Synergistic Effect of Functionalized Nickel Nanoparticles and Quercetin on Inhibition of the SMMC-7721 Cells Proliferation

Current Understanding of Flavonoids in Cancer Therapy and Prevention

Cancer is a major cause of death worldwide, with multiple pathophysiological manifestations. In particular, genetic abnormalities, inflammation, bad eating habits, radiation exposure, work stress, and toxin consumption have been linked to cancer disease development and progression. Recently, natural bioactive chemicals known as polyphenols found in plants were shown to have anticancer capabilities, destroying altered or malignant cells without harming normal cells. Flavonoids have demonstrated antioxidant, antiviral, anticancer, and anti-inflammatory effects. Flavonoid type, bioavailability, and possible method of action determine these biological actions. These low-cost pharmaceutical components have significant biological activities and are beneficial for several chronic disorders, including cancer. Recent research has focused primarily on isolating, synthesizing, and studying the effects of flavonoids on human health. Here we have attempted to summarize our current knowledge of flavonoids, focusing on their mode of action to better understand their effects on cancer.

Application of Quercetin in the Treatment of Gastrointestinal Cancers

Many cellular signaling pathways contribute to the regulation of cell proliferation, division, motility, and apoptosis. Deregulation of these pathways contributes to tumor cell initiation and tumor progression. Lately, significant attention has been focused on the use of natural products as a promising strategy in cancer treatment. Quercetin is a natural flavonol compound widely present in commonly consumed foods. Quercetin has shown significant inhibitory effects on tumor progression via various mechanisms of action. These include stimulating cell cycle arrest or/and apoptosis as well as its antioxidant properties. Herein, we summarize the therapeutic effects of quercetin in gastrointestinal cancers (pancreatic, gastric, colorectal, esophageal, hepatocellular, and oral).

Nickel nanoparticles affect the migration and invasion of HTR-8/SVneo cells by downregulating MMP2 through the PI3K/AKT pathway

Proper migration and invasion of extravillous trophoblast cells into the endometrium in early gestation is essential for successful embryo implantation. The development of nanotechnology has led to the emergence of nickel nanoparticles (Ni NPs), for which attendant health concerns are widespread. Ni NPs are known to affect reproduction and be embryotoxic, but whether they affect the migration and invasion functions of trophoblast cells is unclear. We investigated the effects of Ni NPs on the migration and invasion of HTR-8/SVneo in extravillous trophoblast cells and explored the possible role of the PI3K/AKT/MMP2 signaling pathway in this regard. Results showed that the migration and invasion of cells was significantly inhibited by the exposure of Ni NPs. The protein and mRNA levels of PI3K/AKT/MMP2 signaling pathway were significantly reduced with the increase in Ni NPs concentration. The presence of the PI3K activator 740Y-P partially attenuated the inhibition of cell migration and invasion by Ni NPs, confirming the involvement of this pathway. Thus, Ni NPs inhibit migration and invasion of human trophoblast HTR-8/SVneo cells by downregulating the PI3K/AKT/MMP2 signaling pathway. This study is important for the development of safety evaluation criteria for Ni NPs.

Nanocarriers-loaded with natural actives as newer therapeutic interventions for treatment of hepatocellular carcinoma

Introduction: Cancer has always been a menace for the society. Hepatocellular carcinoma (HCC) is one of the most lethal and 3rdlargest causes of deaths around the world.Area covered: The emergence of natural actives is considered as the greatest boon for fighting cancer. The natural actives take precedence over the traditional chemotherapeutic drugs in terms of their multi-target, multi-level and coordinated effects in the treatment of HCC. Literature reports have indicated the tremendous potential of bioactive natural products in inhibiting the HCC via molecular drug targeting, augmented bioavailability, and the ability for both passive or active targeting and stimulus-responsive drug release characteristics. This review provides a newer treatment approaches involved in the mechanism of action of different natural actives used for the HCC treatment via different molecular pathways. Besides, the promising advantage of natural bioactive-loaded nanocarriers in HCC treatment has also been also presented in this review. Expert opinion: The remarkable outcomes have been observed with therapeutic efficacy of the nanocarriers of natural actives in the treatment of HCC.Furthermore, it requires a thorough assessment of the safety and efficacy evaluation of the nanocarriers for the delivery of targeted natural active ingredients in HCC.].

A review on nanotoxicity and nanogenotoxicity of different shapes of nanomaterials

Nanomaterials (NMs) generally display fascinating physical and chemical properties that are not always present in bulk materials; therefore, any modification to their size, shape, or coating tends to cause significant changes in their chemical/physical and biological characteristics. The dramatic increase in efforts to use NMs renders the risk assessment of their toxicity highly crucial due to the possible health perils of this relatively uncharted territory. The different sizes and shapes of the nanoparticles are known to have an impact on organisms and an important place in clinical applications. The shape of nanoparticles, namely, whether they are rods, wires, or spheres, is a particularly critical parameter to affect cell uptake and site-specific drug delivery, representing a significant factor in determining the potency and magnitude of the effect. This review, therefore, intends to offer a picture of research into the toxicity of different shapes (nanorods, nanowires, and nanospheres) of NMs to in vitro and in vivo models, presenting an in-depth analysis of health risks associated with exposure to such nanostructures and benefits achieved by using certain model organisms in genotoxicity testing. Nanotoxicity experiments use various models and tests, such as cell cultures, cores, shells, and coating materials. This review article also attempts to raise awareness about practical applications of NMs in different shapes in biology, to evaluate their potential genotoxicity, and to suggest approaches to explain underlying mechanisms of their toxicity and genotoxicity depending on nanoparticle shape.

Susceptibility Factors in Chronic Lung Inflammatory Responses to Engineered Nanomaterials

Engineered nanomaterials (ENMs) are products of the emerging nanotechnology industry and many different types of ENMs have been shown to cause chronic inflammation in the lungs of rodents after inhalation exposure, suggesting a risk to human health. Due to the increasing demand and use of ENMs in a variety of products, a careful evaluation of the risks to human health is urgently needed. An assessment of the immunotoxicity of ENMs should consider susceptibility factors including sex, pre-existing diseases, deficiency of specific genes encoding proteins involved in the innate or adaptive immune response, and co-exposures to other chemicals. This review will address evidence from experimental animal models that highlights some important issues of susceptibility to chronic lung inflammation and systemic immune dysfunction after pulmonary exposure to ENMs.

Sex differences in the acute and subchronic lung inflammatory responses of mice to nickel nanoparticles

Nickel nanoparticles (NiNPs) are increasingly used in nanotechnology applications, yet information on sex differences in NiNP-induced lung disease is lacking. The goal of this study was to explore mechanisms of susceptibility between male and female mice after acute or subchronic pulmonary exposure to NiNPs. For acute exposure, male and female mice received a single dose of NiNPs with or without LPS by oropharyngeal aspiration and were necropsied 24 h later. For subchronic exposure, mice received NiNPs with or without LPS six times over 3 weeks prior to necropsy. After acute exposure to NiNPs and LPS, male mice had elevated cytokines (CXCL1 and IL-6) and more neutrophils in bronchoalveolar lavage fluid (BALF), along with greater STAT3 phosphorylation in lung tissue. After subchronic exposure to NiNPs and LPS, male mice exhibited increased monocytes in BALF. Moreover, subchronic exposure of male mice to NiNP only induced higher CXCL1 and CCL2 in BALF along with increased alveolar infiltrates and CCL2 in lung tissue. STAT1 in lung tissue was induced by subchronic exposure to NiNPs in females but not males. Males had a greater induction of IL-6 mRNA in liver after acute exposure to NiNPs and LPS, and greater CCL2 mRNA in liver after subchronic NiNP exposure. These data indicate that susceptibility of males to acute lung inflammation involves enhanced neutrophilia with increased CXCL1 and IL-6/STAT3 signaling, whereas susceptibility to subchronic lung inflammation involves enhanced monocytic infiltration with increased CXCL1 and CCL2. STAT transcription factors appear to play a role in these sex differences. This study demonstrates sex differences in the lung inflammatory response of mice to NiNPs that has implications for human disease.

Quercetin shows anti-tumor effect in hepatocellular carcinoma LM3 cells by abrogating JAK2/STAT3 signaling pathway

Objective

Hepatocellular carcinima is one of the most common tumors in clinic and also one of the leading causes of death from cancer worldwide. Quercetin shows significant effects on blocking the development of various cancers.

Methods

We used the human hepatocellular carcinoma LM3 and nude mice tumor model to assess the effects of quercetin in hepatocellular carcinoma and clarify its mechanism of action. We collected LM3 cell line treated with different doses of quercetin at different time periods and determined the vital indexes. The liver tissues of mice were collected and used for western boltting (WB), Hematoxylin and Eosin (H&E) and TUNEL staining.

Results

Results indicated that quercetin suppressed the Hepatocellular carcinoma (HCC) growth both in vivo and in vitro. Quercetin could disturb LM3 cells proliferation and cell cycle distribution, thus inducing apoptosis. At the same time, quercetin inhibited LM3 cells migration and invasion and promoted HCC autophagy. These effects at least partly depended on the down‐regulation of the activation of JAK2 and STAT3 by quercetin.

Conclusion

Quercetin inhibited hepatocellular carcinoma progression by modulating cell apoptosis, migration, invasion, and autophagy; and its effects were at least partly related with the JAK2/STAT3 signaling pathway.

Quercetin Inhibits the Proliferation of Glycolysis-Addicted HCC Cells by Reducing Hexokinase 2 and Akt-mTOR Pathway

Increased glycolysis in tumor cells is associated with increased risk of tumor progression and mortality. Therefore, disruption of glycolysis, one of the main sources of cellular energy supply, can serve as a target for suppressing tumor growth and progression. Of note, hexokinase-2 (HK2) plays vital roles in glucose metabolism. Moreover, the expression of HK2 alters the metabolic phenotype and supports the continuous growth of tumor cells, making it an attractive target for cancer therapy. Quercetin (QUE), a bioactive flavonoid, has a profound anti-tumor effect on hepatocellular carcinoma (HCC), but the precise underlying mechanism of this effect is unclear. In the present study, we reported that QUE inhibited the proliferation of HCC cells that relied on aerobic glycolysis. We further found that QUE could decrease the protein levels of HK2 and suppress the AKT/mTOR pathway in HCC cells. In addition, QUE significantly restrained the growth of HCC xenografts and decreased HK-2 expression in vivo. Taken together, we have revealed that QUE suppresses the progression of HCC by inhibiting HK2-dependentglycolysis, which may have a promising potential to be an effective treatments for HCC, especially for those patients with high HK2 expression.

Flavonoids in Cancer and Apoptosis

Cancer is the second leading cause of death globally. Although, there are many different approaches to cancer treatment, they are often painful due to adverse side effects and are sometimes ineffective due to increasing resistance to classical anti-cancer drugs or radiation therapy. Targeting delayed/inhibited apoptosis is a major approach in cancer treatment and a highly active area of research. Plant derived natural compounds are of major interest due to their high bioavailability, safety, minimal side effects and, most importantly, cost effectiveness. Flavonoids have gained importance as anti-cancer agents and have shown great potential as cytotoxic anti-cancer agents promoting apoptosis in cancer cells. In this review, a summary of flavonoids and their effectiveness in cancer treatment targeting apoptosis has been discussed.

Anti-Cancerous Potential of Polyphenol-Loaded Polymeric Nanotherapeutics

Recent evidence has extensively demonstrated the anticancer potential of nutraceuticals, including plant polyphenols. Polymeric nanocarrier systems have played an important role in improving the physicochemical and pharmacological properties of polyphenols, thus ameliorating their therapeutic effectiveness. This article summarizes the benefits and shortcomings of various polymeric systems developed for the delivery of polyphenols in cancer therapy and reveals some ideas for future work.

Restoring Effects of Natural Anti-Oxidant Quercetin on Cellular Senescent Human Dermal Fibroblasts

The oxidative damage initiated by reactive oxygen species (ROS) is a major contributor to the functional decline and disability that characterizes aging. The anti-oxidant flavonoid, quercetin, is a plant polyphenol that may be beneficial for retarding the aging process. We examined the restoring properties of quercetin on human dermal fibroblasts (HDFs). Quercetin directly reduced either intracellular or extracellular ROS levels in aged HDFs. To find the aging-related target genes by quercetin, microarray analysis was performed and two up-regulated genes LPL and KCNE2 were identified. Silencing LPL increased the expression levels of senescence proteins such as p16^INK4A and p53 and silencing KCNE2 reversed gene expressions of EGR1 and p-ERK in quercetin-treated aged HDFs. Silencing of LPL and KCNE2 decreased the expression levels of anti-oxidant enzymes such as superoxide dismutase and catalase. Also, the mitochondrial dysfunction in aged HDFs was ameliorated by quercetin treatment. Taken together, these results suggest that quercetin has restoring effect on the cellular senescence by down-regulation of senescence activities and up-regulation of the gene expressions of anti-oxidant enzymes in aged HDFs.

Influence of particle size and dielectric environment on the dispersion behaviour and surface plasmon in nickel nanoparticles

Nickel nanoparticles (NPs) are promising candidates for various applications, including biomedical ones, as they have good magnetic properties as well as high thermal conductivity. We used well-characterized Ni NPs of average Scherrer sizes from 1.31 nm to 22.23 nm and investigated the effects of the primary particle size, size distribution and dielectric environments, and of separately adding non-ionic polyvinylpyrrolidone (PVP), cationic cetyltrimethylammonium bromide (CTAB) and anionic ethylenediaminetetraacetic acid (EDTA) in ethanol, on their stability and agglomeration behaviour using atomic force microscopy (AFM), particle size analysis and zeta potential study through dynamic light scattering (DLS) combined with UV-visible spectroscopy data. The dominant influence of surfactants, additives, particles size and shape on the surface plasmon resonance (SPR) was found. SPR is considerably sensitive to the dielectric environment in addition to size and shape. Moreover, increasing the concentration of PVP led to an enhanced SPR intensity and a shift in its position towards higher wavelength. 1.31 nm NPs with EDTA as an additive yielded the best dispersibility and also showed superparamagnetic behaviour at 300 K, indicating their favourable application potentials.

Polyphenols delivery by polymeric materials: challenges in cancer treatment

Nanotechnology can offer different solutions for enhancing the therapeutic efficiency of polyphenols, a class of natural products widely explored for a potential applicability for the treatment of different diseases including cancer. While possessing interesting anticancer properties, polyphenols suffer from low stability and unfavorable pharmacokinetics, and thus suitable carriers are required when planning a therapeutic protocol. In the present review, an overview of the different strategies based on polymeric materials is presented, with the aim to highlight the strengths and the weaknesses of each approach and offer a platform of ideas for researchers working in the field.

RGD peptide targeted lipid-coated nanoparticles for combinatorial delivery of sorafenib and quercetin against hepatocellular carcinoma

CONTEXT

Combination therapies provide a potential solution to address the tumor heterogeneity and drug resistance issues by taking advantage of distinct mechanisms of action of the multiple therapeutics.

OBJECTIVE

To design arginine-glycineaspartic acid (RGD) modified lipid-coated nanoparticles (NPs) for the co-delivery of the hydrophobic drugs against hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

RGD modified lipid-coated PLGA NPs were developed for the targeted delivery of both sorafenib (SRF) and quercetin (QT) (RGD-SRF-QT NPs). Chemical-physical characteristics and release profiles were evaluated. In vitro cell viability assays were carried out on HCC cells. In vivo antitumor efficacies were evaluated in HCC animal model.

RESULTS AND DISCUSSION

The combination of SRF and QT formulations was more effective than the single drug formulations in both NPs and solution groups. RGD-SRF-QT NPs achieved the most significant tumor growth inhibition effect in vitro and in vivo.

CONCLUSION

The resulting NPs could provide a promising platform for co-delivery of multiple anticancer drugs for achievement of combinational therapy and could offer potential for enhancing the therapeutic efficacy on HCC.

Trioctylphosphine as self-assembly inducer

Nickel nanoparticles (NPs) of different shapes and sizes in polydispersed as well as monodispersed forms were synthesized using trioctylphosphine (TOP), triphenylphosphine (TPP), oleylamine (OA) and their combinations as surfactants to study their self-assembly inducing capabilities. Randomly agglomerated polydispersed NPs were found for TPP and OA, and TPP or OA separately. However, in consolidation with the earlier report of Singh et al., J. Mater. Chem. C, 2014, 2, 8918, NPs formed using TOP only and a combination of TOP with OA naturally exhibited monodispersed NPs associated with natural nanolattice formation without any other external force or surfactants, demonstrating clearly the self-inducing capacity of TOP into monodispersed NPs and their self-assembled nanolattices. Fourier-transformed infra-red (FTIR) data clearly indicated the capping of these surfactants along with acetylacetonate ligands from nickel acetylacetonate precursor on the surface of the NPs. Remarkably, the narrowest zeta potential (ζ) base-widths were observed for samples possessing a self-assembled nanolattice, compared to the broader ones for randomly agglomerated particles.

Flavonoids from tartary buckwheat induce G2/M cell cycle arrest and apoptosis in human hepatoma HepG2 cells

The cytotoxicity and antioxidant activity on human hepatoma cell line HepG2 of three flavonoids homogenous compounds from tartary buckwheat seeds and bran, namely quercetin, isoquercetin, and rutin, were investigated. The total antioxidant competency detection results indicated that the antioxidant capacity of quercetin was the strongest in a biological response system. A [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay showed that quercetin exhibited the strongest cytotoxic effects against the HepG2 cell line. Flow cytometric analysis indicated that quercetin significantly increased the production of reactive oxygen species, and led to the G2/M phase arrest accompanied by an increase of apoptotic cell death after 48 h of incubation. Quercetin-induced cell apoptosis was shown to involve p53 and p21 up-regulation, Cyclin D1, Cdk2, and Cdk7 down-regulation. These results suggested that the induction of G2/M arrest, apoptosis, and cell death by quercetin may associate with increased expression of p53 and p21, decrease of Cyclin D1, Cdk2, and Cdk7 levels, and generation of reactive oxygen species in cells. This study will help to better understand and fully utilize medicinal resources of plant flavonoids.

Acute toxicity of nickel nanoparticles in rats after intravenous injection

This study was carried out to add scientific data in regard to the use of metallic nanoparticles in nanomedicine. The acute toxicity of nickel (Ni) nanoparticles (50 nm), intravenously injected through the dorsal penile vein of Sprague Dawley rats was evaluated in this study. Fourteen days after injection, Ni nanoparticles induced liver and spleen injury, lung inflammation, and caused cardiac toxicity. These results indicate that precautionary measures should be taken with regard to the use of Ni nanoparticles or Ni compounds in nanomedicine.

Apoptotic effect of a novel kefir product, PFT, on multidrug-resistant myeloid leukemia cells via a hole-piercing mechanism

We examined the apoptotic effect of a novel Probiotics Fermentation Technology (PFT) kefir grain product; PFT is a natural mixture composed primarily of Lactobacillus kefiri P-IF, a specific strain of L. kefiri with unique growth characteristics. The aim of this study was to examine the apoptotic effect of PFT on human multidrug-resistant (MDR) myeloid leukemia (HL60/AR) cells in vitro and explore the mechanistic approach underlying its effect. HL60/AR cells were cultured with PFT (0.6–5.0 mg/ml) for 3 days. The apoptotic effect of PFT was assessed through examination of percent apoptosis, caspase 3 activation, Bcl-2 expression levels and changes in mitochondrial membrane potential (MMP). PFT induced apoptosis in HL60/AR cells in a dose-dependent manner which was maximal at 67.5% for 5 mg/ml. Induction of apoptosis was associated with activation of caspase 3, decreased expression of Bcl-2 and decreased polarization of MMP. In addition, PFT showed a unique characteristic of piercing holes in HL60/AR cells, as indicated by AFM studies. This hole induction may be responsible for the apoptotic effect on cancer cells. These results suggest that PFT may act as a potential therapy for the treatment of MDR leukemia.

Label-free in vitro toxicity and uptake assessment of citrate stabilised gold nanoparticles in three cell lines

Background

Reliable in vitro toxicity testing is needed prior to the commencement of in vivo testing necessary for hazard identification and risk assessment of nanoparticles. In this study, the cytotoxicity and uptake of 14 nm and 20 nm citrate stabilised gold nanoparticles (AuNPs) in the bronchial epithelial cell line BEAS-2B, the Chinese hamster ovary cell line CHO, and the human embryonic kidney cell line HEK 293 were investigated.

Methods

Cytotoxicity of the AuNPs was assessed via traditional XTT-, LDH-, and ATP-based assays, followed by cell impedance studies. Dark-field imaging and hyperspectral imaging were used to confirm the uptake of AuNPs into the cells.

Results

Interference of the AuNPs with the XTT- and ATP-based assays was overcome through the use of cell impedance technology. AuNPs were shown to be relatively non-toxic using this methodology; nevertheless CHO cells were the most sensitive cell type with 20 nm AuNPs having the highest toxicity. Uptake of both 14 nm and 20 nm AuNPs was observed in all cell lines in a time- and cell type-dependent manner.

Conclusions

Using the cell impedance and dark-field hyperspectral imaging technologies, it was possible to study the toxicity of AuNPs in different cell lines and show that these cells could internalize AuNPs with their subsequent intracellular aggregation. It was also possible to show that this toxicity would not correlate with the level of uptake but it would correlate with cell-type and the size of the AuNPs. Therefore, these two label-free methodologies used in this study are suitable for in vitro studies on the effects of AuNPs, and could present themselves as appropriate and valuable methodologies for future nanoparticle toxicity and uptake studies.

Chinese herbal medicine-derived compounds for cancer therapy: a focus on hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Hepatocellular carcinoma (HCC) as the major histological subtype of primary liver cancer remains one of the most common malignancies worldwide. Due to the complicated molecular pathogenesis of HCC, the option for effective systemic treatment is quite limited. There exists a critical need to explore and evaluate possible alternative strategies for effective control of HCC. With a long history of clinical use, Chinese herbal medicine (CHM) is emerging as a noticeable choice for its multi-level, multi-target and coordinated intervention effects against HCC. With the aids of phytochemistry and molecular biological approaches, in the past decades many CHM-derived compounds have been carefully studied through both preclinical and clinical researches and have shown great potential in novel anti-HCC natural product development. The present review aimed at providing the most recent developments on anti-HCC compounds derived from CHM, especially their underlying pharmacological mechanisms.

MATERIALS AND METHODS

A systematic search of anti-HCC compounds from CHM was carried out focusing on literatures published both in English (PubMed, Scopus, Web of Science and Medline) and in Chinese academic databases (Wanfang and CNKI database).

RESULTS

In this review, we tried to give a timely and comprehensive update about the anti-HCC effects and targets of several representative CHM-derived compounds, namely curcumin, resveratrol, silibinin, berberine, quercetin, tanshinone II-A and celastrol. Their mechanisms of anti-HCC behaviors, potential side effects or toxicity and future research directions were discussed.

CONCLUSION

Herbal compounds derived from CHM are of much significance in devising new drugs and providing unique ideas for the war against HCC. We propose that these breakthrough findings may have important implications for targeted-HCC therapy and modernization of CHM.

Nano-hole induction by nanodiamond and nanoplatinum liquid, DPV576, reverses multidrug resistance in human myeloid leukemia (HL60/AR)

Recently nanoparticles have been extensively studied and have proven to be a promising candidate for cancer treatment and diagnosis. In the current study, we examined the chemo-sensitizing activity of a mixture of nanodiamond (ND) and nanoplatinum (NP) solution known as DPV576, against multidrug-resistant (MDR) human myeloid leukemia (HL60/AR) and MDR-sensitive cells (HL60). Cancer cells were cultured with different concentrations of daunorubicin (DNR) (1 × 10 ⁻⁹−1 × 10 ⁻⁶ M) in the presence of selected concentrations of DPV576 (2.5%–10% v/v). Cancer cell survival was determined by MTT assay, drug accumulation by flow cytometry and confocal laser scanning microscopy (CLSM), and holes and structural changes by atomic force microscopy (AFM). Co-treatment of HL60/AR cells with DNR plus DPV576 resulted in the reduction of the IC₅₀ to 1/4th. This was associated with increased incidences of holes inside the cells as compared with control untreated cells. On the other hand, HL60 cells did not show changes in their drug accumulation post-treatment with DPV576 and DNR. We conclude that DPV576 is an effective chemo-sensitizer as indicated by the reversal of HL60/AR cells to DNR and may represent a potential novel adjuvant for the treatment of chemo-resistant human myeloid leukemia.

Delivering flavonoids into solid tumors using nanotechnologies

INTRODUCTION

Long-term epidemiological studies have demonstrated that regular ingestion of flavonoids contained in dietary sources is associated with a reduced risk for many chronic diseases including cancer. However, although flavonoids are largely consumed in the diet and high concentrations may exist in the intestine after oral administration, the plasma/tissue concentrations of flavonoids are lower than their effective therapeutic doses due to poor bioavailability, resulting in the limited efficacy of flavonoids in various clinical studies. Therefore, the application of nanotechnology to deliver flavonoids to tumor sites has received considerable attention in recent years.

AREAS COVERED

In this review, after a general review of the potential benefits of flavonoids in cancer therapy and several key factors affecting their bioavailability, the current efforts in improving the delivery efficacy of promising candidates that are particularly important in the human diet, namely quercetin, epigallocatechin-3-gallate (EGCG) and genistein were focused on. Finally, the challenges of developing flavonoid delivery systems that improve flavonoid bioavailability and their anticancer therapy potentials were summarized.

EXPERT OPINION

The design of suitable molecular carriers for flavonoids is an area of research that is in rapid progress. A large number of unheeded promising favonoids are suffering from poor in vivo parameters, their potential benefits deserves further research. Furthermore, more effort should be placed on developing active targeting systems, evaluating the efficacy and toxicity of novel flavonoid delivery systems through small and large scale clinical trials.

Application and validation of an impedance-based real time cell analyzer to measure the toxicity of nanoparticles impacting human bronchial epithelial cells

Nanomaterials are increasingly used in a variety of industrial processes and consumer products. There are growing concerns about the potential impacts for public health and environment of engineered nanoparticles. The aim of this work was to evaluate a novel impedance-based real time cell analyzer (RTCA) as a high-throughput method for screening the cytotoxicity of nanoparticles and to validate the RTCA results using a conventional cytotoxicity test (MTT). A collection of 11 inorganic nanomaterials (Ag(0), Al(2)O(3), CeO(2), Fe(0), Fe(2)O(3), HfO(2), Mn(2)O(3), SiO(2), TiO(2), ZnO, and ZrO(2)) were tested for potential cytotoxicity to a human bronchial epithelial cell, 16HBE14o-. The data collected by the RTCA system was compared to results obtained using a more traditional methyl tetrazolium (MTT) cytotoxicity assay at selected time points following application of nanomaterials. The most toxic nanoparticles were ZnO, Mn(2)O(3) and Ag(0), with 50% response at concentrations lower than 75 mg/L. There was a good correlation in cytotoxicity measurements between the two methods; however, the RTCA method maintained a distinct advantage in continually following cytotoxicity over time. The results demonstrate the potential and validity of the impedance-based RTCA technique to rapidly screen for nanoparticle toxicity.

Nickel nanowires induced and reactive oxygen species mediated apoptosis in human pancreatic adenocarcinoma cells

Background

The ability to evade apoptosis is one of the key properties of cancer. The apoptogenic effect of nickel nanowires (Ni NWs) on cancer cell lines has never been adequately addressed. Due to the unique physicochemical characteristics of Ni NWs, we envision the development of a novel anticancer therapeutics specifically for pancreatic cancer. Thus, we investigated whether Ni NWs induce ROS-mediated apoptosis in human pancreatic adenocarcinoma (Panc-1) cells.

Methods

In this study Ni NWs were fabricated using the electrodeposition method. Synthesized Ni NWs were physically characterized by energy dispersive X-ray analysis, UV-Vis spectroscopy of NanoDrop 2000 (UV-Vis), magnetization study, scanning electron microscopy, and transmission electron microscopy. Assessment of morphological apoptotic characteristics by phase contrast microscopy (PCM), Ni-NWs-induced apoptosis staining with ethidium bromide (EB) and acridine orange (AO) followed by fluorescence microscopy (FM) was performed. For molecular biological and biochemical characterization, Panc-1 cell culture and cytotoxic effect of Ni NWs were determined by using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Quantitative apoptosis was analyzed by flow cytometry staining with propidium iodide through cell cycle arrest and generation of ROS using 2′, 7′-dichlorofluorescein diacetate fluorescence intensity. In all experiments, Panc-1 cancer cells without any treatment were used as the negative controls.

Results

The intracellular uptake of Ni NWs through endocytosis by Panc-1 cells was observed by PCM. EB and AO staining of FM and MTT assay qualitatively and quantitatively confirmed the extent of apoptosis. Flow cytometric cell cycle arrest and ROS generation indicated Ni NWs as inducers of apoptotic cell death.

Conclusion

We investigated the role of Ni NWs as inducers of ROS-mediated apoptosis in Panc-1 cells. These results suggested that Ni NWs could be an effective apoptotic agent for Panc-1 cells and have good potential for further research into a clinical treatment selective for pancreatic cancer.

The Photodynamic Effect of Different Size ZnO Nanoparticles on Cancer Cell Proliferation In Vitro

Nanomaterials have widely been used in the field of biological and biomedicine, such as tissue imaging, diagnosis and cancer therapy. In this study, we explored the cytotoxicity and photodynamic effect of different-sized ZnO nanoparticles to target cells. Our observations demonstrated that ZnO nanoparticles exerted dose-dependent and time-dependent cytotoxicity for cancer cells like hepatocellular carcinoma SMMC-7721 cells in vitro. Meanwhile, it was observed that UV irradiation could enhance the suppression ability of ZnO nanoparticles on cancer cells proliferation, and these effects were in the size-dependent manner. Furthermore, when ZnO nanoparticles combined with daunorubicin, the related cytotoxicity of anticancer agents on cancer cells was evidently enhanced, suggesting that ZnO nanoparticles could play an important role in drug delivery. This may offer the possibility of the great potential and promising applications of the ZnO nanoparticles in clinical and biomedical areas like photodynamic cancer therapy and others.