Next-generation sequencing reveals low-dose effects of cationic dendrimers in primary human bronchial epithelial cells

U2AF1 in various neoplastic diseases and relevant targeted therapies for malignant cancers with complex mutations (Review)

U2 small nuclear RNA auxiliary factor 1 (U2AF1) is a multifunctional protein that plays a crucial role in the regulation of RNA splicing during eukaryotic gene expression. U2AF1 belongs to the SR family of splicing factors and is involved in the removal of introns from mRNAs and exon-exon binding. Mutations in U2AF1 are frequently observed in myelodysplastic syndrome, primary myelofibrosis, chronic myelomonocytic leukaemia, hairy cell leukaemia and other solid tumours, particularly in lung, pancreatic, and ovarian carcinomas. Therefore, targeting U2AF1 for therapeutic interventions may be a viable strategy for treating malignant diseases. In the present review, the pathogenic mechanisms associated with U2AF1 in different malignant diseases were summarized, and the potential of related targeting agents was discussed. Additionally, the feasibility of natural product-based therapies directed against U2AF1 was explored.

Preclinical evaluation of modified carbon nanohorns and their complexation with insulin

The current study emphasizes the minimal toxicity observed in vitro and in vivo for carbon nanohorns (CNHs) modified with third generation polyamidoamine (PAMAM) dendrimers. Initially, we investigated the interactions between CNH-PAMAM and lipid bilayers, which were utilized as representative models of cellular membranes for the evaluation of their toxicity in vitro. We found that the majority of those interactions occur between the modified CNHs and the polar groups of phospholipids, meaning that CNH-PAMAM does not incorporate into the lipid chains, and thus, disruption of the lipid bilayer structure is avoided. This outcome is a very important observation for further evaluation of CNH-PAPAM in cell lines and in animal models. Next, we demonstrated the potential of CNH-PAMAM for complexation with insulin, as a proof of concept for its employment as a delivery platform. Importantly, our study provides comprehensive evidence of low toxicity for CNH-PAMAM both in vitro and in vivo. The assessment of cellular toxicity revealed that the modified CNHs exhibited minimal toxicity, with concentrations of 151 μg mL-1 and 349 μg mL-1, showing negligible harm to EO771 cells and mouse embryonic fibroblasts (MEFs), respectively. Moreover, the histological analysis of the mouse livers demonstrated no evidence of tissue necrosis and inflammation, or any visible signs of severe toxicity. These findings collectively indicate the safe profile of CNH-PAMAM and further contribute to the growing body of knowledge on the safe and efficient utilization of CNH-based nanomaterials in drug and protein delivery applications.

Effects of nanomaterial exposure on telomere dysfunction, hallmarks of mammalian and zebrafish cell senescence, and zebrafish mortality

Environmental and occupational exposure to hazardous substances accelerates biological aging. However, the toxic effects of nanomaterials on telomere and cellular senescence (major hallmarks of the biological aging) remained controversial. This study was to synthesize all published evidence to explore the effects of nanomaterial exposure on the telomere change, cellular senescence and mortality of model animals. Thirty-five studies were included by searching electronic databases (PubMed, Embase and Web of Science). The pooled analysis by Stata 15.0 software showed that compared with the control, nanomaterial exposure could significantly shorten the telomere length [measured as kbp: standardized mean difference (SMD) = -1.88; 95% confidence interval (CI) = -3.13 - - 0.64; % of control: SMD = -1.26; 95%CI = -2.11- - 0.42; < 3 kbp %: SMD = 5.76; 95%CI = 2.92 - 8.60), increase the telomerase activity (SMD = -1.00; 95%CI = -1.74 to -0.26), senescence-associated β-galactosidase levels in cells (SMD = 8.20; 95%CI = 6.05 - 10.34) and zebrafish embryos (SMD = 7.32; 95%CI = 4.70 - 9.94) as well as the mortality of zebrafish (SMD = 3.83; 95%CI = 2.94 - 4.72)]. The expression levels of telomerase TERT, shelterin components (TRF1, TRF2 and POT1) and senescence biomarkers (p21, p16) were respectively identified to be decreased or increased in subgroup analyses. In conclusion, this meta-analysis demonstrates that nanomaterial exposure is associated with telomere attrition, cell senescence and organismal death.

Mechanistic Insights into the Biological Effects of Engineered Nanomaterials: A Focus on Gold Nanoparticles

Nanotechnology has great potential to significantly advance the biomedical field for the benefit of human health. However, the limited understanding of nano-bio interactions leading to unknowns about the potential adverse health effects of engineered nanomaterials and to the poor efficacy of nanomedicines has hindered their use and commercialization. This is well evidenced considering gold nanoparticles, one of the most promising nanomaterials for biomedical applications. Thus, a fundamental understanding of nano-bio interactions is of interest to nanotoxicology and nanomedicine, enabling the development of safe-by-design nanomaterials and improving the efficacy of nanomedicines. In this review, we introduce the advanced approaches currently applied in nano-bio interaction studies-omics and systems toxicology-to provide insights into the biological effects of nanomaterials at the molecular level. We highlight the use of omics and systems toxicology studies focusing on the assessment of the mechanisms underlying the in vitro biological responses to gold nanoparticles. First, the great potential of gold-based nanoplatforms to improve healthcare along with the main challenges for their clinical translation are presented. We then discuss the current limitations in the translation of omics data to support risk assessment of engineered nanomaterials.

Dendrimers as Modifiers of Inorganic Nanoparticles for Therapeutic Delivery in Cancer

The formulation of nanoscale systems with well-defined sizes and shapes is of great interest in applications such as drug and gene delivery, diagnostics and imaging. Dendrimers are polymers that have attracted interest due to their size, shape, branching length, amine density, and surface functionalities. These unique characteristics of dendrimers set them apart from other polymers, their ability to modify nanoparticles (NPs) for biomedical applications. Dendrimers are spherical with multiple layers over their central core, each representing a generation. Their amphiphilic nature and hollow structure allow for the incorporation of multiple drugs or genes, in addition to enabling easy surface modification with cellular receptor-targeting moieties to ensure site-specific delivery of therapeutics. Dendrimers are employed in chemotherapeutic applications for the delivery of anticancer drugs. There are many inorganic NPs currently being investigated for cancer therapy, each with their own unique biological, chemical, and physical properties. To favor biomedical applications, inorganic NPs require suitable polymers to ensure stability, biodegradability and target specificity. The success of dendrimers is dependent on their unique structure, good bioavailability and stability. In this review, we describe the properties of dendrimers and their use as modifiers of inorganic NPs for enhanced therapeutic delivery. Herein, we review the significant developments in this area from 2015 to 2022. Databases including Web of Science, Scopus, Google Scholar, Science Direct, BioMed Central (BMC), and PubMed were searched for articles using dendrimers, inorganic nanoparticles and cancer as keywords.

Role of RNA m6A modification in titanium dioxide nanoparticle-induced acute pulmonary injury: An in vitro and in vivo study

RNA N⁶-methyladenosine (m⁶A) modification regulates the cell stress response and homeostasis, but whether titanium dioxide nanoparticle (nTiO₂)-induced acute pulmonary injury is associated with the m⁶A epitranscriptome and the underlying mechanisms remain unclear. Here, the potential association between m⁶A modification and the bioeffects of several engineered nanoparticles (nTiO₂, nAg, nZnO, nFe₂O₃, and nCuO) were verified thorough in vitro experiments. nFe₂O₃, nZnO, and nTiO₂ exposure significantly increased the global m⁶A level in A549 cells. Our study further revealed that nTiO₂ can induce m⁶A-mediated acute pulmonary injury. Mechanistically, nTiO₂ exposure promoted methyltransferase-like 3 (METTL3)-mediated m⁶A signal activation and thus mediated the inflammatory response and IL-8 release through the degeneration of anti-Mullerian hormone (AMH) and Mucin5B (MUC5B) mRNAs in a YTH m⁶A RNA-binding protein 2 (YTHDF2)-dependent manner. Moreover, nTiO₂ exposure stabilized METTL3 protein by the lipid reactive oxygen species (ROS)-activated ERK1/2 pathway. The scavenging of ROS with ferrostatin-1 (Fer-1) alleviates the ERK1/2 activation, m⁶A upregulation, and the inflammatory response caused by nTiO₂ both in vitro and in vivo. In conclusion, our study demonstrates that m⁶A is a potential intervention target for alleviating the adverse effects of nTiO₂-induced acute pulmonary injury in vitro and in vivo, which has far-reaching implications for protecting human health and improving the sustainability of nanotechnology.

Biomarkers of nanomaterials hazard from multi-layer data

There is an urgent need to apply effective, data-driven approaches to reliably predict engineered nanomaterial (ENM) toxicity. Here we introduce a predictive computational framework based on the molecular and phenotypic effects of a large panel of ENMs across multiple in vitro and in vivo models. Our methodology allows for the grouping of ENMs based on multi-omics approaches combined with robust toxicity tests. Importantly, we identify mRNA-based toxicity markers and extensively replicate them in multiple independent datasets. We find that models based on combinations of omics-derived features and material intrinsic properties display significantly improved predictive accuracy as compared to physicochemical properties alone.

Safety Challenges and Application Strategies for the Use of Dendrimers in Medicine

Dendrimers are used for a variety of applications in medicine but, due to their host–guest and entrapment characteristics, are particularly used for the delivery of genes and drugs. However, dendrimers are intrinsically toxic, thus creating a major limitation for their use in biological systems. To reduce such toxicity, biocompatible dendrimers have been designed and synthesized, and surface engineering has been used to create advantageous changes at the periphery of dendrimers. Although dendrimers have been reviewed previously in the literature, there has yet to be a systematic and comprehensive review of the harmful effects of dendrimers. In this review, we describe the routes of dendrimer exposure and their distribution in vivo. Then, we discuss the toxicity of dendrimers at the organ, cellular, and sub-cellular levels. In this review, we also describe how technology can be used to reduce dendrimer toxicity, by changing their size and surface functionalization, how dendrimers can be combined with other materials to generate a composite formulation, and how dendrimers can be used for the diagnosis of disease. Finally, we discuss future challenges, developments, and research directions in developing biocompatible and safe dendrimers for medical purposes.

Tumor microenvironment based stimuli-responsive CRISPR/Cas delivery systems: A viable platform for interventional approaches

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems have emerged as robust tools in cancer gene therapy due to their simplicity and versatility. Nevertheless, the genome editing efficiency in tumor sites and the clinical applications of CRISPR/Cas have been compromised by non-specific delivery and genotoxicity. Recently, intelligent delivery systems incorporating sensitive materials in response to endogenous stimuli of the tumor microenvironment (TME) have represented viable platforms for tumor-specific genome editing and reduced side effects of CRISPR/Cas. Spurred by this promising direction, this review first introduces the CRISPR/Cas systems widely employed in cancer therapeutic explorations. Various types of CRISPR/Cas delivery systems sensitive to the stimuli in TME and typical dual-/multiple-responsive CRISPR/Cas carriers are further discussed, emphasizing the correlations between sensitive components and spatiotemporal delivery mechanisms. The genome editing efficiencies of CRISPR/Cas-loaded stimuli-responsive carriers are also summarized both in vitro and in vivo. Collectively, stimuli-responsive CRISPR/Cas delivery systems hold great promise for potent cancer gene therapy.

Emerging innate biological properties of nano-drug delivery systems: A focus on PAMAM dendrimers and their clinical potential

Drug delivery systems or vectors are usually needed to improve the bioavailability and effectiveness of a drug through improving its pharmacokinetics/pharmacodynamics at an organ, tissue or cellular level. However, emerging technologies with sensitive readouts as well as a greater understanding of physiological/biological systems have revealed that polymeric drug delivery systems are not biologically inert but can have innate or intrinsic biological actions. In this article, we review the emerging multiple innate biological/toxicological properties of naked polyamidoamine (PAMAM) dendrimer delivery systems in the absence of any drug cargo and discuss their correlation with the defined physicochemical properties of PAMAMs in terms of molecular size (generation), architecture, surface charge and chemistry. Further, we assess whether any of the reported intrinsic biological actions of PAMAMs such as their antimicrobial activity or their ability to sequester glucose and modulate key protein interactions or cell signaling pathways, can be exploited clinically such as in the treatment of diabetes and its complications.

Label-free cell based impedance measurements of ZnO nanoparticles-human lung cell interaction: a comparison with MTT, NR, Trypan blue and cloning efficiency assays

Background

There is a huge body of literature data on ZnOnanoparticles (ZnO NPs) toxicity. However, the reported results are seen to be increasingly discrepant, and deep comprehension of the ZnO NPs behaviour in relation to the different experimental conditions is still lacking. A recent literature overview emphasizes the screening of the ZnO NPs toxicity with more than one assay, checking the experimental reproducibility also versus time, which is a key factor for the robustness of the results. In this paper we compared high-throughput real-time measurements through Electric Cell-substrate Impedance-Sensing (ECIS®) with endpoint measurements of multiple independent assays.

Results

ECIS-measurements were compared with traditional cytotoxicity tests such as MTT, Neutral red, Trypan blue, and cloning efficiency assays. ECIS could follow the cell behavior continuously and noninvasively for days, so that certain long-term characteristics of cell proliferation under treatment with ZnO NPs were accessible. This was particularly important in the case of pro-mitogenic activity exerted by low-dose ZnO NPs, an effect not revealed by endpoint independent assays. This result opens new worrisome questions about the potential mitogenic activity exerted by ZnO NPs, or more generally by NPs, on transformed cells. Of importance, impedance curve trends (morphology) allowed to discriminate between different cell death mechanisms (apoptosis vs autophagy) in the absence of specific reagents, as confirmed by cell structural and functional studies by high-resolution microscopy. This could be advantageous in terms of costs and time spent. ZnO NPs-exposed A549 cells showed an unusual pattern of actin and tubulin distribution which might trigger mitotic aberrations leading to genomic instability.

Conclusions

ZnO NPs toxicity can be determined not only by the intrinsic NPs characteristics, but also by the external conditions like the experimental setting, and this could account for discrepant data from different assays. ECIS has the potential to recapitulate the needs required in the evaluation of nanomaterials by contributing to the reliability of cytotoxicity tests. Moreover, it can overcome some false results and discrepancies in the results obtained by endpoint measurements. Finally, we strongly recommend the comparison of cytotoxicity tests (ECIS, MTT, Trypan Blue, Cloning efficiency) with the ultrastructural cell pathology studies.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01033-w.

Platinum-based chemotherapy via nanocarriers and co-delivery of multiple drugs

Platinum-based anticancer drugs can inhibit the growth of cancer cells by disrupting DNA replication, which makes them widely applicable in clinics for treating tumors and cancers. However, owing to the intrinsic or acquired drug resistance and severe side effects caused in the treatment, their successful clinical applications have been limited. Various strategies have been used to address these challenges. Nanocarriers have been used for platinum drug delivery because they can be effectively deposited in tumor tissues to reduce the damage to normal organs for an enhanced permeability and retention (EPR) effect. Furthermore, for synergizing the function of platinum-based drugs with different mechanisms to decrease the toxicities, multicomponent chemotherapy has become an imperative strategy in clinical cancer treatments. This review aims to introduce the mechanisms of action and limitations of platinum-based drugs in clinics, followed by providing the current advancement of nanocarriers including lipids, polymers, dendrimers, micelles and albumin for platinum drug delivery in cancer treatments. In addition, multicomponent chemotherapy based on platinum drugs is introduced in detail. Finally, the prospects of multicomponent chemotherapy for cancer treatment are discussed as well.

Layered Double Hydroxide Modified Bone Cement Promoting Osseointegration via Multiple Osteogenic Signal Pathways

Poly(methyl methacrylate) (PMMA) bone cement has been widely used in orthopedic surgeries including total hip/knee replacement, vertebral compression fracture treatment, and bone defect filling. However, aseptic loosening of the interface between PMMA bone cement and bone often leads to failure. Hence, the development of modified PMMA that facilitates the growth of bone into the modified PMMA bone cement is key to reducing the incidence of aseptic loosening. In this study, MgAl-layered double hydroxide (LDH) microsheets modified PMMA (PMMA&LDH) bone cement with superior osseointegration performance has been synthesized. The maximum polymerization reaction temperature of PMMA&LDH decreased by 7.0 and 11.8 °C, respectively, compared with that of PMMA and PMMA&COL-I (mineralized collagen I modified PMMA). The mechanical performance of PMMA&LDH decreased slightly in comparison with PMMA, which is beneficial to alleviate stress-shielding osteolysis, and indirectly promote osseointegration. The superior osteogenic ability of PMMA&LDH has been demonstrated in vivo, which boosts bone growth by 2.17- and 18.34-fold increments compared to the PMMA&COL-I and PMMA groups at 2 months, postoperatively. Moreover, transcriptome sequencing revealed four key osteogenic pathways: p38 MAPK, ERK/MAPK, FGF, and TGF-β, which were further confirmed by IPA, qPCR, and Western blot assays. Hence, LDH-modified PMMA bone cement is a promising biomaterial to enhance bone growth with potential applications in relevant orthopedic surgeries.

Cytotoxicity of black phosphorus quantum dots on lung-derived cells and the underlying mechanisms

Black phosphorus quantum dots (BP-QDs) are a new type of zero-dimensional (0D) nanomaterial that has been widely used due of their superior properties in many biomedical fields, but limited studies have focused on the biocompatibility of BP-QDs, particularly in the respiratory system. In this study, we investigated the potential lung cell toxicity of BP-QDs in vitro. Two human lung-derived cells, A549 and Beas-2B, were treated with 5∼20 μg/mL BP-QDs for 24 h. The results showed that BP-QDs triggered significant lung cell toxicity, including a dose-dependent decrease in cell viability, lactate dehydrogenase (LDH) leakage, cell shape changes, cellular oxidative stress and cell cycle arrest. In addition, pretreatment with the classical phagocytosis inhibitor cytochalasin D (Cyto D) alleviated the decrease in cell viability and LDH leakage induced by BP-QDs. In contrast, BP-QDs induced the production of cellular reactive oxygen species (ROS) and decreases in the glutathione level, whereas the ROS scavenger N-acetyl-L-cysteine (NAC) could protect A549 and Beas-2B cells from BP-QD-induced cellular oxidative stress. Taken together, the results from this study indicate that the potential toxic effects and mechanisms of BP-QDs in two different human lung cells should be considered to evaluate the lung cell safety of BP-QDs.

Co-delivery of Sorafenib and CRISPR/Cas9 Based on Targeted Core-Shell Hollow Mesoporous Organosilica Nanoparticles for Synergistic HCC Therapy

The rapid development of CRISPR/Cas9 systems has opened up tantalizing prospects to sensitize cancers to chemotherapy using efficient targeted genome editing, but safety concerns and possible off-target effects of viral vectors remain a major obstacle for clinical application. Thus, the construction of novel nonviral tumor-targeting nanodelivery systems has great potential for the safe application of CRISPR/Cas9 systems for gene-chemo-combination therapy. Here, we report a polyamidoamine-aptamer-coated hollow mesoporous silica nanoparticle for the co-delivery of sorafenib and CRISPR/Cas9. The core-shell nanoparticles had good stability, enabled ultrahigh drug loading, targeted delivery, and controlled-release of the gene-drug combination. The nanocomplex showed >60% EGFR-editing efficiency without off-target effects in all nine similar sites, regulating the EGFR-PI3K-Akt pathway to inhibit angiogenesis, and exhibited a synergistic effect on cell proliferation. Importantly, the co-delivery nanosystem achieved efficient EGFR gene therapy and caused 85% tumor inhibition in a mouse model. Furthermore, the nanocomplex showed high accumulation at the tumor site in vivo and exhibited good safety with no damage to major organs. Due to these properties, the nanocomplex provides a versatile delivery approach for efficient co-loading of gene-drug combinations, allowing for precise gene editing and synergistic inhibition of tumor growth without apparent side effects on normal tissues.

Multiparametric Profiling of Engineered Nanomaterials: Unmasking the Surface Coating Effect

Despite considerable efforts, the properties that drive the cytotoxicity of engineered nanomaterials (ENMs) remain poorly understood. Here, the authors inverstigate a panel of 31 ENMs with different core chemistries and a variety of surface modifications using conventional in vitro assays coupled with omics-based approaches. Cytotoxicity screening and multiplex-based cytokine profiling reveals a good concordance between primary human monocyte-derived macrophages and the human monocyte-like cell line THP-1. Proteomics analysis following a low-dose exposure of cells suggests a nonspecific stress response to ENMs, while microarray-based profiling reveals significant changes in gene expression as a function of both surface modification and core chemistry. Pathway analysis highlights that the ENMs with cationic surfaces that are shown to elicit cytotoxicity downregulated DNA replication and cell cycle responses, while inflammatory responses are upregulated. These findings are validated using cell-based assays. Notably, certain small, PEGylated ENMs are found to be noncytotoxic yet they induce transcriptional responses reminiscent of viruses. In sum, using a multiparametric approach, it is shown that surface chemistry is a key determinant of cellular responses to ENMs. The data also reveal that cytotoxicity, determined by conventional in vitro assays, does not necessarily correlate with transcriptional effects of ENMs.

Pulmonary toxicity and RNA sequencing analyses of mouse in response to exposure to cellulose nanofibrils

OBJECTIVE

The growing applications of nanocelluloses in the fields of advanced nanocomposites, electronics, and medical devices necessitate investigation of their potential adverse effects on human health. The lungs are the primary and the most important route for the entry of nanocelluloses into the human body in occupational settings. However, data on the pulmonary toxicity of cellulose nanofibrils (CNFs) and its molecular mechanism are limited. This study investigated the pulmonary toxicity of CNFs and its genomic expression using the RNA sequencing approach.

MATERIALS AND METHODS

Female C57BL/6 mice were administered CNFs at 50 μg/mouse by oropharyngeal aspiration. Samples were collected at 3 and 14 days after exposure to CNFs (DAEC).

RESULTS

At three DAEC, the microscopic sections of lungs revealed a significant inflammatory response. In terms of gene expression alterations, 94 genes were up-regulated, and 107 genes were down-regulated. Most of these differentially expressed genes were involved in the inflammatory and immune responses, including chemokines, NK cells, killer cell lectin-like receptors, CD antigens, T cell-specific GTPases, immunity-related GTPase family M members, and interferon-induced proteins encoding genes. However, only 9 and 26 genes at 14 DAEC were significantly up- and down-regulated, respectively.

CONCLUSIONS

The pathological analysis of lung sections and the analysis of sequencing data suggested that the homeostasis of mice lungs was restored at 14 DAEC. The findings of this study provide insights into the pulmonary toxicity, and underlying toxicological mechanisms, caused by exposure to CNFs, and are useful for the assessment of the potential toxicity of nanocelluloses.

Novel design of (PEG-ylated)PAMAM-based nanoparticles for sustained delivery of BDNF to neurotoxin-injured differentiated neuroblastoma cells

Brain-derived neurotrophic factor (BDNF) is essential for the development and function of human neurons, therefore it is a promising target for neurodegenerative disorders treatment. Here, we studied BDNF-based electrostatic complex with dendrimer nanoparticles encapsulated in polyethylene glycol (PEG) in neurotoxin-treated, differentiated neuroblastoma SH-SY5Y cells, a model of neurodegenerative mechanisms. PEG layer was adsorbed at dendrimer-protein core nanoparticles to decrease their cellular uptake and to reduce BDNF-other proteins interactions for a prolonged time. Cytotoxicity and confocal microscopy analysis revealed PEG-ylated BDNF-dendrimer nanoparticles can be used for continuous neurotrophic factor delivery to the neurotoxin-treated cells over 24 h without toxic effect. We offer a reliable electrostatic route for efficient encapsulation and controlled transport of fragile therapeutic proteins without any covalent cross-linker; this could be considered as a safe drug delivery system. Understanding the polyvalent BDNF interactions with dendrimer core nanoparticles offers new possibilities for design of well-ordered protein drug delivery systems.

Size-Dependent Pulmonary Impact of Thin Graphene Oxide Sheets in Mice: Toward Safe-by-Design

Safety assessment of graphene-based materials (GBMs) including graphene oxide (GO) is essential for their safe use across many sectors of society. In particular, the link between specific material properties and biological effects needs to be further elucidated. Here, the effects of lateral dimensions of GO sheets in acute and chronic pulmonary responses after single intranasal instillation in mice are compared. Micrometer-sized GO induces stronger pulmonary inflammation than nanometer-sized GO, despite reduced translocation to the lungs. Genome-wide RNA sequencing also reveals distinct size-dependent effects of GO, in agreement with the histopathological results. Although large GO, but not the smallest GO, triggers the formation of granulomas that persists for up to 90 days, no pulmonary fibrosis is observed. These latter results can be partly explained by Raman imaging, which evidences the progressive biotransformation of GO into less graphitic structures. The findings demonstrate that lateral dimensions play a fundamental role in the pulmonary response to GO, and suggest that airborne exposure to micrometer-sized GO should be avoided in the production plant or applications, where aerosolized dispersions are likely to occur. These results are important toward the implementation of a safer-by-design approach for GBM products and applications, for the benefit of workers and end-users.

Epithelial-to-mesenchymal transition is a prognostic marker for patient outcome in advanced stage HNSCC patients treated with chemoradiotherapy

BACKGROUND

The prognosis of patients with HPV-negative advanced stage head and neck squamous cell carcinoma (HNSCC) remains poor. No prognostic markers other than TNM staging are routinely used in clinic. Epithelial-to-mesenchymal transition (EMT) has been shown to be a strong prognostic factor in other cancer types. The purpose of this study was to determine the role of EMT in HPV-negative HNSCC outcomes.

METHODS

Pretreatment tumor material from patients of two cohorts, totalling 174 cisplatin-based chemoradiotherapy treated HPV-negative HNSCC patients, was RNA-sequenced. Seven different EMT gene expression signatures were used for EMT status classification and generation of HNSCC-specific EMT models using Random Forest machine learning.

RESULTS

Mesenchymal classification by all EMT signatures consistently enriched for poor prognosis patients in both cohorts of 98 and 76 patients. Uni- and multivariate analyses show important HR of 1.6-5.8, thereby revealing EMT's role in HNSCC outcome. Discordant classification by these signatures prompted the generation of an HNSCC-specific EMT profile based on the concordantly classified samples in the first cohort (cross-validation AUC > 0.98). The independent validation cohort confirmed the association of mesenchymal classification by the HNSCC-EMT model with poor overall survival (HR = 3.39, p < 0.005) and progression free survival (HR = 3.01, p < 0.005) in multivariate analysis with TNM. Analysis of an additional HNSCC cohort from PET-positive patients with metastatic disease prior to treatment further supports this relationship and reveals a strong link of EMT to the propensity to metastasize.

CONCLUSIONS

EMT in HPV-negative HNSCC co-defines patient outcome after chemoradiotherapy. The generated HNSCC-EMT prediction models can function as strong prognostic biomarkers.

Next-Generation Sequencing Reveals Differential Responses to Acute versus Long-Term Exposures to Graphene Oxide in Human Lung Cells

Numerous studies have addressed the biological impact of graphene-based materials including graphene oxide (GO), yet few have focused on long-term effects. Here, RNA sequencing is utilized to unearth responses of human lung cells to GO. To this end, the BEAS-2B cell line derived from normal human bronchial epithelium is subjected to repeated, low-dose exposures of GO (1 or 5 µg mL^-1 ) for 28 days or to the equivalent, cumulative amount of GO for 48 h. Then, samples are analyzed by using the NovaSeq 6000 sequencing system followed by pathway analysis and gene ontology enrichment analysis of the differentially expressed genes. Significant differences are seen between the low-dose, long-term exposures and the high-dose, short-term exposures. Hence, exposure to GO for 48 h results in mitochondrial dysfunction. In contrast, exposure to GO for 28 days is characterized by engagement of apoptosis pathways with downregulation of genes belonging to the inhibitor of apoptosis protein (IAP) family. Validation experiments confirm that long-term exposure to GO affects the apoptosis threshold in lung cells, accompanied by a loss of IAPs. These studies reveal the sensitivity of RNA-sequencing approaches and show that acute exposure to GO is not a good predictor of the long-term effects of GO.

PAMAM Dendrimer Nanomolecules Utilized as Drug Delivery Systems for Potential Treatment of Glioblastoma: A Systematic Review

Glioblastoma (GB) is a grade IV astrocytoma that maintains a poor prognosis with respect to current treatment options. Despite major advancements in the fields of surgery and chemoradiotherapy over the last few decades, the life expectancy for someone with glioblastoma remains virtually unchanged and warrants a new approach for treatment. Poly(amidoamine) (PAMAM) dendrimers are a type of nanomolecule that ranges in size (between 1 and 100 nm) and shape and can offer a new viable solution for the treatment of intracranial tumors, including glioblastoma. Their ability to deliver a variety of therapeutic cargo and penetrate the blood-brain barrier (BBB), while preserving low cytotoxicity, make them a favorable candidate for further investigation into the treatment of glioblastoma. Here, we present a systematic review of the current advancements in PAMAM dendrimer technology, including the wide spectrum of dendrimer generations formulated, surface modifications, core modifications, and conjugations developed thus far to enhance tumor specificity and tumor penetration for treatment of glioblastoma. Furthermore, we highlight the extensive variety of therapeutics capable of delivery by PAMAM dendrimers for the treatment of glioblastoma, including cytokines, peptides, drugs, siRNAs, miRNAs, and organic polyphenols. While there have been prolific results stemming from aggressive research into the field of dendrimer technology, there remains a nearly inexhaustible amount of questions that remain unanswered. Nevertheless, this technology is rapidly developing and is nearing the cusp of use for aggressive tumor treatment. To that end, we further highlight future prospects in focus as researchers continue developing more optimal vehicles for the delivery of therapeutic cargo.

Silver nanoparticles modulate lipopolysaccharide-triggered Toll-like receptor signaling in immune-competent human cell lines

Silver (Ag) nanoparticles are commonly used in consumer products due to their antimicrobial properties. Here we studied the impact of Ag nanoparticles on immune responses by using cell lines of monocyte/macrophage and lung epithelial cell origin, respectively. Short-term experiments (24 h) showed that Ag nanoparticles reduced the lipopolysaccharide (LPS)-induced secretion of pro-inflammatory cytokines in THP-1 cells under serum-free conditions. ICP-MS analysis revealed that cellular uptake of Ag was higher under these conditions. Long-term exposure (up to 6 weeks) of BEAS-2B cells to Ag nanoparticles also suppressed pro-inflammatory cytokine production following a brief challenge with LPS. Experiments using reporter cells revealed that Ag nanoparticles as well as AgNO₃ inhibited LPS-triggered Toll-like receptor (TLR) signaling. Furthermore, RNA-sequencing of BEAS-2B cells indicated that Ag nanoparticles affected TLR signaling pathways. In conclusion, Ag nanoparticles reduced the secretion of pro-inflammatory cytokines in response to LPS, likely as a result of the release of silver ions leading to an interference with TLR signaling. This could have implications for the use of Ag nanoparticles as antibacterial agents. Further in vivo studies are warranted to study this.

Using Large Datasets to Understand Nanotechnology

Advances in sequencing technologies have made studying biological processes with genomics, transcriptomics, and proteomics commonplace. As a result, this suite of increasingly integrated techniques is well positioned to study drug delivery, a process that is influenced by many biomolecules working in concert. Omics-based approaches can be used to study the vast nanomaterial chemical space as well as the biological factors that affect the safety, toxicity, and efficacy of nanotechnologies. The generation and analysis of large datasets, methods to interpret them, and dataset applications to nanomaterials to date, are demonstrated here. Finally, new approaches for how sequencing-generated datasets can answer fundamental questions in nanotechnology based drug delivery are proposed.

Non-small-cell lung cancer homing peptide-labeled dendrimers selectively transfect lung cancer cells

AIM

Lung cancer gene therapies require reagents to selectively transfect lung tumors after systemic administration.

MATERIALS & METHODS

We created a reagent called NSCLC-NP by attaching a peptide with binding affinity for lung cancer to polyamidoamine dendrimers. The positively charged dendrimers electrostatically bind negatively charged nucleic acids, inhibit endogenous nucleases and transfect cells targeted by the attached peptide.

RESULTS

In vitro, NSCLC-NP complexed to DNA plasmids bound and transfected three human lung cancer cell lines producing protein expression of the plasmid's gene. In vivo, systemically administered NSCLC-NP selectively transfected lung cancer cells growing in RAG1KO mice.

CONCLUSION

The capability of NSCLC-NP to selectively transfect lung cancer allows its future use as a vehicle to implement human lung cancer gene therapy strategies.

Time- and dose-dependent gene expression analysis of macrophage response as a function of porosity of silica nanoparticles

There is a limited amount of information available on gene expression regulation of macrophages in response to changing the time of exposure, concentration, and physicochemical properties of nanomaterials. In this study, RAW264.7 macrophages were treated with spherical nonporous and mesoporous silica nanoparticles of similar size at different incubation times and concentrations. RNA-sequencing was used to study transcriptional profiles. Bioinformatics analyses, functional annotation clustering, and network analyses were employed to understand signaling pathways of cellular response as a function of porosity, incubation time, and concentration. Porosity introduced drastic changes to the genomic response of macrophages at equitoxic concentrations and incubation times. Direct relations between increases in time and concentration with an increased number of differentially expressed genes were observed.

Genotoxic response and damage recovery of macrophages to graphene quantum dots

The potential adverse effects of graphene quantum dots (GQDs) have increasingly attracted attention. Our present study revealed the genotoxic responses of rat alveolar macrophages (NR8383) to aminated graphene QDs (AG-QDs) and detected the cellular recovery after removing AG-QDs. Global gene expression analysis from RNA-sequencing showed that AG-QDs (100 μg/mL) caused significant alterations in expression of 2898 genes after exposure for 24 h. Among these, 1335 and 1563 genes were up-regulated and down-regulated, respectively. Based on the Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) analysis, we found that most of the down-regulated genes were responsive to "cell cycle", which correlated well with the cell cycle arrest data that AG-QDs triggered cell cycle arrest at S (synthesis) and G2/M (second gap/mitosis) phase. The percentages of cells in S and G2/M phase were increased by 4.5%, and 29.0%, respectively. In addition, the up-regulated genes related with "endocytosis" and "phagocytosis" were identified, which could regulate the internalization of AG-QDs by endocytosis and phagocytosis. After removing exposed AG-QDs and re-incubating the cells in fresh medium, the arrest of S and G2/M phase in NR8383 cells was reduced, and the cell cycle gradually recovered. This cellular recovery could be attributed to the cellular excretion of AG-QDs and the up-regulation of the DNA-repair-related genes (Rad51, Brca2, and Atm). The current work provides insights into the potential hazards of AG-QDs in transcriptional level and presented the long-term effects of AG-QDs on organisms in environment.

Rat mRNA expression profiles associated with inhibition of ischemic acute kidney injury by losartan

Objective: Losartan was reported to inhibit the progression of acute kidney injury (AKI), but little is known about the underlying pharmacological mechanisms. In the present study, the mRNA expression profiles in ischemic AKI rat kidney altered by losartan treatment were analyzed by next-generation deep sequencing technology.Methods: Ischemia and reperfusion treatment was applied to induce AKI in Sprague-Dawley (SD) rats. The urea and creatinine contents in rat blood were measured. H&E staining was performed to evaluate the histological alteration of rat kidney tissues under a microscope. The TUNEL method was applied to analyze apoptosis in rat kidney tissues. The mRNA profiles in rat kidney were analyzed using next-generation deep sequencing. Differential gene expression was confirmed by quantitative qRT-PCR.Results: The rat model of AKI induced by ischemia and reperfusion showed significant increases in urea and creatinine levels, accompanied by a disrupted kidney tubular structure and renal cell apoptosis. Losartan treatment effectively inhibited the changes in urea and creatinine, tubular structure, and apoptosis in AKI rat kidney. A large number of mRNAs were found to be differentially expressed in the kidneys of AKI rats treated with losartan, which are involved in multiple processes and signaling pathways. The expression of nine differentially expressed genes such as monocyte chemoattractant protein-1 (CCL2) and suppressor of cytokine signaling 3 (SOCS3) was confirmed by qRT-PCR and Western blot.Conclusion: Losartan caused significant alterations in the gene expression profile in AKI rat kidney, which mediated its anti-AKI effects.

Cationic gold nanoparticles elicit mitochondrial dysfunction: a multi-omics study

Systems biology is increasingly being applied in nanosafety research for observing and predicting the biological perturbations inflicted by exposure to nanoparticles (NPs). In the present study, we used a combined transcriptomics and proteomics approach to assess the responses of human monocytic cells to Au-NPs of two different sizes with three different surface functional groups, i.e., alkyl ammonium bromide, alkyl sodium carboxylate, or poly(ethylene glycol) (PEG)-terminated Au-NPs. Cytotoxicity screening using THP-1 cells revealed a pronounced cytotoxicity for the ammonium-terminated Au-NPs, while no cell death was seen after exposure to the carboxylated or PEG-modified Au-NPs. Moreover, Au-NR3+ NPs, but not the Au-COOH NPs, were found to trigger dose-dependent lethality in vivo in the model organism, Caenorhabditis elegans. RNA sequencing combined with mass spectrometry-based proteomics predicted that the ammonium-modified Au-NPs elicited mitochondrial dysfunction. The latter results were validated by using an array of assays to monitor mitochondrial function. Au-NR3+ NPs were localized in mitochondria of THP-1 cells. Moreover, the cationic Au-NPs triggered autophagy in macrophage-like RFP-GFP-LC3 reporter cells, and cell death was aggravated upon inhibition of autophagy. Taken together, these studies have disclosed mitochondria-dependent effects of cationic Au-NPs resulting in the rapid demise of the cells.

Chronic administration of nano-sized PAMAM dendrimers in vivo inhibits EGFR-ERK1/2-ROCK signaling pathway and attenuates diabetes-induced vascular remodeling and dysfunction

We investigated whether chronic administration of nano-sized polyamidoamine (PAMAM) dendrimers can have beneficial effects on diabetes-induced vascular dysfunction by inhibiting the epidermal growth factor receptor (EGFR)-ERK1/2-Rho kinase (ROCK)-a pathway known to be critical in the development of diabetic vascular complications. Daily administration of naked PAMAMs for up to 4 weeks to streptozotocin-induced diabetic male Wistar rats inhibited EGFR-ERK1/2-ROCK signaling and improved diabetes-induced vascular remodeling and dysfunction in a dose, generation (G6 > G5) and surface chemistry-dependent manner (cationic > anionic > neutral). PAMAMs, AG1478 (a selective EGFR inhibitor), or anti-EGFR siRNA also inhibited vascular EGFR-ERK1/2-ROCK signaling in vitro. These data showed that naked PAMAM dendrimers have the propensity to modulate key (e.g. EGFR) cell signaling cascades with associated pharmacological consequences in vivo that are dependent on their physicochemical properties. Thus, PAMAMs, alone or in combination with vasculoprotective agents, may have a beneficial role in the potential treatment of diabetes-induced vascular complications.

Increasing complexity and interactions of oxidative stress in chronic respiratory diseases: An emerging need for novel drug delivery systems

Oxidative stress is intensely involved in enhancing the severity of various chronic respiratory diseases (CRDs) including asthma, chronic obstructive pulmonary disease (COPD), infections and lung cancer. Even though there are various existing anti-inflammatory therapies, which are not enough to control the inflammation caused due to various contributing factors such as anti-inflammatory genes and antioxidant enzymes. This leads to an urgent need of novel drug delivery systems to combat the oxidative stress. This review gives a brief insight into the biological factors involved in causing oxidative stress, one of the emerging hallmark feature in CRDs and particularly, highlighting recent trends in various novel drug delivery carriers including microparticles, microemulsions, microspheres, nanoparticles, liposomes, dendrimers, solid lipid nanocarriers etc which can help in combating the oxidative stress in CRDs and ultimately reducing the disease burden and improving the quality of life with CRDs patients. These carriers improve the pharmacokinetics and bioavailability to the target site. However, there is an urgent need for translational studies to validate the drug delivery carriers for clinical administration in the pulmonary clinic.

Transcriptome analysis of the effects of Cd and nanomaterial-loaded Cd on the liver in zebrafish

The wide application of engineered nanoparticles to remove heavy metals in aquatic environments has raised concerns over nanomaterial-adsorbed heavy metal toxicity. To ensure safe use of nanomaterial-heavy metal composites, understanding their biological effects at the molecular level is crucial. In the present study, we used the Illumina HiSeq technology to study the transcriptome changes induced by Cd²⁺ and nano-manganese dioxide- or nano-hydroxyapatite-adsorbed CdCl₂ composites (nMnO₂-Cd, nHAP₂₀-Cd, and nHAP₄₀-Cd) in zebrafish liver cells. We identified 545 differentially expressed genes (DEGs), 33 of which were in common between the nMnO₂-Cd, nHAP₂₀-Cd, and nHAP₄₀-Cd groups. The DEGs could be classified in four categories: hydrolases (enzymes involved in various physiological functions, including digestion, immune response, blood coagulation, and reproduction), biological binding (FMN-, actin- and metal ion-binding), metabolic enzymes (e.g., ceramidase, alpha-amylase, carboxylic ester hydrolase, and carboxypeptidase), and cell structure (cell surface, intermediate filament, and muscle myopen protein). The DEGs identified in this study are potentially useful markers to understand the physiological responses induced by Cd²⁺ and nano-Cd composites in zebrafish liver.

Cytotoxicity and Transcriptomic Analysis of Silver Nanoparticles in Mouse Embryonic Fibroblast Cells

The rapid development of nanotechnology has led to the use of silver nanoparticles (AgNPs) in biomedical applications, including antibacterial, antiviral, anti-inflammatory, and anticancer therapies. The molecular mechanism of AgNPs-induced cytotoxicity has not been studied thoroughly using a combination of cellular assays and RNA sequencing (RNA-Seq) analysis. In this study, we prepared AgNPs using myricetin, an anti-oxidant polyphenol, and studied their effects on NIH3T3 mouse embryonic fibroblasts as an in vitro model system to explore the potential biomedical applications of AgNPs. AgNPs induced loss of cell viability and cell proliferation in a dose-dependent manner, as evident by increased leakage of lactate dehydrogenase (LDH) from cells. Reactive oxygen species (ROS) were a potential source of cytotoxicity. AgNPs also incrementally increased oxidative stress and the level of malondialdehyde, depleted glutathione and superoxide dismutase, reduced mitochondrial membrane potential and adenosine triphosphate (ATP), and caused DNA damage by increasing the level of 8-hydroxy-2′-deoxyguanosine and the expressions of the p53 and p21 genes in NIH3T3 cells. Thus, activation of oxidative stress may be crucial for NIH3T3 cytotoxicity. Interestingly, gene ontology (GO) term analysis revealed alterations in epigenetics-related biological processes including nucleosome assembly and DNA methylation due to AgNPs exposure. This study is the first demonstration that AgNPs can alter bulk histone gene expression. Therefore, our genome-scale study suggests that the apoptosis observed in NIH3T3 cells treated with AgNPs is mediated by the repression of genes required for cell survival and the aberrant enhancement of nucleosome assembly components to induce apoptosis.

Cytotoxic Potential and Molecular Pathway Analysis of Silver Nanoparticles in Human Colon Cancer Cells HCT116

Silver nanoparticles (AgNPs) have gained attention for use in cancer therapy. In this study, AgNPs were biosynthesized using naringenin. We investigated the anti-colon cancer activities of biogenic AgNPs through transcriptome analysis using RNA sequencing, and the mechanisms of AgNPs in regulating colon cancer cell growth. The synthesized AgNPs were characterized using UV⁻visible spectroscopy (UV⁻vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscopy (TEM). The AgNPs were spherical with sizes of 2⁻10 nm. Cytotoxicity assays indicated that the AgNPs in HCT116 colorectal cancer cells were very effective at low concentrations. The viability and proliferation of colon cancer cells treated with 5 µg/mL biogenic AgNPs were reduced by 50%. Increased lactate dehydrogenase leakage (LDH), reactive oxygen species (ROS) generation, malondialdehyde (MDA), and decreased dead-cell protease activity and ATP generation were observed. This impaired mitochondrial function and DNA damage led to cell death. The AgNPs upregulated and downregulated the most highly ranked biological processes of oxidation⁻reduction and cell-cycle regulation, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that AgNPs upregulated GADD45G in the p53 pathway. Thus, the AgNP tumor suppressive effects were mediated by cell apoptosis following DNA damage, as well as by mitochondrial dysfunction and cell-cycle arrest following aberrant regulation of p53 effector proteins. It is of interest to mention that, to the best of our knowledge, this study is the first report demonstrating cellular responses and molecular pathways analysis of AgNPs in HCT116 colorectal cancer cells.

Cationic liposomes induce cytotoxicity in HepG2 via regulation of lipid metabolism based on whole-transcriptome sequencing analysis

Backgroud

Cationic liposomes (CLs) can be used as non-viral vectors in gene transfer and drug delivery. However, the underlying molecular mechanism of its cytotoxicity has not been well elucidated yet.

Methods

We herein report a systems biology approach based on whole-transcriptome sequencing coupled with computational method to identify the predominant genes and pathways involved in the cytotoxicity of CLs in HepG2 cell line.

Results

Firstly, we validated the concentration-dependent cytotoxicity of CLs with an IC₅₀ of 120 μg/ml in HepG2 exposed for 24 h. Subsequently, we used whole-transcriptome sequencing to identify 220 (77 up- and 143 down-regulated) differentially expressed genes (DEGs). Gene ontology (GO) and pathway analysis showed that these DEGs were mainly related to cholesterol, steroid, lipid biosynthetic and metabolic processes. Additionally, “key regulatory” genes were identified using gene act, pathway act and co-expression network analysis, and expression levels of 11 interested altered genes were confirmed by quantitative real time PCR. Interestingly, no cell cycle arrest was observed through flow cytometry.

Conclusions

These data are expected to provide deep insights into the molecular mechanism of CLs cytotoxicity.

RNA-sequencing reveals long-term effects of silver nanoparticles on human lung cells

Despite a considerable focus on the adverse effects of silver nanoparticles (AgNPs) in recent years, studies on the potential long-term effects of AgNPs are scarce. The aim of this study was to explore the effects of AgNPs following repeated low-dose, long-term exposure of human bronchial epithelial cells. To this end, the human BEAS-2B cell line was exposed to 1 µg/mL AgNPs (10 nm) for 6 weeks followed by RNA-sequencing (RNA-Seq) as well as genome-wide DNA methylation analysis. The transcriptomics analysis showed that a substantial number of genes (1717) were differentially expressed following AgNP exposure whereas only marginal effects on DNA methylation were observed. Downstream analysis of the transcriptomics data identified several affected pathways including the ‘fibrosis’ and ‘epithelial-mesenchymal transition’ (EMT) pathway. Subsequently, functional validation studies were performed using AgNPs of two different sizes (10 nm and 75 nm). Both NPs increased collagen deposition, indicative of fibrosis, and induced EMT, as evidenced by an increased invasion index, anchorage independent cell growth, as well as cadherin switching. In conclusion, using a combination of RNA-Seq and functional assays, our study revealed that repeated low-dose, long-term exposure of human BEAS-2B cells to AgNPs is pro-fibrotic, induces EMT and cell transformation.

Toxicology of Engineered Nanoparticles: Focus on Poly(amidoamine) Dendrimers

Engineered nanomaterials are increasingly being developed for paints, sunscreens, cosmetics, industrial lubricants, tyres, semiconductor devices, and also for biomedical applications such as in diagnostics, therapeutics, and contrast agents. As a result, nanomaterials are being manufactured, transported, and used in larger and larger quantities, and potential impacts on environmental and human health have been raised. Poly(amidoamine) (PAMAM) dendrimers are specifically suitable for biomedical applications. They are well-defined nanoscale molecules which contain a 2-carbon ethylenediamine core and primary amine groups at the surface. The systematically variable structural architecture and the large internal free volume make these dendrimers an attractive option for drug delivery and other biomedical applications. Due to the wide range of applications, the Organisation for Economic Co-Operation and Development (OECD) have included them in their list of nanoparticles which require toxicological assessment. Thus, the toxicological impact of these PAMAM dendrimers on human health and the environment is a matter of concern. In this review, the potential toxicological impact of PAMAM dendrimers on human health and environment is assessed, highlighting work to date exploring the toxicological effects of PAMAM dendrimers.

Global gene expression analysis of macrophage response induced by nonporous and porous silica nanoparticles

Little is known about the global gene expression profile of macrophages in response to changes in size and porosity of silica nanoparticles (SNPs). Spherical nonporous SNPs of two different diameters, and mesoporous spherical SNPs with comparable size were characterized. Reactive oxygen species, mitochondrial membrane potential, lysosome degradation capacity, and lysosome pH were measured to evaluate the influence of nonporous and mesoporous SNPs on mitochondrial and lysosomal function. RNA-sequencing was utilized to generate transcriptional profiles of RAW264.7 macrophages exposed to non-toxic SNP doses. DESeq2, limma, and BinReg2 software were used to analyze the data based on both unsupervised and supervised strategies to identify genes with greatest differences among NP treatments. Utilizing GATHER and DAVID software, possible induced pathways were studied. We found that mesoporous silica nanoparticles are capable of altering gene expression in macrophages at doses that do not elicit acute cytotoxicity, while gene transcription was minimally affected by nonporous SNPs.

Detailed investigation on how the protein corona modulates the physicochemical properties and gene delivery of polyethylenimine (PEI) polyplexes

Given the various cationic polymers developed as non-viral gene delivery vectors, polyethylenimine (PEI) has been/is frequently used in in vitro transfection.

Carbon Nanotubes as Optical Sensors in Biomedicine

Single-walled carbon nanotubes (SWCNTs) have become potential candidates for a wide range of medical applications including sensing, imaging, and drug delivery. Their photophysical properties (i.e., the capacity to emit in the near-infrared), excellent photostability, and fluorescence, which is highly sensitive to the local environment, make SWCNTs promising optical probes in biomedicine. In this Perspective, we discuss the existing strategies for and challenges of using carbon nanotubes for medical diagnosis based on intracellular sensing as well as discuss also their biocompatibility and degradability. Finally, we highlight the potential improvements of this nanotechnology and future directions in the field of carbon nanotubes for biomedical applications.

Transcriptional profiling reveals gene expression changes associated with inflammation and cell proliferation following short-term inhalation exposure to copper oxide nanoparticles

Our recent studies revealed a dose-dependent proinflammatory response to copper oxide nanoparticles (CuO NPs) in rats following short-term inhalation exposure for five consecutive days. Here transcriptomics approaches were applied using the same model to assess global gene expression in lung tissues obtained 1 day post-exposure and after a recovery period of 22 days from rats exposed to clean air or 6 hour equivalent doses of 3.3 mg m^-3 (low dose) and 13.2 mg m^-3 (high dose). Microarray analyses yielded about 1000 differentially expressed genes in the high-dose group and 200 in low-dose compared to the clean air control group, and less than 20 after the recovery period. Pathway analysis indicated cell proliferation/survival and inflammation as the main processes triggered by exposure to CuO NPs. We did not find significant perturbations of pathways related to oxidative stress. Upregulation of epithelial cell transforming protein 2 (Ect2), a known oncogene, was noted and ECT2 protein was upregulated in the lungs of exposed animals. Proliferation of alveolar epithelial cells was demonstrated based on Ki67 expression. The gene encoding monocyte chemoattractant protein 1 (or CCL2) was also upregulated and this was confirmed by immunohistochemistry. However, no aberrant DNA methylation of inflammation-associated genes was observed. In conclusion, we have found that inhalation of CuO NPs in rats causes upregulation of the oncoprotein ECT2 and the chemokine CCL2 and other proinflammatory markers as well as proliferation in bronchoalveolar epithelium after a short-term inhalation exposure. Thus, pathways known to be associated with neoplastic processes and inflammation were affected in this model.

Cerium oxide nanoparticles inhibit differentiation of neural stem cells

Cerium oxide nanoparticles (nanoceria) display antioxidant properties and have shown cytoprotective effects both in vitro and in vivo. Here, we explored the effects of nanoceria on neural progenitor cells using the C17.2 murine cell line as a model. First, we assessed the effects of nanoceria versus samarium (Sm) doped nanoceria on cell viability in the presence of the prooxidant, DMNQ. Both particles were taken up by cells and nanoceria, but not Sm-doped nanoceria, elicited a temporary cytoprotective effect upon exposure to DMNQ. Next, we employed RNA sequencing to explore the transcriptional responses induced by nanoceria or Sm-doped nanoceria during neuronal differentiation. Detailed computational analyses showed that nanoceria altered pathways and networks relevant for neuronal development, leading us to hypothesize that nanoceria inhibits neuronal differentiation, and that nanoceria and Sm-doped nanoceria both interfere with cytoskeletal organization. We confirmed that nanoceria reduced neuron specific β3-tubulin expression, a marker of neuronal differentiation, and GFAP, a neuroglial marker. Furthermore, using super-resolution microscopy approaches, we could show that both particles interfered with cytoskeletal organization and altered the structure of neural growth cones. Taken together, these results reveal that nanoceria may impact on neuronal differentiation, suggesting that nanoceria could pose a developmental neurotoxicity hazard.

Identification of Gene Transcription Start Sites and Enhancers Responding to Pulmonary Carbon Nanotube Exposure in Vivo

Increased use of nanomaterials in industry, medicine, and consumer products has raised concerns over their toxicity. To ensure safe use of nanomaterials, understanding their biological effects at the molecular level is crucial. In particular, the regulatory mechanisms responsible for the cascade of genes activated by nanomaterial exposure are not well-characterized. To this end, we profiled the genome-wide usage of gene transcription start sites and linked active enhancer regions in lungs of C57BL/6 mice 24 h after intratracheal instillation of a single dose of the multiwalled carbon nanotube (MWCNT) Mitsui-7. Our results revealed a massive gene regulatory response, where expression of key inflammatory genes (e.g., Csf3, Il24, and Fgf23) was increased >100-fold 24 h after Mitsui-7 exposure. Many of the Mitsui-7-responsive transcription start sites were alternative transcription start sites for known genes, and the number of alternative transcription start sites used in a given gene was correlated with overall Mitsui-7 response. Strikingly, genes that were up-regulated after Mitsui-7 exposure only through their main annotated transcription start site were linked to inflammatory and defense responses, while genes up-regulated only through alternative transcription start sites were functionally heterogeneous and not inflammation-associated. Furthermore, we identified almost 12 000 active enhancers, many of which were Mitsui-7-responsive, and we identified similarly responding putative target genes. Overall, our study provides the location and activity of Mitsui-7-induced enhancers and transcription start sites, providing a useful resource for targeted experiments elucidating the biological effects of nanomaterials and the identification of biomarkers for early detection of MWCNT-induced inflammation.

Real-time, label-free monitoring of cell viability based on cell adhesion measurements with an atomic force microscope

Background

The adhesion of cells to an oscillating cantilever sensitively influences the oscillation amplitude at a given frequency. Even early stages of cytotoxicity cause a change in the viscosity of the cell membrane and morphology, both affecting their adhesion to the cantilever. We present a generally applicable method for real-time, label free monitoring and fast-screening technique to assess early stages of cytotoxicity recorded in terms of loss of cell adhesion.

Results

We present data taken from gold nanoparticles of different sizes and surface coatings as well as some reference substances like ethanol, cadmium chloride, and staurosporine. Measurements were recorded with two different cell lines, HeLa and MCF7 cells. The results obtained from gold nanoparticles confirm earlier findings and attest the easiness and effectiveness of the method.

Conclusions

The reported method allows to easily adapt virtually every AFM to screen and assess toxicity of compounds in terms of cell adhesion with little modifications as long as a flow cell is available. The sensitivity of the method is good enough indicating that even single cell analysis seems possible.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-017-0256-7) contains supplementary material, which is available to authorized users.

Transcriptome Analysis Reveals Silver Nanoparticle-Decorated Quercetin Antibacterial Molecular Mechanism

Facile and simple method is developed to synthesize silver-nanoparticle-decorated quercetin nanoparticles (QA NPs). Modification suggests that synergistic quercetin (Qe) improves the antibacterial effect of silver nanoparticles (Ag NPs). Characterization experiment indicates that QA NPs have a diameter of approximately 10 nm. QA NPs show highly effective antibacterial activities against drug-resistant Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). We explore antibacterial mechanisms using S. aureus and E. coli treated with QA NPs. Through morphological changes in E. coli and S. aureus, mechanisms are examined for bacterial damage caused by particulate matter from local dissociation of silver ion and Qe from QA NPs trapped inside membranes. Moreover, we note that gene expression profiling methods, such as RNA sequencing, can be used to predict discover mechanisms of toxicity of QA NPs. Gene ontology (GO) assay analyses demonstrate the molecular mechanism of the antibacterial effect of QA NPs. Regarding cellular component ontology, "cell wall organization or biogenesis" (GO: 0071554) and "cell wall macromolecule metabolic process" (GO: 0044036) are the most represented categories. The present study reports that transcriptome analysis of the mechanism offers novel insights into the molecular mechanism of antibacterial assays.

Systems Biology to Support Nanomaterial Grouping

The assessment of potential health risks of engineered nanomaterials (ENMs) is a challenging task due to the high number and great variety of already existing and newly emerging ENMs. Reliable grouping or categorization of ENMs with respect to hazards could help to facilitate prioritization and decision making for regulatory purposes. The development of grouping criteria, however, requires a broad and comprehensive data basis. A promising platform addressing this challenge is the systems biology approach. The different areas of systems biology, most prominently transcriptomics, proteomics and metabolomics, each of which provide a wealth of data that can be used to reveal novel biomarkers and biological pathways involved in the mode-of-action of ENMs. Combining such data with classical toxicological data would enable a more comprehensive understanding and hence might lead to more powerful and reliable prediction models. Physico-chemical data provide crucial information on the ENMs and need to be integrated, too. Overall statistical analysis should reveal robust grouping and categorization criteria and may ultimately help to identify meaningful biomarkers and biological pathways that sufficiently characterize the corresponding ENM subgroups. This chapter aims to give an overview on the different systems biology technologies and their current applications in the field of nanotoxicology, as well as to identify the existing challenges.