Cellular uptake and toxicity of gold nanoparticles on two distinct hepatic cell models

Role of ESCCAL-1 in regulating exocytosis of AuNPs in human esophageal squamous carcinoma cells

Exocytosis is a critical factor for designing efficient nanocarriers and determining cytotoxicity. However, the research on the exocytosis mechanism of nanoparticles, especially the role of long non-coding RNAs (lncRNAs), has not been reported. In this study, the exocytosis of AuNPs in the KYSE70 cells and the involved molecular pathways of exocytosis are analyzed. It demonstrates that nanoparticles underwent time-dependent release from the cells by exocytosis, and the release of β-hexosaminidase confirms that AuNPs are excreted through lysosomes. Mechanistic studies reveal that lncRNA ESCCAL-1 plays a vital role in controlling the exocytosis of AuNPs through activation of the MAPK pathway, including the phosphorylation of ERK and JNK. The study implies that the ESCCAL-1-mediated pathway plays an important role in the exocytosis of AuNPs in KYSE70 cells. This finding has implications for the role of ESCCAL-1 on the drug resistance of esophagus cancer by controlling lysosome-mediated exocytosis.

Nanomaterials in the environment and their pragmatic voyage at various trophic levels in an ecosystem

In the development of nanotechnology, nanomaterials (NMs) have a huge credential in advancing the existing follow-ups of analytical and diagnosis techniques, drug designing, agricultural science, electronics, cosmetics, sports, textiles and water purification. However, NMs have also grasped attention of researchers onto their toxicity. In the present review, initially the development of notable NMs such as metal and metal-oxide nanoparticles (NPs), magnetic NPs, carbon-based NMs and quantum dots intended to be commercialized along with their applications are discussed. This is followed by the current scenario of NMs in the environment to widen the outlook on the concentration of NPs in the environmental compartments and the frequency of organism exposed to NPs at varied trophic levels. In order to understand the physiochemical and morphological significance of NPs in exhibiting toxicity, fate of NPs in the environment is briefly deliberated. This is further geared-up to glance in-sightedly on the organisms starting from primary producer to primary consumer, secondary consumer, tertiary consumer and decomposers encountering NPs in their habitual niche. The state of NPs to which organisms are exposed, mechanism of NP uptake and toxicity, anomalies faced at each trophic level, concentration of NPs that is liable to cause toxicity and, biotransfer of NPs to the next generation and trophic level are detailed. Finally, the future prospects on bioaccumulation and biomagnification of NP-based products are conversed. Thus, the review would be noteworthy in unveiling the significance of NPs in forthcoming years combined with threat towards each organism in an ecosystem.

Critical parameters to translate gold nanoparticles as radiosensitizing agents into the clinic

Radiotherapy is an inevitable choice for cancer treatment that is applied as combinatorial therapy along with surgery and chemotherapy. Nevertheless, radiotherapy at high doses kills normal and tumor cells at the same time. In addition, some tumor cells are resistant to radiotherapy. Recently, many researchers have focused on high-Z nanomaterials as radiosensitizers for radiotherapy. Among them, gold nanoparticles (GNPs) have shown remarkable potential due to their promising physical, chemical, and biological properties. Although few clinical trial studies have been performed on drug delivery and photosensitization with lasers, GNPs have not yet received Food and Drug Administration approval for use in radiotherapy. The sensitization effects of GNPs are dependent on their concentration in cells and x-ray energy deposition during radiotherapy. Notably, some limitations related to the properties of the GNPs, including their size, shape, surface charge, and ligands, and the radiation source energy should be resolved. At the first, this review focuses on some of the challenges of using GNPs as radiosensitizers and some biases among in vitro/in vivo, Monte Carlo, and clinical studies. Then, we discuss the challenges in the clinical translation of GNPs as radiosensitizers for radiotherapy and proposes feasible solutions. And finally, we suggest that certain areas be considered in future research. This article is categorized under: Therapeutic Approaches and Drug Discovery > NA.

Anti-inflammatory role of gold nanoparticles in the prevention and treatment of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that causes memory and cognitive dysfunction and reduces a person's decision-making and reasoning functions. AD is the leading cause of dementia in the elderly. Patients with AD have increased expression of pro-inflammatory cytokines in the nervous system, and the sustained inflammatory response impairs neuronal function. Meanwhile, long-term use of anti-inflammatory drugs can reduce the incidence of AD to some extent. This confirms that anti-neuroinflammation may be an effective treatment for AD. Gold nanoparticles (AuNPs) are an emerging nanomaterial with promising physicochemical properties, anti-inflammatory and antioxidant. AuNPs reduce neuroinflammation by inducing macrophage polarization toward the M2 phenotype, reducing pro-inflammatory cytokine expression, blocking leukocyte adhesion, and decreasing oxidative stress. Therefore, AuNPs are gradually attracting the interest of scholars and are used for treating inflammatory diseases and drug delivery. Herein, we explored the role and mechanism of AuNPs in treating neuroinflammation in AD. The use of AuNPs for treating AD is a topic worth exploring in the future, not only to help solve a global public health problem but also to provide a reference for treating other neuroinflammatory diseases.

Nanomaterial-based ophthalmic drug delivery

The low bioavailability and side effects of conventional drugs for eye disease necessitate the development of efficient drug delivery systems. Accompanying the developments of nanofabrication techniques, nanomaterials have been recognized as promising tools to overcome these challenges due to their flexible and programmable properties. Given the advances achieved in material science, a broad spectrum of functional nanomaterials capable of overcoming various ocular anterior and posterior segment barriers have been explored to satisfy the demands for ocular drug delivery. In this review, we first highlight the unique functions of nanomaterials suitable for carrying and transporting ocular drugs. Then, various functionalization strategies are emphasized to endow nanomaterials with superior performance in enhanced ophthalmic drug delivery. The rational design of several affecting factors is essential for ideal nanomaterial candidates and is depicted as well. Lastly, we introduce the current applications of nanomaterial-based delivery systems in the therapy of different ocular anterior and posterior segment diseases. The limitations of these delivery systems as well as potential solutions are also discussed. This work will inspire innovative design thinking for the development of nanotechnology-mediated strategies for advanced drug delivery and treatment toward ocular diseases.

Curcumin-reduced gold nanoparticles facilitate IL-12 delivery to a cervical cancer in vitro cell model

Aim: To synthesize curcumin-reduced gold nanoparticles (AuNPs) for the efficient delivery to and expression of the IL-12 gene in cervical cancer (HeLa) cells in vitro. Methods: Curcumin-reduced AuNPs were synthesized, stabilized with poly-L-lysine and PEG, conjugated to IL-12 DNA and physicochemically characterized. Cytotoxicity and IL-12 expression were accessed in vitro. Results & discussion: Stable, spherical AuNPs effectively compacted and protected the IL-12 DNA and tolerated well in vitro. Real-time quantitative PCR and ELISA confirmed the successful delivery and expression of the IL-12 gene in HeLa cells. Conclusion: The favorable attributes of this AuNP-delivery system and the significant IL-12 expression obtained augur well for cytokine-based therapy or immunotherapy in cervical cancer.

Metal-based nanomaterials and nanocomposites as promising frontier in cancer chemotherapy

Cancer is a disease associated with complex pathology and one of the most prevalent and leading reasons for mortality in the world. Current chemotherapy has challenges with cytotoxicity, selectivity, multidrug resistance, and the formation of stemlike cells. Nanomaterials (NMs) have unique properties that make them useful for various diagnostic and therapeutic purposes in cancer research. NMs can be engineered to target cancer cells for early detection and can deliver drugs directly to cancer cells, reducing side effects and improving treatment efficacy. Several of NMs can also be used for photothermal therapy to destroy cancer cells or enhance immune response to cancer by delivering immune-stimulating molecules to immune cells or modulating the tumor microenvironment. NMs are being modified to overcome issues, such as toxicity, lack of selectivity, increase drug capacity, and bioavailability, for a wide spectrum of cancer therapies. To improve targeted drug delivery using nano-carriers, noteworthy research is required. Several metal-based NMs have been studied with the expectation of finding a cure for cancer treatment. In this review, the current development and the potential of plant and metal-based NMs with their effects on size and shape have been discussed along with their more effective usage in cancer diagnosis and treatment.

Customizable Dual-Fluorescent Nanoparticles for Tracing and Quantifying of Cell Transport

Purpose

Nanotechnology-based drug delivery systems (nano-DDS) have been developed to be a promising strategy to improve the efficacy, safety, physicochemical and pharmacokinetic/pharmacodynamics properties of drugs. It is very necessary to elucidate the delivery process in vivo or in cells for the rational design and accurate preparation of nano-DDS. The aim of this study was to construct a nano-DDS to visualize and quantify the intracellular behavior of the loaded cargo and carrier in such a system.

Methods

A carboxyl-terminal end of poly(lactic-co-glycolic acid) polymer was fluorescently labeled with rhodamine B by conjugation of ethylenediamine. Dual-fluorescent nanoparticles (DFPs) were prepared from this fluorescently labeled polymer to encapsulate a fluorescent cargo, coumarin 6. The carrier and cargo of DFPs were monitored by confocal fluorescence microscopy during cellular uptake. Furthermore, the transcellular transportation of DFPs was evaluated quantitatively by measuring the fluorescence intensity.

Results

The obtained fluorescent polymer showed stable and quantifiable characteristics. DFPs could be customized in terms of coumarin 6 content (97.7±1.0%), size (367.3±1.7 nm) and dual-emission fluorescence (green cargo and red carrier). DFPs did not significantly affect cell viability, the integrity of cell monolayers and the microscopic morphology at concentrations below 0.7 mg/mL within 3 h of co-incubation with Caco-2 cells. Multichannel fluorescence monitoring revealed that the fluorescence intensity of the carrier and cargo increased with time, but not synchronously. By calculating the residual, intracellular, and transport amounts of DFPs, the material balance between the total amount of cellular transport and the dose administered was obtained.

Conclusion

Based on the advantages of dual fluorescent labeling, the differential behavior of cell trafficking can be visualized and quantitatively analyzed for the cargo and carrier of DFPs. These results provide insights into the cellular transport process of holistic nanoparticles and complement our understanding of the biological behaviors of nano-DDS.

Green Synthesis and Antiproliferative Activity of Gold Nanoparticles of a Controlled Size and Shape Obtained Using Shock Wave Extracts from Amphipterygium adstringens

In this study, green chemistry was used as a tool to obtain gold nanoparticles using Amphipterygium adstringens extracts as a synthesis medium. Green ethanolic and aqueous extracts were obtained using ultrasound and shock wave-assisted extraction. Gold nanoparticles with sizes ranging between 100 and 150 nm were obtained with ultrasound aqueous extract. Interestingly, homogeneous quasi-spherical gold nanoparticles with sizes between 50 and 100 nm were achieved with shock wave aqueous-ethanolic extracts. Furthermore, 10 nm gold nanoparticles were obtained by the traditional methanolic macerate extraction method. The physicochemical characteristics, morphology, size, stability, and Z potential of the nanoparticles were determined using microscopic and spectroscopic techniques. The viability assay in leukemia cells (Jurkat) was performed using two different sets of gold nanoparticles, with final IC50 values of 87 µM and 94.7 µM, reaching a maximum cell viability decrease of 80% The results do not indicate a significant difference between the cytotoxic effects produced by the gold nanoparticles synthesized in this study and vincristine on normal lymphoblasts (CRL-1991).

Metabolic Disruption of Gold Nanospheres, Nanostars and Nanorods in Human Metastatic Prostate Cancer Cells

Nanomaterials offer a broad spectrum of applications in biomedicine. The shapes of gold nanoparticles could modulate tumor cell behavior. Spherical (AuNP_sp), stars (AuNP_st) and rods (AuNP_r) shapes of polyethylene glycol coated-gold nanoparticles (AuNPs-PEG) were synthesized. Metabolic activity, cellular proliferation, and reactive oxygen species (ROS) were measured and the impact of AuNPs-PEG in metabolic enzymes function was evaluated by RT-qPCR in PC3, DU145, and LNCaP prostate cancer cells. All AuNPs were internalized, and the different morphologies of AuNPs showed to be an essential modulator of metabolic activity. For PC3 and DU145, the metabolic activity of AuNPs was found to rank in the following order from lowest to highest: AuNP_sp-PEG, AuNP_st-PEG, and AuNP_r-PEG. Regarding LNCaP cells, the AuNP_st-PEG were less toxic, followed by AuNP_sp-PEG and AuNP_r-PEG, but it seems not to be dose-dependent. The proliferation was lower in AuNP_r-PEG in PC3 and DU145 cells but was stimulated around 10% in most conditions (0.001-0.1 mM) in LNCaP cells (not statistically significant). For 1 mM, LNCaP cells showed a significant decrease in proliferation only for AuNP_r-PEG. The outcomes of the current study demonstrated that different AuNPs conformations influence cell behavior, and the correct size and shape must be chosen considering its final application in the field of nanomedicine.

Structural parameters of nanoparticles affecting their toxicity for biomedical applications: a review

Rapidly growing interest in using nanoparticles (NPs) for biomedical applications has increased concerns about their safety and toxicity. In comparison with bulk materials, NPs are more chemically active and toxic due to the greater surface area and small size. Understanding the NPs' mechanism of toxicity, together with the factors influencing their behavior in biological environments, can help researchers to design NPs with reduced side effects and improved performance. After overviewing the classification and properties of NPs, this review article discusses their biomedical applications in molecular imaging and cell therapy, gene transfer, tissue engineering, targeted drug delivery, Anti-SARS-CoV-2 vaccines, cancer treatment, wound healing, and anti-bacterial applications. There are different mechanisms of toxicity of NPs, and their toxicity and behaviors depend on various factors, which are elaborated on in this article. More specifically, the mechanism of toxicity and their interactions with living components are discussed by considering the impact of different physiochemical parameters such as size, shape, structure, agglomeration state, surface charge, wettability, dose, and substance type. The toxicity of polymeric, silica-based, carbon-based, and metallic-based NPs (including plasmonic alloy NPs) have been considered separately.

Functionalized biomimetic nanoparticles combining programmed death-1/programmed death-ligand 1 blockade with photothermal ablation for enhanced colorectal cancer immunotherapy

Immune checkpoint blockade therapy targeting programmed death-1 (PD-1) or its major ligand programmed death-ligand 1 (PD-L1) has achieved remarkable success in the treatment of several tumors, including colorectal cancer. However, the efficacy of PD-1/PD-L1 inhibitors is limited in some colorectal cancers within the immunosuppressive tumor microenvironment (such as when there is a lack of immune cell infiltration). Herein, anti-PD-L1 functionalized biomimetic polydopamine-modified gold nanostar nanoparticles (PDA/GNS@aPD-L1 NPs) were developed for synergistic anti-tumor treatment by combining PD-1/PD-L1 blockade with photothermal ablation. PDA/GNS@aPD-L1 NPs were prepared by encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane isolated from anti-PD-L1 single-chain variable fragment (scFv) over-expressing cells. In addition to disrupting PD-1/PD-L1 immunosuppressive signals, the anti-PD-L1 scFv on the membrane of PDA/GNS@aPD-L1 NPs was conducive to the accumulation of PDA-GNS at tumor sites. Importantly, the tumor photothermal ablation induced by PDA-GNS could reverse the immunosuppressive tumor microenvironment, thereby further improving the efficiency of PD-1/PD-L1 blockade therapy. In this study, the synthetized PDA/GNS@aPD-L1 NPs exhibited good biocompatibility, efficient photothermal conversion ability, and enhanced tumor-targeting ability. In vivo studies revealed that a PDA/GNS@aPD-L1 NP-based therapeutic strategy significantly inhibited tumor growth, and prolonged overall survival by further promoting the maturation of dendritic cells (DCs), increasing the infiltration of CD8⁺T cells, and decreasing the number of immunosuppressive cells (such as regulatory T cells and myeloid-derived suppressive cells). Collectively, the developed PDA/GNS@aPD-L1 NP-based therapeutic strategy combines PD-1/PD-L1 blockade with photothermal ablation, which could remodel the tumor microenvironment for effective clinical colorectal cancer therapy. STATEMENT OF SIGNIFICANCE: Immunosuppressive tumor microenvironment is the main challenge facing programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) blockade therapy. By encapsulating photothermal nanoparticles (polydopamine-modified gold nanostar, PDA-GNS) with cell membrane over-expressing anti-PD-L1 single-chain variable fragment, we constructed anti-PD-L1 functionalized biomimetic nanoparticles (PDA/GNS@aPD-L1 NPs). By specific binding to the PD-L1 present on tumor cells, PDA/GNS@aPD-L1 NPs could disrupt PD-1/PD-L1 immunosuppression signaling, and effectively deliver PDA-GNS targeting to tumor sites. Additionally, PDA-GNS-mediated local photothermal ablation of tumors promoted the release of tumor-associated antigens and thus activated anti-tumor immune responses. Meanwhile, hyperthermia facilitates immune cell infiltration by increasing tumor vascular permeability. Therefore, PDA/GNS@aPD-L1 NPs could sensitize tumors to PD-1/PD-L1 blockade therapy by remodeling the immunosuppressive tumor microenvironment, which provides a new strategy for tumor treatment.

The Antimelanoma Biological Assessment of Triterpenic Acid Functionalized Gold Nanoparticles

One of several promising strategies for increasing the bioavailability and therapeutic potential of high-lipophilic biologically active compounds is gold nanoparticle formulation. The current study describes the synthesis and biological antimelanoma evaluation of three triterpen-functionalized gold nanoparticles, obtained using our previously reported antimelanoma benzotriazole-triterpenic acid esters. Functionalized gold nanoparticle (GNP) formation was validated through UV-VIS and FTIR spectroscopy. The conjugate's cytotoxic effects were investigated using HaCaT healthy keratinocytes and A375 human melanoma cells. On A375 cells, all three conjugates demonstrated dose-dependent cytotoxic activity, but no significant cytotoxic effects were observed on normal HaCaT keratinocytes. GNP-conjugates were found to be more cytotoxic than their parent compounds. After treatment with all three GNP-conjugates, 4,6'-diamidino-2-phenylindole (DAPI) staining revealed morphological changes consistent with apoptosis in A375 melanoma cells. Quantitative real-time polymerase chain reaction (RT-qPCR) analysis revealed that the triterpene-GNP conjugate treated A375 melanoma cells had a fold change increase in Bcl-2-associated X protein (BAX) expression and a fold change decrease in B-cell lymphoma 2 (Bcl-2) expression. In A735 melanoma cells, high-resolution respirometry studies revealed that all three GNP-conjugates act as selective inhibitors of mitochondrial function. Furthermore, by examining the effect on each mitochondrial respiratory rate, the results indicate that all three conjugates are capable of increasing the production of reactive oxygen species (ROS), an apoptosis trigger in cancer cells.

Engineered nanomedicines for augmenting the efficacy of colorectal cancer immunotherapy

Colorectal cancer (CRC) is one of the most devastating diseases worldwide. Immunotherapeutic agents for CRC treatment have shown limited efficacy due to the immunosuppressive tumor microenvironment (TME). In this context, various types of nanoparticles (NPs) have been used to reverse the immunosuppressive TME, potentiate the effect of immunotherapeutic agents and reduce their systemic side effects. Many advantages could be offered by NPs, related to drug-loading efficiency, particle size and others that can potentially aid the delivery of immunotherapeutic agents. The recent research on how nano-based immunotherapy can remodel the immunosuppressive TME of CRC and hence boost the antitumor immune response, as well as the challenges that face clinical translation of NPs and future perspectives, are summarized in this review article.

The impact of engineered nanomaterials on the environment: Release mechanism, toxicity, transformation, and remediation

The presence and longevity of nanomaterials in the ecosystem, as well as their properties, account for environmental toxicity. When nanomaterials in terrestrial and aquatic systems are exposed to the prevailing environmental conditions, they undergo various transformations such as dissociation, dissolution, and aggregation, which affects the food chain. The toxicity of nanomaterials is influenced by a variety of factors, including environmental factors and its physico-chemical characteristics. Bioaccumulation, biotransformation, and biomagnification are the mechanisms that have been identified for determining the fate of nanomaterials. The route taken by nanomaterials to reach living cells provides us with information about their toxicity profile. This review discusses the recent advances in the transport, transformation, and fate of nanomaterials after they are released into the environment. The review also discusses how nanoparticles affect lower trophic organisms through direct contact, the impact of nanoparticles on higher trophic organisms, and the possible options for remediation.

Gold Nanoconjugates for miRNA Modulation in Cancer Therapy: From miRNA Silencing to miRNA Mimics

Cancer is a major healthcare burden and cause of death worldwide, with an estimated 19.3 million new cancer cases and 10 million cancer deaths globally only in 2020. While several anticancer therapeutics are available to date, many of these still show low treatment efficacy and high off-target effects and adverse reactions. This prompts a serious need to develop novel therapies that can decrease the side effects and increase treatment efficacy. MicroRNAs (miRNAs) can have a role in tumor development and progression, making them important targets for the improvement of anticancer therapies. In this context, gold nanoparticles have been widely studied for different clinical applications due to their biocompatibility and possibility of customization, and gold nanoconjugates targeting miRNAs are being developed for cancer diagnosis and treatment. Here we summarize the research developed so far and how it can contribute to cancer treatment, discuss how it can be improved, and present the current challenges and future perspectives on their design and application.

Nanoparticles in ocular applications and their potential toxicity

Nanotechnology has been developed rapidly in recent decades and widely applied in ocular disease therapy. Nano-drug delivery systems overcome the bottlenecks of current ophthalmic drug delivery and are characterized with strong biocompatibility, stability, efficiency, sustainability, controllability, and few side effects. Nanoparticles have been identified as a promising and generally safe ophthalmic drug-delivery system based on the toxicity assessment in animals. Previous studies have found that common nanoparticles can be toxic to the cornea, conjunctiva, and retina under certain conditions. Because of the species differences between humans and animals, advanced in vitro cell culture techniques, such as human organoids, can mimic the human organism to a certain extent, bringing nanoparticle toxicity assessment to a new stage. This review summarizes the advanced application of nanoparticles in ocular drug delivery and the potential toxicity, as well as some of the current challenges and future opportunities in nanotoxicological evaluation.

Nanoparticles in the diagnosis and treatment of vascular aging and related diseases

Aging-induced alternations of vasculature structures, phenotypes, and functions are key in the occurrence and development of vascular aging-related diseases. Multiple molecular and cellular events, such as oxidative stress, mitochondrial dysfunction, vascular inflammation, cellular senescence, and epigenetic alterations are highly associated with vascular aging physiopathology. Advances in nanoparticles and nanotechnology, which can realize sensitive diagnostic modalities, efficient medical treatment, and better prognosis as well as less adverse effects on non-target tissues, provide an amazing window in the field of vascular aging and related diseases. Throughout this review, we presented current knowledge on classification of nanoparticles and the relationship between vascular aging and related diseases. Importantly, we comprehensively summarized the potential of nanoparticles-based diagnostic and therapeutic techniques in vascular aging and related diseases, including cardiovascular diseases, cerebrovascular diseases, as well as chronic kidney diseases, and discussed the advantages and limitations of their clinical applications.

A Comparison of the Genotoxic Effects of Gold Nanoparticles Functionalized with Seven Different Ligands in Cultured Human Hepatocellular Carcinoma Cells

Gold nanoparticles (GNPs) have shown great potential in diagnostic and therapeutic applications in diseases, such as cancer. Despite GNP versatility, there is conflicting data regarding the toxicity of their overall functionalization chemistry for improved biocompatibility. This study aimed to determine the possible genotoxic effects of functionalized GNPs in Human hepatocellular carcinoma (HepG2) cells. GNPs were synthesized and biofunctionalized with seven common molecules used for biomedical applications. These ligands were bovine serum albumin (BSA), poly(sodium 4-styrene sulfonate) (PSSNA), trisodium citrate (citrate), mercaptoundecanoic acid (MUA), glutathione (GSH), polyvinylpyrrolidone (PVP), and polyethylene glycol (PEG). Before in vitro genotoxicity assessment, inductively coupled plasma mass spectrometry was used to determine GNP cellular internalization quantitatively, followed by cell-based assays; WST-1 to find IC 30 and ApoPercentage for apoptotic induction time-points. The effect of the GNPs on cell growth in real-time was determined by using xCELLigence, followed by a comet assay for genotoxicity determination. The HepG2 cells experienced genotoxicity for all GNP ligands; however, they were able to initiate repair mechanisms and recover DNA damage, except for two functionalization chemistries.

Epigenetic Regulation in Exposome-Induced Tumorigenesis: Emerging Roles of ncRNAs

Environmental factors, including pollutants and lifestyle, constitute a significant role in severe, chronic pathologies with an essential societal, economic burden. The measurement of all environmental exposures and assessing their correlation with effects on individual health is defined as the exposome, which interacts with our unique characteristics such as genetics, physiology, and epigenetics. Epigenetics investigates modifications in the expression of genes that do not depend on the underlying DNA sequence. Some studies have confirmed that environmental factors may promote disease in individuals or subsequent progeny through epigenetic alterations. Variations in the epigenetic machinery cause a spectrum of different disorders since these mechanisms are more sensitive to the environment than the genome, due to the inherent reversible nature of the epigenetic landscape. Several epigenetic mechanisms, including modifications in DNA (e.g., methylation), histones, and noncoding RNAs can change genome expression under the exogenous influence. Notably, the role of long noncoding RNAs in epigenetic processes has not been well explored in the context of exposome-induced tumorigenesis. In the present review, our scope is to provide relevant evidence indicating that epigenetic alterations mediate those detrimental effects caused by exposure to environmental toxicants, focusing mainly on a multi-step regulation by diverse noncoding RNAs subtypes.

Dynamic alteration of poroelastic attributes as determinant membrane nanorheology for endocytosis of organ specific targeted gold nanoparticles

Background

Efficacy of targeted drug delivery using nanoparticles relies on several factors including the uptake mechanisms such as phagocytosis, macropinocytosis, micropinocytosis and receptor mediated endocytosis. These mechanisms have been studied with respect to the alteration in signaling mechanisms, cellular morphology, and linear nanomechanical properties (NMPs). Commonly employed classical contact mechanics models to address cellular NMPs fail to address mesh like structure consisting of bilayer lipids and proteins of cell membrane. To overcome this technical challenge, we employed poroelastic model which accounts for the biphasic nature of cells including their porous behavior exhibiting both solid like (fluid storage) and liquid like (fluid dissipate) behavior.

Results

In this study, we employed atomic force microscopy to monitor the influence of surface engineering of gold nanoparticles (GNPs) to the alteration of nonlinear NMPs such as drained Poisson’s ratio, effective shear stress, diffusion constant and pore dimensions of cell membranes during their uptake. Herein, we used pancreatic cancer (PDAC) cell lines including Panc1, AsPC-1 and endothelial cell (HUVECs) to understand the receptor-dependent and -independent endocytosis of two different GNPs derived using plectin-1 targeting peptide (PTP-GNP) and corresponding scrambled peptide (sPEP-GNP). Compared to untreated cells, in case of receptor dependent endocytosis of PTP-GNPs diffusion coefficient altered ~ 1264-fold and ~ 1530-fold and pore size altered ~ 320-fold and ~ 260-fold in Panc1 and AsPC-1 cells, respectively. Whereas for receptor independent mechanisms, we observed modest alteration in diffusion coefficient and pore size, in these cells compared to untreated cells. Effective shear stress corresponding to 7.38 ± 0.15 kPa and 20.49 ± 0.39 kPa in PTP-GNP treatment in Panc1 and AsPC-1, respectively was significantly more than that for sPEP-GNP. These results demonstrate that with temporal recruitment of plectin-1 during receptor mediated endocytosis affects the poroelastic attributes of the membrane.

Conclusion

This study confirms that nonlinear NMPs of cell membrane are directly associated with the uptake mechanism of nanoparticles and can provide promising insights of the nature of endocytosis mechanism involved for organ specific drug delivery using nanoparticles. Hence, nanomechanical analysis of cell membrane using this noninvasive, label-free and live-cell analytical tool can therefore be instrumental to evaluate therapeutic benefit of nanoformulations.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01276-1.

The surface coating of iron oxide nanoparticles drives their intracellular trafficking and degradation in endolysosomes differently depending on the cell type

Magnetic nanoparticles (MNPs) are potential theranostic tools that are biodegraded through different endocytic pathways. However, little is known about the endolysosomal network through which MNPs transit and the influence of the surface coating in this process. Here, we studied the intracellular transit of two MNPs with identical iron oxide core size but with two distinct coatings: 3-aminopropyl-trietoxysilane (APS) and dimercaptosuccinic acid (DMSA). Using endolysosomal markers and a high throughput analysis of the associated proteome, we tracked the MNPs intracellularly in two different mouse cell lines, RAW264.7 (macrophages) and Pan02 (tumor cells). We did not detect differences in the MNP trafficking kinetics nor in the MNP-containing endolysosome phenotype in Pan02 cells. Nonetheless, DMSA-MNPs transited at slower rate than APS-MNPs in macrophages as measured by MNP accumulation in Rab7⁺ endolysosomes. Macrophage DMSA-MNP-containing endolysosomes had a higher percentage of lytic enzymes and catalytic proteins than their APS-MNP counterparts, concomitantly with a V-type ATPase enrichment, suggesting an acidic nature. Consequently, more autophagic vesicles are induced by DMSA-MNPs in macrophages, enhancing the expression of iron metabolism-related genes and proteins. Therefore, unlike Pan02 cells, the MNP coating appears to influence the intracellular trafficking rate and the endolysosome nature in macrophages. These results highlight how the MNP coating can determine the nanoparticle intracellular fate and biodegradation in a cell-type bias.

4-Fluoromethamphetamine (4-FMA) induces in vitro hepatotoxicity mediated by CYP2E1, CYP2D6, and CYP3A4 metabolism

4-Fluoromethamphetamine (4-FMA) is an amphetamine-like psychoactive substance with recognized entactogenic and stimulant effects, but hitherto unclear toxicological mechanisms. Taking into consideration that the vast majority of 4-FMA users consume this substance through oral route, the liver is expected to be highly exposed. The aim of this work was to determine the hepatotoxic potential of 4-FMA using in vitro hepatocellular models: primary rat hepatocytes (PRH), human hepatoma cell lines HepaRG and HepG2, and resorting to concentrations ranging from 37 μM to 30 mM, during a 24-h exposure. EC₅₀ values, estimated from the MTT viability assay data, were 2.21 mM, 5.59 mM and 9.57 mM, for each model, respectively. The most sensitive model, PRH, was then co-exposed to 4-FMA and cytochrome P450 (CYP) inhibitors to investigate the influence of metabolism on the toxicity of 4-FMA. Results show that CYP2E1, CYP3A4 and CYP2D6 have major roles in 4-FMA cytotoxicity. Inhibition of CYP2D6 and CYP3A4 led to left-geared shifts in the concentration-response curves of 4-FMA, hinting at a role of these metabolic enzymes for detoxifying 4-FMA, while CYP2E1 inhibition pointed towards a toxifying role of this enzyme in 4-FMA metabolism at physiologically-relevant concentrations. The drug also destabilised mitochondrial membrane potential and decreased ATP levels, increased the production of reactive oxygen and nitrogen species and compromised thiol antioxidant defences. 4-FMA further affected PRH integrity by interfering with the machinery of apoptosis and necrosis, increasing the activity of initiator and effector caspases, and causing loss of cell membrane integrity. Potential for autophagy was also observed. This research contributes to the growing body of evidence regarding the toxicity of new psychoactive substances, in particular regarding their hepatotoxic effects; the apparent influence of metabolism over the resulting cytotoxicity of 4-FMA shows that there is a substantial degree of unpredictability of the consequences for users that could be independent of the dose.

Distribution of gold nanoparticles into the brain: a systematic review and meta-analysis

Despite the widespread use of gold nanoparticles (GNPs), there is no consensus on their distribution to different tissues and organs. The present systematic review and meta-analysis addresses the accumulation of GNPs in brain tissue. Extensive searches were conducted in electronic databases, Medline, Web of Science, EMBASE, and Scopus. Based on inclusion and exclusion criteria, primary and secondary screening was performed. The value of brain accumulation of gold nanoparticle (the percentage of the injection dose of GNPs/gram of brain tissue that applied as effect size (ES) in analysis) and the standard error of the mean were extracted from articles and analyzed by calculating the pooled ES and the pooled confidence interval (CI) using STATA software. p ≤ 0.05 was considered significant. Thirty-eight studies were included in the meta-analysis. The results showed that the amount of GNPs was 0.06% of the injection dose/gram of brain tissue (ES = 0.06, %95 CI: 0.06-0.06, p < 0.0001). Considering the time between injection and tissue harvest (follow-up time), after 1 h the GNPs in brain tissue was 0.288% of the injection dose/gram of tissue (ES = 0.29, 95% CI: 0.25-0.33, p < 0.0001), while after four weeks it was only 0.02% (ES = 0.02, 95% CI: 0.01-0.03, p < 0.0001) of the injection dose/gram of tissue. The amount of GNPs in brain tissue was higher for PEG-coated GNPs compared to uncoated GNPs, and it was 5.6 times higher for rod-shaped GNPs compared to spherical GNPs. The mean amount of GNPs in the brain tissues of animals bearing a tumor was 5.8 times higher than in normal animals.

Characterizing the Role of Biologically Relevant Fluid Dynamics on Silver Nanoparticle Dependent Oxidative Stress in Adherent and Suspension In Vitro Models

Silver nanoparticles (AgNPs) are being employed in numerous consumer goods and applications; however, they are renowned for inducing negative cellular consequences including toxicity, oxidative stress, and an inflammatory response. Nanotoxicological outcomes are dependent on numerous factors, including physicochemical, biological, and environmental influences. Currently, NP safety evaluations are carried out in both cell-based in vitro and animal in vivo models, with poor correlation between these mechanisms. These discrepancies highlight the need for enhanced exposure environments, which retain the advantages of in vitro models but incorporate critical in vivo influences, such as fluid dynamics. This study characterized the effects of dynamic flow on AgNP behavior, cellular interactions, and oxidative stress within both adherent alveolar (A549) and suspension monocyte (U937) models. This study determined that the presence of physiologically relevant flow resulted in substantial modifications to AgNP cellular interactions and subsequent oxidative stress, as assessed via reactive oxygen species (ROS), glutathione levels, p53, NFκB, and secretion of pro-inflammatory cytokines. Within the adherent model, dynamic flow reduced AgNP deposition and oxidative stress markers by roughly 20%. However, due to increased frequency of contact, the suspension U937 cells were associated with higher NP interactions and intracellular stress under fluid flow exposure conditions. For example, the increased AgNP association resulted in a 50% increase in intracellular ROS and p53 levels. This work highlights the potential of modified in vitro systems to improve analysis of AgNP dosimetry and safety evaluations, including oxidative stress assessments.

Toxicological evaluation of fluorescent 11-mercaptoundecanoic gold nanoclusters as promising label-free bioimaging probes in different cancer cell lines

Due to advancement in nanomaterials and increasing use of functionalized gold nanoclusters (AuNCs) in different biomedical applications, better understanding of their potential cytotoxicity is necessary. Interactions of ultra-small fluorescent AuNCs with mammalian cells remains up to this day poorly understood, therefore, cytotoxic evaluation of thoroughly characterized ca. 2.5 nm spherical water-soluble 11-mercaptoundecanoic acid coated AuNCs (AuNC@M) with diverse fluorescent properties in variety of mammalian cancer cell lines was performed. Cell viability was assessed by traditional MTT assay and xCELLigence real time cell analyzer. Cell apoptosis was evaluated via an Annexin V-FITC/propidium iodide (PI) assay. Confocal fluorescence imaging confirmed that tested AuNC@M entered live cells and were homogeneously distributed in their cytoplasm. The results suggested that the cytotoxicity of tested nanoclusters was very low, or near the control level at concentrations 0.1 and 0.5 mg/mL in the cell lines after 24 h exposition. The purity of tested AuNC@M had no relevant effect on cell viability and no differences were observed after 24 h in our study. The low toxicity toward cancer cells further strengthens our view that AuNC@M are promising label-free fluorescent probes for bio-labelling and bio-imaging, or they can even serve as platforms for antitumor drug delivery systems.