复乳法制备胰岛素PLGA纳米粒影响包封率因素考察

以Poloxamer188为乳化剂，乙酸乙酯为有机溶剂，采用复乳法制备了胰岛素乳酸／羟基乙酸共聚物（PLGA）纳米粒，考察了乳化剂和PLGA的浓度。内水相中胰岛素的浓度为pH，溶剂挥发方法和内水相中加入聚乙烯醇（PVA）等实验各因素对胰岛素PLGA纳米粒包封率的影响。结果表明，乳化剂的浓度较高，PLGA的浓度较小，内水相的pH接近胰岛素的pI(5．3），胰岛素的浓度较低，缩短有机溶剂挥发时间及内水相中加入PVA有利于提高胰岛素的包封率，经实验条件优化后制备的胰岛素PLGA纳米纳平均粒径为149．6nm，多分散性系数小于0．1，包封率提高到42．8％。     

胰岛素固体脂质纳米粒的制备及其包封率的测定

目的 制备胰岛素固体脂质纳米粒(Ins-SLNs),考察其理化性质,并建立测定包封率的方法.方法 通过复乳/溶剂扩散法制备Ins-SLNs,考察其形态、粒径分布、Zeta电位;通过改变pH,调节Zeta电位后,采用冷冻高速离心分离纳米粒与游离Ins的方法,测定Ins-SLNs的包封率.结果 复乳法制备的Ins-SLNs在扫描电镜下均呈球形,分布均匀,平均粒径为114.7±4.68 nm,Zeta电位为-54.36±2.04 mV;包封率测定方法的线性范围为1.047～100.47μg·ml-1,平均回收率为98.37%,RSD=1.02%;测得3批Ins-SLNs样品的平均包封率为97.78%.结论 所用制备工艺简单,制得的纳米粒包封率较高;包封率的测定方法方便、灵敏、准确.     

胸腺五肽三甲基壳聚糖纳米粒包封率的测定

目的　建立胸腺五肽三甲基壳聚糖纳米粒中胸腺五肽包封率的测定方法。方法　将纳米粒超速冷冻离心后,用HPLC法测定胸腺五肽的含量,分析柱为C1 8柱,流动相为0 . 1mol·L-1 磷酸盐缓冲液(pH 7.0 ) -乙腈(94∶6 ) ,检测波长2 75nm。结果　线性范围5～4 0 0 μg·ml-1 ,回收率98.8%,RSD =2 %。结论　方法方便、灵敏、准确,可测定三甲基壳聚糖纳米粒中胸腺五肽的包封率。     

左旋多巴固体脂质纳米粒的制备及包封率测定

目的:用微乳法制备左旋多巴固体脂质纳米粒(LDP-SLN),并建立包封率的测定方法。方法:通过绘制三元相图,采用微乳法制备LDP-SLN,用TEM和激光粒度仪进行了颗粒形貌和粒径分布的研究,用葡聚糖凝胶层析法分离测定包封率。对其粒径、形态、包封率等理化性质进行研究,并考察其稳定性。结果:实验制得LDP-SLN为稳定的略泛蓝色乳光的纳米混悬液,在透射电镜下显示为较为均匀的球体,激光粒度测定平均粒径为108nm,多分散系数1.153;4℃放置2个月,粒径、包封率无显著变化。包封率测定的线性范围为2～100mg·mL-1,线性良好(r=0.9999),精密度符合要求,LDP-SLN上柱洗脱后分离度和回收率均符合要求。结论:该研究中制备了物理性质较为稳定的LDP-SLN,建立了合适的包封率测定方法,并考查初步稳定性较好。     

复乳法制备阿柔比星A的聚乳酸聚乙醇酸共聚物纳米粒影响包封率因素考察

以含阿柔比星A(Aclarubicin A，ACRB-A)的酸性溶液为内水相，采用复乳法制备ACRB-A(PLGA)纳米粒。考察了有机溶剂、油酸的量、稳定剂种类、投药量、乳化剂、Na2SO4的量和外水相的pH值几个主要因素对ACRB-APLGA纳米粒包封率的影响。结果表明，以二氯甲烷和丙酮为有机溶剂、油酸(15mg)、右旋糖酐-70、ACRB-A的浓度(Smg／ml)、以F68和Tween-80为乳化剂、2％的Na2SO4和外水相的pH等于8有利于提高ACRB-A的包封率。经实验条件优化后制备的ACRB-A PLGA包封率为85．41％，纳米粒粒径为272nm，粒径分散指数为0．213。     

负载胰岛素壳聚糖接枝醋酸乙烯酯纳米粒的制备和性能

目的:制备负载胰岛素壳聚糖-醋酸乙烯酯共聚物纳米粒并研究其性能。方法:用自由基聚合法合成壳聚糖-醋酸乙烯酯共聚物,该聚合物在水中形成具有疏水核心、亲水表面的纳米粒。采用正交设计试验研究了投料比、引发剂浓度和反应时间对纳米粒粒径的影响。结果:对纳米粒进行了热重分析和红外表征。测定纳米粒的形态、粒径和表面电位(Zeta电位),以胰岛素为模型药物,研究纳米粒的包封和释药性能。结论:纳米粒呈球形,粒径均匀,表面荷正电。胰岛素的包封率可达90%以上。pH6.8的磷酸盐缓冲液中胰岛素释放较慢。结论:该纳米制剂具有较好的物理性能和体外缓释特性。     

咪喹莫特固体脂质纳米粒包封率的测定

目的:建立咪喹莫特固体脂质纳米粒包封率的测定方法。方法:采用热乳匀法制备咪喹莫特固体脂质纳米粒。用葡聚糖凝胶柱色谱法分离含药固体脂质纳米粒与游离药物,以蒸馏水和1．0×10-3mol·L-1盐酸溶液为洗脱液,用HPLC法测定游离药物量。结果:凝胶柱色谱法能够将包封药物和游离药物分开。游离咪喹莫特在0．335-2．69μg·ml-1浓度范围内,线性关系良好(r=0．999 9)。游离药物柱回收率为98．6％,柱的加样回收率为97．7％。样品的平均包封率为(51．43±0．88)％。结论:该方法操作简便,结果准确,可用于咪喹莫特固体脂质纳米粒包封率测定。     

离子凝胶法制备壳聚糖纳米粒的影响因素研究

目的 探讨离子凝胶法制备壳聚糖纳米粒(CS-NPs)的影响因素.方法 用碱降解法制备高脱乙酰度的壳聚糖(CS),并以之为材料,采用离子凝胶法制备CS-NPs,以微粒的平均粒径、分散度和Zeta电位为指标,考察CS及三聚磷酸钠(TPP)的质量浓度、CS/TPP质量比、CS溶液pH值和CS溶液温度对制备CS-NPs的影响....     

壳聚糖-甲基丙烯酸甲酯共聚物纳米粒的制备和表征

目的制备壳聚糖-甲基丙烯酸甲酯共聚物纳米粒。方法用自由基聚合法合成壳聚糖-甲基丙烯酸甲酯共聚物,该聚合物在水中形成具有疏水核心、亲水表面的纳米粒。测定纳米粒的形态、粒径和表面电位(Zeta电位),并研究了壳聚糖含量、聚合物总浓度和引发剂浓度对纳米粒粒径的影响。以胰岛素为模型药物,研究纳米粒的包封和释药性能。结果纳米粒呈球形,粒径均匀,表面荷正电。胰岛素的包封率可达90%以上。pH 5.8的磷酸盐缓冲液中胰岛素的释放较慢,16 h释放量为66.8%。结论该纳米制剂具有较好的物理性能和体外缓释特性。     

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。     

Formulation and characterization of an oily-based system for oral delivery of insulin

The present work explored the possibility of formulating an oral insulin delivery system by combining the advantages of nanoencapsulation and the use of oily vehicle. The parameters affecting formulation such as association efficiency were characterized. The preparation was evaluated for its chemical, physical and biological stability. The preparation has unimodal particle size distribution with a mean diameter of 108 ± 9 nm. Insulin was protected from gastric enzymes by incorporation into lipid-based formulation. The results of RP HPLC and ELISA indicated that insulin was able to withstand the preparation procedure. Insulin in the preparations was stable for a period of one month at storage temperatures of 4 and 25 °C. It was also biologically active and stable as demonstrated by the remarkable reduction of blood glucose levels of the STZ-diabetic rats after oral administration of the preparation. Moreover, hypoglycemic effect of nanoparticles administered orally was sustained for a longer period of time compared to the subcutaneous injection. These results clearly evidenced the ability of the nanoparticles to enhance the pharmacological response of insulin when given orally and could be used to deliver other peptides.     

Chitosan Nanoparticles for Plasmid DNA Delivery: Effect of Chitosan Molecular Structure on Formulation and Release Characteristics

Chitosan can be useful as a nonviral vector for gene delivery. Although there are several reports to form chitosan-pDNA particles, the optimization and effect on transfection remain insufficient. The chitosan-pDNA nanoparticles were formulated using complex coacervation and solvent evaporation techniques. The important parameters for the encapsulation efficiency were investigated, including molecular weight and deacetylation degree of chitosan. We found that encapsulation efficiency of pDNA is directly proportional with deacetylation degree, but there is an inverse proportion with molecular weight of chitosan. DNA-nanoparticles in the size range of 450–820 nm depend on the formulation process. The surface charge of the nanoparticles prepared with complex coacervation method was slightly positive with a zeta potential of +9 to +18 mV; nevertheless, nanoparticles prepared with solvent evaporation method had a zeta potential ～ +30 mV. The pDNA-chitosan nanoparticles prepared by using high deacetylation degree chitosan having 92.7%, 98.0%, and 90.4% encapsulation efficiency protect the encapsulated pDNA from nuclease degradation as shown by electrophoretic mobility analysis. The release of pDNA from the formulation prepared by complex coacervation was completed in 24 hr whereas the formulation prepared by evaporation tecnique released pDNA in 96 hr, but these release profiles are not statistically significant compared with formulations with similar structure p >. 05). According to the results, we suggest nanoparticles have the potential to be used as a transfer vector in further studies.     

基因壳聚糖纳米粒表面修饰和转染研究

目的：研究递送基因纳米粒表面修饰对体外基因转染的影响。方法：利用末端活化的聚乙二醇(PEG)制备PEG化基因壳聚糖纳米粒;通过两端活化的PEG将糖蛋白配基连接到纳米粒表面,完成肝靶向纳米粒的制备;用透射电镜观察表面修饰对纳米粒粒径大小、粒子形态的影响;使用蛋白质测定试剂盒测算纳米粒表面蛋白连接量;利用体外转染实验考察表面修饰对纳米粒转染活性的影响;用倒置荧光显微镜观察并用流式细胞仪测定转染结果。结果：纳米粒PEG化使转染效率大幅度升高,半乳糖基牛血清白蛋白(Galn—BSA)使体系的转染效率比PEG化纳米粒略有下降,但比不经修饰的纳米粒转染活性高。壳聚糖纳米粒的表面PEG化能提高纳米粒的体外稳定性,从而提高体外转染效率,并适合于进行冷冻干燥。结论：长循环壳聚糖基因递送纳米粒在基因治疗研究中可能会发挥重要作用。     

Preparation,Characterization and Protein Loading of Hexanoyl-Modified Chitosan Nanoparticles

Hexanoyl chitosan was synthesized through a coupling reaction between chitosan and hexanoic anhydride. Proton nuclear magnetic resonance (¹HNMR) and fourier-transform infrared (FTIR) spectroscopy studies showed the formation of hexanoyl chitosan. The nanoparticles of hexanoyl chitosan were prepared through ionotropic gelation with tripolyphosphate (TPP) followed by sonication. The hexanoyl chitosan-TPP nanoparticles exhibited uniform spherical shape with smooth surface as observed by atomic force microscopy and transmission electron microscopy. The particle size of nanoparticles was between 54.1 to 724 nm with a mean diameter of 324 nm. At 0.2, 0.4, and 0.6 mg/mL bovine serum albumin initial concentration, the encapsulation efficiency and loading capacity of hexanoyl-chitosan-TPP nanoparticles were 58.2, 44.5, and 28.1%, and 14.1, 23.4, and 30.3%, respectively.     

壳聚糖包覆脂质体递药系统的研究进展

脂质体在药物传递方面被广泛研究,但因结构稳定性差等因素使其应用受到了限制.壳聚糖是一种阳离子多糖,具有良好的生物相容性、生物降解性以及生物黏附性,并且可经化学改性成为性能更佳的壳聚糖衍生物.近年来,壳聚糖及其衍生物包覆脂质体在载药方面的研究得到了越来越多学者的关注.壳聚糖或其衍生物修饰脂质体,可提高其稳定性、黏附渗透性...     

叶酸和聚乙二醇双修饰的壳聚糖纳米粒的制备及其性能表征

目的 利用离子交联和化学交联相结合的方法制备壳聚糖纳米粒子(NPs),并对NPs分别进行了叶酸(FA)和聚乙二醇(PEG)的修饰。方法 通过红外光谱进行结构验证;用扫描电镜和粒度分析仪对粒子的微观形态、粒径、电位等进行了表征;通过与Hela细胞摄取实验对其靶向作用进行验证。结果 离子交联和化学交联相结合的方法制备壳聚糖纳米粒子粒径在200 nm左右并且粒径分布窄,修饰后的NPs(FA-NPs、PEG-NPs及FA+PEG-NPs)粒径不受功能基团修饰的影响。激光共聚焦试验证明FA-NPs及FA+PEG-NPs能显著提高细胞对粒子的摄取,而PEG-NPs则明显降低其对粒子的摄取。结论 FA+PEG-NPs有望成为一种新型的药物载体,用于抗癌药物对癌细胞的主动靶向。     

Nasal Delivery of Insulin Using Novel Chitosan Based Formulations: A Comparative Study in Two Animal Models Between Simple Chitosan Formulations and Chitosan Nanoparticles

Purpose. To investigate whether the widely accepted advantages associated with the use of chitosan as a nasal drug delivery system, might be further improved by application of chitosan formulated as nanoparticles. Methods. Insulin-chitosan nanoparticles were prepared by the ionotropic gelation of chitosan glutamate and tripolyphosphate pentasodium and by simple complexation of insulin and chitosan. The nasal absorption of insulin after administration in chitosan nanoparticle formulations and in chitosan solution and powder formulations was evaluated in anaesthetised rats and/or in conscious sheep. Results. Insulin-chitosan nanoparticle formulations produced a pharmacological response in the two animal models, although in both cases the response in terms of lowering the blood glucose levels was less (to 52.9 or 59.7% of basal level in the rat, 72.6% in the sheep) than that of the nasal insulin chitosan solution formulation (40.1% in the rat, 53.0% in the sheep). The insulin-chitosan solution formulation was found to be significantly more effective than the complex and nanoparticle formulations. The hypoglycaemic response of the rat to the administration of post-loaded insulin-chitosan nanoparticles and insulin-loaded chitosan nanoparticles was comparable. As shown in the sheep model, the most effective chitosan formulation for nasal insulin absorption was a chitosan powder delivery system with a bioavailability of 17.0% as compared to 1.3% and 3.6% for the chitosan nanoparticles and chitosan solution formulations, respectively. Conclusion. It was shown conclusively that chitosan nanoparticles did not improve the absorption enhancing effect of chitosan in solution or powder form and that chitosan powder was the most effective formulation for nasal delivery of insulin in the sheep model.     

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.     

HPLC法测定不同包载体系中丁硫酸亚砜胺纳米粒的包封率

摘 要 目的：建立不同包载体系中丁硫酸亚砜胺（BSO）纳米粒包封率的测定方法。方法: 采用超速离心法分离不同包载体系BSO纳米粒中游离的BSO,以HPLC法检测纳米粒中BSO的包封率。色谱柱：WondaSil C₁₈柱（250 mm×4.6 mm,5 μm）,流动相：甲醇-水（20∶80）,流速：0.4 ml·min^-1,检测波长：210 nm,柱温：30°C,进样量：20 μl。 结果: BSO在2.0~320.0 μg·mL^-1浓度范围内具有良好的线性关系（r=0.999 7）,平均回收率为101.05%,RSD为0.74%（n=9）。HP/CaCO₃/CaHEPO₄/ BSO纳米粒中BSO平均包封率为25.63%,HP/PS/CaCO₃/BSO纳米囊泡中BSO平均包封率为58.62%。结论:该法重复性好、准确度高、灵敏度强,适用于BSO纳米粒中药物包封率的测定。HP/PS/CaCO₃/BSO纳米囊泡包载体系的包封率优于HP/CaCO₃/CaHEPO₄/ BSO纳米球包载体系。     

Curcumin Encapsulated Casein Nanoparticles: Enhanced Bioavailability and Anticancer Efficacy

The poor water solubility and bioactivity of drugs can be potentially improved by using suitable nanocarriers. Herein, an economically viable methodology is developed for encapsulation of hydrophobic anticancer agent, curcumin in casein nanoparticles (CasNPs). The successful encapsulation of curcumin was evident from the structural, thermal and spectroscopic analysis of curcumin encapsulated CasNPs (Cur-CasNPs). The CasNPs and Cur-CasNPs samples were lyophilized for their long-term stability and lyophilized powders are found to be stable for more than 6 months at 4–8 °C. From DLS studies, it has been observed that the variation in average size of drug formulations before and after reconstitution were less than 5%. Further, it shows good water-dispersibility, enhanced bioavailability and pH dependent charge conversal feature. Cur-CasNPs showed pH dependent release characteristics with higher at mild acidic environment and enhanced toxicity towards cancer cells (MCF-7) as compared to normal cells (CHO). Moreover, the CasNPs are non-toxic in nature and the developed nanoformulation of drug exhibits substantial cellular internalization and enhanced toxicity towards MCF-7 cells over pure drug, indicating their potential applications.