粒径和MePEG相对分子质量对隐形纳米粒体外巨噬细胞吞噬和大鼠体内长循环的影响

目的考察粒径和单甲氧基聚乙二醇(methoxypolyethyleneglycol，MePEG)相对分子质量对重组人肿瘤坏死因子(recombinant human tumor necrosis factor-α，rHuTNF-α)隐形纳米粒体外巨噬细胞吞噬和大鼠体内长循环的影响。方法复乳法制备3种不同粒径(约为80，170和240 nm)和表面用3种不同相对分子质量MePEG(M_r为2 000，5 000和10 000)修饰的重组人肿瘤坏死因子聚乙二醇化聚十六烷基氰基丙烯酸酯［poly(methoxypolyethyleneglycol cyanoａcrylate-co-n-hexadecyl cyanoacrylate)，PEG-PHDCA］隐形纳米粒。进行不同纳米粒体外巨噬细胞吞噬和大鼠体内药代动力学试验，并加以比较。结果粒径相同时，随着MePEG相对分子质量的增加，巨噬细胞吞噬量减小，血浆半衰期延长；相同MePEG(M_r=5 000)修饰时，随着粒径的减小，巨噬细胞吞噬量减小，大鼠血浆半衰期延长。粒径和MePEG相对分子质量与隐形纳米粒体外巨噬细胞摄取和大鼠体内长循环性质间有良好的线性相关性。其中，PEG_{5 000}-PHDCA纳米粒(80.0 nm)体外减小巨噬细胞吞噬和大鼠体内长循环的能力最强。结论实验范围内，粒径和MePEG相对分子质量对重组人肿瘤坏死因子隐形纳米粒体外巨噬细胞吞噬和大鼠体内长循环有显著影响。     

维A酸隐形泡囊的制备及其体外性质的研究

目的 制备维A酸隐形泡囊并考察其理化、体外生物学性质.方法 考察隐形泡囊的形态和粒径分布,经凝胶色谱分离,再用分光光度法测定维A酸的含量,计算包封率,测定冻干品的载药量;以普通泡囊的结果作为对照,考察巨噬细胞摄取率和癌细胞生长抑制率.结果 维A酸泡囊和隐形泡囊的平均粒径分别为33、41 μm,包封率分别为91.4%、93.10%,载药量分别为3.15%、2.82%.隐形泡囊规避巨噬细胞的吞噬能力提高26%以上;隐形泡囊与原药对癌细胞的生长抑制率相同.结论 所制维A酸隐形泡囊的包封率高、操作方法简便;隐形泡囊既可保持较高抗癌活性,又能规避吞噬.     

聚乙二醇修饰对羟喜树碱隐形纳米囊泡的肿瘤靶向和抑瘤作用的影响

目的探讨聚乙二醇相对分子质量对载羟喜树碱(HCPT)的聚乙二醇化聚十六烷基氰基丙烯酸酯纳米囊泡(PEG-PHDCA)在S180肉瘤小鼠体内的肿瘤靶向性及抗肿瘤作用的影响。方法选用司盘60和PEG-PHDCA为载体材料,制备HCPT的PEG-PHDCA隐形纳米囊泡,进行S180肉瘤小鼠瘤内药动学试验和抑瘤试验。结果PEG相对分子质量为2 000、5 000、10 000的PEG-PHDCA纳米囊泡在S180肉瘤小鼠肿瘤中125I-HCPT的AUC分别为HCPT的9.21、13.82、9.48倍;对S180肉瘤小鼠抑瘤率分别为88%、97.1%、80.8%,普通纳米粒PHDCA组抑瘤率为41.8,而原药组抑瘤率仅为17.3%。结论PEG修饰纳米囊泡明显优于原药和未经PEG修饰纳米囊泡,PEG相对分子质量为5 000,粒径为80 nm左右时,载HCPT的隐形纳米囊泡具有最佳肿瘤靶向作用。     

肺靶向顺铂隐形泡囊的研制及其体外生物学性质

目的 研制具有肺部靶向作用的隐形泡囊并进行体外抗癌细胞的实验评价.方法 将亲水聚合物与胆固醇相连,考察含不同种类亲水链及含不同密度亲水链的隐形泡囊的包封率、稳定性和巨噬细胞吞噬作用,以最佳泡囊处方进行癌细胞生长抑制实验.结果 用PluronieF68合成的胆固醇结合物所制隐形泡囊的包封率和固有水化层厚度较高,粒径合适;当胆固醇/Chol-PluronicF68的重鼍比为1:2.52时,泡囊的包封率、稳定性和体外规避巨噬细胞摄取等均较好,并具有和顺铂相似的抑制癌细胞生长的作用,粒径平均为8.432±O.043μm,有71.30%以上在被动肺靶向要求的7-25μm范围内,抑制癌细胞生长的结果与原料药顺铂相同.结论 隐形泡囊制备简单,具有一定的隐形效果,能保持原药的抗癌活性,粒径范围符合被动肺靶向的要求.     

大豆多糖对S180荷瘤小鼠免疫调节作用的研究

目的 从免疫学角度探讨大豆多糖对荷瘤小鼠抗肿瘤作用的机制。方法 采用分光光度计测定大豆多糖对S₁₈₀荷瘤小鼠巨噬细胞一氧化氮生成量的影响,利用酶标仪测定大豆多糖对S₁₈₀荷瘤小鼠腹腔巨噬细胞吞噬功能的影响,定量溶血分光光度法检测B细胞功能。结果 与对照组比较,大豆多糖各组均能显著提高小鼠巨噬细胞的吞噬活性,同时能明显提高荷瘤小鼠巨噬细胞产生一氧化氮的能力,并能使体内B淋巴细胞数量增加而提高抗体生成量。结论 大豆多糖通过调节荷瘤小鼠免疫功能发挥抗肿瘤作用。     

大豆多糖对S180荷瘤小鼠免疫调节作用的研究

目的 从免疫学角度探讨大豆多糖对荷瘤小鼠抗肿瘤作用的机制。方法 采用分光光度计测定大豆多糖对S₁₈₀荷瘤小鼠巨噬细胞一氧化氮生成量的影响,利用酶标仪测定大豆多糖对S₁₈₀荷瘤小鼠腹腔巨噬细胞吞噬功能的影响,定量溶血分光光度法检测B细胞功能。结果 与对照组比较,大豆多糖各组均能显著提高小鼠巨噬细胞的吞噬活性,同时能明显提高荷瘤小鼠巨噬细胞产生一氧化氮的能力,并能使体内B淋巴细胞数量增加而提高抗体生成量。结论 大豆多糖通过调节荷瘤小鼠免疫功能发挥抗肿瘤作用。     

国产麦迪霉素的组分分离和鉴定

用柱层析法分离得到国产MDM的二个成分，其结构经波谱分析和其它理化性质的分析，证明是SF-837A₁和Leucomycin A₆，质谱结果表明，它们都含有碳霉氨基糖，碳霉糖和内酯环。     

包含四氧化三铁纳米粒的聚电解质微囊的制备

本文以生物相容性四氧化三铁纳米粒 (ferrosoferric oxide nanoparticles, Fe₃O₄ NPs) 及聚烯丙基胺盐酸盐 (poly allyamine hydrochloride, PAH) 为囊材, 制备包含Fe₃O₄ NPs的聚电解质微囊。本文采用化学共沉淀法制备Fe₃O₄ NPs, 并对其表观形态、红外光谱、粒径及zeta电位、成膜性能及磁学性质进行考察; 以Fe₃O₄ NPs和PAH作为囊材, 碳酸钙粒子为模板, 通过迭层自组装技术制备聚电解质微囊。结果得到粒径为 (4.9 ± 1.2) μm、分布均匀、饱和磁化强度为8.94 emu·g⁻¹、具有超顺磁性的聚电解质微囊。以罗丹明B异硫氰酸酯标记的牛血清白蛋白 (Rhodamin B isothiocyanate labeled bovine serum albumin, RBITC-BSA) 作为模型药物, 利用囊膜的pH敏感特性将其载入囊内。荧光显微镜观察和包封率测定结果表明, 该聚电解质微囊可成功实现大分子药物的包载, 测得包封率和载药量分别达到 (86.08 ± 3.36) %和 (8.01 ± 0.30) mg·mL⁻¹。     

聚合物囊泡的稳定性及H+透膜特性考察

目的 以嵌段聚合物制备聚合物囊泡并考察其稳定性，测定聚合物囊泡膜层的H⁺跨膜渗透特性，及1,4-二氧六环对膜渗透性能的影响，作为聚合物囊泡载药的基础。方法 以二嵌段共聚物PEG-PLGA在溶液中自组装制备聚合物囊泡，采用pH敏感荧光探针HPTS对囊泡的H⁺透膜特性进行考察，并与PBD-b-PEO、PS-b-PEO制备的囊泡及脂质体进行比较。考察不同浓度的1,4-二氧六环对聚合物囊泡膜渗透特性的作用。结果 HPTS的荧光激发光谱有pH依赖性，囊泡外水相中H⁺浓度与t^1/2呈线性相关，不同膜壁厚度的聚合物囊泡的膜渗透能力有显著区别。3种聚合物囊泡对比脂质体，H⁺透膜系数分别降低了2.39×10⁴ 、3.38×10⁴、5.48×10⁸倍。1,4-二氧六环对囊泡膜的渗透性具有调节作用，且存在浓度依赖关系。结论 聚合物囊泡的膜渗透显著低于脂质体，稳定性更好，1,4-二氧六环可调节囊泡膜的渗透性，从而调节药物的装载和释放。     

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。     

Stealth PEG-PHDCA niosomes: effects of chain length of PEG and particle size on niosomes surface properties, in vitro drug release, phagocytic uptake, in vivo pharmacokinetics and antitumor activity

A series of novel niosomes with the amphiphilic copolymer of poly (methoxy-polyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate) (PEG-PHDCA) acted as surface modification materials were prepared and Hydroxycamptothecin (HCPT) was used as a model drug. This work concentrated on the effects of PEG chain length and particle sizes on the niosomes surface properties, in vitro drug release, phagocytic uptake, in vivo pharmacokinetics and antitumor activity. Within the range of PEG Mw from 2000 to 10000, the increasing zeta potential (from -16.08 to -5.25 mv) and thicker fixed aqueous layer (3.82 to 5.78 nm) would facilitate the niosomes' stealth effects, while the reduced PEG chain density (from 0.53 to 0.17 PEG/nm2) and the quickened speed of drug release would diminish the effects. As a result, the PEG5000-PHDCA niosomes had the least phagocytic uptake, the longest half-life of 11.46 h and the best tumor inhibition rate of 97.1%. In the groups different in particle size (PEG5000-PHDCA niosomes from 92.5 to 204.6 nm), the bigger particles could be uptaken by macrophages more quickly, regardless of the changes of other physicochemical parameters. Correspondingly, PEG5000-PHDCA niosomes with particle sizes of 92.5, 144.2, 204.6 nm could extend the half-life of HCPT to 11.46, 6.33, 4.46 h, respectively. At last, the tumor inhibition rate of PEG5000-PHDCA niosomes (92.5 nm) at a dose of 2 mg/kg was five times that of HCPT injection at 4 mg/kg. The stealth effects of the PEG-PHDCA niosomes and the enhanced stability of lactone form of HCPT were accountable for the powerful antitumor effects of niosomes.     

In vivo tumor targeting of tumor necrosis factor-alpha-loaded stealth nanoparticles: effect of MePEG molecular weight and particle size.

The aim of this study is to reveal the influence of methoxypolyethyleneglycol (MePEG) molecular weight and particle size of stealth nanoparticles on their in vivo tumor targeting properties. Three sizes (80, 170 and 240nm) of poly methoxypolyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate (PEG-PHDCA) nanoparticles loading recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) were prepared at different MePEG molecular weights (MW=2000, 5000 and 10,000) using double emulsion method. The opsonization in mouse serum was evaluated by Coomassie brilliant blue staining of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Phagocytosis was evaluated by incubating (125)I-rHuTNF-alpha-loaded nanoparticles with mouse macrophages (RAW264.7). The pharmacokinetics, biodistribution and tumor targeting studies were performed in S-180 tumor-bearing mice. Higher MePEG molecular weight provided thicker fixed aqueous layer thickness (FALT) and smaller particle size offered higher surface MePEG density. The serum protein adsorption and phagocytic uptake were markedly decreased for the nanoparticles with higher MePEG molecular weight or smaller size. The particles (80nm) made of PEG(5000)-PHDCA, possessing a thicker FALT (5.16nm) and a shortest distance (0.87nm) between two neighboring MePEG chains, showed the strongest capacity of decreasing protein adsorption and phagocytic uptake. These particles extended the half-life of rHuTNF-alpha in S-180 tumor-bearing mice by 24-fold (from 28.2 min to 11.33 h), elevated the rHuTNF-alpha peak concentration in S-180 tumors by 2.85-fold and increased the area under the intratumoral rHuTNF-alpha concentration curve by 7.44-fold. The results of the present study showed PEG-PHDCA nanoparticles with higher MePEG molecular weight and smaller particle size could achieve higher in vivo tumor targeting efficiency.     

Body distribution and in situ evading of phagocytic uptake by macrophages of long-circulating poly （ethylene glycol） cyanoacrylate-co-nhexadecyl cyanoacrylate nanoparticles

AIM: To investigate the body distribution in mice of [14C]-labeled poly methoxyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate (PEG-PHDCA) nanoparticles and in situ evading of phagocytic uptake by mouse peritoneal macrophages. METHODS: PEG-PHDCA copolymers were synthesized by condensation of methoxypolyethylene glycol cyanoacetate with [14C]-hexadecyl-cyanoacetate. [14C]-nanoparticles were prepared using the nanoprecipitation/solvent diffusion method, while fluorescent nanoparticles were prepared by incorporating rhodamine B. In situ phagocytic uptake was evaluated by flow cytometry. Body distribution in mice was evaluated by determining radioactivity in tissues using a scintillation method. RESULTS: Phagocytic uptake by macrophages can be efficiently evaded by fluorescent PEG-PHDCA nanoparticles. After 48 h, 31% of the radioactivity of the stealth [14C]-PEG-PHDCA nanoparticles after iv injection was still found in blood, whereas non-stealth PHDCA nanoparticles were cleaned up from the bloodstream in a short time. The distribution of stealth PEG-PHDCA nanoparticles and non-stealth PHDCA nanoparticals in mice was poor in lung, kidney, and brain, and a little higher in hearts. Lymphatic accumulation was unusually high for both stealth and non-stealth nanoparticles, typical of lymphatic capture. The accumulation of stealth PEG-PHDCA nanoparticles in the spleen was 1.7 times as much as that of non-stealth PHDCA (P< 0.01). But the accumulation of stealth PEG-PHDCA nanoparticles in the liver was 0.8 times as much as that of non-stealth PHDCA (P< 0.05). CONCLUSION: PEGylation leads to long-circulation of nanoparticles in the bloodstream, and splenotropic accumulation opens up the potential for further development of spleen-targeted drug delivery.     

氟尿嘧啶隐形泡囊的制备及其体外性质的研究

目的制备氟尿嘧啶隐形泡囊并考察其理化性质和体外细胞毒性。方法用自制Plu-Chol,以改良注入法制备氟尿嘧啶隐形泡囊,考察泡囊的形态、粒径、电位、包封率和体外释放特性,通过MTT比色法比较泡囊与原药对Hela细胞的作用效应。结果氟尿嘧啶隐形泡囊在电镜下的外观为球形,平均粒径为904.87±0.45 nm,Zeta电位为-66.75 mV,包封率为30.93%±1.71%;体外释放符合Weibull distribution模型,且具有明显的缓释性(氟尿嘧啶隐形泡囊释药t1/2为游离氟尿嘧啶的3.75倍);细胞毒性试验表明泡囊对Hela细胞的杀伤作用明显优于原药(IC50降低了83.95%,P<0.01)。结论所制氟尿嘧啶隐形泡囊的操作简单,对肿瘤细胞的杀伤力显著强于原药。     

Characterization of niosomes prepared with various nonionic surfactants for paclitaxel oral delivery

Nonionic surfactant based vesicles (niosomes) are novel drug delivery systems formed from the self‐assembly of nonionic amphiphiles in aqueous media. In the present study niosomal formulations of Paclitaxel (PCT), an antineoplastic agent, were prepared using different surfactants (Tween 20, 60, Span 20, 40, 60, Brij 76, 78, 72) by film hydration method. PCT was successfully entrapped in all of the formulations with encapsulation efficiencies ranging between 12.1 ± 1.36% and 96.6 ± 0.482%. Z‐average sizes of the niosomes were between 229.3 and 588.2 nm. Depending on the addition of the negatively charged dicetyl phosphate to the formulations negative zeta potential values were obtained. High surface charges showed that niosomes can be suspended in water well and this is beneficial for their storage and administration. PCT released from niosomes by a diffusion controlled mechanism. The slow release observed from these formulations might be beneficial for reducing the toxic side effects of PCT. The niosome preparation method was found to be repeatable in terms of size distribution, zeta potential and % drug loading values. The efficiency of niosomes to protect PCT against gastrointestinal enzymes (trypsin, chymotrypsin, and pepsin) was also evaluated for PCT oral delivery. Among all formulations, gastrointestinal stability of PCT was well preserved with Span 40 niosomes. © 2009 Wiley‐Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 2049–2060, 2010     

Influence of size,surface coating and fine chemical composition on the in vitro reactivity and in vivo biodistribution of lipid nanocapsules versus lipid nanoemulsions in cancer models

Lipid nanocapsules (LNCs) and lipid nanoemulsions (LNEs) are biomimetic synthetic nanocarriers. Their in vitro and in vivo performance was evaluated as a function of their size (25, 50 and 100 nm) and the surface PEG chain length. Analysis methods included complement activation test, particle uptake in macrophage and HEK293(β3) cells and biodistribution studies with tumor-grafted mice by fluorescence imaging. A particular attention was paid to keep the concentration of each nanocarrier and to the amount of fluorescent dye in comparable conditions between the in vitro and in vivo studies. Under these conditions, no significant differences were found among the three tested particle sizes and the two nanocarrier types. Longer PEG chains on the LNE surface provided better stealth properties, whereas PEG modification on the LNC formulations inhibited the production of stable nanocarriers. Passive accumulation of LNCs and LNEs in different tumor types depended on the degree of tumor vascularization.From the Clinical EditorThis study of lipid nanocapsules and lipid nanoemulsions compares their vitro and in vivo performance as a function of size and surface PEG chain length, demonstrating no significant difference among the tested particle sizes. Longer PEG chains on the LNE surface provided better stealth properties, whereas PEG modification on the LNC formulations inhibited the production of stable nanocarriers.     

Determination of the Thickness of the Fixed Aqueous Layer Around Polyethyleneglycol-coated Liposomes

Abstract

The zeta potentials of adriamycin-encapsulating liposomes containing 1-(monomethoxy polyethyl-eneglycol)-2,3-dimyristoylglycerol (PEG-DMG) were measured in an isotonic solution of 10mM lactate buffer (pH 4.0) with sodium chloride and sucrose. The negativity of the zeta potentials of adriamycin-encapsulating liposomes containing PEG-DMG decreased with increases in NaCl concentration more steeply than that of adriamycin-encapsulating liposomes without PEG coating. From this observation, the electrical potential distributions near the membrane surfaces were shown to be different between adriamycin-encapsulating liposomes with and without PEG coating. Based on these zeta potential data, the thickness of the fixed aqueous layer around PEG-DMG-containing adriamycin liposomes was determined from the slope of In zeta potential versus Debye-Hiickel parameter plot. As a result, a correlation was indicated to exist between the circulation time of liposomes and the thickness of the aqueous layer around the liposomes.     

Physicochemical properties and skin permeation of Span 60/Tween 60 niosomes of ellagic acid

Ellagic acid (EA) is a potent antioxidant phytochemical substance which has limitation to use due to its poor biopharmaceutical properties, low solubility and low permeability. The aim of the present study was to develop niosomal formulations obtained from the mixture of Span 60 and Tween 60 that could encapsulate EA for dermal delivery. The EA-loaded niosomes were prepared with 1:0, 2:1, 1:1, 0:1 Span 60 and Tween 60, using polyethylene glycol 400 (PEG 400), propylene glycol (PG) or methanol (MeOH) as a solubilizer. The influence of formulations on vesicle size, entrapment efficiency and stability of EA-loaded niosomes was investigated. It was found that all ratios of surfactants could produce EA-loaded niosomes when using 15% (v/v) PG, 15% (v/v) PEG 400 or 20% (v/v) MeOH. The niosomes were spherical multilamellar vesicles showing the localization of EA in the vesicles. The vesicle sizes of the niosomes after extrusion were 124-752 nm with PI less than 0.4. The percentages of entrapment efficiency (% E.E.) of all EA-loaded niosomes varied between 1.35% and 26.75% while PEG 400 niosomes gave the highest % E.E. The most stable and highest entrapped formulation was 2:1 Span 60 and Tween 60 niosomes. Additionally, the in vitro skin permeation revealed that penetration of EA from the niosomes depended on vesicle size, the amount of EA entrapped and the added solubilizers which could act as a permeation enhancer. From skin distribution study, the EA-loaded niosomes showed more efficiency in the delivery of EA through human epidermis and dermis than EA solution. The results indicated that the Span 60 and Tween 60 niosomes may be a potential carrier for dermal delivery of EA.