Spray freeze drying for dry powder inhalation of nanoparticles

Formulating nanoparticles for delivery to the deep lung is complex and many techniques fail in terms of nanoparticle stability. Spray freeze drying (SFD) is suggested here for the production of inhalable nanocomposite microcarriers (NCM). Different nanostructures were prepared and characterized including polymeric and lipid nanoparticles. Nanoparticle suspensions were co-sprayed with a suitable cryoprotectant into a cooled, stainless steel spray tower, followed by freeze drying to form a dry powder while equivalent compositions were spray dried (SD) as controls. SFD-NCM possess larger specific surface areas (67–77 m²/g) and lower densities (0.02 g/cm³) than their corresponding SD-NCM. With the exception of NCM of lipid based nanocarriers, SFD produced NCM with a mass median aerodynamic diameter (MMAD) of 3.0 ± 0.5 μm and fine particle fraction (FPF ⩽ 5.2 μm) of 45 ± 1.6% with aerodynamic performances similar to SD-NCM. However, SFD was superior to SD in terms of maintaining the particle size of all the investigated polymeric and lipid nanocarriers following reconstitution (S_f/S_i ratio for SFD ≈ 1 versus >1.5 for SD). The SFD into cooled air proved to be an efficient technique to prepare NCM for pulmonary delivery while maintaining the stability of the nanoparticles.     

铈纳米颗粒在辐射领域的研究进展

随着核技术在工业，医学领域等方面应用的迅速发展，人们遭受辐射损伤的可能性也随之增加。辐射损伤防治药物是救治与防护辐射损伤最为有效和直接的手段，但目前的辐射损伤防治药物作用效果有限。铈纳米材料因独特的价态结构，使其具有多种酶学模拟活性和可再生性，体现出优越的抗氧化性，强大的清除自由基功能，可以保护细胞免受辐射损伤，可作为理想的辐射防护剂，并应用于多种生物学领域。对相关文献进行查阅可知，铈纳米颗粒的抗氧化性、高SOD模拟活性、清除自由基能力以及抗辐射能力均源自于Ce³⁺/Ce⁴+相互间的转化、氧空位的形成。本文主要介绍铈纳米颗粒的抗辐射活性基础、辐射防护效应及放疗增敏方面的研究进展，为铈纳米颗粒在辐射方向领域提供理论依据与参考。     

Antifouling paint formulations with ZnO and Fe2O3 nano-paints for marine applications

The specific objective of the work is to develop antifouling paint formulations for coating marine vessels and structures using nanoparticles as functional additives. The Preparation of nano paints was undertaken by embedding the ZnO and Fe₂O₃ nanoparticles in linseed alkyd resin and mixing them with soya lecithin, mineral turpentine oil, and also thickener was also added. By using these various nano paints formulations, fouling properties was reduced with increased anti-bacterial properties based on which the coatings were examined for their corrosion properties. The development of antifouling paints with nanoparticles as biocides is expected to significantly improve the efficacy of antifouling paints.The results obtained suggest that with an increase in the concentration of nanoparticles, there was an improvement in the antifouling and anti-corrosion. It was also observed that the mild steel specimens were coated with antifouling paint formulations when immersed in the seawater for 120 days for testing and the properties were observed by utilizing Scanning electron microscopy, SEM - EDX, X-ray beam Diffraction, and Fourier transform infrared spectroscopy. It found an improvement in anti-fouling showed by Fe₂O₃ coated specimens and an improvement utilizing ZnO when contrasted with bare paint.     

Application of nanoparticle technology in the treatment of Systemic lupus erythematous

Systemic lupus erythematous (SLE) is a chronic heterogeneous multisystem autoimmune disease characterized by loss of tolerance to self-antigens and production of numerous autoantibodies. Current therapeutic approaches used to treat inflammatory autoimmune diseases are associated with debilitating side effects. In spite of significant advances in therapeutic options and increased understanding of the pathogenesis, novel therapeutic approaches are needed for treatment of SLE. Nanoparticle-based delivery systems that selectively deliver drugs to inflamed tissue or specific cell have the potential to improve drug delivery. This article reviews recent nanotechnology-based therapeutics strategies that are being developed for the treatment of SLE.     

外泌体的生物学特征及其作为靶向药物载体在恶性肿 瘤的应用

肿瘤治疗过程中会出现很多严重的不良反应，如何将药物特异性导向癌细胞就成为了肿瘤治疗中亟需解决的问 题。外泌体是由细胞分泌的、纳米级别的、双层脂质的盘状囊泡结构。正常细胞与肿瘤细胞均可分泌外泌体，供体细胞分泌的 外泌体携带着蛋白质、脂质和核糖核酸（包括microRNA和lncRNA），可直接被同组织内其周围的受体细胞所吸收；同时外泌体 几乎存在于唾液、血液、尿液、脑脊髓液等所有体液中，通过体液运输被不同组织内受体细胞所吸收，为受体细胞的生长提供必 要的营养物质。肿瘤细胞中往往可对外释放出高于正常组织的外泌体，在肿瘤发展过程中外泌体对肿瘤的生长、转移和血管 生成起到重要的作用；同时癌细胞所分泌的外泌体中有着可用来区别与其他细胞外泌体不同的特征性分子，可作为肿瘤临床 诊断的分子标志物，也可作为肿瘤分级、精准治疗及预后评估的重要依据。鉴于此，本文收集国外内相关研究资料，对外泌体 的生物学特征进行总结，并综述了其在临床肿瘤诊断、治疗中的作用及应用潜力，并对外泌体进一步的发展方向进行展望，以 期能为外泌体在临床肿瘤精准治疗中的应用提供理论支持。     

Comparative study of mucoadhesive and mucus-penetrative nanoparticles based on phospholipid complex to overcome the mucus barrier for inhaled delivery of baicalein

Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein–phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced in vitro cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.     

Influencing factors and strategies of enhancing nanoparticles into tumors in vivo

The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.     

纳米石墨碳对人L-02细胞系生长状况的影响

目的研究纳米石墨碳对人正常肝细胞系L-02生长状况的影响。方法电子显微镜观察纳米石墨碳颗粒的形态,激光粒度分析仪测定其粒径及Zeta电位;流式细胞术检测纳米石墨碳作用24 h对L-02肝细胞生长周期的影响;电镜观察细胞剖面,用以考察纳米石墨碳颗粒对L-02肝细胞亚显微结构的影响。结果电镜下纳米石墨碳颗粒呈微小球形,粒径在20～50 nm,表面带负电荷,电位值为-14.8 mV;流式细胞检测结果示实验组L-02肝细胞G0/G1细胞百分数低于对照组,G2/M细胞百分数高于对照组,S期细胞百分数高于对照组;电镜观察纳米石墨碳在细胞质和细胞核内均有分布,实验组肝细胞内的线粒体与对照组无明显差异,胞膜核膜均完整。结论纳米石墨碳颗粒促进了L-02肝细胞的增殖,纳米石墨碳颗粒可以很好地进入到L-02肝细胞内部,未见其对细胞亚显微结构造成损伤。     

Oxidative stress and DNA damage responses in rat and mouse lung to inhaled carbon nanoparticles

Abstract

We have investigated whether short-term nose-only inhalation exposure to electric spark discharge-generated carbon nanoparticles (～60 nm) causes oxidative stress and DNA damage responses in the lungs of rats (152 μg/m³; 4 h) and mice (142 μg/m³; 4 h, or three times 4 h). In both species, no pulmonary inflammation and toxicity were detected by bronchoalveolar lavage or mRNA expression analyses. Oxidative DNA damage (measured by fpg-comet assay), was also not increased in mouse whole lung tissue or isolated lung epithelial cells from rat. In addition, the mRNA expressions of the DNA base excision repair genes OGG1, DNA Polβ and XRCC1 were not altered. However, in the lung epithelial cells isolated from the nanoparticle-exposed rats a small but significant increase in APE-1 mRNA expression was measured. Thus, short-term inhalation of carbon nanoparticles under the applied exposure regimen, does not cause oxidative stress and DNA damage in the lungs of healthy mice and rats.