改良自乳化-溶剂扩散法制备甲基莲心碱纳米粒的研究

目的制备甲基莲心碱纳米粒(NEF-NP),并采用正交试验设计对甲基莲心碱纳米粒制备工艺进行优化。方法以包封率和载药量为评价指标,采用聚乳酸-羟基乙酸共聚物(PLGA)为载体,丙酮-无水乙醇为有机溶剂,通过正交设计优化改良自乳化-溶剂扩散法制备载NEF的PLGA载药纳米粒的处方工艺。结果优化的最佳处方工艺为:PLGA的浓度为20 mg.mL-1,NEF的投药量为3.3 mg,PVA浓度为1.0%,水相与有机相的体积比为8∶1。最佳条件下制得的纳米粒平均包封率达(70.35±1.16)%,载药量(2.33±1.08)%,平均粒径为(213.5±2.7)nm。结论最佳处方工艺制备的NEF-PLGA纳米粒具有较高的包封率、载药量和较小的粒径。     

沉淀法制备甲基莲心碱聚乳酸-羟基乙酸共聚物纳米粒

目的:制备甲基莲心碱聚乳酸-羟基乙酸共聚物纳米粒(Nef-PLGA-NPs)。方法:以聚乳酸-羟基乙酸共聚物(PLGA)为载体,丙酮为有机溶剂,通过正交试验设计优化沉淀法制备甲基莲心碱PLGA纳米粒的工艺。结果:最佳工艺条件为:PLGA的质量浓度为10 mg.mL-1,Nef的质量浓度为1.0 mg.mL-1,水相与有机相的体积比为20∶1。纳米粒平均包封率为(85.3±0.8)%,平均载药量为(7.75±0.07)%,平均粒径为(82.9±1.2)nm。结论:优化条件下采用沉淀法制备的甲基莲心碱PLGA纳米粒包封率高、载药量大,平均粒径小。     

盐酸吉西他滨壳聚糖纳米粒的制备及其体外释药特性研究

目的:优化盐酸吉西他滨壳聚糖纳米粒的制备参数,考察纳米粒体外释药特性。方法:以壳聚糖为辅料,采用离子交联法制备盐酸吉西他滨壳聚糖纳米粒,以包封率、载药量、粒径为参考指标设计试验,确定优化制备参数,以透射电镜观察其表观特征,考察纳米粒体外释药程度。结果:以优化参数制备的盐酸吉西他滨壳聚糖纳米粒包封率为(78.93±1.52)%,载药量为(11.71±0.88)%,纳米粒的平均粒径为(169±24)nm,体外释放试验表明纳米粒中盐酸吉西他滨的释放过程符合Higuchi方程。结论:盐酸吉西他滨可以通过离子交联法制备壳聚糖纳米粒,其粒径、包封率、载药量可控,具有缓释效果。     

N-琥珀酰壳聚糖纳米粒的制备及体外评价

目的制备N-琥珀酰壳聚糖纳米粒并对其进行体外评价。方法采用乳化溶剂挥发法制备N-琥珀酰壳聚糖纳米粒;以包封率、载药量及粒径为指标,采用正交设计法对处方进行优化;考察其理化特征及体外释药行为。结果纳米粒包封率及载药量分别为62.36%和18.98%,平均粒径及zeta电位分别为(206.6±64.7)nm和(-27.2±0.2)mV;1 h药物释放达到45%,随后药物的释药行为是一个缓释过程。结论作者采用乳化溶剂挥发法成功制得N-琥珀酰壳聚糖纳米粒。该方法制得纳米粒包封率较高,制备工艺简单。     

半乳糖化阿霉素白蛋白纳米粒的制备及其质量评价

目的:制备半乳糖化阿霉素白蛋白纳米粒,并考察了其形态、粒径、载药量、包封率和体外释药特性.方法:采用相分离法制备阿霉素白蛋白纳米粒,并在其表面偶联半乳糖苷,使之成为半乳糖化白蛋白纳米粒.激光扫描电子显微镜观察纳米粒的形态,马尔文激光粒度仪测定其粒径分布.采用紫外分光光度法测定纳米粒的载药量和包封率,并初步研究其体外释药特性.结果:电镜结果显示阿霉素纳米粒呈类球型,平均粒径为316.3 nm,纳米粒载药量为3.12%,包封率达91.82%,48 h体外累积释药率为55.71%.结论:本方法制备阿霉素纳米粒工艺简单且包封率较高.体外释药结果显示半乳糖化阿霉素白蛋白纳米粒具有明显的缓释作用.     

多西紫杉醇白蛋白纳米粒的制备及体外评价

目的：制备多西紫杉醇白蛋白纳米粒，考察白蛋白和多西紫杉醇的处方量及乙醇加入量等因素对其形态、粒径、Zeta电位、收率、包封率、载药量和体外释药特性的影响，并对处方工艺进行优化。方法：采用去溶剂化-化学交联法制备多西紫杉醇白蛋白纳米粒，透射电镜观察纳米粒形态，马尔文激光粒度仪测定其粒径分布及Zeta电位，考马斯亮兰-酶标仪法测定纳米粒收率，HPLC法测定纳米粒包封率和载药量；以累积释药百分率为指标，通过方程拟合释药曲线，考察制剂的体外释药特性。处方优化采用星点设计-效应面优化法，应用SAS统计软件对数据进行处理。结果：优化处方制得的纳米粒为类球形，平均粒径65．3nm，Zeta电位-31．4mV，纳米粒收率95．0％，包封率74．3％，载药量4．65％，制剂24小时体外累积释药百分率为74．4％。结论：难溶性抗癌药物多西紫杉醇可以采用去溶剂化-化学交联法制备成白蛋白纳米粒，其粒径小，稳定性高，可显著提高多西紫杉醇在水相中的浓度。其优化处方中药物的释放显著慢于原料药磷酸盐缓冲溶液的释放，具有缓释效果。     

5-氟尿嘧啶共聚物纳米粒的制备及其药剂学性质

目的 以生物可降解材料Pluronic P105-PAGA共聚物制备5-氟尿嘧啶(5-FU)纳米粒,并考察纳米粒的药剂学特性.方法 采用透析法制备纳米粒,以包封率和载药量为指标,应用星点设计效应面优化法优化处方,并考察其表面特征、包封率、载药量、粒径、体外释放等性质.结果 5-FU-Pluronic P105-PAGA纳米粒为圆整的类球形实体粒子,平均粒径为175 nm,载药量为22.37%,包封率为95.26%,有突释现象,体外12 h累积释放率为80.4%.结论 所制纳米粒具有高包封率和载药量,粒径适宜,具有一定的缓控释作用.     

紫杉醇纳米粒-微球系统的研制

目的制备紫杉醇纳米粒-微球系统(taxol nanoparticals-in-microsphere system,TAX-NiMS),并考察其体外释放特性。方法以聚乳酸-羟基乙酸共聚物(poly(lactic-co-glycolic acid),PLGA)为载体,采用乳化溶剂挥发法制备紫杉醇纳米粒(taxol nanoparticals,TAX-NPs)。以包封率、载药量及粒径为考察指标,采用单因素试验法优化处方。采用内源乳化凝胶法,以海藻酸钙为包裹材料,制备包覆TAX-NPs的微球系统。在扫描电镜和透射电镜下观察TAX-NiMS的表面和内部形态,并测定其粒径及体外释放特性。结果纳米粒优化处方:PLGA质量浓度为100 g·L-1,聚乙烯醇质量浓度为10 g·L-1,油相与水相体积比为1∶10,超声功率为300 W。微球优化处方:海藻酸钠(NaALG)质量浓度为15 g·L-1,Span-80质量浓度为10 g·L-1,Ca CO3与Na ALG质量比为1∶3,油相与水相体积比为1∶5。此条件下制备的TAX-NiMS的包封率、载药量和平均粒径分别为(84.33±1.11)%、(1.12±0.15)%和(2.678±0.014)μm。TAX-NiMS的12h释放量仅达到16.51%。结论 TAX-NiMS的制备方法稳定可控,且突释效应显著减小,为药物新剂型的开发提供了思路。     

以叶酸修饰的乳酸-羟基乙酸共聚物为载体的紫杉醇靶向纳米粒的构建与评价

目的 以叶酸修饰的生物可降解材料乳酸-羟基乙酸共聚物(PLGA-PEG-FOL)为载体,构建紫杉醇靶向纳米粒并进行评价。方法 采用乳化-分散法,以溶液稳定性、粒径和包封率为评价指标,通过考察乳化剂的用量、有机相种类、水相与有机相比例、聚合物分子量、药载比、剪切速度等因素对纳米粒制备的影响,确定最优处方和制备工艺,并对纳米粒的形态、粒径、Zeta电位、包封率及载药量进行评价。结果 合成了载体PLGA-PEG-FOL;制备的紫杉醇靶向纳米粒为均匀球形粒子,粒径为(88.2±6.7)nm,Zeta电位为(56.5±4.2)mV,包封率为(92.9±3.2)%,载药量为(4.8±1.3)%。结论 纳米粒制备方法简便易行,重现性好。制备的纳米粒大小均匀,粒度分布较窄,包封率和载药量较高。     

汉黄芩素固体脂质纳米粒的制备及体外释放度考察

目的:制备汉黄芩素固体脂质纳米粒并对其体外释放度进行考察.方法:采用乳化分散-超声法制备汉黄芩素固体脂质纳米粒,以包封率和载药量为评价指标,进行正交试验筛选最优处方,并对最优处方的外观、粒径和体外释放度进行考察.结果:制得的纳米粒为均一球形,平均粒径为(153 ±34)nm,其平均载药量为(60.53±2.17)％,平均包封率为(85.54±4.16)％,48 h累积释放达80％.结论:本试验获得了较理想的汉黄芩素固体脂质纳米粒,其体外释放具有缓释作用.     

A Heterogeneously Structured Composite Based on Poly(lactic-co-glycolic acid) Microspheres and Poly(vinyl alcohol) Hydrogel Nanoparticles for Long-Term Protein Drug Delivery

Purpose. To prepare a heterogeneously structured composite based on poly (lactic-co-glycolic acid) (PLGA) microspheres and poly(vinyl alcohol) (PVA) hydrogel nanoparticles for long-term protein drug delivery. Methods. A heterogeneously structured composite in the form of PLGA microspheres containing PVA nanoparticles was prepared and named as PLGA-PVA composite microspheres. A model protein drug, bovine serum albumin (BSA), was encapsulated in the PVA nanoparticles first. The BSA-containing PVA nanoparticles was then loaded in the PLGA microspheres by using a phase separation method. The protein-containing PLGA-PVA composite microspheres were characterized with regard to morphology, size and size distribution, BSA loading efficiency, in vitroBSA release, and BSA stability. Results. The protein-containing PLGA-PVA composite microspheres possessed spherical shape and nonporous surface. The PLGA-PVA composite microspheres had normal or Gaussian size distribution. The particle size ranged from 71.5 m to 282.7 m. The average diameter of the composite microspheres was 180 m. The PLGA-PVA composite microspheres could release the protein (BSA) for two months. The protein stability study showed that BSA was protected during the composite microsphere preparation and stabilized inside the PLGA-PVA composite microspheres. Conclusions. The protein-containing PLGA-PVA composite may be suitable for long-term protein drug delivery.     

粒细胞-巨噬细胞集落刺激因子壳聚糖缓释纳米粒的制备

目的:研究以生物可降解壳聚糖纳米粒作为粒细胞-巨噬细胞集落刺激因子(GM-CSF)新型缓释系统的可行性。方法:以三聚磷酸钠为交联剂,采用离子交联法制备负载GM-CSF和牛血清白蛋白(BSA)的纳米粒。用透射电镜观测纳米粒径和形态;用紫外分光光度计、荧光分光光度计分别测定BSA和GM-CSF包封率,并考察制剂体外药物释放情况。结果:纳米粒形态多呈球形,平均粒径为201nm,GM-CSF和BSA包封率分别为62.1%、58.5% ,3d时体外累积释放率分别为69%、82%。结论:应用离子交联法可制备负载GM-CSF的壳聚糖缓释纳米粒。     

Preparation, characterization and pharmacokinetic studies of tacrolimus-dimethyl-β-cyclodextrin inclusion complex-loaded albumin nanoparticles

The purpose of the study is to develop a new formulation for clinically used anti-cancer agent tacrolimus (FK506) to minimize the severe side effects. Toward this end, a new formulation method has been developed by complexation of FK506 with an hydrophilic cyclodextrin derivative, heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) using ultrasonic means. The resulting complex displays dramatically enhanced solubility of FK506. Then bovine serum albumin (BSA) nanoparticles were prepared directly from the preformed FK506/DM-β-CD inclusion complex by the desolvation-chemical crosslinking method, with the size of 148.4-262.9 nm. Stable colloidal dispersions of the nanoparticles were formed with zeta potentials of the range of -24.9 to -38.4 mV. The entrapment efficiency of FK506 was increased as high as 1.57-fold. Moreover, notably FK506 was released from the nanoparticles in a sustained manner. As demonstrated, pharmacokinetic studies reveal that, as compared with FK506-loaded BSA nanoparticles, the FK506/DM-β-CD inclusion complex-loaded BSA nanoparticles have significant increase at T(max), t(1/2), MRT and decrease at C(max). In summary, these results suggest that the drug/DM-β-CD inclusion complex-loaded BSA nanoparticles display significantly improved delivery efficiency for poorly soluble FK506 or its derivatives.     

Development and characterization of glutathione-conjugated albumin nanoparticles for improved brain delivery of hydrophilic fluorescent marker

Abstract

The glutathione-conjugated bovine serum albumin (BSA) nanoparticles were constructed in the present exploration as a novel biodegradable carrier for brain-specific drug delivery with evaluation of its in vitro and in vivo delivery properties. BSA nanocarriers were activated and conjugated to the distal amine functions of the glutathione via carbodiimide chemistry using EDAC as a mediator. These nanoparticles were characterized for particle shape, average size, SPAN value, drug entrapment and in vitro drug release. Further, presence of glutathione on the surface of BSA nanoparticles was confirmed by Ellman’s assay, which has suggested that approximately 750 units of glutathione were conjugated per BSA nanoparticle. To evaluate the brain delivery properties of the glutathione-conjugated BSA nanoparticles fluorescein sodium was used as a model hydrophilic compound. Permeability and neuronal uptake properties of developed formulations were evaluated against the MDCK-MDR1 endothelial and neuro-glial cells, respectively. The permeability of glutathione-conjugated BSA nanoparticles across the monolayer of MDCK-MDR1 endothelial tight junction was shown significantly higher than that of unconjugated nanoparticles and fluorescein sodium solution. Similarly, glutathione-conjugated nanoparticles exhibited considerably higher uptake by neuro-glial cells which was inferred by high fluorescence intensity under microscope in comparison to unconjugated nanoparticles and fluorescein sodium solution. Following an intravenous administration, nearly three folds higher fluorescein sodium was carried to the rat brain by glutathione-conjugated nanoparticles as compared to unconjugated nanoparticles. The significant in vitro and in vivo results suggest that glutathione-conjugated BSA nanoparticles is a promising brain drug delivery system with low toxicity.     

The Characteristics and Mechanisms of Uptake of PLGA Nanoparticles in Rabbit Conjunctival Epithelial Cell Layers

PURPOSE: To delineate the characteristics and mechanisms of uptake of biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles in primary cultured rabbit conjunctival epithelial cells (RCECs). METHODS: Poly(D,L-lactide-co-glycolide) nanoparticles (PLGA 50:50. 101 nm in diameter) containing 6-coumarin (as a fluorescent marker) were used. The effect of size was studied using various particle sizes (100 nm, 800 nm, and 10 microm). The effect of cytochalasin D, nocodazole, and metabolic inhibitors on nanoparticle uptake was investigated. The capability of nanoparticles to enhance the uptake of an encapsulated protein. BSA bound to Texas red (TR-BSA), was evaluated. RESULTS: Maximal uptake of nanoparticles at 37 degrees C occurred at 2 h, and 100-nm particles had the highest uptake in RCECs in comparison with 800-nm and 10-microm particles. Nanoparticle uptake was saturable over the 0.1-4 mg/ml concentration range. Nanoparticle uptake was confirmed by confocal microscopy and was inhibited significantly by coumarin-free nanoparticles (of similar size), by lower incubation temperature, and by the presence of metabolic inhibitors and cytochalasin D. The uptake of encapsulated TR-BSA in RCECs at 4 h was 28% higher than free BSA application. CONCLUSION: Our findings suggest that PLGA nanoparticle uptake in primary cultured rabbit conjunctival epithelial cells occurs most likely by adsorptive-type endocytosis.     

Preparation of sub-100-nm beta-lactoglobulin (BLG) nanoparticles

Sub-100-nm nanoparticles were prepared from beta-lactoglobulin (BLG) with a narrow size distribution by a desolvation method using glutaraldehyde for cross-linking. With pre-heating of the BLG solution to 60 degrees C and subsequent pH readjustment to 9.0, nanoparticles of 59 +/- 5 nm were obtained with improved uniformity. Bovine serum albumin (BSA) nanoparticles, prepared under similar conditions for comparison, were larger and less uniform. The half-width of 80% particle distribution was used to compare the uniformity of particle size distribution. The stability of the nanoparticles was investigated by degradation tests at neutral and acidic pHs with and without proteolytic enzymes, trypsin and pepsin. The degradation time, determined by a graphical approach, was used to compare the relative stabilities of BLG and BSA nanoparticles. The particles of BLG were more stable than those of BSA in acidic and neutral media with and without added enzymes.     

制备工艺对多柔比星白蛋白纳米粒理化性质、体外释放及药动学的影响

分别采用去溶剂化法和乳化交联法制备多柔比星牛血清白蛋白(BSA)纳米粒,以BSA收率、包封率、载药量和粒径等为评价指标,优选处方工艺,并比较两种制备工艺所得制品的差异.结果表明,去溶剂化法和乳化交联法所得纳米粒外观均呈球形,差异不大,BSA收率、包封率、载药量、粒径及ζ电位分别为96.5％、92.9％,98.5％、97.4％,4.3％、3.6％,132.4、172.9 nm,-27.7、-19.9 mV.但制备工艺对体外释放行为和大鼠体内药动学行为影响较大,去溶剂化法和乳化交联法制备的多柔比星BSA纳米粒在生理盐水中48 h累积释放率分别为44.2％、63.8％;大鼠尾静脉给药后,去溶剂化法和乳化交联法所得制品的AUC分别是原药的1.5倍(P＜0.05)和1.1倍(P＞0.05),前法所得纳米粒在大鼠体内具有一定的缓释效果,而后法所得制品没有.     

Preparation of sub-100-nm β-lactoglobulin (BLG) nanoparticles

Sub-100-nm nanoparticles were prepared from β-lactoglobulin (BLG) with a narrow size distribution by a desolvation method using glutaraldehyde for cross-linking. With pre-heating of the BLG solution to 60°C and subsequent pH readjustment to 9.0, nanoparticles of 59?±?5?nm were obtained with improved uniformity. Bovine serum albumin (BSA) nanoparticles, prepared under similar conditions for comparison, were larger and less uniform. The half-width of 80% particle distribution was used to compare the uniformity of particle size distribution. The stability of the nanoparticles was investigated by degradation tests at neutral and acidic pHs with and without proteolytic enzymes, trypsin and pepsin. The degradation time, determined by a graphical approach, was used to compare the relative stabilities of BLG and BSA nanoparticles. The particles of BLG were more stable than those of BSA in acidic and neutral media with and without added enzymes.