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1.
The high success of silver nanoparticles (AgNPs), mainly associated with their proved antimicrobial properties, has led to an increasing spread in our close environment. Although many studies have been carried out to detect potential toxicity of AgNPs, most of them have been developed under unrealistic exposure conditions. In terms of human risk, the evaluation of long-term exposures to subtoxic doses of NPs remains a challenge. Here, we have determined different transformation-related end points under a scenario of 6 weeks long-term exposure to low noncytotoxic AgNPs concentrations (0.5 and 1?μg/mL) in Caco-2 cells. A significant uptake of AgNPs was demonstrated by using confocal microscopy showing a high presence of AgNPs in both the cytoplasm and the nucleus. As for the assayed parameters of cell transformation such as ability to growth without requiring adherence to a surface (soft-agar assay), the secretion of extracellular matrix metalloproteinase to the medium (zymography), migration capacity and ability of the secretome of exposed cells to promote tumor growth, significant effects were detected in all cases, with the exception of the extracellular matrix metalloproteinases (MMP2 and MMP9) secretion. Our results point out the potential carcinogenic risk associated with AgNPs exposure under long-term exposure conditions, as well as the importance of using realistic exposure scenarios to test nanomaterials.  相似文献   

2.
高艳丽  刘赛 《中国药理学通报》2011,27(11):1504-1509
目的研究Caco-2细胞对负载维生素D3的、FITC标记的自组装海藻酸钠纳米粒(sSAN-VD3-FITC)的摄取及其影响因素,分析其通过Caco-2细胞吸收模型的跨膜转运特点。方法①采用激光共聚焦显微镜检测sSAN-VD3-FITC的摄取,分析作用时间的影响;②采用Caco-2细胞模型研究其跨膜转运,检测接受液的荧光强度,观察其转运特点。计算表观渗透系数(Papp),分析作用时间对转运的影响。结果①sSAN-VD3-FITC作用1 h后细胞质内出现荧光颗粒,4 h后荧光强度增强。②转运接受液的荧光强度、累积转运量较空白对照组均明显升高(P<0.05),均存在时间依赖性(P<0.05)。Papp较稳定,但随作用时间的延长逐渐减小。结论 sSAN-VD3可被Caco-2细胞摄取,并受作用时间的影响;可通过Caco-2细胞模型进行跨膜转运,并存在时间依赖性,表明其可经胃肠道给药吸收入血。  相似文献   

3.
Aim: Statin disposition and response are greatly determined by the activities of drug metabolizing enzymes and efflux/uptake transporters. There is little information on the regulation of these proteins in human cells after statin therapy. In this study, the effects of atorvastatin and simvastatin on mRNA expression of efflux (ABCB1, ABCG2 and ABCC2) and uptake (SLCO1B1, SLCO2B1 and SLC22A1) drug transporters in Caco-2 and HepG2 cells were investigated.
Methods: Quantitative real-time PCR was used to measure mRNA levels after exposure of HepG2 and Caco-2 cells to statins. Results: Differences in mRNA basal levels of the transporters were as follows: ABCC2〉ABCG2〉ABCB1〉SLCO1B1〉〉〉SLC22A1〉SLCO2B1 for HepG2 ceils, and SLCO2B1〉〉ABCC2〉ABCB1〉ABCG2〉〉〉SLC22A1 for Caco-2 cells. While for HepG2 cells, ABCC2, ABOG2 and SLCO2B1 mRNA levels were significantly up-regulated at 1, 10 and 20 pmol/L after 12 or 24 h treatment, in Caco-2 cells, only the efflux transporter ABCB1 was significantly down-regulated by two-fold following a 12 h treatment with atorvastatin. Interestingly, whereas treatment with simvastatin had no effect on mRNA levels of the transporters in HepG2 cells, in Caco-2 cells the statin significantly down-regulated ABCB1, ABCC2, SLC22A1, and SLCO2B1 mRNA levels after 12 or 24 h treatment.
Conclusion: These findings reveal that statins exhibits differential effects on mRNA expression of drug transporters, and this effect depends on the cell type. Furthermore, alterations in the expression levels of drug transporters in the liver and/or intestine may con- tribute to the variability in oral disposition of statins.  相似文献   

4.
目的建立关附甲素的LC-MS测定法,研究其在Ca-co-2细胞上的摄取特性。方法采用ShimadzuVP–ODS,C8柱,(250mm×2.1 mm,5μm),流动相:乙腈∶水=30∶70(V/V),用0.2%冰乙酸溶液,加入二乙胺适量调pH至4.0左右,流速:0.2 ml.min-1,电喷雾离子化(ES1)方式,采用选择性离子检测法,检测离子为正离子,关附甲素的选择性离子:[M+H],m/z 430。考察温度、药物浓度、时间和pH值对关附甲素在Caco-2细胞上摄取的影响。结果关附甲素在0.2~50.0μmol.L-1的范围内呈良好的线性关系(r=0.9988),最低定量限0.2μmol.L-1。关附甲素在Caeo-2细胞上的摄取具有一定的浓度、时间和pH值依赖性,其摄取表现为被动扩散。结论该法灵敏、简单,专属性强,关附甲素在Caco-2细胞上具有良好的摄取。  相似文献   

5.
To investigate the effect of extracellular chelation at the apical, basolateral or both sides on the resistance and permeability of epithelial cell layers, we used 15 days cultures of a human intestinal adenocarcinoma cell line (Caco-2) and hydrophilic FITC-labeled dextran model compounds of various molecular weights. Transport of these hydrophilic compounds is restricted to the paracellular pathway in which the tight junctions form a barrier. Tight junctions are dependent on extracellular calcium and magnesium for their integrity and function. Calcium and magnesium chelation with 2.5 mM EDTA at the apical and basolateral side of the monolayer resulted in a drastic drop, up to 80% of the initial value, in trans-epithelial electrical resistance after 60 min. Application at the basolateral side resulted in a drop of 40% in resistance, while application on the apical side almost did not give any effect. The same pattern was also found in transepithelial clearance studies with fluorescein-Na and FITC-labeled dextran model compounds with molecular weights ranging from 4000 to 500 000. After 2.5 mM EDTA treatment on both sides a maximal (1400-fold) enhancement in transport clearance occurred for the dextran molecule with molecular weight 20 000 (Stokes-Einstein molecular radius 30 Å). For basolateral calcium and magnesium chelation similar results were found, however, with lesser maximal effects. For apical application no transport enhancement could be found with 2.5 mM EDTA. These results have shown that transport of hydrophilic compounds through epithelial monolayers is enhanced more effectively by basolateral application of EDTA than by apical application.  相似文献   

6.
目的: 研究儿茶素(Catechin,Cat)对Caco-2细胞胆固醇摄取的影响,以及可能的作用机制。方法: 利用胆固醇:甲基β环糊精复合物(Chol:MβCD)建立Caco-2细胞脂质蓄积模型。不同浓度的儿茶素(20、40、60 μmol·L-1)处理细胞24 h,结合油红O染色法观察细胞内的脂质蓄积,酶法测定细胞内胆固醇含量及分布,qRT-PCR及Westernblot检测胆固醇代谢相关基因NPC1L1和SREBP-2的表达。结果: 与空白组相比,Chol:MβCD处理组细胞内红色脂滴颗粒以及胆固醇含量明显增加。20~60 μmol·L-1儿茶素不仅可以不同程度地减少细胞内红染脂滴的形成,而且可以显著降低细胞内总胆固醇和游离胆固醇的含量,以及胆固醇酯在总胆固醇中的比例。此外,儿茶素可以剂量依赖性地降低胆固醇代谢相关基因NPC1L1及SREBP-2的mRNA和蛋白表达。其中以60 μmol·L-1 Cat处理组的作用最为显著(P<0.01)。结论: 儿茶素可能通过下调胆固醇代谢相关基因NPC1L1和SREBP-2的表达,进而减少Caco-2细胞摄取胆固醇及蓄积。  相似文献   

7.
mRNA expression profiles had previously been measured in Caco-2 cells (human colonic carcinoma cells) using either custom-designed spotted oligonucleotide arrays or Affymetrix GeneChip oligonucleotide arrays. The Caco-2 cells used were from different clones and were examined under slightly different culture conditions commonly encountered when Caco-2 cells are used as a model tissue for studying intestinal transport and metabolism in different laboratories. In this study, we compared gene expression profiles of Caco-2 cells generated with different arrays to assess the validity of conclusions derived from the 2 independent studies, with a focus on changes in transporter and ion channel mRNA expression levels on Caco-2 cell differentiation. Significant changes in expression levels upon differentiation were observed with 78 genes, with probes common to both arrays. Of these, 18 genes were upregulated and 36 genes were downregulated. The 2 arrays yielded discrepant results for 24 genes, showing significant changes upon differentiation. The results from the 2 arrays correlated well for genes expressed above average levels (r = 0.75, P < 0.01, n = 25) and poorly for genes expressed at low levels (r = 0.08, P > 0.05, n = 25). Overall correlation across the 2 platforms was r = 0.45 (P < 0.01) for the 78 genes, with similar results from both arrays. Despite differences in experimental conditions and array technology, similar results were obtained for most genes.  相似文献   

8.

Aim:

To compare the anti-cancer activity and cellular uptake of curcumin (Cur) delivered by targeted and non-targeted drug delivery systems in multidrug-resistant cervical cancer cells.

Methods:

Cur was entrapped into poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Cur-NPs) in the presence of modified-pluronic F127 stabilizer using nano-precipitation technique. On the surface of Cur-NPs, the carboxy-terminal of modified pluronic F127 was conjugated to the amino-terminal of anti-P-glycoprotein (P-gp) (Cur-NPs-APgp). The physical properties of the Cur-NPs, including particle size, zeta potential, particle morphology and Cur release kinetics, were investigated. Cellular uptake and specificity of the Cur-NPs and Cur-NPs-APgp were detected in cervical cancer cell lines KB-V1 (higher expression of P-gp) and KB-3-1 (lower expression of P-gp) using fluorescence microscope and flow cytometry, respectively. Cytotoxicity of the Cur-NPs and Cur-NPs-APgp was determined using MTT assay.

Results:

The particle size of Cur-NPs and Cur-NPs-APgp was 127 and 132 nm, respectively. The entrapment efficiency and actual loading of Cur-NPs-APgp (60% and 5 μg Cur/mg NP) were lower than those of Cur-NPs (99% and 7 μg Cur/mg NP). The specific binding of Cur-NPs-APgp to KB-V1 cells was significantly higher than that to KB-3-1 cells. Cellular uptake of Cur-NPs-APgp into KB-V1 cells was higher, as compared to KB-3-1 cells. However, the cellular uptake of Cur-NPs and Cur-NPs-IgG did not differ between the two types of cells. Besides, the cytotoxicity of Cur-NPs-APgp in KB-V1 cells was higher than those of Cur and Cur-NPs.

Conclusion:

The results demonstrate that Cur-NPs-APgp targeted to P-gp on the cell surface membrane of KB-V1 cells, thus enhancing the cellular uptake and cytotoxicity of Cur.  相似文献   

9.
The angiotensin-converting enzyme (ACE)-inhibitor ceronapril (SQ 29852) is shown to be a substrate of the intestinal dipeptide transporter. Uptake by Caco-2 cells, grown as confluent monolayers, follows a major saturable pathway (Km, 0.91 ± 0.11 mM; 90% at 1 mM) together with a minor passive component (kJ, 32.3 ± 6.6 ng (106 cells)−1 (20 min)−1. Uptake was inhibited by competition with dipeptides such as l-AIa-l-Pro (Ki, 2.96 mM) and l-Phe-Gly (Ki, 3.84 mM) but not by cephalosporins such as cephalexin. In contrast, transport was non-saturable, flux increased linearly with concentration and data were consistent with a passive transepithelial transport mechanism. Transport profiles showed a biphasic dependence upon time with an initial flux of 0.83 ± 0.02 ng insert−1 min−1 (k1) and a terminal value of 1.65 ± 0.08 ng insert−1 min−1 ((k2) at 100 μM. It is concluded that the basolateral efflux is retarded so that the passive paracellular transport controls the overall transepithelial transport characteristics in the Caco-2 model. Carrier-mediated uptake into intestinal enterocytres, followed by rate-limiting basolateral efflux, may explain the extended tmax in vivo following oral administration.  相似文献   

10.
Oral drug delivery to treat diabetes is being increasingly researched. The mucus and the epithelial cell layers hinder drug delivery. We designed a self-ablating nanoparticle to achieve smart oral delivery to overcome the gastrointestinal barrier. We used the zwitterionic dilauroyl phosphatidylcholine, which exhibits a high affinity toward Oligopeptide transporter 1, to modify poly(lactic-co-glycolic acid) nanoparticles and load hemagglutinin-2 peptide to facilitate its escape from lysosomes. Nanoparticles exhibit a core–shell structure, the lipid layer is degraded by the lysosomes when the nanoparticles are captured by lysosomes, then the inner core of the nanoparticles gets exposed. The results revealed that the self-ablating nanoparticles exhibited higher encapsulation ability than the self-assembled nanoparticles (77% vs 64%) and with better stability. Quantitative cellular uptake, cellular uptake mechanisms, and trans-monolayer cellular were studied, and the results revealed that the cellular uptake achieved using the self-ablating nanoparticles was higher than self-assembling nanoparticles, and the number of uptake pathways via which the self-ablating nanoparticles functioned were higher than the self-assembling nanoparticles. Intestinal mucus permeation, in vivo intestinal circulation, was studied, and the results revealed that the small self-assembling nanoparticles exhibit a good extent of intestinal uptake in the presence of mucus. In vitro flip-flop, intestinal circulation revealed that the uptake of the self-ablating nanoparticles was 1.20 times higher than the self-assembled nanoparticles. Pharmacokinetic study and the pharmacodynamic study showed that the bioavailability and hypoglycemic effect of self-ablating nanoparticles were better than self-assembled nanoparticles.  相似文献   

11.
12.
Recent study suggested that the presence of phytochemicals in food could interact with nanoparticles (NPs) and consequently reduce the toxicity of NPs, which has been attributed to the antioxidant properties of phytochemicals. In this study, we investigated the interactions between ZnO NPs and two flavonoids baicalein (Ba) or baicalin (Bn) as well as the influence of the interactions on the toxicity of ZnO NPs to Caco-2 cells. The antioxidant properties of Ba and Bn were confirmed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, with Ba being stronger. However, the presence of Ba or Bn did not significantly affect cytotoxicity, intracellular superoxide or release of inflammatory cytokines of Caco-2 cells after ZnO NP exposure. When Ba was present, the cellular viability of Caco-2 cells after exposure to ZnO NPs was slightly increased, associated with a modest decrease of intracellular Zn ions, but these effects were not statistically different. Ba was more effective than Bn at changing the hydrodynamic sizes, Zeta potential and UV–Vis spectra of ZnO NPs, which indicated that Ba might increase the colloidal stability of NPs. Taken together, the results of the present study indicated that the anti-oxidative phytochemical Ba might only modestly protected Caco-2 cells from the exposure to ZnO NPs associated with an insignificant reduction of the accumulation of intracellular Zn ions. These results also indicated that when assessing the combined effects of NPs and phytochemicals to cells lining gastrointestinal tract, it might be necessary to evaluate the changes of colloidal stability of NPs altered by phytochemicals.  相似文献   

13.
目的以Caco-2细胞单层模型,首次研究了蜕皮甾酮的口服吸收与转运特性。方法采用普通Caco-2细胞模型、表达活性CYP3A4酶的Caco-2细胞模型,分别从AP→BL方向和BL→AP方向研究蜕皮甾酮的摄取和跨膜转运规律。结果蜕皮甾酮在2种模型中的表观渗透系数(Papp)在0.1×10-6~1×10-6cm.s-1之间,药物吸收情况为1%~10%;在4 h的实验过程中,4种浓度蜕皮甾酮的ER值均小于1.5。结论研究表明,蜕皮甾酮主要以被动扩散的方式被细胞摄取和转运,其跨膜转运特性未受到CYP3A4-介导机制的影响。  相似文献   

14.
《Nanotoxicology》2013,7(4):339-347
Abstract

A series of highly monodisperse silicon nanoparticles (Si NPs) with either positively (amine), neutral (azide) or negatively (carboxylic acid) charged covalently attached organic monolayers were synthesized and investigated for their cytotoxicity. Infrared data confirmed the presence of these covalently attached surface groups. The Si NPs were characterized by absorption and fluorescence spectroscopy. The cytotoxicity was investigated in Caco-2 cells by determining the cell viability and proliferation. The IC50 values for the Si NPs ranged from 20 μg/l for the amine-terminated Si NPs, via 550–850 μg/l for the azide-terminated Si NPs to non-toxic (no measureable IC50) for the carboxylic acid-terminated Si NPs. These results indicate a trend in cytotoxicity, depending on surface charge, i.e., that positively charged Si NPs are more cytotoxic than negatively charged Si NPs. Interestingly, it appeared that the cytotoxicity of the Si NP-NH2 depends strongly on the presence of fetal calf serum in the medium.  相似文献   

15.
《Nanotoxicology》2013,7(8):1361-1372
Abstract

Despite human gastrointestinal exposure to nanoparticles (NPs), data on NPs toxicity in intestinal cells are quite scanty. In this study we evaluated the toxicity induced by zinc oxide (ZnO) and titanium dioxide (TiO2) NPs on Caco-2 cells. Only ZnO NPs produced significant cytotoxicity, evaluated by two different assays. The presence of foetal calf serum in culture medium significantly reduced ZnO NPs toxicity as well as ion leakage and NP-cell interaction. The two NPs increased the intracellular amount of reactive oxygen species (ROS) after 6 h treatment. However, only ZnO NPs increased ROS and induced IL-8 release both after 6 and 24 h. Experimental data indicate a main role of chemical composition and solubility in ZnO NPs toxicity. Moreover our results suggest a key role of oxidative stress in ZnO NPs cytotoxicity induction related both to ion leakage and to cell interaction with NPs in serum-free medium.  相似文献   

16.
Context: PLGA nanoparticles have been widely utilised to encapsulate lipophilic drugs for sustained release.

Objective: This study was to enhance encapsulation efficiency and drug loading for the poorly lipophilic drug dihydroartemisinin (DHA) in PLGA nanoparticles, where amphiphilic phospholipid was employed as the intermediate. Materials and methods: DHA-phospholipid complex formulation was optimised using the response surface method. DHA-phospholipid complex-nanoparticles (DHA-PLC-NPs) were prepared using the solvent evaporation method. Results: The particle size, zeta potential, entrapment efficiency and drug loading of the nanoparticles were 265.3?±?7.9?nm, ?21.4?±?6.3?mV, 74.2?±?6.5% and 2.80?±?0.35%, respectively. Compared with the rapidly released free form, DHA underwent sustained release from the nanoparticles. DHA-PLC-NPs presented stronger cell proliferative inhibition than DHA treatment alone and apoptosis was obviously induced after DHA-PLC-NPs treatment. Conclusion: Phospholipid complexes are useful intermediate to improve the lipophilicity of drugs, the interaction with the hydrophobic core of PLGA and the encapsulation efficiency of poorly lipophilic drugs in polymeric nanoparticles.  相似文献   

17.
Beck  G. F.  Irwin  W. J.  Nicklin  P. L.  Akhtar  S. 《Pharmaceutical research》1996,13(7):1028-1037
Purpose. Oral bioavailability for antisense oligonucleotides has recently been reported but the mechanistic details are not known. The proposed oral delivery of nucleic acids will, therefore, require an understanding of the membrane binding interactions, cell uptake and transport of oligonucleotides across the human gastro-intestinal epithelium. In this initial study, we report on the cell-surface interactions of oligonucleotides with human intestinal cells. Methods. We have used the Caco-2 cell line as an in vitro model of the human intestinal epithelium to investigate the membrane binding interactions of 20-mer phosphodiester (PO) and phosphorothioate (PS) oligonucleotides. Results. The cellular association of both an internally [3H]-labelled and a 5end [32P]-labelled PS oligonucleotide (3.0% at 0.4 µM extracellular concentration) was similar and was an order of magnitude greater than that of the 5end [32P]-labelled PO oligonucleotide (0.2%) after 15 minutes incubation in these intestinal cells. The cellular association of PS was highly saturable with association being reduced to 0.9% at 5 µM whereas that of PO was less susceptible to competition (0.2% at 5 µM, 0.1% at 200 µM). Differential temperature-dependence was demonstrated; PS interactions were temperature-independent whereas the cellular association of PO decreased by 75% from 37°C to 17°C. Cell association of oligonucleotides was length and pH-dependent. A decrease in pH from 7.2 to 5.0 resulted in a 2- to 3-fold increase in cell-association for both backbone types. This enhanced association was not due to changes in lipophilicity as the octanol:aqueous buffer distribution coefficients remained constant over this pH range. The ability of NaCl washes to remove surface-bound PS oligonucleotides in a concentration-dependent manner suggests their binding may involve ionic interactions at the cell surface. Cell-surface washing with the proteolytic enzyme, Pronase®, removed approximately 50% of the cell-associated oligonucleotide for both backbone types. Conclusions. Binding to surface proteins seems a major pathway for binding and internalization for both oligonucleotide chemistries and appear consistent with receptor (binding protein)-mediated endocytosis. Whether this binding protein-mediated entry of oligonucleotides can result in efficient transepithelial transport, however, requires further study.  相似文献   

18.
In this study, we investigated the extent of the cytotoxicity effect of oxidised lipids and whether tea catechins namely (-)epigallocatechin-3 gallate (EGCG) decreased lipid peroxidation in caco-2 cells. Cells treated with 0-100mug/ml fish oil or methyl linoleate (ML) oxidised by UV irradiation for 24h, 48h and 72h, indicated a substantial decrease in cell viability especially in samples treated with 100mug/ml oxidised lipid. Addition of malondialdehyde (MDA) and hydroxynonenal (50muM) also reduced cell viability. Using EGCG (50muM) increased the viability of cells treated with 24h oxidised mackerel oil (72% live and 28% dead) compared with 48h oxidised mackerel oil (89% live and 11% dead) and 72h oxidised mackerel oil (71% live and 29% dead) as monitored by the MTT assay. Apoptosis of caco-2 cells by oxidised fish oil and ML and protection by EGCG was confirmed using fluorescence microscopy and caspase-3 presence by Western blotting.  相似文献   

19.
目的制备载阿霉素的介孔二氧化硅纳米粒(mesoporous silica nanoparticles,MSN),对其理化性质及细胞摄取行为进行初步研究。方法通过聚合法制备MSN,透射电镜表征纳米粒的形态,动态光散射粒径测定仪测定粒子的平均粒径及分布。紫外分光光度计测定阿霉素的负载行为,MTT比色分析法研究粒子的细胞毒性,激光共聚焦显微镜观察其人乳腺癌MCF-7细胞对载药粒子的摄取。结果纳米粒分布均一,平均粒径约70 nm(PDI<0.1),载药量质量分数达到20%。MCF-7细胞对载药粒子的摄取较快,空白纳米粒具有较低的细胞毒性。结论介孔二氧化硅纳米粒具有较高的药物载药量和良好的生物相容性,能较快地被对人乳腺癌MCF-7细胞摄取,有望成为一种新型的药物化疗载体。  相似文献   

20.
Nanoparticles (NPs) can be absorbed via M cells of Peyer’s patches after oral delivery leading to passive lymphatic targeting followed by systemic drug delivery. Hence, the study was aimed to formulate PLGA NPs of lopinavir. The NPs were prepared by nanoprecipitation, optimized by 33 factorial design and characterized by TEM, DSC, FTIR studies and safety was assessed by MTT assay. In vivo pharmacokinetic studies were performed in rats. The NPs were discrete spherical structures having particle size of 142.1?±?2.13?nm and entrapment of 93.03?±?1.27%. There was absence of drug-polymer interaction. Confocal images revealed the penetration and absorption of coumarin-loaded NPs in Caco-2 cells and intestine after oral delivery. There was 3.04 folds permeability and 13.9 folds bioavailability enhancement from NPs. The NPs can be promising delivery system for antiretroviral drug by delivering the drug to lymph (major HIV reservoir site) via direct absorption through intestine before reaching systemic circulation.  相似文献   

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