脂质体肺部给药系统的应用

介绍脂质体作为肺部给药载体的优点及其在抗感染药物、抗哮喘药物、抗肿瘤药物、多肽蛋白类药物、基因药物及抗氧剂的应用。     

Lactose-Conjugated PLGA Nanoparticles for Enhanced Delivery of Rifampicin to the Lung for Effective Treatment of Pulmonary Tuberculosis

Lactose conjugated poly(lactic co-glycolic acid) nanoparticles (L-PLGA-NPs) were investigated for lung delivery of rifampicin for effective treatment of pulmonary tuberculosis. Lactose-PLGA conjugate was synthesized using lactose and PLGA and characterized by infrared spectroscopy. L-PLGA-NPs were prepared by the solvent displacement method. NPs were characterized for shape, particle size, zeta potential, and percent drug entrapment. The size of NPs was found to be in the range 121-184 nm and maximum drug payload was found to be 38.4-42.2%. Average size and drug payload was found to be greater in the case of L-PLGA-NPs as compared to unconjugated NPs. The results of the in vitro release profile, which was determined using the dialysis technique, demonstrated that noncoupled NPs release a comparatively higher percent of drug than lactose coupled NPs. Fluorescence studies revealed the enhanced uptake of L-PLGA-NPs in the lung tissue when compared with unmodified PLGA NPs. Intravenous administration of free drug solution resulted in a high concentration of drug in serum while it was much less in the case of PLGA NPs. Coupling of the NPs with lactose significantly enhanced the lung uptake of drug, which is reflected in the recovery of a higher percentage of dose from the lungs as compared to that recovered in the case of uncoupled drug-loaded NPs and plain drug solution.     

The Development and Mechanism Studies of Cationic Chitosan-Modified Biodegradable PLGA Nanoparticles for Efficient siRNA Drug Delivery

Purpose  

In order to improve siRNA delivery for possible clinical applications, we developed biodegradable chitosan-modified poly(D,L-lactide-co-glycolide) (CHT-PLGA) nanoparticles with positive surface charge, high siRNA loading, high transfection efficiency and low toxicity.     

Design of Nanosuspensions and Freeze-Dried PLGA Nanoparticles as a Novel Approach for Ophthalmic Delivery of Pranoprofen

Pranoprofen (PF)-loaded poly (lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) were optimized and characterized as a means of exploring novel formulations to improve the biopharmaceutical profile of this drug. These systems were prepared using the solvent displacement technique, with polyvinyl alcohol (PVA) as a stabilizer. A factorial design was applied to study the influence of several factors (the pH of the aqueous phase and the stabilizer, polymer and drug concentrations) on the physicochemical properties of the NPs. After optimization, the study was performed at two different aqueous phase pH values (4.50 and 5.50), two concentrations of PF (1.00 and 1.50 mg/mL), three of PVA (5, 10, and 25 mg/mL), and two of PLGA (9.00 and 9.50 mg/mL). These conditions produced NPs of a size appropriate particle size for ocular administration (around 350 nm) and high entrapment efficiency (80%). To improve their stability, the optimized NPs were lyophilized. X-ray, FTIR, and differential scanning calorimetry analysis confirmed the drug was dispersed inside the particles. The release profiles of PF from the primary nanosuspensions and rehydrated freeze-dried NPs were similar and exhibited a sustained drug delivery pattern. The ocular tolerance was assessed by an HET-CAM test. No signs of ocular irritancy were detected (score 0). © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3153–3164, 2014     

壳寡糖-水杨酸接枝物纳米粒用于释放阿霉素的研究

目的 考察壳寡糖/水杨酸纳米粒负载碱化阿霉素的可能性,评价制备而得的微粒给药系统理化性质及其体外释放行为。方法 以碳二亚胺为交联偶合剂合成壳寡糖/水杨酸接枝共聚物,三硝基苯磺酸法测定水杨酸接枝率。运用超声分散法制备壳寡糖/水杨酸空白纳米粒,芘荧光法测定纳米粒临界聚集浓度,动态光散射法测定微粒粒径和表面电位,MTT法考察空白纳米粒的细胞毒性。以碱化阿霉素为模型药物,透析法制备壳寡糖/水杨酸载药纳米粒,经透射电镜考察载药纳米粒的形态,对其体外释放行为进行了研究。结果 合成得到的壳寡糖分子量=9000/水杨酸理论投料量=50%的实际接枝率为16.92%,空白纳米粒的临界聚集浓度为867.0 μg/mL,空白纳米粒的粒径和表面Zeta电位分别为434.0 nm和48.6 mV,对人肝癌细胞Hep-G2的半数抑制浓度为1745μg/mL。在碱化阿霉素理论投药量为10%时壳寡糖/水杨酸载药纳米粒的实际载药量为8.52%,包封率为93.15%。;载药纳米粒的粒径和表面电位分别为214.2 nm和33.6 mV。体外释放结果表明药物的释放呈现pH敏感性;并主要以溶蚀的方式从载体内部释放出来。结论 壳寡糖/水杨酸接枝物可以有效包裹碱化阿霉素并成为粒径均一的纳米粒给药系统。载药纳米粒具有pH敏感和缓释作用。壳寡糖/水杨酸接枝物有望成为潜在的难溶性药物的载体材料。     

Sustained Cytoplasmic Delivery and Anti-viral Effect of PLGA Nanoparticles Carrying a Nucleic Acid-Hydrolyzing Monoclonal Antibody

Purpose  

Cytoplasmic delivery of a monoclonal antibody (mAb) with nucleic acid-hydrolyzing activity (3D8 scFv) using poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) was investigated for persistent anti-viral effect.     

脂质体药物传输系统的研究进展

概述脂质体药物传输系统的发展与基本特点，重点综述了这一给药系统中的主动载药、立体稳定脂质体、阳离子脂质体、脂质体的主动释药等研究新进展。在新型药物传输系统中，脂质体是一种最有希望的、广泛适用的、已被深入研究的给药系统。     

口服载药纳米粒的研究进展

综述近年来口服载药纳米粒的有关研究进展，着重从制备方法、表面修饰、药物释放及应用几个方面进行介绍。作为一种新型给药系统，纳米粒在口服给药方面具有广阔的开发及应用前景。     

Sphingosine-Based Liposome as DNA Vector for Intramuscular Gene Delivery

Purpose. The aim of this study was to develop a labile sphingosine-based liposome for intramuscular gene delivery. Methods. Sphingosine-based liposomes were formulated in a range of solutions with phosphatidylcholine, then were associated to DNA. The physico-chemical characteristics of the sphingosine/EPC liposomes and sphingosine/EPC/DNA lipoplexes were determined. DNA stability within sphingosine-based liposomes was evaluated in the presence of a nuclease and mouse serum. In vivo gene transfer was studied by intramuscular injection with and without the electrotransfer technique. Results. By increasing the charge ratios, colloidally stable sphingosine/DNA particles with a 170 nm average diameter and a positive potential were obtained. Ethidium bromide was still able to insert into plasmid DNA within the lipoplexes, even though plasmid DNA was demonstrated to be complexed to the lipid by gel electrophoresis. Additionally, DNA was shown to be accessible to DNase I, but significantly resistant to serum enzymatic digestion. Upon intramuscular injection, lipoplexes induced an inhibition of gene expression as compared with naked DNA. Conclusions. The cationic sphingosine/EPC/DNA complexes form weakly compacted structure, potentially labile in vivo, which might be useful for in vivo gene transfer.     

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.     

Lipid-based Nanoparticles for Nucleic Acid Delivery

Abstract Lipid-based colloidal particles have been extensively studied as systemic gene delivery carriers. The topic that we would like to emphasize is the formulation/assembly of lipid-based nanoparticles (NP) with diameter under 100 nm for delivering nucleic acid in vivo. NP are different from cationic lipid–nucleic acid complexes (lipoplexes) and are vesicles composed of lipids and encapsulated nucleic acids with a diameter less than 100 nm. The diameter of the NP is an important attribute to enable NP to overcome the various in vivo barriers for systemic gene delivery such as: the blood components, reticuloendothelial system (RES) uptake, tumor access, extracellular matrix components, and intracellular barriers. The major formulation factors that impact the diameter and encapsulation efficiency of DNA-containing NP include the lipid composition, nucleic acid to lipid ratio and formulation method. The particle assembly step is a critical one to make NP suitable for in vivo gene delivery. NP are often prepared using a dialysis method either from an aqueous-detergent or aqueous-organic solvent mixture. The resulting particles have diameters about 100 nm and nucleic acid encapsulation ratios are >80%. Additional components can then be added to the particle after it is formed. This ordered assembly strategy enables one to optimize the particle physico-chemical attributes to devise a biocompatible particle with increased gene transfer efficacy in vivo. The components included in the sequentially assembled NP include: poly(ethylene glycol) (PEG)-shielding to improve the particle pharmacokinetic behavior, a targeting ligand to facilitate the particle–cell recognition and in some case a bioresponsive lipid or pH-triggered polymer to enhance nucleic acid release and intracellular trafficking. A number of groups have observed that a PEG-shielded NP is a robust and modestly effective system for systemic gene or small interfering RNA (siRNA) delivery.     

Mucoadhesive Hybrid Polymer/Liposome Pastes Based on Modified Polysaccharides

Mucoadhesive hybrid polymer/liposome paste is a new drug delivery system presenting controllable and tailorable delivery mechanism. By using mucoadhesive material, the delivery can be more specific and local. Here, we present a study investigating the effect of polymer type, concentration, functional end group, and cross-linking on the release profile of nanoliposomes from polymer pastes. Polymer pastes can be expected to combine the mucoadhesion mechanisms of dry and wet dosage forms but have not been studied extensively. To better understand the mucoadhesion of pastes, we investigated a series of pastes based on the same polymer and used different chemical modifications that can produce interactions at different levels. Native and thiolated polymers presented enhanced mucoadhesion in a wet environment in comparison to acrylated polymers which dissolved rapidly because of the enhanced solubility of PEG chains in water. Paste cross-linking resulted in a sustained release profile compared to non–cross-linked pastes. Pectin-SH pastes, especially 3% (w/v), showed a linear liposomal release profile which is ascribed to the combination of ionic cross-linking and disulfide bridging. By configuring the polymer type or concentration, we can control the release mechanisms and achieve distinct inherent properties which can be applied for diverse medical applications.     

Heparin Immobilized Porous PLGA Microspheres for Angiogenic Growth Factor Delivery

Purpose Heparin immobilized porous poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres were prepared for sustained release of basic fibroblast growth factor (bFGF) to induce angiogenesis.Materials and Methods Porous PLGA microspheres having primary amine groups on the surface were prepared using an oil-in-water (O/W) single emulsion method using Pluronic F-127 as an extractable porogen. Heparin was surface immobilized via covalent conjugation. bFGF was loaded into the heparin functionalized (PLGA-heparin) microspheres by a simple dipping method. The bFGF loaded PLGA-heparin microspheres were tested for in vitro release and in vivo angiogenic activity.Results PLGA microspheres with an open-porous structure were formed. The amount of conjugated amine group onto the microspheres was 1.93 ± 0.01 nmol/mg-microspheres, while the amount of heparin was 95.8 pmol/mg-microspheres. PLGA-heparin microspheres released out bFGF in a more sustained manner with a smaller extent of initial burst than PLGA microspheres, indicating that surface immobilized heparin controlled the release rate of bFGF. Subcutaneous implantation of bFGF loaded PLGA-heparin microspheres in mice significantly induced the formation of new vascular microvessels.Conclusions PLGA microspheres with an open porous structure allowed significant amount of heparin immobilization and bFGF loading. bFGF loaded PLGA-HP microspheres showed sustained release profiles of bFGF in vitro, demonstrating reversible and specific binding of bFGF to immobilized heparin. They also induced local angiogenesis in vivo in an animal model.     

脂蟾毒配基-乳酸羟基乙酸共聚物纳米粒的制备与表征

目的:制备、表征脂蟾毒配基-乳酸羟基乙酸共聚物纳米粒(RPN)。方法:用乳酸羟基乙酸共聚物为载体材料,采用超声乳化-溶剂挥发法制备RPN,以粒径、载药量、包封率和体外释放度表征其质量。用反相-高效液相色谱法测定RPN含量和体外释放度,色谱柱为HYPERSILC18(250 mm×4.6 mm,5μm),流动相为甲醇-0.05%冰醋酸水溶液(9∶1,V/V),检测波长为298 nm。结果:RPN的平均粒径为(232.3±2.3)nm,载药量为(18.3±0.3)%,包封率为(72.3±1.2)%,体外药物呈两相释放。结论:RPN载药量较高,体外释放试验显示具有明显的缓释作用。     

载塞来昔布-聚乳酸/羟基乙酸共聚物纳米粒的制备及表征

目的:制备载塞来昔布-聚乳酸/羟基乙酸共聚物(PLGA)纳米粒,并对其进行表征。方法:采用乳化-溶剂蒸发法制备塞来昔布-PLGA纳米粒,以包封率、粒径为指标,首选Plackett-Burman试验设计筛选出对纳米粒性质影响显著的处方和工艺变量,然后对筛选出的变量(PLGA质量分数、超声功率、超声时间)应用Box-Behnken效应面法进一步优化,并进行验证。采用粒度分析仪测定最优处方工艺所制纳米粒的粒径分布和Zeta电位,采用透射电镜考察其形态,并考察纳米粒的体外释药行为和稳定性(25、5℃)。结果:最优处方工艺为PLGA质量分数30.0%、超声功率180 W、超声时间8 min;所制纳米粒的包封率和粒径分别为(85.7±4.1)%、(226.1±36.1)nm(n=3),粒径分布为(176.2±41.2)nm,多分散系数为0.211±0.021,Zeta电位为(-37.3±1.6)m V;电镜下微乳粒径均一,呈球状或椭圆形,24 h累积释放度为52.4%;纳米粒在5℃条件下放置3个月内稳定。结论:成功制得塞来昔布-PLGA纳米粒。     

Ternary Polymeric Nanoparticles for Oral siRNA Delivery

Purpose

Poor stability and inefficient absorption in the intestinal tract are major barriers confronting oral delivery of siRNA. We aimed to uncover if ternary polymeric nanoparticles (cationic polymer/siRNA/anionic component) can overcome these obstacles through changing the formulation-related parameters.

Methods

Ternary polymeric nanoparticles were prepared by ionic gelation of chitosan, N-trimethyl chitosan (TMC), or thiolated trimethyl chitosan (TTMC) with tripolyphosphate (TPP) or hyaluronic acid (HA), and siRNA was simultaneously encapsulated. Structural stabilities and siRNA protection of these nanoparticles were assessed in simulated intestinal milieu. Their transport across ex vivo rat ileum, macrophage uptake, in vitro gene silencing, and in vivo biodistribution after oral administration were investigated.

Results

Ternary polymeric nanoparticles formed by TTMC, siRNA, and TPP (TTMC/siRNA/TPP nanoparticles) showed suitable structural stability and siRNA protection in the intestinal tract, good permeability across ex vivo rat ileum, superior cellular uptake and gene silencing efficiency in Raw 264.7 cells, and high systemic biodistribution after oral administration.

Conclusions

TTMC/siRNA/TPP nanoparticles demonstrated efficient gene silencing in vitro and systemic biodistribution in vivo, therefore, they were expected to be potential vehicles for oral siRNA delivery.     

壳聚糖载药纳米粒研究进展

目的介绍壳聚糖载药纳米粒近年来的研究进展。方法总结壳聚糖纳米粒的制备方法、释药特性、生物摄取及其应用。结果不同的制备方法可得到不同粒径和表面特性的壳聚糖纳米粒。壳聚糖纳米粒改变了壳聚糖的摄取机制，广泛应用于药物的器官靶向、DNA转染效率提高、药物的非注射途释给药等方面。结论壳聚糖纳米粒作为一种新型的药物载体，具有重要的研究开发价值。     

纳米粒作为肽类和蛋白质类药物的载体

用纳米粒作为肽类和蛋白质药物的载体可以有效地克服肽类和蛋白质类药物在体内稳定性差、吸收不佳、半衰期短等缺陷，从而显著地增强疗效。本文从制备方法、体内吸收、药效学等三方面对近年来这一领域的研究进展进行综述，并介绍了最新的研究动向。     

多肽修饰脂质体靶向药物递送系统研究进展

目的介绍近年来多肽修饰脂质体靶向药物递送系统的研究进展。方法查阅和归纳总结近几年相关文献。结果阐述了精氨酸-甘氨酸-天冬氨酸（RGD）多肽、丙氨酸-脯氨酸-精氨酸-脯氨酸-甘氨酸（APRPG）多肽、细胞穿透肽（CPP）、血管活性肠肽（VIP）等修饰脂质体的研究进展。多肽修饰的包载药物的脂质体可以增加药物在体内的选择性,减少药物毒副作用,提高药物治疗指数。结论多肽分子是机体内一类重要的生物活性物质,将其作为导向物以配体-受体特异性结合的方式应用于靶向药物递送系统,具有良好的研究价值和应用前景。     

Intracellular Delivery of Saquinavir in Biodegradable Polymeric Nanoparticles for HIV/AIDS

Purpose This study aims at developing poly(ethylene oxide)-modified poly(epsilon-caprolactone) (PEO-PCL) nanoparticulate system as an intracellular delivery vehicle for saquinavir, an anti-HIV protease inhibitor.Materials and Methods Saquinavir-loaded PEO-PCL nanoparticles were prepared by a solvent displacement process. The formed nanoparticles were characterized for size, surface charge, and surface presence of PEO chains. Cellular uptake and distribution of the nanoparticle was examined in THP-1 human monocyte/macrophage (Mo/Mac) cell line. Intracellular saquinavir concentrations were measured as a function of dose and duration of incubation.Results The PEO-PCL nanoparticles had a smooth surface and spherical shape and showed a relatively uniform size distribution with a mean particle diameter of approximately 200 nm. The surface presence of PEO chains was confirmed by an increase in the –C–O–(ether) signature of the C1s spectra in electron spectroscopy for chemical analysis. Rapid cellular uptake of rhodamine-123 encapsulated PEO-PCL nanoparticles was observed in THP-1 cells. Intracellular saquinavir concentrations when administered in the nanoparticle formulation were significantly higher than from aqueous solution.Conclusions This study shows that PEO-PCL nanoparticles provide a versatile platform for encapsulation of saquinavir and subsequent intracellular delivery in Mo/Mac cells.