胰岛素聚乳酸纳米粒的初步研究

目的　研制一种新型的胰岛素 (INS)纳米粒 (NP)制剂。方法　以聚乳酸 (PLA)为载体材料 ,采用溶剂 -非溶剂法制备了INS -PLA -NP ,观察形态并测定粒径。给正常大鼠皮下注射 2U·kg-1INS溶液和 2U·kg-1INS -PLA -NP并观察降血糖作用。结果　INS -PLA -NP平均粒径为 84 34± 14 76nm ,给药后 0 5h血糖即降至最低(43 82 %± 10 4 1% ) ,并具有良好的缓释作用 ,药理相对生物利用度达到 133 5 1%。结论　制备工艺可行且制得的INS -PLA -NP在形态、粒径、载药特性、释药过程等方面令人满意     

纳米粒制剂研究进展

该文主要介绍了纳米粒制剂所应具备的要求、特点及影响因素,概述了壳聚糖纳米粒、磁性纳米粒、长循环纳米粒等的研究进展,还介绍了纳米粒在肿瘤诊治、制备智能化药物和中药开发中的应用等,以资纳米粒制剂的进一步研究与开发。     

胰岛素硬脂酸纳米粒的制备及其降血糖作用

采用乳化 -溶剂挥发法制备胰岛素硬脂酸纳米粒 ,通过透射电镜考察其形态 ,HPL C法测定其含量和包封率 ;建立了糖尿病大鼠模型 ,评价制品的降血糖效果。结果表明 :制品的平均粒径为 5 5 .3nm ,平均包封率为 (40 .12±2 .85 ) % ,含量为 5 .16± 0 .36 IU / ml;给糖尿病大鼠分别口服 10 IU/ kg和 2 0 IU/ kg的纳米粒 ,与口服胰岛素溶液(2 0 IU / kg)相比 ,其降血糖效果均有特别显著性差异 (P<0 .0 1) ,与皮下注射胰岛素注射液 (1IU / kg)相比 ,其相对生物利用度分别为 34.5 0 %和 4 4 .6 9% ,说明硬脂酸可试用为蛋白质、多肽类药物口服给药的有效载体。     

口服胰岛素聚乳酸纳米粒的研制

目的　研制一种新型的口服胰岛素 (INS)纳米粒制剂。方法　以溶剂 非溶剂法制备了INS PLA NP ,进行了形态、粒径、包封率、载药量等主要性质的考察。以糖尿病小鼠为动物模型 ,初步考察了口服INS PLA NP后的降血糖药效。结果　制得的INS PLA NP均匀圆整 ,平均粒径为 (84 .34± 14 .76 )nm ,平均包封率为 (6 5 .93± 3.4 5 ) % ,平均载药量为 (0 .6 2± 0 .0 3)u·mg-1。糖尿病小鼠口服 5 0 ,6 0 ,80u·kg-1剂量的INS PLA NP后均表现出显著的降血糖作用。而口服 4 0u·kg-1剂量的INS PLA NP无效。结论　使用PLA NP作INS口服给药的载体具有可行性。     

口服胰岛素聚乳酸纳米粒的研制

目的　研制一种新型的口服胰岛素(INS)纳米粒制剂。方法　以溶剂 非溶剂法制备了INS-PLA-NP ,进行了形态、粒径、包封率、载药量等主要性质的考察。以糖尿病小鼠为动物模型,初步考察了口服INS PLA NP后的降血糖药效。结果　制得的INS PLA-NP均匀圆整,平均粒径为(84.34±14.76)nm ,平均包封率为(65.93±3.45) % ,平均载药量为(0.62±0.03)u·mg^-1。糖尿病小鼠口服50,60 ,80u·kg^-1剂量的INS-PLA NP后均表现出显著的降血糖作用。而口服4 0u·kg^-1剂量的INS-PLA NP无效。结论　使用PLA NP作INS口服给药的载体具有可行性。     

口服胰岛素羧甲基壳聚糖纳米粒的制备及评价

目的:研制一种生物利用度高且具有缓释作用的口服胰岛素制剂。方法:通过钙离子交联制备羧甲基壳聚糖纳米粒,采用正交试验优化纳米粒制备条件,以透射电镜观察纳米粒形态,激光粒度分析仪测定粒度,高效液相色谱法测定纳米粒包封率和载药量,并对胰岛素的体外释放性能进行考察。结果:优化工艺制备的纳米粒外观形态圆整,平均粒径为(256.1±11.2)nm,包封率为(45±0.41)%,载药量为(17.2±0.33)%,药理相对生物利用度为14.71%。结论:口服载胰岛素羧甲基壳聚糖纳米粒具有降血糖作用和显著的缓释作用,药理相对生物利用度高。     

口服胰岛素聚乳酸纳米粒的胃肠道吸收与药效学研究

目的　考察口服胰岛素聚乳酸纳米粒 (INS PLA NP)在胃肠道不同部位的吸收以及吸收促进剂脱氧胆酸 (DOC)对吸收的影响。方法　在正常大鼠胃肠道不同部位 (胃、小肠、结肠 )分别给予含与不含吸收促进剂DOC的INS PLA NP后 ,观察降血糖效果。结果　大鼠灌胃给药后未能显示降血糖效果 ,添加DOC后仍基本无效。小肠直接给药后表现出和缓持久的降血糖效果 ,而DOC在小肠给药中能明显加快INS PLA NP的吸收并增强药效 ,但这一促进吸收作用存在一定的限度。结肠给药也基本无效 ,添加DOC后可产生强度不大的降血糖作用。结论　INS PLA NP主要在小肠吸收 ,DOC对于这一吸收具有促进作用     

胰岛素硬脂酸纳米粒的制备与结构分析

目的：研究胰岛素硬脂酸纳米粒的结构及抗消化酶特点。方法：采用透射电镜和激光散射法测定其形态和粒径大小：荧光扫描、聚丙烯酰胺凝胶电泳和抗消化酶降解等方法研究胰岛素在硬脂酸纳米粒中的包封情况。结果：胰岛素硬脂酸纳米粒为球形，平均粒径为55．3nm，多分散性指数为0．643。荧光扫描显示胰岛素硬脂酸纳米粒中无胰岛素荧光发射峰；聚丙烯酰胺凝胶电泳图谱中未见胰岛素条带；胰岛素硬脂酸纳米粒中的胰岛素可抵抗消化酶降解。结论：胰岛素被包裹在硬脂酸纳米粒中。     

口服纳米粒递送胰岛素研究进展

药物治疗糖尿病的最新进展当属口服胰岛素,而制备口服胰岛素需要将胰岛素包埋进载体使其避免胃肠降解。可突破肠上皮屏障达到良好降糖效果的口服载体多种多样,其中利用纳米材料制备胰岛素载体(INS-NPs)的研究最热,主要有以下优势:加强药物稳定性,大大提升生物利用率;实现靶向定位释药,降低药物对机体的毒副作用;控制释放药物时量,使药物在体内的作用更加明显等。针对上述优势并结合相关研究结论,本文从生物利用率、降糖时效和控释作用3个方面简述口服纳米粒在糖尿病治疗中的新进展。     

脱氧胆酸对胰岛素聚乳酸纳米粒在大鼠小肠吸收的影响

目的 :探讨脱氧胆酸 (DOC)对胰岛素聚乳酸纳米粒 (Ins PLA NP)在小肠吸收的影响。方法 :在正常大鼠小肠分别给予含与不含吸收促进剂DOC的Ins PLA NP后 ,观察降血糖效果。结果 :Ins PLA NP小肠直接给药表现出和缓持久的降血糖效果 ,而DOC在小肠给药中能明显加快Ins PLA NP的吸收并增强药效 ,给药后 0 5h血糖下降至用药前的 (35 49± 6 6 4) % ,显著的降血糖作用可维持 2h左右。结论 :DOC对于Ins PLA NP在小肠部位的吸收具有促进作用     

Alginate/Chitosan Nanoparticles are Effective for Oral Insulin Delivery

Purpose To evaluate the pharmacological activity of insulin-loaded alginate/chitosan nanoparticles following oral dosage in diabetic rats. Methods Nanoparticles were prepared by ionotropic pre-gelation of an alginate core followed by chitosan polyelectrolyte complexation. In vivo activity was evaluated by measuring the decrease in blood glucose concentrations in streptozotocin induced, diabetic rats after oral administration and flourescein (FITC)-labelled insulin tracked by confocal microscopy. Results Nanoparticles were negatively charged and had a mean size of 750 nm, suitable for uptake within the gastrointestinal tract due to their nanosize range and mucoadhesive properties. The insulin association efficiency was over 70% and insulin was released in a pH-dependent manner under simulated gastrointestinal conditions. Orally delivered nanoparticles lowered basal serum glucose levels by more than 40% with 50 and 100 IU/kg doses sustaining hypoglycemia for over 18 h. Pharmacological availability was 6.8 and 3.4% for the 50 and 100 IU/kg doses respectively, a significant increase over 1.6%, determined for oral insulin alone in solution and over other related studies at the same dose levels. Confocal microscopic examinations of FITC-labelled insulin nanoparticles showed clear adhesion to rat intestinal epithelium, and internalization of insulin within the intestinal mucosa. Conclusion The results indicate that the encapsulation of insulin into mucoadhesive nanoparticles was a key factor in the improvement of its oral absorption and oral bioactivity.     

肠溶包衣胰岛素-壳聚糖复合物纳米粒的制备及体内外性质

目的制备肠溶包衣的胰岛素壳聚糖复合物纳米粒,并对其理化性质、体外释药以及在糖尿病模型大鼠体内的降血糖效果进行研究。方法采用离子交联法制备胰岛素壳聚糖复合物纳米粒,使用羟丙基甲基纤维素酞酸酯(HP55)对其进行肠溶包衣;通过扫描电子显微镜观察其表观形态,用激光粒度测定仪测定其粒径大小,用Zeta电势测定仪测定其Zeta电势,使用HPLC法测定离心上清夜中胰岛素浓度,计算包封率。结果制备得到的纳米粒均匀、圆整,包衣前后粒径分别为(281±10)nm和(328±13)nm,Zeta电势分别为(30.4±6.97)mV和(33.7±6.69)mV,包封率分别为78.5%和74.3%;肠溶包衣纳米粒在人工胃液和肠液中的释药速率均明显低于未包衣纳米粒,突释效应显著减小;未包衣复合物纳米粒能够显著降低糖尿病模型大鼠的血糖浓度,其降糖效果能持续20 h以上,肠溶包衣后,降糖效果明显增强;肠溶包衣前后在模型大鼠体内24 h相对生物利用度分别为11.12%和16.29%。结论肠溶包衣胰岛素壳聚糖复合物纳米粒可以有效抑制胰岛素的突释,促进其吸收,显著降低模型大鼠的血糖浓度,能够作为胰岛素口服给药的有效载体。     

胰岛素壳聚糖胶态纳米粒的制备及体外释药性能

采用离子趋向凝胶化法制备了胰岛素壳聚糖胶态微粒,并考察了外观、粒径和体外释药性能.所得产品呈球形,表面光滑圆整,平均粒径为276nm,多分散系数为0.08.体外释药呈pH依赖性,释药速度受载药量及泊洛沙姆188含量的影响.     

Enhancement of Nasal Absorption of Insulin Using Chitosan Nanoparticles

Purpose. To investigate the potential of chitosan nanoparticles as a system for improving the systemic absorption of insulin following nasal instillation. Methods. Insulin-loaded chitosan nanoparticles were prepared by ionotropic gelation of chitosan with tripolyphosphate anions. They were characterized for their size and zeta potential by photon correlation spectroscopy and laser Doppler anemometry, respectively. Insulin loading and release was determined by the microBCA protein assay. The ability of chitosan nanoparticles to enhance the nasal absorption of insulin was investigated in a conscious rabbit model by monitoring the plasma glucose levels. Results. Chitosan nanoparticles had a size in the range of 300–400 nm, a positive surface charge and their insulin loading can be modulated reaching values up to 55% [insulin/nanoparticles (w/w): 55/100]. Insulin association was found to be highly mediated by an ionic interaction mechanism and its release in vitro occurred rapidly in sink conditions. Chitosan nanoparticles enhanced the nasal absorption of insulin to a greater extent than an aqueous solution of chitosan. The amount and molecular weight of chitosan did not have a significant effect on insulin response. Conclusions. Chitosan nanoparticles are efficient vehicles for the transport of insulin through the nasal mucosa.     

Chitosan Reduced Gold Nanoparticles as Novel Carriers for Transmucosal Delivery of Insulin

Purpose Colloidal metallic systems have been recently investigated in the area of nanomedicine. Gold nanoparticles have found themselves useful for diagnostic and drug delivery applications. Herein we have reported a novel method for synthesis of gold nanoparticles using a natural, biocompatible and biodegradable polymer; chitosan. Use of chitosan serves dual purpose by acting as a reducing agent in the synthesis of gold nanoparticles and also promotes the penetration and uptake of peptide hormone insulin across the mucosa. To demonstrate the use of chitosan reduced gold nanoparticles as carriers for drug delivery, we report herein the transmucosal delivery of insulin loaded gold nanoparticles. Materials and Methods Gold nanoparticles were prepared using different concentrations of chitosan (from 0.01% w/v up to 1% w/v). The gold nanoparticles were characterized for surface plasmon band, zeta potential, surface morphology, in vitro diffusion studies and fluorescence spectroscopy. The in vivo studies in diabetic male Wistar rats were carried out using insulin loaded chitosan reduced gold nanoparticles. Results Varying concentrations of chitosan used for the synthesis of gold nanoparticles demonstrated that the nanoparticles obtained at higher chitosan concentrations (>0.1% w/v) were stable showing no signs of aggregation. The nanoparticles also showed long term stability in terms of aggregation for about 6 months. Insulin loading of 53% was obtained and found to be stable after loading. Blood glucose lowering at the end of 2 h following administration of insulin loaded gold nanoparticles to diabetic rats was found to be 30.41 and 20.27% for oral (50 IU/kg) and nasal (10 IU/kg), respectively. Serum gold level studies have demonstrated significant improvement in the uptake of chitosan reduced gold nanoparticles. Conclusions The synthesis of gold nanoparticles using a biocompatible polymer, chitosan would improve its surface properties for binding of biomolecules. Our studies indicate that oral and nasal administration of insulin loaded chitosan reduced gold nanoparticles has led to improved pharmacodynamic activity. Thus, chitosan reduced gold nanoparticles loaded with insulin prove to be promising in controlling the postprandial hyperglycemia.     

高分子化学材料负载短效胰岛素对糖尿病大鼠的降血糖作用

目的研究高分子化学材料制备水凝胶负载短效胰岛素对糖尿病大鼠的降糖作用。方法大鼠以65mg·kg^-1剂量腹腔注射链脲佐菌素制备糖尿病大鼠模型,随机分为模型组、常规组(常规胰岛素注射)、水凝胶组(水凝胶负载短效胰岛素注射),另设正常对照组,每组10只。监测各组大鼠药物干预后24 h内血糖的变化;高糖灌胃后血糖的变化;观察药物干预后肝肾功能水平变化。结果 24h内模型组大鼠血糖无明显变化,常规组与水凝胶组的血糖均于3h时显著下降至最低点后上升,但水凝胶组的血糖上升至12 h后再次下降,并于24 h内维持在原水平的49.3%~55.6%,显著低于同时间常规组的血糖(P<0.05)。高糖灌胃后常规组大鼠血糖于0.5 h下降,于1.5~2.5 h维持于原水平的59.8%~66.4%,显著低于同时间段模型组血糖(P<0.05),水凝胶组血糖值自0.5h持续显著下降(P<0.05),2.5~3.5h时血糖值均较同时间常规组血糖值明显降低(P<0.05),实验过程中无明显低血糖。同时,水凝胶组大鼠的谷丙转氨酶及谷草转氨酶显著低于模型组,其中谷草转氨酶明显低于常规组,但高于正常对照组(P<0.05)。结论高分子化学材料水凝胶负载短效胰岛素后使其不仅降糖效果优于常规胰岛素,并且作用时间明显延长,可进一步应用于胰岛素新剂型的开发。     

壳聚糖和壳聚糖-EDTA轭合物双层包覆脂质体对胰岛素口服吸收的影响

目的研究壳聚糖和CEC双层包覆胰岛素脂质体的吸收状况,并验证其有效性。方法采用逆相蒸发制备胰岛素脂质体;用酶-苯酚法测定血糖值;用放射免疫法测定血清胰岛素含量,并采用Pkanalyst程序进行拟合。结果 Ch-CEC双层包覆的胰岛素脂质体对负载葡萄糖的正常大鼠的血糖升高具有抑制作用;以皮下注射胰岛素(Ins)为对照,Ch-CEC双层包覆的胰岛素脂质体经糖尿病模型大鼠和beagle犬给药后的相对药理生物利用度均大于9%,具有较好的降血糖作用。另外,在beagle犬降血糖实验中,根据血清胰岛素浓度-时间曲线的曲线下面积(AUC)计算Ch-CEC双层包覆的胰岛素脂质体灌胃给药的相对生物利度为12.67%。结论壳聚糖-CEC双层包覆胰岛素脂质体有利于改善胰岛素口服生物利用度。     

Effects of Various Protease Inhibitors on the Intestinal Absorption and Degradation of Insulin in Rats

The effects of protease inhibitors on the intestinal absorption of insulin were investigated in situ in closed small and large intestinal loops in rats, and the stability of insulin was examined in homoge-nates of the small and large intestine. The intestinal absorption of insulin was evaluated by its hypoglycemic effect. When insulin alone was administered into small or large intestinal loops, no marked hypoglycemic response was observed in either region. Of the coadministered protease inhibitors, soybean trypsin inhibitor (1.5, 10 mg/ml) marginally promoted insulin absorption from the large intestine, whereas aprotinin (10 mg/ml) did to a moderate degree. However, a significant hypoglycemic effect was obtained following large intestinal administration of insulin with 20 mM of Na-glycocholate, camostat mesilate and bacitracin, when compared with the controls. In contrast, we found little hypoglycemic effect following small intestinal coadministration of insulin with these protease inhibitors. In the stability experiment, bacitracin, camostat mesilate and Na-glycocholate were effective in reducing insulin degradation in both small and large intestinal homogenates. It was found that the reduction in the proteolytic rate of insulin was related to the decrease in plasma glucose concentration by these protease inhibitors in the large intestine. These findings suggest that coadministration of protease inhibitors would be useful for improving the large intestinal absorption of insulin.