复合三联抗结核药聚乳酸-羟基乙酸缓释微球的制备及体外释药特性

目的 :制备复合异烟肼(H)、利福平(R)、吡嗪酰胺(Z)的聚乳酸-羟基乙酸(HRZ/PLGA)缓释微球,观察其理化性质和体外缓释特性。方法:以PLGA(450mg)为载体,避光条件下称取H(40mg)、R(60mg)、Z(125mg),采用复乳-溶剂挥发法制备HRZ/PLGA缓释微球,应用扫描电镜观察微球的形态特征;应用高效液相色谱法(HPLC)测定其载药量、包封率;采用溶出法、HPLC于3h、6h、12h、1d、2d、3d、6d、9d、12d、15d、20d、25d、30d、40d、50d测定H、R、Z三种药物的浓度,观察其是否均大于10倍最低抑菌浓度(MIC),计算其日均释药率、累计释药率。结果:HRZ/PLGA微球在电镜下观察呈圆球形,平均粒径为10.3±4.7μm;H、R、Z三种药物的载药量分别为(18.02±0.36)%、(22.46±0.24)%、(21.68±0.37)%,包封率分别为(54.79±1.13)%、(72.35±0.39)%、(67.21±0.68)%;体外缓释试验显示微球缓释前12d左右,三种药物的累计缓释度均超过了50%,日均释药率分别为5.05%、4.89%、6.86%;第12天后三药的缓释基本趋于稳定,日均释药率分别为0.17%、0.26%、0.16%;三种药物缓释到50d时均大于10倍MIC。结论:HRZ/PLGA微球具有优良的载药及药物缓释效果,是一种理想的复合抗结核药物缓释系统。     

局部用雷帕霉素聚乳酸乙醇酸共聚物缓释微球的制备及释药研究

目的：介绍雷帕霉素（RAPA）聚乳酸乙醇酸共聚物（PLGA）缓释微球的制备方法,建立高效液相色谱法（HPLC）测定体系以检测微球中雷帕霉素含量,检测微球性状并进行体外释药实验。方法：以聚乳酸乙醇酸共聚物为载体,采用W/O/W乳剂-扩散溶剂挥发法制备雷帕霉素缓释微球,扫描电镜检测微球外观及微球粒径,HPLC检测微球载药量、包封率及体外释药量。结果：所制微球光滑圆整,大小均一,平均粒径：（121.18±27.83）μm,载药率：（14.39±1.32）%,包封率：（72.92±4.29）%,体外释放实验显示1～4天有突释,随后平稳释药至第10天累积释药率达80%。结论：采用制备工艺稳定,所制微球载药量及包封率均较高,形态完整,大小均一,体外释药较为平稳并且具有明显的缓释作用。     

聚乳酸聚乙醇酸／RNAⅢ抑制肽缓释微球的制备及评价

目的探讨聚乳酸聚乙醇酸（PLGA）／RNAⅢ抑制肽（RIP）缓释微球的合理制备方法,测定其载药率和体外释药特征。方法采用改良复乳－溶剂挥发法制备PLGA／RIP缓释微球,观察其表征,测定缓释微球的载药率和包封率。采用高效液相色谱法测定不同时点PLGA／RIP的释放速度,观察PLGA／RIP微球的体外释药特点。结果采用改良复乳－溶剂挥发法制备的PLGA／RIP缓释微球粒径均匀、表面光滑,包封率约为（68．22±6．20）％,载药率为（15．35±3．26）％。PLGA／RIP释药动力学方程为y=31．016x＋59．611,符合Huguchi方程。结论采用改良复乳-溶剂挥发法制备的PLGA／RIP缓释微球粒径均匀、表面光滑,包封率和载药率较高,体外释放动力学符合Huguchi方程,是理想的缓释载药体系。     

bFGF壳聚糖微球的制备及检测

目的探讨以壳聚糖为载体、采用乳化交联法制备的bFGF壳聚糖微球体外释放特性,为下一步实验奠定基础。方法应用0.6%三聚磷酸钠溶液作为交联剂,1.5%壳聚糖溶液作为载体,采用乳化交联法制备bFGF壳聚糖微球。激光粒度及Zeta电位分析仪检测微球粒径分布,扫描电镜观察形态;ELISA法计算bFGF壳聚糖微球载药量、包封率及体外释药规律。结果 bFGF壳聚糖微球粒径为20.312～24.152μm;扫描电镜观察显示微球表面光滑圆整,无明显孔隙,分布均匀,分散性好。载药量和包封率分别为(7.57±0.34)mg/g及95.14%±1.58%。bFGF壳聚糖微球可持续体外释放bFGF 24 d;bFGF浓度随时间延长逐渐升高,第24天达(820.45±21.34)ng/mL;微球体外释药具有突释效应,突释率为18.08%,24 d累计释放率为82.05%。结论乳化交联法制备bFGF壳聚糖微球操作简便,微球表面光滑、分布均匀,分散性好,载药量和包封率均较高,体外释药较稳定且释放率较高,是一种较理想的制备bFGF壳聚糖微球的方法。     

rhBMP-2明胶纳米微球制备及体外缓释效果研究

目的制备重组人骨形态发生蛋白2(recombinant human bone morphogenetic protein-2,rhBMP-2)明胶纳米微球并检测其体外缓释效果。方法 "二次凝聚法"制备明胶纳米微球,扫描电镜、透射电镜和粒径分析仪检测纳米微球的表面形态、内部结构、粒径,计算其溶胀率;将rhBMP-2与明胶纳米微球复合,计算其包封率和载药量,并对其体外缓释效果进行检测。结果明胶纳米微球的表面形态良好,分散均一,内部结构多孔隙、通道,平均粒径(171.49±50.12)nm,溶胀率为1.83;rhBMP-2明胶纳米微球的包封率为(98.13±0.131)%,载药量为(58.89±0.079)ng/mg;rhBMP-2明胶纳米微球释药时间在1个月以上,呈"双相缓释",第1天为"突释相",释药量约为7%,以后平缓释放呈"缓释相",40%左右的药物于28 d内释放,约60%的药物在1个月以后释放。结论成功制备rhBMP-2明胶纳米微球,不但包封率高,而且体外缓释效果好。     

不同比例三联抗结核药物复合缓释材料的释药性能观察

目的 :观察不同比例三联抗结核药物复合缓释材料在模拟体液中的药物释药性能。方法 :以聚乳酸-羟基乙酸(PLGA)作为载体,采用双乳、喷涂、冷冻干燥溶剂挥发法制备不同比例抗结核药物的复合缓释材料:A组,异烟肼(INH,H)∶利福平(RFP,R)∶吡嗪酰胺(PZA,Z)=15∶15∶30;B组,H∶R∶Z=20∶30∶50;C组,H∶R∶Z=30∶30∶120;D组,H∶R∶Z=80∶120∶250。药物总质量与PLGA之比为1∶5。扫描电子显微镜(SEM)观察HRZ/PLGA复合缓释材料的表面形态,高效液相色谱法(HPLC)检测其在模拟体液中H、R、Z三种药物的释放浓度,计算药物累计释放量及释放率,分析其体外缓释性能。结果:A组和B组缓释材料表面分散均匀,空隙规则、分布均匀,直径分别为23.07±0.38μm和25.67±1.26μm;C组和D组缓释材料分散欠均匀,空隙不规则、分布欠均匀,直径分别为31.25±1.98μm和45.67±3.26μm。A组H、R、Z分别于42d、56d、42d的累计缓释度超过50%,于70d时的阶段释药量分别为157.43±057μg、129.29±0.14μg、196.43±0.28μg,浓度分别为28.486μg/ml、23.525μg/ml、39.265μg/ml。B组H、R、Z分别于35d、42d、35d的累计缓释度超过50%,于70d时阶段释药量分别为9.89±0.96μg、21.71±0.42μg、51.12±0.87μg,浓度分别为1.789μg/ml、1.618μg/ml、10.242μg/ml。C组H、R、Z分别于21d、35d、42d的累计缓释度均超过50%,于70d时阶段释药量分别为1.76±0.49μg、8.43±0.31μg、81.14±0.58μg,浓度分别为0.352μg/ml、1.618μg/ml、10.242μg/ml。D组H、R、Z分别于28d、42d、35d的累计缓释度均超过50%,于70d时阶段释药量分别为1.71±0.21μg、14.01±0.42μg、65.57±0.26μg,浓度分别为0.312μg/ml、2.128μg/ml、13.516μg/ml。70d时A组三种药物浓度均大于各自的10倍最低抑菌浓度(MIC),且A组分散均匀,空隙规则、分布均匀,直径约为23.07±0.38μm,三种药物在不同的时间段释放行为不相同,前14d药物缓释规律按Higuchi方程拟合最好,即前14d三种药物按照扩散的形式进行缓释,14d后三种药物按照零级动力学缓释曲线释放,即等量缓释。其余3组均有药物未达到10倍MIC。结论:复合HRZ/PLGA缓释材料具有优良的载药及药物缓释效果,是一种理想的复合药物缓释系统,其中H∶R∶Z=15∶15∶30的HRZ/PLGA缓释材料为较佳配方。     

重组人骨形态发生蛋白-2壳聚糖纳米微球的制备及检测

目的 制备负载重组人骨形态发生蛋白-2(rhBMP-2)壳聚糖纳米微球,并检测其粒径、形态、降解及药理特性,以评估壳聚糖纳米微球作为rhBMP-2缓释载体的可行性.方法 以壳聚糖为原料、三聚磷酸钠为交联剂,通过离子交联法制备负载rhBMP-2壳聚糖纳米微球,应用透视电镜观察微球的形态、激光粒径,分析其粒径分布、溶菌酶降解,了解降解特性.通过酶联免疫吸附实验(ELISA)检测rhBMP-2壳聚糖微球的载药率、包封率和释药规律.结果 离子交联法制备的壳聚糖纳米微球,平均粒径大小为230nm,成球性较好,包封率和载药率分别为(66.867±4.575)％、(33.437±2.290)μg/mg;体外释药试验rhBMP-2可以从壳聚糖纳米微球中缓慢释放,释放行为符合双向动力学规律,整个释放过程可达30 d.结论 离子交联法可成功制备壳聚糖纳米微球并具有缓释rhBMP-2的能力,为进一步应用于骨组织工程研究提供实验依据.     

载异烟肼、利福平白蛋白纳米粒在兔体内的药代动力学研究

目的 :研究载异烟肼(Isoniazid,INH)、利福平(Rifampicin,RFP)牛血清白蛋白(Bovine serum albumin,BSA)纳米粒经新西兰大白兔静脉给药后的体内药代动力学特征及其相关参数。方法 :16只新西兰大白兔随机分为2组:纳米粒组8只,INH、RPP对照组8只。经耳缘静脉分别滴注等计量的载INH、RFP白蛋白纳米粒和普通对照品(INH 11.43mg/kg、RFP 12mg/kg)。采用高效液相色谱分析方法测定各自INH、RFP的血浆药物浓度。对比研究静脉给药后两种剂型药物在不同时间(0、0.5、1、1.5、2、2.5、3、4、6、8、12、24、36、48、72、96、120h)兔体内的血浆药代动力学参数,包括最大血药浓度(Cmax)、生物半衰期(T1/2)、血药浓度时间曲线下的面积(AUC)及体内平均驻留时间(MRT),以DAS 2.0药动学程序进行血药浓度数据拟合分析。结果:给药后两组药物的血药浓度-时间曲线显示:纳米粒药组INH、RFP血药浓度相对稳定,药物浓度持续缓慢下降,给药后96h INH仍能检测到,RFP则为48h。INH的Cmax=9.79±1.38(mg/L),T1/2=28.10±6.69(h),AUC=22.34±8.81(mg/L·h),MRT=15.13±5.48(h);RFP的Cmax=16.79±3.74(mg/L),T1/2=14.13±3.78(h),AUC=116.64±66.26(mg/L·h),MRT=15.89±2.49(h)。对照组中INH的Cmax=9.52±2.19(mg/L),T1/2=1.92±0.80(h),AUC=20.97±3.11(mg/L·h),MRT=2.03±0.62(h);RFP的Cmax=12.50±1.58(mg/L),T1/2=2.87±0.78(h),AUC=50.05±14.50(mg/L·h),MRT=3.70±0.99(h)。对照组INH、RFP血药浓度快速下降,分别在给药后24h和12h检测不到。结论 :载异烟肼、利福平白蛋白纳米粒在兔体内的药代动力学过程符合双隔室模型(权重系数为1/cc)。白蛋白纳米粒可有效改变异烟肼和利福平的药动学行为并具有显著的缓释效果。     

载莫西沙星聚乳酸-羟基乙酸缓释微球的制备与体外释放研究

目的制备用于治疗脊柱结核的载莫西沙星聚乳酸-羟基乙酸(PLGA)缓释微球,观察其体外理化特性和缓释性能。方法以PLGA为药物载体,采用优化O/W乳化-溶剂挥发法制备载莫西沙星-PLGA缓释微球,用光学显微镜和扫描电子显微镜观察微球的形态特征。采用超声破碎法震碎微球,然后检测莫西沙星-PLGA缓释微球的载药率和包封率。采用恒温振荡法观察药物的体外释放规律。结果光学显微镜下观察莫西沙星-PLGA缓释微球成圆形,表面光滑,分散均匀。扫描电子显微镜下观察缓释微球成球良好,颗粒规整,大小均匀,微球间无粘连,微球聚集不明显且表面分布有较均匀的微孔。莫西沙星-PLGA缓释微球粒径为12～20(15.6±4.3)μm,载药率为(21.5±0.31)%,包封率为(77.4±1.6)%。莫西沙星-PLGA缓释微球的体外药物释放过程较为平稳,前14 d为突释期,突释期内累计释放率为55.3%,到50 d时体外累积释放率为92.3%。结论制备的载莫西沙星-PLGA缓释微球形态良好、大小均匀且体外释放性能良好。     

载异烟肼、利福平纳米羟基磷灰石-硫酸钙人工骨体外降解及释药研究

目的:观察载异烟肼(isoniazid,INH)、利福平(rifampicin,RFP)纳米羟基磷灰石(n HA)-硫酸钙(CSH)人工骨体外降解情况并探讨其释药性能。方法:将制备好的人工骨置于37℃模拟体液中降解,分别于24h、72h及1、2、4、6、8、10、12周九个时相点取出,采用扫描电子显微镜观察人工骨表面降解程度,测量其质量变化,采用电子万能试验机测试每个时相点人工骨的抗压强度。将人工骨置于37℃PBS中释药,采用高效液相色谱法(HPLC)分别检测24h、72h及1、2、4、6、8、10、12周九个时相点时的INH、RFP的释放浓度,并计算出累计释药百分数,观察药物的缓释程度。结果:随着浸泡时间的延长,人工骨体积逐渐减小,颜色变白;扫描电镜观察人工骨表面晶体结构逐渐消失,孔隙减少,最终人工骨表面被无结构的降解物所覆盖;人工骨的质量及其抗压强度都随着人工骨的降解而逐渐减小,第8周时抗压强度仍接近松质骨的强度。人工骨释药过程中,INH于24h、72h及1、2、4、6、8周时相点时的累计释药百分数分别为:44.58%、71.06%、90.23%、95.98%、98.27%、99.72%、100.00%,10、12周时未检出。RFP于24h、72h及1、2、4、6、8、10、12周九个时相点时的累计释药百分数分别为:2.70%、16.82%、39.96%、61.71%、83.88%、96.38%、97.63%、98.00%、98.26%。结论:载异烟肼、利福平纳米羟基磷灰石-硫酸钙人工骨在体外稳定降解,并具有持续时间较长的有效缓释性能。     

牙体牙弓颌骨阻力中心及其临床意义

牙体、牙弓及颌骨的阻力中心在正畸矫治力系统中具有重要的意义,也是正畸学领域争论较多的一个问题。Dermaut等研究表明,当力作用于物体阻力中心时,物体将发生平动,否则将发生平动和转动的复合运动。目前,国内外多数学者认为牙体、牙弓及颌骨存在阻力中心,但其位置存在争议。本文就牙体、牙弓及颌骨的阻力中心及其临床意义作一综述。     

Hazards and complications of endoscopic transurethral ureterolithotripsy and lithoextraction and means of prevention

Complications related to ureterolithotomy and ultrasonic ureterolithotripsy performed under the control of visual endoscope were analyzed in 86 ureterolithiasis patients, methods of their prevention discussed. All the aforementioned complications were distributed into three groups: inapplicability of surgery due to anatomic and functional defects of lower and upper urinary tracts, intraoperative, and postoperative complications. The commonest ones were ureteral abruption and perforation, acute pyelonephritis, temporary vesicoureteral reflux. Their control measures were considered as relative methods of treatment: immediate surgical intervention in case of ureteral abruption, renal catheterization in patients with insignificant ureteral perforation or acute pyelonephritis. Adequate ureteroscopy, careful consideration of pro- and contraindications, catheterization of renal pelvis and urinary bladder performed within 2-3 days after the surgery and adequate antibacterial therapy are the most decisive steps in the control of aforementioned complications.     

Characterisation and differentiation of chondroblastomas and chondromyxoidfibromas - presence and expression of collagen types I and II

AIM: Chondroblastomas and chondromyxoidfiibromas are rare benign skeletal neoplasms with reported overlapping histology. Aim of this study was to analyse the biochemical composition of the matrix of these tumour entities in order to further characterise the cellular phenotypes of these neoplasms using typical cell biological marker genes. METHODS: The matrix compositions of chondroblastomas and chondromyxoidfibromas were analyzed by HE-histology, histochemistry, and immunolocalization techniques. Cellular gene expression patterns were detected by mRNA in situ hybridization. RESULTS: Chondroblastomas are rich in collagen type I and show foci of an osteoid-like matrix, whereas collagen type II as a typical marker of chondrocytic differentiation was not detected in any of the specimens. Chondromyxoidfiibromas had foci of chondroid appearance with chondroblastic cellular differentiation characterised by collagen type II expression. CONCLUSION: These results characterise chondroblastomas and chondromyxoidfiibromas as skeletal neoplasms that have a different biology and which can be distinguished by matrix protein expression products: collagen type II, the typical marker of chondroblast differentiation, could only be detected in chondromyxoidfibromas, but not in chondroblastomas. Thus, both neoplasms are clearly different on the cell biological level.     

Effect of smoking and abstention on oxidative burst and reactivity of neutrophils and monocytes

BACKGROUND: Smoking is associated with surgical wound infections, impaired wound healing, and tissue-destructive disorders. The mechanisms are largely unknown, but changes in the function and activity of inflammatory cells may be involved. METHODS: Seventy healthy volunteers (54 smokers and 16 never smokers) were included. The smokers were studied while they smoked and after 20 days of abstinence. After the first 10 days of abstinence, they were randomized to double-blind treatment with transdermal nicotine patch 25 mg per day or placebo. Venous blood neutrophils and monocytes were sampled and isolated. In 22 randomly selected smokers and in all never smokers, the oxidative burst and chemotaxis were determined by a chemiluminescence response assay and a modified Boyden chamber technique, respectively. Stimulants were opsonized zymosan, formyl-Met-Leu-Phe, and zymosan-activated serum. RESULTS: The neutrophil and monocyte oxidative burst was 50% and 68% lower, respectively, in smokers compared to never smokers (P < .05). Neutrophil chemotaxis was 93% higher in smokers (P < .05). Monocyte chemotaxis was lower in smokers compared to never smokers (P < .05). After 20 days of abstinence, neutrophil oxidative burst increased to the level of never smokers (P < .05); monocyte oxidative burst increased by 50% (P < .05). Chemotaxis was only marginally affected. The changes induced by abstinence were less pronounced in the transdermal nicotine patch group compared to the placebo group. CONCLUSIONS: Smoking attenuates the oxidative burst of inflammatory cells and increases chemotaxis. Three weeks of abstinence normalize the oxidative burst, but affect chemotaxis only marginally.