的影响

目的通过测定菌落总数、理化性质和感官品质,研究超高压对鸡全蛋液杀菌效果及贮藏期的影响。方法以市售鲜鸡蛋为原料制备全蛋液,以沙门氏菌和大肠杆菌模拟高染菌情况(>106 CFU/mL),研究25℃下采用超高压(压强为150~400 MPa,保压时间为2.5~12.5 min)对全蛋液微生物(菌落总数、大肠杆菌菌落总数、沙门氏菌是否检出)、物理特性和感官品质的影响。结果经超高压杀菌后,蛋白质变性率、白度和粘度上升,起泡性和感官评分下降;在贮藏期间,白度、起泡性和pH值不断下降,粘度先上升后下降。结论在300 MPa,7.5 min条件下超高压杀菌,鸡全蛋液符合GB 2749-2015《食品安全国家标准蛋与蛋制品》微生物限量要求和感官要求,且对蛋液物理特性影响较小。经此条件杀菌的鸡全蛋液可在4℃下贮藏20 d。     

A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings

A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings based on the carbon-13 isotope breath test has been designed and constructed. Important stages of the work included (i) calculating a low-aberration mass analyzer, (ii) manufacturing and testing special gas inlet system, and (iii) creating a small-size collector of ions. The proposed instrument ensures ¹³C/¹²C isotopic ratio measurement to within 1.7‰ (pro mille) accuracy, which corresponds to requirements for a diagnostic tool. Preliminary medical testing showed that the mass spectrometer is applicable to practical diagnostics. The instrument is also capable of measuring isotopic ratios of other light elements, including N, O, B (for BF₂+ ions), Ar, Cl, and S.