Uptake of gold nanoparticles in murine macrophage cells without cytotoxicity or production of pro-inflammatory mediators

Abstract

More information characterizing the biological responses to nanoparticles is needed to allow the U.S. Food and Drug Administration to evaluate the safety and effectiveness of products with nano-scale components. The potential cytotoxicity and inflammatory responses of Au NPs (60 nm, NIST standard reference materials) were investigated in murine macrophages. Cytotoxicity was evaluated by MTT and LDH assays. Cytokines (IL-6, TNF-α), nitric oxide, and ROS were assayed to assess inflammatory responses. Morphological appearance and localization of particles were examined by high resolution illumination microscopy, transmission electron microscopy (TEM), and scanning TEM coupled with EDX spectroscopy. Results showed no cytotoxicity and no elevated production of proinflammatory mediators; however, imaging analyses demonstrated cellular uptake of Au NPs and localization within intracellular vacuoles. These results suggest that 60 nm Au NPs, under the exposure conditions tested, are not cytotoxic, nor elicit pro-inflammatory responses. The localization of Au NPs in intracellular vacuoles suggests endosomal containment and an uptake mechanism involving endocytosis.     

Influence of hardness on the bioavailability of silver to a freshwater snail after waterborne exposure to silver nitrate and silver nanoparticles

Abstract

The release of Ag nanoparticles (AgNPs) into the aquatic environment is likely, but the influence of water chemistry on their impacts and fate remains unclear. Here, we characterize the bioavailability of Ag from AgNO₃ and from AgNPs capped with polyvinylpyrrolidone (PVP AgNP) and thiolated polyethylene glycol (PEG AgNP) in the freshwater snail, Lymnaea stagnalis, after short waterborne exposures. Results showed that water hardness, AgNP capping agents, and metal speciation affected the uptake rate of Ag from AgNPs. Comparison of the results from organisms of similar weight showed that water hardness affected the uptake of Ag from AgNPs, but not that from AgNO₃. Transformation (dissolution and aggregation) of the AgNPs was also influenced by water hardness and the capping agent. Bioavailability of Ag from AgNPs was, in turn, correlated to these physical changes. Water hardness increased the aggregation of AgNPs, especially for PEG AgNPs, reducing the bioavailability of Ag from PEG AgNPs to a greater degree than from PVP AgNPs. Higher dissolved Ag concentrations were measured for the PVP AgNPs (15%) compared to PEG AgNPs (3%) in moderately hard water, enhancing Ag bioavailability of the former. Multiple drivers of bioavailability yielded differences in Ag influx between very hard and deionized water where the uptake rate constants (k_uw, l?g^?1?d^?1?±?SE) varied from 3.1?±?0.7 to 0.2?±?0.01 for PEG AgNPs and from 2.3?±?0.02 to 1.3?±?0.01 for PVP AgNPs. Modeling bioavailability of Ag from NPs revealed that Ag influx into L. stagnalis comprised uptake from the NPs themselves and from newly dissolved Ag.     

Nanoparticles for the delivery of zoledronic acid to prostate cancer cells: A comparative analysis through time lapse video-microscopy technique

Time-lapse live cell imaging is a powerful tool for studying the responses of cells to drugs. Zoledronic acid (ZOL) is the most potent aminobiphosphonate able to induce cell growth inhibition at very low concentrations. The lack of clear evidence of ZOL-induced anti-cancer effects is likely due to its unfavorable pharmacokinetic profile. The use of nanotechnology-based formulations allows overcoming these limitations in ZOL pharmaco-distribution. Recently, stealth liposomes (LIPOs) and new self-assembly PEGylated nanoparticles (NPs) encapsulating ZOL were developed. Both the delivery systems showed promising anticancer activity in vitro and in vivo.In this work, we investigated the cytostatic effect of these novel formulations (LIPOs and NPs) compared with free ZOL on 2 different prostate cancer cell lines, PC 3 and DU 145 and on prostate epithelial primary cells EPN using time lapse video-microscopy (TLVM). In PC3 cells, free ZOL showed a significant anti-proliferative effect but this effect was lower than that induced by LIPOs and NPs encapsulating ZOL; moreover, LIPO-ZOL was more potent in inducing growth inhibition than NP-ZOL. On the other hand, LIPO-ZOL slightly enhanced the free ZOL activity on growth inhibition of DU 145, while the anti-proliferative effect of NP-ZOL was not statistically relevant. These novel formulations did not induce anti-proliferative effects on EPN cells. Finally, we evaluated cytotoxic effects on DU145 where, LIPO-ZOL induced the highest cytotoxicity compared with NP-ZOL and free ZOL. In conclusion, ZOL can be transformed in a powerful anticancer agent, if administered with nanotechnology-based formulations without damaging the healthy tissues.     

纳米二氧化硅与肺癌的关系

研究肺癌发生机制并用于指导临床治疗成为迫切的需要。近年研究显示,纳米二氧化硅（纳米SiO2）可能参与细胞损伤、炎症反应、氧化反应、肺的纤维化等机制,与肿瘤的生物学行为密切相关,因此深入研究纳米SiO2与肺癌的关系对肺癌发病机制的研究具有重要意义。     

负载奥沙利铂纳米粒子的制备及抗肿瘤效果研究

目的:采用聚乙二醇-聚乳酸羟基乙酸(mPEG-PLGA)二亲嵌段共聚物为载体,制备负载奥沙利铂的纳米粒子(nanoparticle,NP),全面考察其性质及体内抗肿瘤效果.方法:通过双乳化挥发法,制备奥沙利铂载药纳米粒子,考察纳米粒子的形态、粒径分布、稳定性、体外释放特性及体内抗肿瘤效果等性质.结果:所制得奥沙利铂纳米粒子为较规则的圆球形,平均粒径200.6-242.1 nm,稳定性实验提示其稳定性良好;平均包封率和载药量分别为(65.62±1.27)％和(3.21±0.02)％,体外释放曲线显示了奥沙利铂纳米粒子良好的缓释特性.体内实验中,相比对照组和空白组,纳米粒子组能明显抑制肿瘤的生长,相对裸药组能明显降低药物的毒副反应,且能够延长小鼠的平均生存期.结论:实验结果为肿瘤“带瘤生存”的治疗理念提供了新的思路和科学依据.     

Effect of intravitreal injection of bevacizumab-chitosan nanoparticles on retina of diabetic rats

AIM:To investigate the effects of intravitreal injection of bevacizumab-chitosan nanoparticles on pathological morphology of retina and the expression of vascular endothelial growth factor (VEGF) protein and VEGF mRNA in the retina of diabetic rats.METHODS: Seventy-two 3-month aged diabetic rats were randomly divided into 3 groups, each containing 24 animals and 48 eyes. Both eyes of the rats in group A were injected into the vitreous at the pars plana with 3μL of physiological saline, while in groups B and C were injected with 3μL (75μg) of bevacizumab and 3μL of bevacizumab-chitosan nanoparticles (containing 75μg of bevacizumab), respectively. Immunohistochemistry was used to assess retinal angiogenesis, real-time PCR assay was used to analyse the expression of VEGF mRNA, and light microscopy was used to evaluate the morphology of retinal capillaries.RESULTS:Real-time PCR assay revealed that the VEGF mRNA expression in the retina before injection was similar to 1 week after injection in group A (P>0.05), while theVEGF mRNA expression before injection significantly differed from those 4 and 8 weeks after injection (P<0.05). Retinal expression of VEGF protein and VEGF mRNA was inhibited 1 week and 4 weeks after injection (P<0.05) in group B, and the expression of VEGF protein and VEGF mRNA was obviously inhibited until 8 weeks after injection (P<0.05) in group C. Using multiple comparisons among group A, group B, and group C, the VEGF expression before injection was higher than at 1, 4 and 8 weeks after injection (P<0.05). The amount of VEGF expression was higher 8 weeks after injection than 1 week or 4 weeks after injection, and also higher 1 week after injection compared with 4 weeks after injection (P<0.05). No toxic effect on SD rats was observed with bevacizumab-chitosan nanoparticles injection alone.CONCLUSION: The results offer a new approach for inhibiting angiogenesis of diabetic retinopathy and indicate that the intravitreal injection of bevacizumab inhibits VEGF expression in retina, and bevacizumab-chitosan nanoparticles have a longer duration of action.     

Medicinal Chemistry Based Approaches and Nanotechnology‐Based Systems to Improve CNS Drug Targeting and Delivery

The central nervous system (CNS) is protected by various barriers, which regulate nervous tissue homeostasis and control the selective and specific uptake, efflux, and metabolism of endogenous and exogenous molecules. Among these barriers is the blood–brain barrier (BBB), a physical and physiological barrier that filters very efficiently and selectively the entry of compounds from the blood to the brain and protects nervous tissue from harmful substances and infectious agents present in the bloodstream. The BBB also prevents the entry of potential drugs. As a result, various drug targeting and delivery strategies are currently being developed to enhance the transport of drugs from the blood to the brain. Following a general introduction, we briefly overview in this review article the fundamental physiological properties of the BBB. Then, we describe current strategies to bypass the BBB (i.e., invasive methods, alternative approaches, and temporary opening) and to cross it (i.e., noninvasive approaches). This section is followed by a chapter addressing the chemical and technological solutions developed to cross the BBB. A special emphasis is given to prodrug‐targeting approaches and targeted nanotechnology‐based systems, two promising strategies for BBB targeting and delivery of drugs to the brain.     

Targeting by cmHsp70.1-antibody coated and survivin miRNA plasmid loaded nanoparticles to radiosensitize glioblastoma cells

Nanoparticles (NP) as carriers for anti-cancer drugs have shown great promise. Specific targeting of NP to malignant cells, however, remains an unsolved problem. Conjugation of antibodies specific for tumor membrane antigens to NP represents one approach to improve specificity and to increase therapeutic efficacy. In the present study, for the first time a novel membrane heat shock protein (Hsp70)-specific antibody (cmHsp70.1) was coupled to human serum albumin (HSA) NP, loaded with microRNA (miRNA) plasmids to target the inhibitor of apoptosis protein survivin. The physicochemical properties of monodisperse miRNA-loaded NP showed a diameter of 180 nm to 220 nm, a plasmid incorporation of more than 95% and a surface binding capacity of the antibody of 70–80%. Antibody-conjugated NP displayed an increased cellular uptake in U87MG and LN229 glioblastoma cells compared to isotype control antibody, PEG-coupled controls and peripheral blood lymphocytes (PBL). Survivin expression was significantly reduced in cells treated with the Hsp70-miRNA-NP as compared to non-conjugated NP. Hsp70-miRNA-NP enhanced radiation-induced increase in caspase 3/7 activity and decrease in clonogenic cell survival. In summary, cmHsp70.1 miRNA-NP comprise an enhanced tumor cell uptake and increased therapeutic efficacy of radiation therapy in vitro and provide the basis for the development of antibody-based advanced carrier systems for a tumor cell specific targeting.     

纳米壳聚糖对MC3T3-E1成骨细胞生长的影响

背景：已有体内急性毒理实验证实,壳聚糖纳米微囊的半数致死量高于2000 mg/kg,但其具体致病机制目前尚不明确。
　　目的：分析纳米壳聚糖作为骨替代材料对MC3T3-E1成骨细胞生长及大鼠肝、肾等器官生理功能的影响。方法：将MC3T3-E1成骨细胞分别在含0(对照)、10 mg/L、100 mg/L、1 g/L、10 g/L纳米壳聚糖的DMEM培养液中培养,检测各组细胞A值。透射电镜观察10 g/L纳米壳聚糖溶液培养MC3T3-E1成骨细胞24 h后的细胞形态变化。采用PBS制备10 g/L纳米壳聚糖悬浮液,分别以166.67,16.67 mg/kg经腹腔注射至SD大鼠体内4周,每周3次,正常对照组注射等量生理盐水,血清生化指标分析大鼠肝、肾功能,病理切片观察组织形态学改变、炎症细胞浸润情况。
　　结果与结论：与对照组比较,10 mg/L、100 mg/L、1 g/L、10 g/L的纳米壳聚糖溶液均抑制MC3T3-E1细胞的生长(P<0.05)。透射电镜见团聚的壳聚糖存在于MC3T3-E1细胞浆中,细胞表面的伪足形成,细胞膜呈波浪状起伏,细胞核变性、碎裂及固缩。与正常对照组比较,注射纳米壳聚糖悬浮液两组大鼠血尿素氮、Na+水平均有明显升高(P<0.05),高剂量组K+水平明显降低(P<0.01);肝脏、肾脏均出现组织细胞凋亡现象,高剂量组凋亡更加明显。表明纳米壳聚糖可导致细胞凋亡,超过一定剂量可造成肾功能受损,对机体生理功能造成影响。     

利福平聚乳酸-羟基乙酸共聚物纳米粒雾化吸入给药肺靶向性研究

目的研究利福平聚乳酸-羟基乙酸共聚物纳米粒雾化吸入给药的肺靶向性。方法分别将利福平聚乳酸-羟基乙酸共聚物纳米粒混悬液(RFP-PLGA-NPs)和利福平注射液(RFP-Sol)以雾化吸入方式给予SD大鼠,在不同时间点测定利福平在大鼠肺组织中的浓度,计算相应药动学参数,比较2种制剂在肺组织中药动学过程,并评价靶向性。结果 RFP-Sol和RFP-PLGA-NPs的Tmax分别为(1.50±0.01)h和(2.00±0.08)h,Cmax分别为(0.83±0.07)mg.L 1和(5.02±0.05)mg.L 1,AUC0→∞分别为(6.24±0.24)mg.h.L 1和(35.80±6.34)mg.h.L 1,CL分别为(4.801±0.18)L.h 1.kg 1和(0.85±0.15)L.h 1.kg 1。通过对re和Ce等靶向性指标进行分析,RFP-PLGA-NPs在肺组织中的re和Ce均>1。结论与RFP-Sol相比,RFP-PLGA-NPs经雾化吸入给药后,明显提高了肺组织中药物的分布并且延缓消除,有显著的缓释性,从而降低药物对全身的不良反应,提高对肺结核的治疗作用。