PLGA微球载药量和包封率的影响因素及控制

PLGA是乳酸和羟基乙酸的共聚物,具有良好的生物相容性和生物可降解性,已经广泛应用于缓控释给药系统的研究.针对目前PLGA微球存在载药量和包封率低的问题,根据国内外文献,综述了影响PLGA微球载药量和包封率的因素,包括PLGA、药物、溶剂、添加剂等方面,为研究PLGA微球载药量和包封率提供思路.     

骨保护素-聚乳酸羟基乙酸缓释微球的制备及体外释药性能研究

目的 以聚乳酸羟基乙酸(PLGA)为载体构建载有骨保护素(OPG)的微球,筛选出缓释效果最佳的制备条件,并研究载药微球的体外释放特性.方法 采用复乳溶剂挥发法,以不同的搅拌速度、聚乙烯醇(PVA)浓度、PLGA浓度制备OPG-PLGA微球并测定其载药量和包封率,通过正交试验优化制备条件;以磷酸盐缓冲液作为释放介质考察载药微球的体外释放特性.结果 以PLGA聚合物浓度400 mg/ml、搅拌速度400 r/min、PVA浓度2％为条件制备的载药微球具有最优的载药量和包封率,分别为6.21×10-和75.10％,体外释药试验显示微球持续释放时间达到30 d,具有良好缓释效果.结论 采用优化条件制备的OPG-PLGA微球具有较高的包封率和载药量,同时具有良好的缓释效果,为用于拔牙位点保存术的缓释药物研究提供了基础.     

乳酸-羟基乙酸共聚物缓释纳米微球的制备及体外释药评价

目的 以乳酸-羟基乙酸共聚物[poly(lactic-co-glycohc acid),PLGA]为材料,制备缓释局麻药利多卡因(Lidocaine,LID)-PLGA长效缓释微球.方法 采用乳化溶媒挥发法制备微球;采用紫外分光光度法测定微球载药量、包封率和体外药物释放.结果 纳米微球形态光滑圆整,球体大小均匀,微球粒径为(174.5±15.2)nm,微球载药量和包封率分别为12.48%和54.30%,微球体外释放符合Higuchi方程,半衰期t1/2=3.45 d.结论 LID-PLGA纳米微球具有明显缓释作用.     

正交设计优化川芎嗪乳酸-羟基乙酸共聚物微球处方与制备工艺

目的 制备川芎嗪PLGA微球并考察其物理化学性质及体外释药性.方法 采用O/W型乳化-溶剂挥发法制备川芎嗪PLGA微球,正交试验设计优化处方组成和制备工艺,对微球的外观形态、粒径及粒度分布、包封率和载药量等理化性质进行了检测.结果 以优化处方制备的川芎嗪PLGA微球为圆球形,粒度分布较均匀,平均粒径为(10±2.2)μm,包封率为(81.36±1.15)%,载药量为(8.2±0.43)%,药物体外释放可延长至768h,释药特性符合Weibull方程,经差示扫描量热法(DSC)分析证明,形成了新的物相,表明载药微球确已形成.结论 采用O/W型乳化-溶剂挥发法制备的川芎嗪PLGA微球包封率和栽药量高,粒径均匀,具有明显的缓释作用.     

生物降解型尼索地平微球的研究

目的制备尼索地平的PLGA微球,并研究其体内外释药行为.方法采用溶剂挥发法制备微球,电镜下观察微球形态,HPLC法测定微球的载药量、包封率及累积释药量.采用HPLC法测定家兔体内的血药浓度.结果微球形态圆整,表面光滑.微球的粒径为15.3±3.8μm,载药量为21.16%,包封率为85.40%.微球的体外释药行为的拟合方程为1-Q=0.7654(1-t/t     

重组人血管内皮抑制素的聚集稳定性及其PLGA缓释微球的制备与体外释放

目的:制备重组人血管内皮抑制素(rh-endostatin, rh-Endo)的聚乳酸-羟基乙酸\[poly(lactic-co-glycolic acid),PLGA\]微球,并对微球的体外释放特性进行考察。方法:以聚乳酸-羟基乙酸为载体,采用复乳法制备重组人血管内皮抑制素聚乳酸-羟基乙酸微球,建立了高效液相色谱法测定rh-Endo含量和体外释药量。结果:微球外观圆整,平均粒径122.7 μm,载药量为1.28%,包封率为38.65%,250 μg/ml的rh-Endo标准溶液4℃、室温条件下放置108 h后,溶液仍呈现较好的稳定性。28 d的体外释放可达67.37%。结论:以可生物降解的PLGA作为载体材料,能够将rh-Endo制成缓释微球。     

艾塞那肽缓释微球的制备和体外释放的研究

目的制备载艾塞那肽的聚乳酸-羟基乙酸共聚物[poly(lactic-co-glycolicacid),PLGA]微球,并对其体外释药特性进行考察。方法以聚乳酸-羟基乙酸共聚物为载体,采用凝聚法(W/O/O)制备载艾塞那肽缓释注射微球,建立了高效液相色谱测定艾塞那肽含量的方法和微球中药物提取方法,考察微球粒径大小、外观、包封率、载药量等理化性质,并对微球体外释放特性进行了考察。结果微球球形较圆整,平均粒径为(51.2±1.97)μm,实际载药量为(4.50±0.13)%,包封率在(96.5±2.68)%,首日突释率为(13.19±1.39)%,28 d的体外累积释放率可达(88.6±0.73)%。结论以生物可降解的PLGA为载体,用W/O/O法制备的艾塞那肽微球工艺稳定可控,重现性好,可在体外缓释一个月,在糖尿病治疗中具有良好的应用前景。     

多柔比星长效注射微球的体外释放研究

目的:考察多柔比星(Dox)微球的体外释放特性及药物在制备工艺和体外释放过程中的稳定性.方法:以乳酸-羟乙酸共聚物(PLGA)为载体材料,用改进的复乳法(W/O/W)制备载Dox长效注射微球;考察粒径大小、外观、包封率、载药量等理化性质;用紫外分光光度法检测了体外释放溶液中的药物含量,考察了微球的体外释药特性及影响因素;用高效液相色谱法评价了微球制备工艺和体外释放过程对Dox稳定性的影响.结果:微球球形圆整,分散性好,平均粒径为85 μm,包封率为95.1%,载药量为14.8%.随着PLGA浓度的增加,W/O体积比的减小,微球释放速度减慢,突释效应减小.制备工艺对Dox的稳定性无明显影响,而Dox在体外释放过程中随着释放时间的延长逐渐有降解峰产生,10 d后降解峰面积占2.46%.结论:用复乳法制备载Dox微球,通过对PLGA浓度和油水体积比的调节,可以得到不同释放速度的微球.     

羟基乙酸乙基纤维素微球的研制

目的研究用于肝动脉栓塞治疗的羟基乙酸乙基纤维素微球的制备方法及其体外释药特征。方法选用乙基纤维素为载体,加入羟基乙酸,采用复乳法制备羟基乙酸乙基纤维素微球,以外观、粒径、载药量、包封率为考察指标,从微球的圆整度、光滑度、大小均匀度、含药量对微球综合评价,并采用恒温振荡透析法测定微球的体外药物释放特性。结果和结论羟基乙酸乙基纤维素微球外观光滑,球形圆整,平均粒径(233.38±1.62) μm,载药量114.32 μg/mg,包封率78.61%,微球体外可释放药物72 h。羟基乙酸乙基纤维素微球可满足进一步动物实验要求,为化学腐蚀性药物用于肝动脉栓塞的研究提供重要的参考依据。     

新型nHA/PLGA纳米复合微球对大鼠颅骨缺损的修复作用

目的 探讨新型纳米羟基磷灰石（nHA）/聚丙交酯-乙交酯（PLGA）纳米复合微球对大鼠颅骨缺损的修复作用,为该材料的临床应用提供依据。     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

APPLICATION OF LORNOXICAM TO PATIENT-CONTROLLED ANALGESIA IN PATIENTS UNDERGOING ABDOMINAL SURGERIES

FOR anesthesiologis s ,treatingpostoperativepainhas alwaysbeen a problem.Althoughopioidshave been provedtobe effective,theirsideeffectscouldnotbeignored.With thedevelopmentofscienceand pharmacology,many drugs with aspectsof satisfactoryanalgesicefficacyand couldbe welltoleratedby patientshave been developed.And lornoxicamisone of them, which isa non-steroidalanti-inflammatorydrug (NSAID ), with analgesic, anti-infl-ammatory,andantipyreticproperties.Itseliminationhalf-time(3 to 5 hours) isle…     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.     

Scientific principles and rigorous processes should be followed in developing clinical guidelines for therapeutic interventions of integrative medicine

A clinical guideline for the therapeutic interventions of integrative medicine may be defined as a written document which states a series of recommendations on therapeutic interventions of integrative medicine for a special disease or condition. The guideline may provide assistance to medical professionals in making clinical decisions aimed at improving the clinical outcome of patients and reducing the costs of medical care（~＇4~. Recommendations issued by a guideline should be based on the best available evidence in both Western and Chinese medicine. For fulfilling this purpose, the development of clinical guidelines for therapeutic interventions in the field of integrative medicine should follow scientific principles and undergo a rigorous processes.