Akt signaling-associated metabolic effects of dietary gold nanoparticles in Drosophila

Nanoparticle-based drug delivery systems to modulate tumor immune response for glioblastoma treatment

Glioblastoma (GBM) is a primary central nervous system neoplasm, characterized by a grim prognosis and low survival rates. This unfavorable therapeutic outcome is partially attributed to the inadequate immune infiltration and an immunosuppressive microenvironment, which compromises the effectiveness of conventional radiotherapy and chemotherapy. To this end, precise modulation of cellular dynamics in the immune system has emerged as a promising approach for therapeutic intervention. The advent of nanoparticle-based therapies has revolutionized cancer treatment and provided highly effective options. Consequently, various strategically designed nano-delivery platforms have been established to promote the efficacy of immune therapy against GBM. This review delves into the recent advancements in nano-based delivery systems that are designed to modulate immune cells in GBM microenvironment, and explores their multifaceted mechanisms, including the blockade of immune checkpoints, the restraint of immunosuppressive cells, the coordination of tumor-associated macrophages, the activation of innate immune cells, and the stimulation of adaptive immunity. Collectively, this summary not only advances the comprehension involved in modulating antitumor immune responses in GBM, but also paves the way for the development of innovative therapeutic strategies to conquer GBM. STATEMENT OF SIGNIFICANCE: Glioblastoma (GBM) is the most lethal brain tumor, with a median survival rate of merely 12-16 months after diagnosis. Despite surgical, radiation and chemotherapy treatments, the two-year survival rate for GBM patients is less than 10 %. The treatment of GBM is challenging mainly because several issues associated with the GBM microenvironment have not yet been resolved. Most recently, novel drug delivery approaches, based on the clear understanding of the intrinsic properties of GBM, have shown promise in overcoming some of the obstacles. In particular, taking account of the highly immunosuppressive tumor microenvironment in GBM, recent advancements in nano-based delivery systems are put forward to stimulate immune cells in GBM and unravel their multifaceted mechanisms. This review summarizes the latest nanoparticle-based drug delivery systems to modulate tumor immune response for glioblastoma treatment. Moreover, the development trends and challenges of nanoparticle-based drug delivery systems in modulating the immunity of GBM are predicted, which may facilitate widespread regimens springing up for successfully treating GBM.

Emerging nanoparticle platforms for CpG oligonucleotide delivery

Unmethylated cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs), which were therapeutic DNA with high immunostimulatory activity, have been applied in widespread applications from basic research to clinics as therapeutic agents for cancer immunotherapy, viral infection, allergic diseases and asthma since their discovery in 1995. The major factors to consider for clinical translation using CpG motifs are the protection of CpG ODNs from DNase degradation and the delivery of CpG ODNs to the Toll-like receptor-9 expressed human B-cells and plasmacytoid dendritic cells. Therefore, great efforts have been devoted to the advances of efficient delivery systems for CpG ODNs. In this review, we outline new horizons and recent developments in this field, providing a comprehensive summary of the nanoparticle-based CpG delivery systems developed to improve the efficacy of CpG-mediated immune responses, including DNA nanostructures, inorganic nanoparticles, polymer nanoparticles, metal-organic-frameworks, lipid-based nanosystems, proteins and peptides, as well as exosomes and cell membrane nanoparticles. Moreover, future challenges in the establishment of CpG delivery systems for immunotherapeutic applications are discussed. We expect that the continuously growing interest in the development of CpG-based immunotherapy will certainly fuel the excitement and stimulation in medicine research.

Drosophila melanogaster as a dynamic in vivo model organism reveals the hidden effects of interactions between microplastic/nanoplastic and heavy metals

Plastic waste in different environments has been constantly transforming into microplastic/nanoplastic (MNPLs). As they may coexist with other contaminants, they may behave as vectors that transport various toxic trace elements, including metals. Because the impact of exposure to such matter on health still remains elusive, the abundant presence of MNPLs has lately become a pressing environmental issue. Researchers have been utilizing Drosophila melanogaster as a dynamic in vivo model in genetic research for some time. The fly has also recently gained wider recognition in toxicology and nanogenotoxicity studies. The use of nanoparticles in numerous medical and consumer products raises serious concern, since many in vitro studies have shown their toxic potential. However, there is rather limited in vivo research into nanomaterial genotoxicity using mice or other mammalians owing to high costs and ethical concerns. In this context, Drosophila, thanks to its genetic tractability, short life span, with its entire life cycle lasting about 10 days, and distinct developmental stages, renders this organism an excellent model in testing toxic effects mediated by MNPLs. This review therefore aims to encourage research entities to employ Drosophila as a model in their nanogenotoxicity experiments focusing on impact of MNPLs at the molecular level.

Gold Nanoparticles Disrupt the IGFBP2/mTOR/PTEN Axis to Inhibit Ovarian Cancer Growth

By exploiting the self-therapeutic properties of gold nanoparticles (GNPs) a molecular axis that promotes the growth of high-grade serous ovarian cancer (HGSOC), one of the deadliest gynecologic malignancies with poorly understood underlying molecular mechanisms, has been identified. The biodistribution and toxicity of GNPs administered by intravenous or intraperitoneal injection, both as a single dose or by repeated dosing over two weeks are first assessed; no biochemical or histological toxicity to vital organs is found. Using an orthotopic patient-derived xenograft (PDX) model of HGSOC, the authors then show that GNP treatment robustly inhibits tumor growth. Investigating the molecular mechanisms underlying the GNP efficacy reveals that GNPs downregulate insulin growth factor binding protein 2 (IGFBP2) by disrupting its autoregulation via the IGFBP2/mTOR/PTEN axis. This mechanism is validated by treating a cell line-based human xenograft tumor with GNPs and an mTOR dual-kinase inhibitor (PI-103), either individually or in combination with GNPs; GNP and PI-103 combination therapy inhibit ovarian tumor growth similarly to GNPs alone. This report illustrates how the self-therapeutic properties of GNPs can be exploited as a discovery tool to identify a critical signaling axis responsible for poor prognosis in ovarian cancer and provides an opportunity to interrogate the axis to improve patient outcomes.

Mechanisms and biological impacts of graphene and multi-walled carbon nanotubes on Drosophila melanogaster: Oxidative stress, genotoxic damage, phenotypic variations, locomotor behavior, parasitoid resistance, and cellular immune response

The use of graphene and multi-walled carbon nanotubes (MWCNTs) has now become rather common in medical applications as well as several other areas thanks to their useful physicochemical properties. While in vitro testing offers some potential, in vivo research into toxic effects of graphene and MWCNTs could yield much more reliable data. Drosophila melanogaster has recently gained significant popularity as a dynamic eukaryotic model in examining toxicity, genotoxicity, and biological effects of exposure to nanomaterials, including oxidative stress, cellular immune response against two strains (NSRef and G486) of parasitoid wasp (Leptopilina boulardi), phenotypic variations, and locomotor behavior risks. D. melanogaster was used as a model organism in our study to identify the potential risks of exposure to graphene (thickness: 2-18 nm) and MWCNTs in different properties (as pure [OD: 10-20 nm short], modified by amide [NH₂ ] [OD: 7-13 nm length: 55 μm], and modified by carboxyl [COOH] [OD: 30-50 nm and length: 0.5-2 μm]) at concentrations ranging from 0.1 to 250 μg/ml. Significant effects were observed at two high doses (100 and 250 μg/ml) of graphene or MWCNTs. This is the first study to report findings of cellular immune response against hematopoiesis and parasitoids, nanogenotoxicity, phenotypic variations, and locomotor behavior in D. melanogaster.

Design and Encapsulation of Immunomodulators onto Gold Nanoparticles in Cancer Immunotherapy

The aim of cancer immunotherapy is to reactivate autoimmune responses to combat cancer cells. To stimulate the immune system, immunomodulators, such as adjuvants, cytokines, vaccines, and checkpoint inhibitors, are extensively designed and studied. Immunomodulators have several drawbacks, such as drug instability, limited half-life, rapid drug clearance, and uncontrolled immune responses when used directly in cancer immunotherapy. Several strategies have been used to overcome these limitations. A simple and effective approach is the loading of immunomodulators onto gold-based nanoparticles (GNPs). As gold is highly biocompatible, GNPs can be administered intravenously, which aids in increasing cancer cell permeability and retention time. Various gold nanoplatforms, including nanospheres, nanoshells, nanorods, nanocages, and nanostars have been effectively used in cancer immunotherapy. Gold nanostars (GNS) are one of the most promising GNP platforms because of their unusual star-shaped geometry, which significantly increases light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. As a result, GNPs are a useful vehicle for delivering antigens and adjuvants that support the immune system in killing tumor cells by facilitating or activating cytotoxic T lymphocytes. This review represents recent progress in encapsulating immunomodulators into GNPs for utility in a cancer immunotherapeutic regimen.

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.

Drosophila as a model for assessing nanopesticide toxicity

One of the fastest-moving fields in today's world of applied science, nanotechnology allows the control and design of matter on an extremely small scale, so it has now become an integral part of various industries and scientific areas, such as agriculture, food sector, healthcare and engineering. Understanding the interactions between nanopesticides and edible plants, as well as non-target animals, is crucial in assessing the potential impact of nanotechnology products on the environment, agriculture and human health. The dramatic increase in efforts to use nanopesticides renders the risk assessment of their toxicity and genotoxicity highly crucial due to the potential adverse impact of this relatively uncharted territory. Such widespread use naturally increases our exposure to nanopesticides, raising concerns over their possible adverse effects on humans and non-target organisms, which might include severe impairment of both male and female reproductive capacity. We therefore need better insight into such effects to derive conclusive evidence on the safety or toxicity/genotoxicity of nanopesticides, and Drosophila melanogaster (fruit fly) can prove an ideal model organism for the risk assessment and toxicological classification of nanopesticides, as it bears striking similarities to various systems in human body. This editorial review attempts to summarize our current knowledge derived from previous in vivo studies to examine the impact of several nanomaterials on various species of mammals and non-target model organisms at the genetic, cellular, and molecular levels, attracting attention to the possible mechanisms and potential toxic/genotoxic effects of nanopesticides widely used in agriculture on D. melanogaster as a non-target organism.

Nanotechnology-based Drug Delivery, Metabolism and Toxicity

BACKGROUND

Nanoparticles (NPs) are being used extensively owing to their increased surface area, targeted delivery and enhanced retention. NPs have the potential to be used in many disease conditions. Despite widespread use, their toxicity and clinical safety still remain a major concern.

OBJECTIVE

The purpose of this study was to explore the metabolism and toxicological effects of nanotherapeutics.

METHODS

Comprehensive, time-bound literature search was done covering the period from 2010 till date. The primary focus was on the metabolism of NP including their adsorption, degradation, clearance, and bio-persistence. This review also focuses on updated investigations on NPs with respect to their toxic effects on various in vitro and in vivo experimental models.

RESULTS

Nanotechnology is a thriving field of biomedical research and an efficient drug delivery system. Further their applications are under investigation for diagnosis of disease and as medical devices.

CONCLUSION

The toxicity of NPs is a major concern in the application of NPs as therapeutics. Studies addressing metabolism, side-effects and safety of NPs are desirable to gain maximum benefits of nanotherapeutics.

Role of Serotonin Transporter in Eye Development of Drosophila melanogaster

Serotonin transporter (SerT) in the brain is an important neurotransmitter transporter involved in mental health. However, its role in peripheral organs is poorly understood. In this study, we investigated the function of SerT in the development of the compound eye in Drosophila melanogaster. We found that SerT knockdown led to excessive cell death and an increased number of cells in S-phase in the posterior eye imaginal disc. Furthermore, the knockdown of SerT in the eye disc suppressed the activation of Akt, and the introduction of PI3K effectively rescued this phenotype. These results suggested that SerT plays a role in the healthy eye development of D.melanogaster by controlling cell death through the regulation of the PI3K/Akt pathway.

Challenges and Opportunities from Basic Cancer Biology for Nanomedicine for Targeted Drug Delivery

Background:

Effective cancer therapy is still a great challenge for modern medical research due to the complex underlying mechanisms of tumorigenesis and tumor metastasis, and the limitations commonly associated with currently used cancer therapeutic options. Nanotechnology has been implemented in cancer therapeutics with immense potential for improving cancer treatment.

Objective:

Through information about the recent advances regarding cancer hallmarks, we could comprehensively understand the pharmacological effects and explore the mechanisms of the interaction between the nanomaterials, which could provide opportunities to develop mechanism-based nanomedicine to treat human cancers.

Methods:

We collected related information and data from articles.

Results:

In this review, we discussed the characteristics of cancer including tumor angiogenesis, abnormalities in tumor blood vessels, uncontrolled cell proliferation markers, multidrug resistance, tumor metastasis, cancer cell metabolism, and tumor immune system that provide opportunities and challenges for nanomedicine to be directed to specific cancer cells and portray the progress that has been accomplished in application of nanotechnology for cancer treatment.

Conclusion:

The information presented in this review can provide useful references for further studies on developing effective nanomedicine for the treatment of cancer.

Nitrogen doped carbon quantum dots demonstrate no toxicity under in vitro conditions in a cervical cell line and in vivo in Swiss albino mice

Carbon quantum dots (CQDs) and their derivatives have potential applications in the field of biomedical imaging. Toxicity is one of the critical parameters that can hamper their success in biological applications. In this context, our goal was to systematically investigate both in vivo and in vitro toxicity of nitrogen doped carbon quantum dots (NCQDs). In vivo toxic effects were evaluated for 30 days in Swiss albino mice at two different concentrations (5.0 mg per kg body weight (BW) and 10.0 mg per kg BW) of NCQDs. Results of haematological, serum biochemical, antioxidant and histopathological parameters showed no noteworthy defects at both of these concentrations. An in vitro assessment was performed against the human cervical cancer cell line (HeLa cells) at the concentration of 0-400 μg ml^-1. The LDH profile, DNA fragmentation, apoptosis, and growth cycle of cells showed no apparent toxicity of NCQDs. The overall study offers highly biocompatible N-doped carbon quantum dots, which may be considered as an attractive material for future biomedical applications.

Targeting the mTOR Signaling Pathway Utilizing Nanoparticles: A Critical Overview

Proteins of the mammalian target of rapamycin (mTOR) signaling axis are overexpressed or mutated in cancers. However, clinical inhibition of mTOR signaling as a therapeutic strategy in oncology shows rather limited progress. Nanoparticle-based mTOR targeted therapy proposes an attractive therapeutic option for various types of cancers. Along with the progress in the biomedical applications of nanoparticles, we start to realize the challenges and opportunities that lie ahead. Here, we critically analyze the current literature on the modulation of mTOR activity by nanoparticles, demonstrate the complexity of cellular responses to functionalized nanoparticles, and underline challenges lying in the identification of the molecular mechanisms of mTOR signaling affected by nanoparticles. We propose the idea that subcytotoxic doses of nanoparticles could be relevant for the induction of subcellular structural changes with possible involvement of mTORC1 signaling. The evaluation of the mechanisms and therapeutic effects of nanoparticle-based mTOR modulation will provide fundamental knowledge which could help in developing safe and efficient nano-therapeutics.

The effects of a human food additive, titanium dioxide nanoparticles E171, on Drosophila melanogaster - a 20 generation dietary exposure experiment

In this study, fruit flies (Drosophila melanogaster) were exposed to an estimated daily human E171 consumption concentration for 20 generations. Exposure to E171 resulted in: a change in normal developmental and reproductive dynamics, reduced fecundity after repetitive breeding, increased genotoxicity, the appearance of aberrant phenotypes and morphologic changes to the adult fat body. Marks of adaptive evolution and directional selection were also exhibited. The larval stages were at a higher risk of sustaining damage from E171 as they had a slower elimination rate of TiO2 compared to the adults. This is particularly worrisome, since among the human population, children tend to consume higher daily concentrations of E171 than do adults. The genotoxic effect of E171 was statistically higher in each subsequent generation compared to the previous one. Aberrant phenotypes were likely caused by developmental defects induced by E171, and were not mutations, since the phenotypic features were not transferred to any progeny even after 5 generations of consecutive crossbreeding. Therefore, exposure to E171 during the early developmental period carries a higher risk of toxicity. The fact that the daily human consumption concentration of E171 interferes with and influences fruit fly physiological, ontogenetic, genotoxic, and adaptive processes certainly raises safety concerns.

Inhibition of Epithelial-Mesenchymal Transition and Tissue Regeneration by Waterborne Titanium Dioxide Nanoparticles

Titanium dioxide nanoparticles (TiO₂NPs) are among the most widely manufactured nanomaterials with broad applications in food industry, cosmetics, and medicine. Although the toxicity of TiO₂NPs at high doses has been extensively explored, the potential health risks of TiO₂NPs exposure at nontoxic concentrations remain poorly understood. Epithelial-mesenchymal transition (EMT) plays pivotal roles in a diversity of physiological and pathological processes, including tissue regeneration and cancer metastasis. In this study, we find that the cellular uptake of TiO₂NPs inhibits EMT-mediated cell remodeling and cell migration without exhibiting cytotoxicity. Further investigation reveals that TiO₂NPs suppress the process of EMT through the blockade of transforming growth factor-β (TGFβ) signaling. Particularly, TiO₂NPs interact with the TGFβ receptor TβRI/II complex, induce its lysosomal degradation, and thereby downregulate expression of TGFβ target genes. Moreover, we show that waterborne TiO₂NPs do not elicit toxicity in healthy tissues but hamper EMT-mediated wound healing in two animal models. Long-term exposure of TiO₂NPs in environmental water and drinking water impede the regeneration of amputated fin in zebrafish and the recovery of intestinal mucosal damage in colitic mice. Our results reveal the previously unknown effects of TiO₂NPs during tissue remodeling and repair, which have significant implications in their risk assessment and management.

Mapping the Glyco-Gold Nanoparticles of Different Shapes Toxicity, Biodistribution and Sequestration in Adult Zebrafish

Glyconanotechnology offers a broad range of applications across basic and translation research. Despite the tremendous progress in glyco-nanomaterials, there is still a huge gap between the basic research and therapeutic applications of these molecules. It has been reported that complexity and the synthetic challenges in glycans synthesis, the cost of the high order in vivo models and large amount of sample consumptions limited the effort to translate the glyco-nanomaterials into clinical applications. In this regards, several promising simple animal models for preliminary, quick analysis of the nanomaterials activities has been proposed. Herein, we have studied a systematic evaluation of the toxicity, biodistribution of fluorescently tagged PEG and mannose-capped gold nanoparticles (AuNPs) of three different shapes (sphere, rod, and star) in the adult zebrafish model, which could accelerate and provide preliminary results for further experiments in the higher order animal system. ICP-MS analysis and confocal images of various zebrafish organs revealed that rod-AuNPs exhibited the fast uptake. While, star-AuNPs displayed prolong sequestration, demonstrating its potential therapeutic efficacy in drug delivery.

Gold nanoparticles enhance the differentiation of embryonic stem cells into dopaminergic neurons via mTOR/p70S6K pathway

AIM

This study aimed to investigate the effect of gold nanoparticles (AuNPs) on differentiation of mouse embryonic stem cells (ESCs) into dopaminergic (DA) neurons and explore the possible underlying molecular mechanisms.

MATERIALS & METHODS

The efficiency of AuNPs on DA neuron differentiation was evaluated by observing fluorescence in TH promoter-engineered GFP-reporter ESCs, western blot and real-time PCR. The possible signal pathway was determined by western blot.

RESULTS

Compared with feeder-free control condition, AuNPs are able to enhance fate specification of ESCs into DA neurons. Moreover, mTOR/p70S6K signaling pathway was found involving in this AuNPs-mediated DA neuron differentiation.

CONCLUSION

Our findings may lead future insight investigation into the underlying mechanisms and potential application of AuNPs in stem cell research.

Advances in DNA Nanostructure-Based Smart Drug Delivery Systems

Highly specific deoxyribonucleic acid (DNA) base-pairing not only carries genetic information, but also provides the basis for self-assembly of novel nanostructures with programmable shapes and sizes. Unlike single-stranded and double-stranded DNA, DNA nanostructures exhibit good cellular permeability. They also have characteristics of uniform size, easy functionalization, precise addressability, excellent water solubility and high biocompatibility. Due to their unique properties, these tailored molecular devices are ideal nanoscale systems for targeting cells and triggering cellular responses. Recent progress in the field of DNA nanotechnology has demonstrated effectiveness and advantages of DNA nanostructures as smart and targeted drug delivery systems or imaging agents within living organisms. In this review, we summarize the recent advances in structure design, cargo loading and cellular delivery of DNA nanocarriers, and discuss their potential in therapeutic applications.

Mechanism of ROS scavenging and antioxidant signalling by redox metallic and fullerene nanomaterials: Potential implications in ROS associated degenerative disorders

BACKGROUND

The balance between oxidation and anti-oxidation is believed to be critical in maintaining healthy biological systems. However, our endogenous antioxidant defense systems are incomplete without exogenous antioxidants and, therefore, there is a continuous demand for exogenous antioxidants to prevent stress and ageing associated disorders. Nanotechnology has yielded enormous variety of nanomaterials (NMs) of which metallic and carbonic (mainly fullerenes) NMs, with redox property, have been found to be strong scavengers of ROS and antioxidants in preclinical in vitro and in vivo models.

SCOPE OF REVIEW

Redox activity of metal based NMs and membrane translocation time of fullerene NMs seem to be the major determinants in ROS scavenging potential exhibited by these NMs. A comprehensive knowledge about the effects of ROS scavenging NMs in cellular antioxidant signalling is largely lacking. This review compiles the mechanisms of ROS scavenging as well as antioxidant signalling of the aforementioned metallic and fullerene NMs.

MAJOR CONCLUSIONS

Direct interaction between NMs and proteins does greatly affect the corona/adsorption formation dynamics but such interaction does not provide the explanation behind diverse biological outcomes induced by NMs. Indirect interaction, however, that could occur via NMs uptake and dissolution, NMs ROS induction and ROS scavenging property, and NMs membrane translocation time seem to work as a central mode of interaction.

GENERAL SIGNIFICANCE

The usage of potential antioxidant NMs in biological systems would greatly impact the field of nanomedicine. ROS scavenging NMs hold great promise in the future treatment of ROS related degenerative disorders.

Silica Nanoparticles Target a Wnt Signal Transducer for Degradation and Impair Embryonic Development in Zebrafish

Many types of biocompatible nanomaterials have proven of low cytotoxicity and hold great promise for various applications in nanomedicine. Whereas they generally do not cause apparent organ toxicity or tissue damage in adult animals, it is yet to determine their biological consequences in more general contexts. In this study, we investigate how silica nanoparticles (NPs) affect cellular activities and functions under several physiological or pathological conditions. Although silica NPs are generally regarded as "inert" nanocarriers and widely employed in biomedical studies, we find that they actively affect Wnt signaling in various types of cell lines, diminishing its anti-adipogenic effect in preadipocytes and pro-invasive effect in breast cancer cells, and more significantly, impair Wnt-regulated embryonic development in Zebrafish. We further demonstrate that intracellular silica NPs block Wnt signal transduction in a way resembling signaling molecules. Specifically, silica NPs target the Dvl protein, a key component of Wnt signaling cascade, for lysosomal degradation. As Wnt signaling play significant roles in embryonic development and adipogenesis, the observed physiological effects beyond toxicity imply potential risk of obesity, or developmental defects in somitogenesis and osteogenesis upon exposure to silica NPs. In addition, given the clinical implications of Wnt signaling in tumorigenesis and cancer metastasis, our work also establishes for the first time a molecular link between nanomaterials and the Wnt signaling pathway, which opens new door for novel applications of unmodified silica NPs in targeted therapy for cancers and other critical illness.

Dietary Iron Oxide Nanoparticles Delay Aging and Ameliorate Neurodegeneration in Drosophila

Dietary iron oxide nanoparticles are shown to ameliorate neurodegeneration in a Drosophelia Alzheimer's disease model. Iron oxide nanoparticles can mimic catalase and can decompose reactive oxygen species (ROS). This has potential therapeutic uses for aging, metabolic disorders, and neurodegenerative diseases, in which increased production of ROS is closely implicated.

Biomedical Potential of mTOR Modulation by Nanoparticles

Modulation of the mammalian target of rapamycin (mTOR), the principal regulator of cellular homeostasis, underlies the biological effects of engineered nanoparticles, including regulation of cell death/survival and metabolic responses. Understanding the mechanisms and biological actions of nanoparticle-mediated mTOR modulation may help in developing safe and efficient nanotherapeutics to fight human disease.

Drosophotoxicology: An Emerging Research Area for Assessing Nanoparticles Interaction with Living Organisms

The rapid development of nanotechnology allowed the fabrication of a wide range of different nanomaterials, raising many questions about their safety and potential risks for the human health and environment. Most of the current nanotoxicology research is not standardized, hampering any comparison or reproducibility of the obtained results. Drosophotoxicology encompasses the plethora of methodological approaches addressing the use of Drosophila melanogaster as a choice organism in toxicology studies. Drosophila melanogaster model offers several important advantages, such as a relatively simple genome structure, short lifespan, low maintenance cost, readiness of experimental manipulation comparative to vertebrate models from both ethical and technical points of view, relevant gene homology with higher organisms, and ease of obtaining mutant phenotypes. The molecular pathways, as well as multiple behavioral and developmental parameters, can be evaluated using this model in lower, medium or high throughput type assays, allowing a systematic classification of the toxicity levels of different nanomaterials. The purpose of this paper is to review the current research on the applications of Drosophila melanogaster model for the in vivo assessment of nanoparticles toxicity and to reveal the huge potential of this model system to provide results that could enable a proper selection of different nanostructures for a certain biomedical application.

Targeting and retention enhancement of quantum dots decorated with amino acids in an invertebrate model organism

The use of quantum dots (QDs) in biological imaging applications and targeted drug delivery is expected to increase. However, the efficiency of QDs in drug targeting needs to be improved. Here, we show that amino acids linked to CdTe QDs significantly increased the targeted transfer efficiency and biological safety in the invertebrate model Bombyx mori. Compared with bare QDs530, the transfer efficiency of Ala- and Gly-conjugated QDs (QDs530-Ala and QDs530-Gly) in circulatory system increased by 2.6 ± 0.3 and 1.5 ± 0.3 times, and increased by 7.8 ± 0.9 and 2.9 ± 0.2 times in target tissue silk glands, respectively, after 24 h of QDs exposure. Meanwhile, the amount of conjugated QDs decreased by (68.4 ± 4.4)% and (46.7 ± 9.1)% in the non-target tissue fat body, and the speed at which they entered non-target circulating blood cells significantly decreased. The resultant QDs530-Ala revealed a better structural integrity in tissues and a longer retention time in hemolymph than that of QDs530 after exposure via the dorsal vessel. On the other hand, QDs530-Ala significantly reduced the toxicity to hemocytes, silk gland, and fat body, and reduced the amount of reactive oxygen species (ROS) in tissues.

Drosophila melanogaster as a suitable in vivo model to determine potential side effects of nanomaterials: A review

Despite being a relatively new field, nanoscience has been in the forefront among many scientific areas. Nanoparticle materials (NM) present interesting physicochemical characteristics not necessarily found in their bulky forms, and alterations in their size or coating markedly modify their physical, chemical, and biological properties. Due to these novel properties there is a general trend to exploit these NM in several fields of science, particularly in medicine and industry. The increased presence of NM in the environment warrants evaluation of potential harmful effects in order to protect both environment and human exposed populations. Although in vitro approaches are commonly used to determine potential adverse effects of NM, in vivo studies generate data expected to be more relevant for risk assessment. As an in vivo model Drosophila melanogaster was previously found to possess reliable utility in determining the biological effects of NM, and thus its usage increased markedly over the last few years. The aims of this review are to present a comprehensive overview of all apparent studies carried out with NM and Drosophila, to attain a clear and comprehensive picture of the potential risk of NM exposure to health, and to demonstrate the advantages of using Drosophila in nanotoxicological investigations.

Bioinert Anodic Alumina Nanotubes for Targeting of Endoplasmic Reticulum Stress and Autophagic Signaling: A Combinatorial Nanotube-Based Drug Delivery System for Enhancing Cancer Therapy

Although nanoparticle-based targeted delivery systems have gained promising achievements for cancer therapy, the development of sophisticated strategies with effective combinatorial therapies remains an enduring challenge. Herein, we report the fabrication of a novel nanomaterial, so-called anodic alumina nanotubes (AANTs) for proof-of-concept cancer therapy by targeting cell signaling networks. This strategy is to target autophagic and endoplasmic reticulum (ER) stress signaling by using thapsigargin (TG)-loaded AANTs cotreated with an autophagy inhibitor 3-methyladenine (3-MA). We first show that AANTs are nontoxic and can activate autophagy in different cell types including human fibroblast cells (HFF), human monocyte cells (THP-1), and human breast cancer cells (MDA-MB 231-TXSA). Treatment with 3-MA at a nontoxic dose reduced the level of autophagy induced by AANTs, and consequently sensitized breast cancer cells to AANTs-induced cellular stresses. To target autophagic and ER stress signaling networking, breast cancer cells were treated with 3-MA together with AANTs loaded with the prototype ER stress inducer TG. We demonstrated that 3-MA enhanced the cancer cell killing effect of AANTs loaded with TG. This effect was associated with enhanced ER stress signaling due to the combination effect of TG and 3-MA. These findings not only demonstrate the excellent biocompatibility of AANTs as novel biomaterials but also provide new opportunities for developing ER- and autophagy-targeted delivery systems for future clinical cancer therapy.

Disruptive chemicals, senescence and immortality

Carcinogenesis is thought to be a multistep process, with clonal evolution playing a central role in the process. Clonal evolution involves the repeated 'selection and succession' of rare variant cells that acquire a growth advantage over the remaining cell population through the acquisition of 'driver mutations' enabling a selective advantage in a particular micro-environment. Clonal selection is the driving force behind tumorigenesis and possesses three basic requirements: (i) effective competitive proliferation of the variant clone when compared with its neighboring cells, (ii) acquisition of an indefinite capacity for self-renewal, and (iii) establishment of sufficiently high levels of genetic and epigenetic variability to permit the emergence of rare variants. However, several questions regarding the process of clonal evolution remain. Which cellular processes initiate carcinogenesis in the first place? To what extent are environmental carcinogens responsible for the initiation of clonal evolution? What are the roles of genotoxic and non-genotoxic carcinogens in carcinogenesis? What are the underlying mechanisms responsible for chemical carcinogen-induced cellular immortality? Here, we explore the possible mechanisms of cellular immortalization, the contribution of immortalization to tumorigenesis and the mechanisms by which chemical carcinogens may contribute to these processes.

Transportation and fate of gold nanoparticles in oilseed rape

In this work, we demonstrate the mild effect of AuNPs on the growth of oilseed rape seedlings and suggest their potential application as vehicles for gene delivery in plants.

Antioxidant and antigenotoxic properties of CeO2 NPs and cerium sulphate: Studies with Drosophila melanogaster as a promising in vivo model

Although in vitro approaches are the most used for testing the potential harmful effects of nanomaterials, in vivo studies produce relevant information complementing in vitro data. In this context, we promote the use of Drosophila melanogaster as a suitable in vivo model to characterise the potential risks associated to nanomaterials exposure. The main aim of this study was to evaluate different biological effects associated to cerium oxide nanoparticles (Ce-NPs) and cerium (IV) sulphate exposure. The end-points evaluated were egg-to-adult viability, particles uptake through the intestinal barrier, gene expression and intracellular reactive oxygen species (ROS) production by haemocytes, genotoxicity and antigenotoxicity. Transmission electron microscopy images showed internalisation of Ce-NPs by the intestinal barrier and haemocytes, and significant expression of Hsp genes was detected. In spite of these findings, neither toxicity nor genotoxicity related to both forms of cerium were observed. Interestingly, Ce-NPs significantly reduced the genotoxic effect of potassium dichromate and the intracellular ROS production. No morphological malformations were detected after larvae treatment. This study highlights the importance of D. melanogaster as animal model in the study of the different biological effects caused by nanoparticulated materials, at the time that shows its usefulness to study the role of the intestinal barrier in the transposition of nanomaterials entering via ingestion.

Long-term effects of nanoparticles on nutrition and metabolism

Nanoparticles have shown great potential in biological and biomedical applications due to their distinct physical and chemical properties. In the meanwhile, the biosafety of nanoparticles has also raised intense concerns worldwide. To address such concerns, great efforts have been made to examine short-term effects of nanoparticles on cell survival and proliferation. More recently, exploration of long-term effects of nanomaterials, particularly those with promising biomedical applications in vivo, has aroused significant interest. For example, gold nanoparticles (AuNPs) are generally considered non-toxic to cell growth, whereas recent studies suggest that AuNPs might have long-term effects on cellular metabolism and energy homeostasis. In this Review, recent advances in this direction are summarized. Further, possible mechanisms under which nanoparticles regulate metabolic signaling pathways, potential long-term effects on cellular anabolic or catabolic processes, and their implications in human health and metabolic disorders are discussed.

A fruit fly in the nanoworld: once again Drosophila contributes to environment and human health

Drosophila was the most important model organism used in the fields of medicine and biology over the last century. Recently, Drosophila was successfully used in several studies in the field of nanotoxicology. However, only a part of its potential has been exploited in this field until now. In fact, apart from macroscopic observations of the effect due to the interaction between nanomaterials and living organism (i.e. lifespan, fertility, phenotypic aberrations, etc.), Drosophila has the potential to be a very useful tool to deeply analyze the molecular pathways involved in response to the interactions at nano-bio level. The aim of this editorial is to encourage the use of Drosophila by the different research groups working in the fields of nanotoxicology and nanomedicine, in order to define the effects induced by nanomaterials at molecular level for their subsequent exploitation in the field of nanomedicine.

Self-assembly of poly-adenine-tailed CpG oligonucleotide-gold nanoparticle nanoconjugates with immunostimulatory activity

Synthetic unmethylated cytosine-guanine (CpG) oligodeoxynucleotides (CpG ODNs) possess high immunostimulatory activity and have been widely used as a therapeutic tool for various diseases including infection, allergies, and cancer. A variety of nanocarriers have been developed for intracellular delivery of CpG ODNs that are otherwise nonpermeable through the cellular membrane. For example, previous studies showed that gold nanoparticles (AuNPs) could efficiently deliver synthetic thiolated CpG ODNs into cultured cells and induce expression of proinflammatory cytokines. Nevertheless, the necessity of using thiolated CpG ODNs for the modification of AuNPs inevitably complicates the synthesis of the nanoconjugates and increases the cost. A new approach is demonstrated for facile assembly of AuNP-CpG nanoconjugates for cost-effective drug delivery. It is found that non-thiolated, diblock ODNs containing a CpG motif and a poly-adenine (polyA) tail can readily self-assemble on the surface of AuNPs with controllable and tunable density. Such nanoconjugates are efficiently delivered into RAW264.7 cells and induce immune response in a Toll-like receptor 9 (TLR9)-dependent manner. Under optimal conditions, polyA-CpG-AuNPs show significantly higher immunostimulatory activity than their thiolated counterpart. In addition, the immunostimulatory activity of CpG-AuNPs can be modulated by varying the length of the polyA tail. In vivo induction of immune responses in mice is demonstrated by using polyA-tailed CpG-AuNP nanoconjugates.

Ingestion of gallium phosphide nanowires has no adverse effect on Drosophila tissue function

Engineered nanoparticles have been under increasing scrutiny in recent years. High aspect ratio nanoparticles such as carbon nanotubes and nanowires have raised safety concerns due to their geometrical similarity to asbestos fibers. III-V epitaxial semiconductor nanowires are expected to be utilized in devices such as LEDs and solar cells and will thus be available to the public. In addition, clean-room staff fabricating and characterizing the nanowires are at risk of exposure, emphasizing the importance of investigating their possible toxicity. Here we investigated the effects of gallium phosphide nanowires on the fruit fly Drosophila melanogaster. Drosophila larvae and/or adults were exposed to gallium phosphide nanowires by ingestion with food. The toxicity and tissue interaction of the nanowires was evaluated by investigating tissue distribution, activation of immune response, genome-wide gene expression, life span, fecundity and somatic mutation rates. Our results show that gallium phosphide nanowires applied through the diet are not taken up into Drosophila tissues, do not elicit a measurable immune response or changes in genome-wide gene expression and do not significantly affect life span or somatic mutation rate.

Gold nanoparticles: emerging paradigm for targeted drug delivery system

The application of nanotechnology in medicine, known as nanomedicine, has introduced a plethora of nanoparticles of variable chemistry and design considerations for cancer diagnosis and treatment. One of the most important field is the design and development of pharmaceutical drugs, based on targeted drug delivery system (TDDS). Being inspired by physio-chemical properties of nanoparticles, TDDS are designed to safely reach their targets and specifically release their cargo at the site of disease for enhanced therapeutic effects, thereby increasing the drug tissue bioavailability. Nanoparticles have the advantage of targeting cancer by simply being accumulated and entrapped in cancer cells. However, even after rapid growth of nanotechnology in nanomedicine, designing an effective targeted drug delivery system is still a challenging task. In this review, we reveal the recent advances in drug delivery approach with a particular focus on gold nanoparticles. We seek to expound on how these nanomaterials communicate in the complex environment to reach the target site, and how to design the effective TDDS for complex environments and simultaneously monitor the toxicity on the basis of designing such delivery complexes. Hence, this review will shed light on the research, opportunities and challenges for engineering nanomaterials with cancer biology and medicine to develop effective TDDS for treatment of cancer.