纳米脂质体研究新进展

纳米脂质体具有许多优点,在药学领域有着广泛的应用.本文综述了纳米脂质体的制备方法、质量控制和应用等方面的研究新进展,并对前景进行了展望.     

槲皮素及其纳米脂质体在Caco-2细胞的吸收特性研究

目的研究黄酮类化合物槲皮素及其纳米脂质体在Caco-2单层细胞模型中的吸收特性,探讨其纳米脂质体促进槲皮素吸收的作用及机制。方法采用乳化蒸发-低温固化法,制备槲皮素纳米脂质体;采用高效液相色谱法和酶标仪分别测定Caco-2细胞对槲皮素原料、槲皮素普通脂质体和槲皮素纳米脂质体的吸收。结果 Caco-2细胞对槲皮素纳米脂质体的吸收效果较佳,槲皮素原料和槲皮素普通脂质体吸收量均随着槲皮素浓度的增加而呈线性关系,而槲皮素纳米脂质体非呈线性关系。结论槲皮素制备成为纳米脂质体能促进槲皮素在Caco-2细胞模型中的吸收。槲皮素原料和槲皮素普通脂质体在Caco-2细胞模型上的吸收为被动扩散,而槲皮素纳米脂质体为被动扩散和主动转运混合方式。     

槲皮素长循环纳米脂质体的制备与质量评价

目的 制备槲皮素长循环纳米脂质体,并进行质量评价.方法 采用乳化蒸发-低温固化法制备槲皮素长循环纳米脂质体;以形态、粒径、包封率和载药量等作为纳米脂质体质量评价指标.结果 采用乳化蒸发-低温固化法制备的槲皮素长循环纳米脂质体平均粒径为172.63 nm,包封率为85.90%,载药量为23.55%.结论 该试验制备的槲皮...     

阿霉素磁纳米脂质体的制备研究

目的采用超小超顺磁纳米粒(USPIOs)作为内部磁性物质,制备阿霉素磁纳米脂质体,并探讨如何得到高效磁包封和药物包封的阿霉素磁纳米脂质体。方法采用逆相蒸发法,以USPIOs为磁核,制备阿霉素磁纳米脂质体,以透射电镜观察到的形态、磁纳米脂质体的粒径、其中包裹的铁含量、药物包封率为指标,考察阿霉素磁纳米脂质体制备时最佳的脂质和磁纳米粒比例。结果当USPIOs用量为1 mg·m L-1时,磷脂用量在6.5 mg·m L-1时,可形成包裹较完全的磁纳米脂质体。得到的磁纳米脂质体粒径为274.3 nm,包裹的铁含量可达(51.43±2.69)%,药物包封率可达(63.38±15.29)%。在4℃条件下放置1个月以内,形态仍较稳定。结论阿霉素磁纳米脂质体的形成与脂质体浓度和磁纳米粒浓度有很大关系,通过摸索条件,可得到最佳磁纳米粒包封率和药物包封率的磁纳米脂质体,这为下一步阿霉素磁纳米脂质体的性质考察奠定基础。     

正交试验优选槲皮素纳米脂质体冻干粉制备工艺

目的制备含有不同冻干保护剂的槲皮素纳米脂质体(QUE-NL)冻干粉,筛选出最佳制备工艺。方法采用正交试验法,以纳米脂质体包封率和载药量等作为评价指标,采用多指标综合分析方法优选槲皮素纳米脂质体冻干粉冻干保护剂的最佳比例。结果槲皮素纳米脂质体冻干粉的最佳制备工艺为水∶油相比例为1.5∶1.0,冻干保护剂选用麦芽糖和甘露醇,5%甘露醇+5%麦芽糖(1∶1),以此制备工艺制得的纳米脂质体冻干粉包封率和载药量较为理想。结论以优选工艺制备槲皮素纳米脂质体冻干粉的方法简易、可行。     

人表皮活性因子柔性纳米脂质体的制备及相关性质研究

目的 制备人表皮活性因子（EGF）柔性纳米脂质体,并对其相关性质进行研究.方法 利用逆相蒸发-冷冻干燥法制备EGF柔性纳米脂质体,采用酶联免疫吸附法（ELISA）测定EGF的含量,电镜观察其形态,并考察其包封率或载药量、变形性及稳定性.结果 所制备的EGF柔性纳米脂质体为多室脂质体.其平均粒径为（81.62±3.67） nm,Zeta电位为（60.12±7.58） mV;平均包封率为（37.86±4.77）％;平均载药量为（6.58±1.27）％.证实了EGF柔性纳米脂质体具有高度的变形性;冻干的EGF柔性纳米脂质体具有较高的稳定性.结论 EGF柔性纳米脂质体的制备方法可行,含量测定方法简单、可靠,稳定性和变形性高,可能成为透皮转运的有效载体.     

盐霉素钠纳米脂质体的制备及表征

目的制备并表征盐霉素钠纳米脂质体(SLN)。方法采用薄膜分散法制备盐霉素钠纳米脂质体,通过调节脂质体中胆固醇比例,以盐霉素钠包封率为评价指标,筛选盐霉素钠纳米脂质体的优化处方。结果透射电镜显示盐霉素钠纳米脂质体形态圆整,分散性良好,激光粒度仪显示盐霉素钠纳米脂质体平均粒径为99.0nm,Zeta电位为-33.5mV,包封率为85.7%,载药量为6.7%。通过脂质体包裹,盐霉素钠在水中的最高浓度可提高15倍,并证明其具有一定缓释效果。结论笔者得到了粒径大小在100nm左右,形态均一,包封率和载药量较高的盐霉素钠纳米脂质体,为进一步测定其杀伤肿瘤活性奠定了坚实的制剂学基础。     

N-三甲基壳聚糖包覆司帕沙星纳米脂质体离体角膜滞留性及刺激性研究

摘 要 目的：对N-三甲基壳聚糖（TMC）包覆司帕沙星（SL）纳米脂质体的角膜滞留性及兔眼刺激性进行考察。方法: 采用悬挂泡技术和束缚泡技术,对TMC包覆SL纳米脂质体、SL纳米脂质体及SL滴眼液在兔离体眼球表面的接触角及解吸附动力学进行研究;以Draize评分法评价3种SL制剂多次给药后对兔眼的刺激性。结果: 离体角膜表面接触角的大小顺序为：SL滴眼液＞SL纳米脂质体＞TMC包覆SL纳米脂质体,与SL滴眼液相比,两种SL纳米脂质体的解吸时间明显延长,且以TMC包覆的SL纳米脂质体解析时间最长。3种SL制剂在多次给药后,对兔眼无明显的刺激性。结论:与普通滴眼液相比,SL纳米脂质体具有较好的角膜滞留性,TMC包覆后,滞留性进一步增强,并具有较好的安全性,值得进一步开发研究。     

羧甲基壳聚糖包衣尼莫地平纳米脂质体药效学研究

目的：研究羧甲基壳聚糖（CMC）包衣尼莫地平（NMD）纳米脂质体对小鼠脑缺氧及脑栓塞的影响。方法：采用亚硝酸钠所致小鼠脑缺氧实验以及诱导剂致小鼠脑栓塞实验,观察CMC包衣NMD纳米脂质体对小鼠脑缺氧及脑栓塞的影响,并与市售NMD注射液,普通NMD脂质体,CMC包衣NMD脂质体,NMD纳米脂质体进行比较。结果：CMC包衣NMD纳米脂质体能显著延长小鼠亚硝酸钠中毒后的存活时间,提高小鼠对抗脑栓塞的能力。结论：CMC包衣NMD纳米脂质体对小鼠脑缺氧以及脑栓塞有明显的预防保护作用。     

槲皮素纳米脂质体冻干粉针的制备及其质量评价

目的:研究槲皮素纳米脂质体冻干粉针的制备方法,并对其进行初步的质量评价。方法:以乳化蒸发-低温固化法和冷冻干燥法制备含有不同冻干保护剂的槲皮素纳米脂质体(QUE-NL)冻干粉,以包封率为评价指标,对制备工艺和处方进行单因素考察,并考察其理化性质,筛选出最佳配方。并对冻于粉针进行稳定性影响因素试验。结果:该法制得的脂质体包封率较佳;制备过程中,槲皮素纳米脂质体的包封率受药脂比影响较大,受胆固醇磷脂比影响较小;采用5%甘露醇+5%麦芽糖作为冻干保护剂冻干效果更好;所得冻于粉针对温度、光照较为敏感,也易受湿度影响。结论:5%甘露醇+5%麦芽糖是槲皮素纳米脂质体较合适的冻干保护剂,初步的稳定性考察结果表明,槲皮素纳米脂质体冻干粉针宜低温、避光、密封保存。以本试验方法制备的槲皮素纳米脂质体冻干粉粒径较小,包封率高,稳定性好,制备工艺合理可行。     

Influence of the insertion of a cationic peptide on the size and shape of nanoliposomes: A light scattering investigation

Nanoliposomes are widely used for drug delivery in the human body. Cell-penetrating peptides are amphiphilic peptides inserting in the lipid bilayer of these lipid vesicles to induce the fusion with target cells. Separation by size exclusion chromatography coupled with the analysis by light scattering detectors provides both the hydrodynamic radius and the radius of gyration of all the liposomes in a sample. In this paper, the influence of the insertion of a cationic peptide, K₂LA₁₂, on the size and shape of anionic liposomes has been studied by this approach. The results obtained highlighted an increase in size and a slight deformation of the lipid vesicles depending on the concentration of peptides incorporated into the lipid bilayers.     

Chitosan films incorporated with nettle (Urtica dioica L.) extract-loaded nanoliposomes: I. Physicochemical characterisation and antimicrobial properties

The objective of this study was to characterise and compare physical, mechanical and antimicrobial properties of chitosan-based films, containing free or nanoencapsulated nettle (Urtica dioica L.) extract (NE) at concentrations of 0, 0.5, 1 and 1.5% w/w. Nanoliposomes were prepared using soy-lecithin by thin-film hydration and sonication method to generate an average size of 107–136?nm with 70% encapsulation efficiency. The information on FT-IR reflected that some new interaction have occurred between chitosan and nanoliposomes. Despite the increasing yellowness and decreasing whiteness indexes, the nanoliposomes incorporation improved the thermal properties and mechanical stiffness and caused to decrease water vapour permeability (WVP), moisture uptake and water solubility. The possible antimicrobial activity of the films containing NE-loaded nanoliposomes against Staphylococcus aureus was decreased in comparison to free NE-incorporated films, which could be due to the inhibition effect of the encapsulation that prevents the release of NE from the matrix.     

Use of remote film loading methodology to entrap sirolimus into liposomes: preparation, characterization and in vivo efficacy for treatment of restenosis

The main objective of this study was to formulate an effective controlled-release liposomal drug delivery system for sirolimus (SIR), a potent antiproliferative and anti-inflammatory drug, to be used for the treatment of restenosis following local vascular delivery. Liposomes were prepared using remote film loading method and characterized with regard to entrapment efficiency (EE), size distribution and zeta potential. The effects of key formulation and proceeding variables on both EE and drug release were studied using a fractional factorial design. By means of this entrapment technique, 98% SIR incorporation was achieved. Nanoliposomes were found to have average size of 110 nm and zeta potential of -9 mV. Developed formulations were found to have prolonged drug release for up to 3 weeks in vitro; this was best fitted by the Higuchi model. Other scopes of this work were to determine the applicability of sirolimus-loaded nanoliposomes (SIR-L) as drug carriers for the treatment of restenosis and to evaluate the effect of the presence of rigid lipids on the in vivo efficacy of the liposomal carrier of SIR. In vivo studies in balloon injured rat carotid arteries revealed the potential of SIR-loaded liposomes as efficient local and controlled drug delivery systems to reduce restenosis.     

Influence of chitosan coating on the liposomal surface on physicochemical properties and the release profile of nanocarrier systems

Chitosan-coated nanoliposomes containing etofenprox or alpha-cypermethrin prepared by ultrasonic homogenization maintained a size distribution in the nanometre range. Nanoliposomes were constructed using different types and concentrations of chitosan to regulate the mean size and surface charge. As the chitosan concentration (0.1-0.5%, w/v) and the degree of deacetylation increased, surface charge also increased. The encapsulation efficiency and release profile were measured by gas chromatography. Encapsulation efficiency decreased slightly as chitosan concentration increased (0.1-0.5%, w/v). As the intrinsic surface charge or concentration of the coating material increased, the release period of the entrapped core material was extended (chitosans A and B; 0.1 and 0.3%, w/v). The results indicate that diverse preparation conditions could affect the physicochemical properties and release profile of the resulting nanocarrier systems.     

Influence of chitosan coating on the liposomal surface on physicochemical properties and the release profile of nanocarrier systems

Chitosan-coated nanoliposomes containing etofenprox or alpha-cypermethrin prepared by ultrasonic homogenization maintained a size distribution in the nanometre range. Nanoliposomes were constructed using different types and concentrations of chitosan to regulate the mean size and surface charge. As the chitosan concentration (0.1–0.5%, w/v) and the degree of deacetylation increased, surface charge also increased. The encapsulation efficiency and release profile were measured by gas chromatography. Encapsulation efficiency decreased slightly as chitosan concentration increased (0.1–0.5%, w/v). As the intrinsic surface charge or concentration of the coating material increased, the release period of the entrapped core material was extended (chitosans A and B; 0.1 and 0.3%, w/v). The results indicate that diverse preparation conditions could affect the physicochemical properties and release profile of the resulting nanocarrier systems.     

Effect of curcumin-associated and lipid ligand-functionalized nanoliposomes on aggregation of the Alzheimer's Aβ peptide

The effect of various types of nanoliposomes (associated with curcumin, phosphatidic acid, cardiolipin, or GM1 ganglioside) on the aggregation of the amyloid-β_1-42 (Aβ_1-42) peptide was investigated. Nanoliposomes incorporating curcumin (curcumin-liposomes) were prepared by adding curcumin in the lipid phase during liposome preparation, whereas curcumin surface-decorated liposomes were prepared by using a curcumin-lipid conjugate (lipid-S-curcumin liposomes) or by attaching a curcumin derivative on preformed liposomes by click chemistry (click-curcumin liposomes). The lipid ligands (phosphatidic acid, cardiolipin, or GM1) were also incorporated into nanoliposomes during their formation. All nanoliposomes with curcumin, or the curcumin derivative, were able to inhibit the formation of fibrillar and/or oligomeric Aβ in vitro. Of the three forms of curcumin liposomes tested, the click-curcumin type was by far the most effective. Liposomes with lipid ligands only inhibited Aβ fibril and oligomer formation at a very high ratio of liposome to peptide. Curcumin-based liposomes could be further developed as a novel treatment for Alzheimer's disease.

From the Clinical Editor

In this paper, the potential clinical applicability of curcumin-based nanpoarticles is investigated on the aggregation of amyloid-β1-42, a key protein in the pathogenesis of Alzheimer’s disease. Future extensions of this work may pave the way to a novel therapeutic approach to AD.     

Superiority of liquid crystalline cubic nanocarriers as hormonal transdermal vehicle: comparative human skin permeation-supported evidence

ABSTRACT

Objectives: The aim of this investigation was to explore the feasibility of various nanocarriers to enhance progesterone penetration via the human abdominal skin.

Methods: Four progesterone-loaded nanocarriers; cubosomes, nanoliposomes, nanoemulsions and nanomicelles were formulated and characterized regarding particle size, zeta potential, % drug encapsulation and in vitro release. Structural elucidation of each nanoplatform was performed using transmission electron microscopy. Ex vivo skin permeation, deposition ability and histopathological examination were evaluated using Franz diffusion cells.

Results: Each nanocarrier was fabricated with a negative surface, nanometric size (≤ 270 nm), narrow size distribution and reasonable encapsulation efficiency. In vitro progesterone release showed a sustained release pattern for 24 h following a non-Fickian transport diffusion mechanism. All nanocarriers exhibited higher transdermal flux relative to free progesterone. Cubosomes revealed a higher skin penetration with transdermal steady flux of 48.57.10^–2 ± 0.7 µg/cm² h. Nanoliposomes offered a higher percentage of skin progesterone deposition compared to other nanocarriers. Based on the histopathological examination, cubosomes and nanoliposomes were found to be biocompatible for transdermal application. Confocal laser scanning microscopy confirmed the ability of fluoro-labeled cubosomes to penetrate through the whole skin layers.

Conclusion: The elaborated cubosomes proved to be a promising non-invasive nanocarrier for transdermal hormonal delivery.     

Improving Intracellular Doxorubicin Delivery Through Nanoliposomes Equipped with Selective Tumor Cell Membrane Permeabilizing Short-Chain Sphingolipids

Purpose

To improve nanoliposomal-doxorubicin (DoxNL) delivery in tumor cells using liposome membrane-incorporated short-chain sphingolipids (SCS) with selective membrane-permeabilizing properties. DoxNL bilayers contained synthetic short-chain derivatives of known membrane microdomain-forming sphingolipids; C₈-glucosylceramide (C₈-GluCer), C₈-galactosylceramide (C₈-GalCer) or C₈-lactosylceramide (C₈-LacCer).

Methods

DoxNL enriched with C₈-GluCer or C₈-GalCer were developed, optimized and characterized with regard to size, stability and drug retention. In vitro cytotoxic activity was studied in a panel of human tumor cell lines and normal cells. Intracellular Dox delivery was measured by flow cytometry and visualized by fluorescence microscopy. For a further understanding of the involved drug delivery mechanism confocal microscopy studies addressed the cellular fate of the nanoliposomes, the SCS and Dox in living cells.

Results

C₈-LacCer-DoxNL aggregated upon Dox loading. In tumor cell lines SCS-DoxNL with C₈-GluCer or C₈-GalCer demonstrated strongly increased Dox delivery and cytotoxicity compared to standard DoxNL. Surprisingly, this effect was much less pronounced in normal cells. Nanoliposomes were not internalized, SCS however transfered from the nanoliposomal bilayer to the cell membrane and preceded cellular uptake and subsequent nuclear localization of Dox.

Conclusion

C₈-GluCer or C₈-GalCer incorporated in DoxNL selectively improved intracellular drug delivery upon transfer to tumor cell membranes by local enhancement of cell membrane permeability.     

Using liposomes to target infection and inflammation induced by foreign body injuries or medical implants

Importance of the field: Foreign body (FB) injuries occur under many circumstances: at work, when practising a hobby, in car accidents, or in violence-afflicted zones. Owing to the nature of these injuries, they are not restricted to a certain part of the body and may affect several organs simultaneously. In general, an FB will be surgically removed when it is a cause of pain or infection or when jeopardizing a critical biological function. However, in many cases removing the FB is not possible owing to risk of harming adjacent delicate tissue. Furthermore, often when surgically removing the FB, microscopic fragments or debris remain at the site of invasion, becoming a cause of pain and recurring infection and inflammation. FB-related complications can also originate from micro- or nanoparticles released by degradation of medical implants. The use of advanced drug delivery technologies to target the tissue surrounding the FB, or the FB itself, may be of therapeutic benefit. Liposomes, vesicles with an aqueous core entrapped in one or more lipid bilayers, are widely used as drug delivery systems. Previous studies show that nanoliposomes can effectively target infected and inflamed tissue. The working hypothesis of this paper is that nanoliposomes, of specific lipid composition, may be used to target FB under conditions of inflammation.

Areas covered in this review: A comprehensive literature review regarding the use of liposomes for targeting and treating infection and inflammation, as well as a prospective on conjugates that can improve FB targeting in vivo.

What the reader will gain: The article aims to assess whether nanoliposomes loaded with a therapeutic compound may be advantageous for treating FB-related pathologies.

Take home message: Nanoliposomes are promising candidates for targeting FB-induced infection and inflammation. Certain properties, related to the micro-anatomy and physiology of inflammation as well as to the liposome physicochemical properties, make possible ‘passive’ targeting of the FB region. Conjugating specific ligands to the surface of the liposomes can improve their efficacy by adding an element of ‘active’ targeting. Despite the great clinical need, the use of nano-based technologies to target and treat FB-induced infection, inflammation and pain has not been exploited yet. The use of drug-loaded nanoliposomes for this application seems to be most promising and should be evaluated with high priority.