Gold Nanoparticle-Induced Cell Death and Potential Applications in Nanomedicine

Machine Learning-Driven discovery of immunogenic cell Death-Related biomarkers and molecular classification for diabetic ulcers

In this study, we redefine the diagnostic landscape of diabetic ulcers (DUs), a major diabetes complication. Our research uncovers new biomarkers linked to immunogenic cell death (ICD) in DUs by utilizing RNA-sequencing data of Gene Expression Omnibus (GEO) analysis combined with a comprehensive database interrogation. Employing a random forest algorithm, we have developed a diagnostic model that demonstrates improved accuracy in distinguishing DUs from normal tissue, with satisfactory results from ROC analysis. Beyond mere diagnosis, our model categorizes DUs into novel molecular classifications, which may enhance our comprehension of their underlying pathophysiology. This study bridges the gap between molecular insights and clinical practice. It sets the stage for transformative strategies in DUs management, marking a significant step forward in personalized medicine for diabetic patients.

Tau- and α-synuclein-targeted gold nanoparticles: applications, opportunities, and future outlooks in the diagnosis and therapy of neurodegenerative diseases

The use of nanomaterials in medicine offers multiple opportunities to address neurodegenerative disorders such as Alzheimer's and Parkinson's disease. These diseases are a significant burden for society and the health system, affecting millions of people worldwide without sensitive and selective diagnostic methodologies or effective treatments to stop their progression. In this sense, the use of gold nanoparticles is a promising tool due to their unique properties at the nanometric level. They can be functionalized with specific molecules to selectively target pathological proteins such as Tau and α-synuclein for Alzheimer's and Parkinson's disease, respectively. Additionally, these proteins are used as diagnostic biomarkers, wherein gold nanoparticles play a key role in enhancing their signal, even at the low concentrations present in biological samples such as blood or cerebrospinal fluid, thus enabling an early and accurate diagnosis. On the other hand, gold nanoparticles act as drug delivery platforms, bringing therapeutic agents directly into the brain, improving treatment efficiency and precision, and reducing side effects in healthy tissues. However, despite the exciting potential of gold nanoparticles, it is crucial to address the challenges and issues associated with their use in the medical field before they can be widely applied in clinical settings. It is critical to ensure the safety and biocompatibility of these nanomaterials in the context of the central nervous system. Therefore, rigorous preclinical and clinical studies are needed to assess the efficacy and feasibility of these strategies in patients. Since there is scarce and sometimes contradictory literature about their use in this context, the main aim of this review is to discuss and analyze the current state-of-the-art of gold nanoparticles in relation to delivery, diagnosis, and therapy for Alzheimer's and Parkinson's disease, as well as recent research about their use in preclinical, clinical, and emerging research areas.

Nanomaterials-induced programmed cell death: Focus on mitochondria

Nanomaterials are widely utilized in several domains, such as everyday life, societal manufacturing, and biomedical applications, which expand the potential for nanomaterials to penetrate biological barriers and interact with cells. Multiple studies have concentrated on the particular or improper utilization of nanomaterials, resulting in cellular death. The primary mode of cell death caused by nanotoxicity is programmable cell death, which includes apoptosis, ferroptosis, necroptosis, and pyroptosis. Based on our prior publications and latest research, mitochondria have a vital function in facilitating programmed cell death caused by nanomaterials, as well as initiating or transmitting death signal pathways associated with it. Therefore, this review takes mitochondria as the focal point to investigate the internal molecular mechanism of nanomaterial-induced programmed cell death, with the aim of identifying potential targets for prevention and treatment in related studies.

A Journey of Challenges and Victories: A Bibliometric Worldview of Nanomedicine since the 21st Century

Nanotechnology profoundly affects the advancement of medicine. Limitations in diagnosing and treating cancer and chronic diseases promote the growth of nanomedicine. However, there are very few analytical and descriptive studies regarding the trajectory of nanomedicine, key research powers, present research landscape, focal investigative points, and future outlooks. Herein, articles and reviews published in the Science Citation Index Expanded of Web of Science Core Collection from first January 2000 to 18th July 2023 are analyzed. Herein, a bibliometric visualization of publication trends, countries/regions, institutions, journals, research categories, themes, references, and keywords is produced and elaborated. Nanomedicine-related academic output is increasing since the COVID-19 pandemic, solidifying the uneven global distribution of research performance. While China leads in terms of publication quantity and has numerous highly productive institutions, the USA has advantages in academic impact, commercialization, and industrial value. Nanomedicine integrates with other disciplines, establishing interdisciplinary platforms, in which drug delivery and nanoparticles remain focal points. Current research focuses on integrating nanomedicine and cell ferroptosis induction in cancer immunotherapy. The keyword "burst testing" identifies promising research directions, including immunogenic cell death, chemodynamic therapy, tumor microenvironment, immunotherapy, and extracellular vesicles. The prospects, major challenges, and barriers to addressing these directions are discussed.

The Refined Application and Evolution of Nanotechnology in Enhancing Radiosensitivity During Radiotherapy: Transitioning from Gold Nanoparticles to Multifunctional Nanomaterials

Radiotherapy is a pivotal method for treating malignant tumors, and enhancing the therapeutic gain ratio of radiotherapy through physical techniques is the direction of modern precision radiotherapy. Due to the inherent physical properties of high-energy radiation, enhancing the therapeutic gain ratio of radiotherapy through radiophysical techniques inevitably encounters challenges. The combination of hyperthermia and radiotherapy can enhance the radiosensitivity of tumor cells, reduce their radioresistance, and holds significant clinical utility in radiotherapy. Multifunctional nanomaterials with excellent biocompatibility and safety have garnered widespread attention in tumor hyperthermia research, demonstrating promising potential. Utilizing nanotechnology as a sensitizing carrier in conjunction with radiotherapy, and high atomic number nanomaterials can also serve independently as radiosensitizing carriers. This synergy between tumor hyperthermia and radiotherapy may overcome many challenges currently limiting tumor radiotherapy, offering new opportunities for its further advancement. In recent years, the continuous progress in the synthesis and design of novel nanomaterials will propel the future development of medical imaging and cancer treatment. This article summarizes the radiosensitizing mechanisms and effects based on gold nanotechnology and provides an overview of the advancements of other nanoparticles (such as bismuth-based nanomaterials, magnetic nanomaterials, selenium nanomaterials, etc.) in the process of radiation therapy.

Photothermally sensitive gold nanocage augments the antitumor efficiency of immune checkpoint blockade in immune "cold" tumors

Introduction

Immune checkpoint blockade (ICB) has revolutionized the therapy landscape of malignancy melanoma. However, the clinical benefits from this regimen remain limited, especially in tumors lacking infiltrated T cells (known as "cold" tumors). Nanoparticle-mediated photothermal therapy (PTT) has demonstrated improved outcomes in the ablation of solid tumors by inducing immunogenic cell death (ICD) and reshaping the tumor immune microenvironment. Therefore, the combination of PTT and ICB is a promising regimen for patients with "cold" tumors.

Methods

A second near-infrared (NIR-II) light-activated gold nanocomposite AuNC@SiO2@HA with AuNC as a kernel, silica as shell, and hyaluronic acid (HA) polymer as a targeting molecule, was synthesized for PTT. The fabricated AuNC@SiO2@HA nanocomposites underwent various in vitro studies to characterize their physicochemical properties, light absorption spectra, photothermal conversion ability, cellular uptake ability, and bioactivities. The synergistic effect of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy was evaluated using a mouse model of immune "cold" melanoma. The tumor-infiltrating T cells were assessed by immunofluorescence staining and flow cytometry. Furthermore, the mechanism of AuNC@SiO2@HA-induced T-cell infiltration was investigated through immunochemistry staining of the ICD-related markers, including HSP70, CRT, and HMGB1. Finally, the safety of AuNC@SiO2@HA nanocomposites was evaluated in vivo.

Results

The AuNC@SiO2@HA nanocomposite with absorption covering 1064 nm was successfully synthesized. The nano-system can be effectively delivered into tumor cells, transform the optical energy into thermal energy upon laser irradiation, and induce tumor cell apoptosis in vitro. In an in vivo mouse melanoma model, AuNC@SiO2@HA nanocomposites significantly induced ICD and T-cell infiltration. The combination of AuNC@SiO2@HA and anti-PD-1 antibody synergistically inhibited tumor growth via stimulating robust T lymphocyte immune responses.

Discussion

The combination of AuNC@SiO2@HA-mediated PTT and anti-PD-1 immunotherapy proposed a neoteric strategy for oncotherapy, which efficiently convert the immune "cold" tumors into "hot" ones.

Assessment of the potential cerebellar toxicity of gold nanoparticles on the structure and function of adult male albino rats

BACKGROUND

The regular use of gold nanoparticles (Au-NPs) may increase the likelihood of human exposure to these nanoparticles (NPs) and raises concerns about toxicity.

AIM

This study investigated the short-term impact of exposure to Au-NPs on inducing cerebellar pathology in rats, and whether the dose or duration of exposure was more important.

METHODOLOGY

The study used two concentrations of Au-NPs (25 and 50 particles per million) and 18 rats were randomly assigned to three groups. Assessments of the animals were done via behavioral, gene expression, histological, and immunohistochemistry analyses.

RESULTS

Both concentrations of Au-NPs caused cerebellar pathology, as assessed through the investigation test battery. The Au-NPs50 group displayed more injury and decreased mobility compared with the control and the Au-NPs25 group. The Au-NPs25 group showed an increase in supported rearing and significant up-regulation of the Rgc32 gene compared with the control. The Trkb gene was insignificantly up-regulated in both Au-NPs groups compared with the control.

CONCLUSION

The study indicates that exposure to Au-NPs can cause cerebellar pathology in rats and that the toxicity is more dependent on dose than the duration of exposure. These findings have significant implications for the safe use of Au-NPs in various applications.

Nano-sized warriors: zinc chromium vanadate nanoparticles as a dual solution for eradicating waterborne enterobacteriaceae and fighting cancer

The revolution of biomedical applications has opened new avenues for nanotechnology. Zinc Chromium vanadate nanoparticles (VCrZnO4 NPs) have emerged as an up-and-coming candidate, with their exceptional physical and chemical properties setting them apart. In this study, a one-pot solvothermal method was employed to synthesize VCrZnO4 NPs, followed by a comprehensive structural and morphological analysis using a variety of techniques, including X-Ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Energy-dispersive X-ray, and X-ray photoelectron spectroscopy. These techniques confirmed the crystallinity of the NPs. The VCrZnO4 NPs were tested for their antibacterial activity against primary contaminants such as Enterobacteriaceae, including Shigella flexneri, Salmonella cholerasis, and Escherichia coli, commonly found in hospital settings, using the broth dilution technique. The results indicated a stronger antibacterial activity of VCrZnO4 NPs against Shigella and Salmonella than E. coli. Electron microscopy showed that the NPs caused severe damage to the bacterial cell wall and membrane, leading to cell death. In addition, the study evaluated the anticancer activities of the metal complexes in vitro using colorectal cancer cells (HCT-116) and cervical cancer cells (HELA), along with non-cancer cells and human embryonic kidney cells (HEK-293). A vanadium complex demonstrated efficient anticancer effects with half-inhibitory concentrations (IC₅₀) of 38.50+3.50 g/mL for HCT-116 cells and 42.25+4.15 g/mL for HELA cells. This study highlights the potential of Zinc Chromium vanadate nanoparticles as promising candidates for antibacterial and anticancer applications. Various advanced characterization techniques were used to analyze the properties of nanomaterials, which may help develop more effective and safer antibacterial and anticancer agents in the future.

Implications of ferroptosis in silver nanoparticle-induced cytotoxicity of macrophages

Metal nanoparticles (NPs) are widely used in daily life and commercial activities owing to their unique physicochemical properties. Consequently, there is an increasing risk of daily and occupational exposure to metal NPs, which raises concerns regarding their health hazards. Programmed cell deaths (PCDs) have been clarified to be involved in metal NP-induced cytotoxicity, including apoptosis, autophagy, and pyroptosis. However, whether and how ferroptosis, a newly recognized PCD, contributes to metal NP-induced cell death remain unclear. In this study, we investigated the ferroptotic effects of two representative metal NPs, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), on macrophages in vitro. Our results revealed that AgNPs, rather than AuNPs, induced non-apoptotic PCD, accompanied by lipid peroxidation and iron homeostasis disorders, which are two hallmarks of ferroptosis, in macrophages. Treatment with a ferroptosis inhibitor (ferrostatin-1) and iron chelator (deferoxamine) reversed AgNP-induced PCD, corroborating the induction of ferroptosis upon exposure to AgNPs. Moreover, our results revealed that smaller AgNPs elicited greater ferroptotic effects on macrophages than larger ones. Importantly, ferroptosis in AgNP-treated macrophages was mainly triggered by AgNPs per se rather than by Ag ions. Overall, our study highlights the ferroptotic effects elicited by AgNPs in macrophages, which will promote the understanding of their cytotoxic effects and facilitate the safer design of metal nanoproducts.

Gold nanoparticles inhibit tumor growth via targeting the Warburg effect in a c-Myc-dependent way

Gold nanoparticles (AuNPs) are prospective tools for nano-based medicine that can directly target cellular biological processes to influence cell fate and function. Studies have revealed the essential role of AuNPs in metabolic remodeling for macrophage polarization. Nevertheless, as a hallmark of cancer cells, metabolic changes in tumor cells in response to AuNPs have not yet been reported. In the present study, polymer- and folate-conjugated AuNPs with satisfactory biocompatibility and tumor-targeting activity were synthesized to investigate their underlying roles in tumor metabolism. Tumor cells were significantly suppressed by AuNPs in vitro and in vivo, with little cytotoxicity in non-tumor cells. Subcellular localization showed that AuNPs localized in the mitochondria of tumor cells and impaired their structure and function, leading to excessive oxidative stress and mitochondrial apoptosis. Metabolic stress, with decreased glycolysis and insufficient nutrients, was also caused by AuNPs exposure in tumor cells. Mechanistically, the key enzymes (GLUT1 and HK2) for glycolysis modulation were remarkably reduced by AuNPs in a c-Myc-dependent manner. The present study demonstrated a new mechanism for AuNPs in the inhibition of tumor growth, that is, via directly targeting glycolysis and depriving energy. These findings provide new strategies for the design of nano-based medicines and anti-glycolytic therapeutics to inhibit the development of malignant tumors. STATEMENT OF SIGNIFICANCE: Gold nanoparticles (AuNPs) have acquired ever-increasing interest for applications in cancer treatment and diagnosis due to their high biosafety and facile surface modification. Recent studies have shown that AuNPs can work as active agents to directly target the cellular processes and harbor antitumor properties, while the underlying mechanisms remain largely unknown. From the present findings, the stabilized AuNPs showed direct inhibition effects on tumor growth by glycolysis inhibition and energy deprivation. These results provide new insights of AuNPs for tumor treatments, which will further contribute to the development of promising nano-based medicines and anti-glycolytic therapies.

Application of Gold Nanoparticles as Radiosensitizer for Metastatic Prostate Cancer Cell Lines

More than 50% of all prostate cancer (PCa) patients are treated by radiotherapy (RT). Radioresistance and cancer recurrence are two consequences of the therapy and are related to dose heterogeneity and non-selectivity between normal and tumoral cells. Gold nanoparticles (AuNPs) could be used as potential radiosensitizers to overcome these therapeutic limitations of RT. This study assessed the biological interaction of different morphologies of AuNPs with ionizing radiation (IR) in PCa cells. To achieve that aim, three different amine-pegylated AuNPs were synthesized with distinct sizes and shapes (spherical, AuNP_sp-PEG, star, AuNP_st-PEG, and rods, AuNP_r-PEG) and viability, injury and colony assays were used to analyze their biological effect on PCa cells (PC3, DU145, and LNCaP) when submitted to the accumulative fraction of RT. The combinatory effect of AuNPs with IR decreased cell viability and increased apoptosis compared to cells treated only with IR or untreated cells. Additionally, our results showed an increase in the sensitization enhancement ratio by cells treated with AuNPs and IR, and this effect is cell line dependent. Our findings support that the design of AuNPs modulated their cellular behavior and suggested that AuNPs could improve the RT efficacy in PCa cells.

Gold Nanoparticles Induced Size Dependent Cytotoxicity on Human Alveolar Adenocarcinoma Cells by Inhibiting the Ubiquitin Proteasome System

Gold nanoparticles (AuNPs) are widely used in biomedicine due to their remarkable therapeutic applications. However, little is known about their cytotoxic effects on the ubiquitin proteasome system (UPS). Herein, the cytotoxicity of different sizes of AuNPs (5, 10, and 80 nm) on the UPS was investigated with a particular focus on deubiquitinating enzymes (DUBs) such as ubiquitin-specific proteases (USP) and ubiquitin carboxyl-terminal hydrolases (UCHL-1) in human alveolar epithelial adenocarcinoma (A549). It was found that all sizes of AuNPs reduced the percentage of viable A549 cells and increased lactate dehydrogenase (LDH) release, measured using the MTT and LDH assays, respectively. Furthermore, the 5 nm AuNPs were found to exhibit greater cytotoxicity than the 10 and 80 nm AuNPs. In addition, apoptosis and necrosis were activated through reactive oxygen species (ROS) generation due to AuNPs exposure. The internalisation of AuNPs in A549 cells increased with increasing particle size (80 > 10 > 5 nm). Interestingly, the expression of USP7, USP8, USP10, and UCHL-1 was significantly (p < 0.001) downregulated upon treatment with 5-30 µg/mL of all the AuNPs sizes compared to control cells. Moreover, the inhibition of these proteins triggered mitochondrial-related apoptosis through the upregulation of poly (ADP-ribose) polymerase (PARP), caspase-3, and caspase-9. Collectively, these results indicate that AuNPs suppress the proliferation of A549 cells and can potentially be used as novel inhibitors of the proteasome.

Gold Nanoparticles in Triple-Negative Breast Cancer Therapeutics

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer with enhanced metastasis and poor survival. Though chemotherapy, radiotherapy, photothermal therapy (PTT), photodynamic therapy (PDT), and gene delivery are used to treat TNBC, various side effects limit these therapeutics against TNBC. In this review article, we have focused on the mechanism of action of gold nanoparticles (AuNPs) to enhance the efficacy of therapeutics with targeted delivery on TNBC cells.

METHODS

Research data were accumulated from PubMed, Scopus, Web of Science, and Google Scholar using searching criteria "gold nanoparticles and triple-negative breast cancer" and "gold nanoparticles and cancer". Though we reviewed many old papers, the most cited papers were from the last ten years.

RESULTS

Various studies indicate that AuNPs can enhance bioavailability, site-specific drug delivery, and efficacy of chemotherapy, radiotherapy, PTT, and PDT as well as modulate gene expression. The role of AuNPs in the modulation of TNBC therapeutics through the inhibition of cell proliferation, progression, and metastasis has been proved in vitro and in vivo studies. As these mechanistic actions of AuNPs are most desirable to develop drugs with enhanced therapeutic efficacy against TNBC, it might be a promising approach to apply AuNPs for TNBC therapeutics.

CONCLUSION

This article reviewed the mechanism of action of AuNPs and their application in the enhancement of therapeutics against TNBC. Much more attention is required for studying the role of AuNPs in developing them either as a single or synergistic anticancer agent against TNBC.

Identification of immunogenic cell death-related gene classification patterns and immune infiltration characterization in ischemic stroke based on machine learning

Ischemic stroke (IS) accounts for more than 80% of strokes and is one of the leading causes of death and disability in the world. Due to the narrow time window for treatment and the frequent occurrence of severe bleeding, patients benefit less from early intravenous thrombolytic drug therapy. Therefore, there is an urgent need to explore the molecular mechanisms poststroke to drive the development of new therapeutic approaches. Immunogenic cell death (ICD) is a type of regulatory cell death (RCD) that is sufficient to activate the adaptive immune response of immunocompetent hosts. Although there is growing evidence that ICD regulation of immune responses and immune responses plays an important role in the development of IS, the role of ICD in the pathogenesis of IS has rarely been explored. In this study, we systematically evaluated ICD-related genes in IS. The expression profiles of ICD-related genes in IS and normal control samples were systematically explored. We conducted consensus clustering, immune infiltration analysis, and functional enrichment analysis of IS samples using ICD differentially expressed genes. The results showed that IS patients could be classified into two clusters and that the immune infiltration profile was altered in different clusters. In addition, we performed machine learning to screen nine signature genes that can be used to predict the occurrence of disease. We also constructed nomogram models based on the nine risk genes (CASP1, CASP8, ENTPD1, FOXP3, HSP90AA1, IFNA1, IL1R1, MYD88, and NT5E) and explored the immune infiltration correlation, gene-miRNA, and gene-TF regulatory network of the nine risk genes. Our study may provide a valuable reference for further elucidation of the pathogenesis of IS and provide directions for drug screening, personalized therapy, and immunotherapy for IS.

Biological Response of Human Cancer Cells to Ionizing Radiation in Combination with Gold Nanoparticles

Simple Summary

Various types of metallic nanoparticles and especially gold nanoparticles (AuNPs) have been utilized in radiation studies to enhance the radiosensitization of cancer cells while minimizing detrimental effects in normal tissue. The aim of our study was to investigate the biological responses of various human cancer cells to gold-nanoparticle-induced radiosensitization. This was accomplished by using different AuNPs and several techniques in order to provide valuable insights regarding the multiple adverse biological effects, following ionizing radiation (IR) in combination with AuNPs. Insightful methodologies such as transmission electron microscopy were employed to identify comprehensively the complexity of the biological damage occurrence. Our findings confirm that AuNP radiosensitization may occur due to extensive and/or complex DNA damage, cell death, or cellular senescence. This multiparameter study aims to further elucidate the biological mechanisms and at the same time provide new information regarding the use of AuNPs as radiosensitizers in cancer treatment.

Abstract

In the context of improving radiation therapy, high-atomic number (Z) metallic nanoparticles and, more importantly, gold-based nanostructures are developed as radiation enhancers/radiosensitizers. Due to the diversity of cell lines, nanoparticles, as well as radiation types or doses, the resulting biological effects may differ and remain obscure. In this multiparameter study, we aim to shed light on these effects and investigate them further by employing X-irradiation and three human cancer cell lines (PC3, A549, and U2OS cells) treated by multiple techniques. TEM experiments on PC3 cells showed that citrate-capped AuNPs were found to be located mostly in membranous structures/vesicles or autophagosomes, but also, in the case of PEG-capped AuNPs, inside the nucleus as well. The colony-forming capability of cancer cells radiosensitized by AuNPs decreased significantly and the DNA damage detected by cytogenetics, γH2AX immunostaining, and by single (γH2AX) or double (γH2AX and OGG1) immunolocalization via transmission electron microscopy (TEM) was in many cases higher and/or persistent after combination with AuNPs than upon individual exposure to ionizing radiation (IR). Moreover, different cell cycle distribution was evident in PC3 but not A549 cells after treatment with AuNPs and/or irradiation. Finally, cellular senescence was investigated by using a newly established staining procedure for lipofuscin, based on a Sudan Black-B analogue (GL13) which showed that based on the AuNPs’ concentration, an increased number of senescent cells might be observed after exposure to IR. Even though different cell lines or different types and concentrations of AuNPs may alter the levels of radiosensitization, our results imply that the complexity of damage might also be an important factor of AuNP-induced radiosensitization.

An immunogenic cell death-related regulators classification patterns and immune microenvironment infiltration characterization in intracranial aneurysm based on machine learning

Background

Immunogenic Cell Death (ICD) is a novel way to regulate cell death and can sufficiently activate adaptive immune responses. Its role in immunity is still emerging. However, the involvement of ICD in Intracranial Aneurysms (IA) remains unclear. This study aimed to identify biomarkers associated with ICDs and determine the relationship between them and the immune microenvironment during the onset and progression of IA

Methods

The IA gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) in IA were identified and the effects of the ICD on immune microenvironment signatures were studied. Techniques like Lasso, Bayes, DT, FDA, GBM, NNET, RG, SVM, LR, and multivariate analysis were used to identify the ICD gene signatures in IA. A consensus clustering algorithm was used for conducting the unsupervised cluster analysis of the ICD patterns in IA. Furthermore, enrichment analysis was carried out for investigating the various immune responses and other functional pathways. Along with functional annotation, the weighted gene co-expression network analysis (WGCNA), protein-protein interaction (PPI) network and module construction, identification of the hub gene, and co-expression analysis were also carried out.

Results

The above techniques were used for establishing the ICD gene signatures of HMGB1, HMGN1, IL33, BCL2, HSPA4, PANX1, TLR9, CLEC7A, and NLRP3 that could easily distinguish IA from normal samples. The unsupervised cluster analysis helped in identifying three ICD gene patterns in different datasets. Gene enrichment analysis revealed that the IA samples showed many differences in pathways such as the cytokine-cytokine receptor interaction, regulation of actin cytoskeleton, chemokine signaling pathway, NOD-like receptor signaling pathway, viral protein interaction with the cytokines and cytokine receptors, and a few other signaling pathways compared to normal samples. In addition, the three ICD modification modes showed obvious differences in their immune microenvironment and the biological function pathways. Eight ICD-regulators were identified and showed meaningful associations with IA, suggesting they could severe as potential prognostic biomarkers.

Conclusions

A new gene signature for IA based on ICD features was created. This signature shows that the ICD pattern and the immune microenvironment are closely related to IA and provide a basis for optimizing risk monitoring, clinical decision-making, and developing novel treatment strategies for patients with IA.

Gold Nanoparticles Contact with Cancer Cell: A Brief Update

The fine-tuning of the physicochemical properties of gold nanoparticles has facilitated the rapid development of multifunctional gold-based nanomaterials with diagnostic, therapeutic, and therapeutic applications. Work on gold nanoparticles is increasingly focusing on their cancer application. This review provides a summary of the main biological effects exerted by gold nanoparticles on cancer cells and highlights some critical factors involved in the interaction process (protein corona, tumor microenvironment, surface functionalization). The review also contains a brief discussion of the application of gold nanoparticles in target discovery.

Systematic and mechanistic analysis of AuNP-induced nanotoxicity for risk assessment of nanomedicine

For decades, nanoparticles (NPs) have been widely implemented in various biomedical fields due to their unique optical, thermal, and tunable properties. Particularly, gold nanoparticles (AuNPs) have opened new frontiers in sensing, targeted drug delivery, imaging, and photodynamic therapy, showing promising results for the treatment of various intractable diseases that affect quality of life and longevity. Despite the tremendous achievements of AuNPs-based approaches in biomedical applications, few AuNP-based nanomedicines have been evaluated in clinical trials, which is likely due to a shortage of understanding of the biological and pathological effects of AuNPs. The biological fate of AuNPs is tightly related to a variety of physicochemical parameters including size, shape, chemical structure of ligands, charge, and protein corona, and therefore evaluating the effects of these parameters on specific biological interactions is a major ongoing challenge. Therefore, this review focuses on ongoing nanotoxicology studies that aim to characterize the effect of various AuNP characteristics on AuNP-induced toxicity. Specifically, we focus on understanding how each parameter alters the specific biological interactions of AuNPs via mechanistic analysis of nano-bio interactions. We also discuss different cellular functions affected by AuNP treatment (e.g., cell motility, ROS generation, interaction with DNA, and immune response) to understand their potential human health risks. The information discussed herein could contribute to the safe usage of nanomedicine by providing a basis for appropriate risk assessment and for the development of nano-QSAR models.

Efficacy of ivermectin against colon cancer induced by dimethylhydrazine in male wistar rats

Colon cancer (CC) is a common form of cancer worldwide. According to growing incidence of cancer and little information about the possible protective role of Ivermectin (IVM) on colon cancer, this study aimed to investigate the chemoprotective role of IVM against colon cancer induced by Dimethylhydrazine (DMH) in Male Wistar Rats. Based on LD_50, three doses of IVM (0.25, 0.5, and 1 mg/kg) were applied before assayingthe antioxidant status, apoptotic markers, and microscopic analysis. Our result showed that glutathione (GSH) level was significantly increased in low dose of IVM-treated rats. Hight levels of oxidative stress and tissue damage consumed GSH and catalase (CAT), and dismutase (SOD) as indicated by significant drop in the treated groups. mRNA levels of Bax and caspase-3 were upregulated in rats treated with the high dose. Contrastingly, the expression of Bcl-2 was significantly downregulated with high dose. Changes in genes expression proved that IVM triggered apoptosis in treated groups compared to untreated control group. Microscopic analysis showed that rats treated with DMH exhibited high development of colorectal tumor. After induction of colorectal tumor, medium and high dose of DMH induced reduction in medullary carcinoma with great incidence of lymphoid nodules and desmoplastic reaction. In conclusion, this study demonstrates the potential of IVM as an anticancer drug against colon cancer in male Wistar rats.

Folic Acid and Chitosan-Functionalized Gold Nanorods and Triangular Silver Nanoplates for the Delivery of Anticancer Agents

Background

Advances in the field of nanotechnology have shed light on the applications of nanoparticles for cancer treatment.

Methods

Folic acid and chitosan-functionalized gold nanorods (FACS-R) and triangular silver nanoplates (FACS-T) were synthesized and their properties were elucidated by UV-visible spectrophotometry, Fourier-transform infrared spectroscopy, field emission transmission electron microscopy and high-resolution X-ray diffraction.

Results

The average size of the FACS-R was determined to be a transverse length of 13.1 ± 1.8 nm and a longitudinal length of 47.2 ± 8.9 nm with an aspect ratio of 3.6. The average size of FACS-T was measured to be 31.8 ± 7.7 nm. Colloidal solutions of FACS-R and FACS-T were stable on the shelf at ambient temperature for 14 days in the dark. Anticancer agents were encapsulated in FACS-R and FACS-T. FACS-T showed a higher encapsulation efficiency with docetaxel, paclitaxel and diallyl disulfide than FACS-R. The cell viability on human gastric adenocarcinoma cells (AGS), human epithelial cervix adenocarcinoma cells (HeLa) and human colorectal adenocarcinoma cells (HT-29) after treatment with anticancer agent-encapsulated FACS-R and FACS-T was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Interestingly, paclitaxel-encapsulated FACS-R and FACS-T showed the highest percentages of early and late apoptosis on HeLa cells. A cell cycle analysis demonstrated increased G2/M arrest on HeLa cells with docetaxel and paclitaxel-encapsulated FACS-R and FACS-T. The FACS-T induced more G2/M arrest on HeLa cells than the FACS-R. To assess applications in near-infrared photothermal therapy (PTT), the cell viability on HeLa cells with the anticancer agent-encapsulated FACS-R and FACS-T was assessed in the presence or absence of 808 nm laser irradiation. The results showed that 808 nm laser irradiation significantly decreased cell viability.

Conclusion

Collectively, the triangular silver nanoplates were more effective than the gold nanorods for PTT. We believe that as-prepared nanoparticles have remarkable features and will become promising future nanomedicine.

Multimodal bioimaging using nanodiamond and gold hybrid nanoparticles

Hybrid core–shell nanodiamond-gold nanoparticles were synthesized and characterized as a novel multifunctional material with tunable and tailored properties for multifunctional biomedical applications. The combination of nanostructured gold and nanodiamond properties afford new options for optical labeling, imaging, sensing, and drug delivery, as well as targeted treatment. ND@Au core–shell nanoparticles composed of nanodiamond (ND) core doped with Si vacancies (SiV) and Au shell were synthesized and characterized in terms of their biomedical applications. Several bioimaging modalities based on the combination of optical and spectroscopic properties of the hybrid nano-systems are demonstrated in cellular and developing zebrafish larvae models. The ND@Au nanoparticles exhibit isolated ND’s Raman signal of sp3 bonded carbon, one-photon fluorescence of SiV with strong zero-phonon line at 740 nm, two-photon excited fluorescence of nanogold with short fluorescence lifetime and strong absorption of X-ray irradiation render them possible imaging agent for Raman mapping, Fluorescence imaging, two-photon Fluorescence Lifetime Imaging (TP-FLIM) and high-resolution hard-X-ray microscopy in biosystems. Potential combination of the imaging facilities with other theranostic functionalities is discussed.

Determinants of gold nanoparticle interactions with Proteins: Off-Target effect study

Photothermal therapy is one of the promising approaches toward cancer treatment. To date, several compounds have been developed for this application, among which nanoparticles are attracting ever-increasing attention. One of the obstacles in developing efficient photothermal nanoparticle agents is their off-target effect which is mainly mediated via non-specific interactions with proteins. Such interaction not only reduces the bioavailability of the agent but also will cause protein aggregation that can be lethal. So, gaining knowledge on the mechanisms mediating such interactions will facilitate development of more effective agents. Our last studies showed the mechanism of action of two modified gold nanoparticles, folic acid functionalized gold nanoparticles (FA-AuNPs) and gold shelled Fe₃O₄ nanoparticles (AuFeNPs), as photothermal agents. In the current work, we focus on the interaction of these two NPs with human serum albumin (HSA) and human hemoglobin (Hb) as model proteins. The complex formation between NPs and proteins was investigated by fluorescence spectroscopy, dynamic light scattering and circular dichroism. Our data distinguishes the very distinct mode of interaction of charged and neutral NPs with proteins. While the interaction of neutral AuFeNP to proteins is protein dependent, charged nanoparticles FA-AuNP interact indistinguishably with all proteins via electrostatic interactions. Moreover, complexes obtained from FA-AuNPs with proteins are more stable than that of AuFeNP. However, the secondary structure content of proteins in the presence of NPs indicates the insignificant effect of NPs on the secondary structure of these proteins. Our data propose that the charge functionalization of the NPs is an effective way for modulating the interaction of nanoparticles with proteins.

Adaptation of a Bacterial Bioluminescent Assay to Monitor Bioeffects of Gold Nanoparticles

Our current study aimed to adapt a bioluminescent bacteria-based bioassay to monitor the bioeffects of gold nanoparticles (AuNPs). Luminous marine bacteria Photobacterium phosphoreum and AuNPs modified with polyvinylpyrrolidone were employed; low-concentration (≤10−3 g/L) bioeffects of AuNPs were studied. Bioluminescence intensity was used as an indicator of physiological activity in bacteria. Two additional methods were used: reactive oxygen species (ROS) content was estimated with a chemiluminescent luminol method, and bacterial size was monitored using electron microscopy. The bacterial bioluminescent response to AuNPs corresponded to the “hormesis” model and involved time-dependent bioluminescence activation, as well as a pronounced increase in the number of enlarged bacteria. We found negative correlations between the time courses of bioluminescence and the ROS content in bacterial suspensions, demonstrating the relationship between bioluminescence activation and bacterial ROS consumption. The combined effects of AuNPs and a beta-emitting radionuclide, tritium, revealed suppression of bacterial bioluminescent activity (as compared to their individual effects) and a reduced percentage of enlarged bacteria. Therefore, we demonstrated that our bacteria-based bioluminescence assay is an appropriate tool to study the bioeffects of AuNPs; the bioeffects can be further classified within a unified framework for rapid bioassessment.

Size-Dependent Cytotoxic and Molecular Study of the Use of Gold Nanoparticles against Liver Cancer Cells

The size of nanomaterials influences physicochemical parameters, and variations in the size of nanomaterials can have a significant effect on their biological activities in cells. Due to the potential applicability of nanoparticles (NPs), the current work was designed to carry out a size-dependent study of gold nanoparticles (GNPs) in different dimensions, synthesized via a colloidal solution process. Three dissimilar-sized GNPs, GNPs-1 (10–15 nm), GNPs-2 (20–30 nm), and GNPs-3 (45 nm), were prepared and characterized via transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), hydrodynamic size, zeta potential, and UV-visible spectroscopy, and applied against liver cancer (HepG2) cells. Various concentrations of GNPs (1, 2, 5, 10, 50, and 100 µg/mL) were applied against the HepG2 cancer cells to assess the percentage of cell viability via MTT and NRU assays; reactive oxygen species (ROS) generation was also used. ROS generation was increased by 194%, 164%, and 153% for GNPs-1, GNPs-2, and GNPs-3, respectively, in the HepG2 cells. The quantitative polymerase chain reaction (qPCR) data for the HepG2 cells showed up-regulation in gene expression of apoptotic genes (Bax, p53, and caspase-3) when exposed to the different-sized GNPs, and defined their respective roles. Based on the results, it was concluded that GNPs of different sizes have the potential to induce cancer cell death.

Self-assembled gel tubes, filaments and 3D-printing with in situ metal nanoparticle formation and enhanced stem cell growth

This paper reports simple strategies to fabricate self-assembled artificial tubular and filamentous systems from a low molecular weight gelator (LMWG). In the first strategy, tubular ‘core–shell’ gel structures based on the dibenzylidenesorbitol-based LMWG DBS-CONHNH₂ were made in combination with the polymer gelator (PG) calcium alginate. In the second approach, gel filaments based on DBS-CONHNH₂ alone were prepared by wet spinning at elevated concentrations using a ‘solvent-switch’ approach. The higher concentrations used in wet-spinning prevent the need for a supporting PG. Furthermore, this can be extended into a 3D-printing method, with the printed LMWG objects showing excellent stability for at least a week in water. The LMWG retains its unique ability for in situ precious metal reduction, yielding Au nanoparticles (AuNPs) within the tubes and filaments when they are exposed to AuCl₃ solutions. Since the gel filaments have a higher loading of DBS-CONHNH₂, they can be loaded with significantly more AuNPs. Cytotoxicity and viability studies on human mesenchymal stem cells show that the DBS-CONHNH₂ and DBS-CONHNH₂/alginate hybrid gels loaded with AuNPs are biocompatible, with the presence of AuNPs enhancing stem cell metabolism. Taken together, these results indicate that DBS-CONHNH₂ can be shaped and 3D-printed, and has considerable potential for use in tissue engineering applications.

Simple fabrication and 3D-printing methods are used to generate tubes and filaments from self-assembled gels, which can be loaded in situ with gold nanoparticles, with the resulting gels encouraging stem cell proliferation.

Engineered nanomaterials induce alterations in biological barriers: focus on paracellular permeability

Engineered nanoparticles (ENPs) are widely used in medical diagnosis and treatment, as food additives and as energy materials. ENPs may exert adverse or beneficial effects on the human body, which may be linked to interactions with biological barriers. In this review, the authors summarize the influences of four typical metal/metal oxide nanomaterials (Ag, TiO₂, Au, ZnO nanoparticles) on the paracellular permeability of biological barriers. Disruptions on tight junctions, adhesion junctions, gap junctions and desmosomes via complex signaling pathways, such as the MAPK, PKC and ROCK signaling pathways, affect paracellular permeability. Reactive oxygen species and cytokines underlie the mechanism of ENP-triggered alterations in paracellular permeability. This review provides the information necessary for the cautious application of nanoparticles in medicine and life sciences in the future.

Green synthesis of metallic nanoparticles using pectin as a reducing agent: a systematic review of the biological activities

CONTEXT

Pectin is a plant heteropolysaccharide that is biocompatible and biodegradable, enabling it to be an excellent reducing agent (green synthesis) for metallic nanoparticles (MNPs). Nevertheless, in the biological industry, pectin has been left behind in synthesising MNPs, for no known reason.

OBJECTIVE

To systematically review the biological activities of pectin synthesised MNPs (Pe-MNPs).

METHODS

The databases Springer Link, Scopus, ScienceDirect, Google Scholar, PubMed, Mendeley, and ResearchGate were systematically searched from the date of their inception until 10^th February 2020. Pectin, green synthesis, metallic nanoparticles, reducing agent and biological activities were among the key terms searched. The data extraction was focussed on the biological activities of Pe-MNPs and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations for systematic reviews.

RESULTS

A total of 15 studies outlined 7 biological activities of Pe-MNPs in the only three metals that have been explored, namely silver (Ag), gold (Au) and cerium oxide (CeO₂). The activities reported from the in vitro and in vivo studies were antimicrobial (9 studies), anticancer (2 studies), drug carrier (3 studies), non-toxic (4 studies), antioxidant (2 studies), wound healing (1 study) and anti-inflammation (1 study).

CONCLUSIONS

This systematic review demonstrates the current state of the art of Pe-MNPs biological activities, suggesting that Ag and Au have potent antibacterial and anticancer/chemotherapeutic drug carrier activity, respectively. Further in vitro, in vivo, and clinical research is crucial for a better understanding of the pharmacological potential of pectin synthesised MNPs.

Natural polysaccharides based self-assembled nanoparticles for biomedical applications - A review

In recent years, nanoparticles (NPs) derived from the self-assembly of natural polysaccharides have shown great potential in the biomedical field. Here, we described several self-assembly modes of natural polysaccharides in detail, summarized the natural polysaccharides mostly used for self-assembly, and provided insights into the current applications and achievements of these self-assembled NPs. As one of the most widespread substances in nature, most natural polysaccharides exhibit advantages of biodegradability, low immunogenicity, low toxicity, and degradable properties. Therefore, they have been fully explored, and the application of chitosan, hyaluronic acid, alginate, starch, and their derivatives has been extensively studied, especially in the fields of biomedical. Polysaccharides based NPs were proved to improve the solubility of insoluble drugs, enhance tissue target ability and realize the controlled and sustained release of drugs. When modified by hydrophobic groups, the amphiphilic polysaccharides can self-assemble into NPs. Other driven forces of self-assembly include electrostatic interaction and hydrogen bonds. Up to the present, polysaccharides-based nanoparticles have been widely applied for tumor treatment, antibacterial application, gene therapy, photodynamic therapy and transporting insulin.

Biocompatibility and Cytotoxicity of Gold Nanoparticles: Recent Advances in Methodologies and Regulations

Recent advances in the synthesis of metal nanoparticles (MeNPs), and more specifically gold nanoparticles (AuNPs), have led to tremendous expansion of their potential applications in different fields, ranging from healthcare research to microelectronics and food packaging. The properties of functionalised MeNPs can be fine-tuned depending on their final application, and subsequently, these properties can strongly modulate their biological effects. In this review, we will firstly focus on the impact of MeNP characteristics (particularly of gold nanoparticles, AuNPs) such as shape, size, and aggregation on their biological activities. Moreover, we will detail different in vitro and in vivo assays to be performed when cytotoxicity and biocompatibility must be assessed. Due to the complex nature of nanomaterials, conflicting studies have led to different views on their safety, and it is clear that the definition of a standard biosafety label for AuNPs is difficult. In fact, AuNPs' biocompatibility is strongly affected by the nanoparticles' intrinsic characteristics, biological target, and methodology employed to evaluate their toxicity. In the last part of this review, the current legislation and requirements established by regulatory authorities, defining the main guidelines and standards to characterise new nanomaterials, will also be discussed, as this aspect has not been reviewed recently. It is clear that the lack of well-established safety regulations based on reliable, robust, and universal methodologies has hampered the development of MeNP applications in the healthcare field. Henceforth, the international community must make an effort to adopt specific and standard protocols for characterisation of these products.

Synthesis, Chemical-Physical Characterization, and Biomedical Applications of Functional Gold Nanoparticles: A Review

Relevant properties of gold nanoparticles, such as stability and biocompatibility, together with their peculiar optical and electronic behavior, make them excellent candidates for medical and biological applications. This review describes the different approaches to the synthesis, surface modification, and characterization of gold nanoparticles (AuNPs) related to increasing their stability and available features useful for employment as drug delivery systems or in hyperthermia and photothermal therapy. The synthetic methods reported span from the well-known Turkevich synthesis, reduction with NaBH4 with or without citrate, seeding growth, ascorbic acid-based, green synthesis, and Brust-Schiffrin methods. Furthermore, the nanosized functionalization of the AuNP surface brought about the formation of self-assembled monolayers through the employment of polymer coatings as capping agents covalently bonded to the nanoparticles. The most common chemical-physical characterization techniques to determine the size, shape and surface coverage of AuNPs are described underlining the structure-activity correlation in the frame of their applications in the biomedical and biotechnology sectors.

Electrospun polyvinyl-alcohol/gum arabic nanofibers: Biomimetic platform for in vitro cell growth and cancer nanomedicine delivery

The design of powerful in vitro cell culture platforms to support precision medicine can contribute to predict therapeutic success of cancer patients. Electrospun nanofibers applied to cell culture can mimic extracellular matrix and improve in vitro cell behavior. Here, we describe biocompatible blended polyvinyl-alcohol (PVA)/gum arabic (GA) extracellular matrix (ECM)-like nanofibers for in vitro cell cultures capable of delivering nanocomposite for desired biomedical application. Therefore, PVA/GA ECM-like electrospun nanofibers were developed and characterized. Heat treatment was used to crosslink the nanofibers and biocompatibility was evaluated, which demonstrated the ability of developed platform to provide a cell culture-friendly environment. Previous work demonstrated that GA-gold nanoparticles (GA-AuNPs) in non-cytotoxic concentrations can reduce key metastatic cellular events such as invasion and colony formation of metastatic melanoma cells. Thus, crosslinked nanofibers were functionalized with GA-AuNPs and its cellular delivery was evaluated. GA-AuNPs were efficiently adsorbed onto the PVA/GA nanofibers surface and the system effectively delivered the nanocomposites to metastatic melanoma cells. In conclusion, the described biocompatible system could be prospected as a valuable in vitro tool for precision medicine.

Gold Nanorods are Selective Cytotoxic Agents

BACKGROUND

Gold nanorods (GNRs) are very promising agents that have multiple applications in medicine and biology. However, the cytotoxic effects of GNRs have not been fully explored.

OBJECTIVE

Therefore, the main objective of this study was to determine the selective cytotoxic effect of GNRs towards several human tumor cell lines.

METHODS

To address this issue, three sizes of GNRs (10-nm, 25-nm, and 50-nm) were tested against two human tumor cell lines, namely, human hepatoma HepG2 and human prostate PC3 cancer cells. As GNRs are usually stored in soft tissues inside living bodies, we also tested the effect of GNRs on murine splenocyte viability. To determine if the GNRs displayed selectivity cytotoxicity towards cancer cells, active GNRs with the size showing the least cytotoxicity to splenocytes were then tested against a panel of 11 human tumor cell lines and two human non-tumor cell lines.

RESULTS

Our results showed that the most cytotoxic size of GNRs is 10-nm, followed by the 25-nm GNRs, while the 50-nm GNRs did not show a significant effect. In addition, the 25-nm GNRs were the least cytotoxic to splenocytes when tested for 24 and 48 h. These GNRs showed a selective cytotoxic effect to prostate cancer PC3 cells with median inhibitory concentration (IC50) = 8.3 + 0.37 µM, myeloblastic leukemia HL60 cells (IC50 = 19.7 + 0.89 µM), cervical cancer HeLa cells (IC50 = 24.6 + 0.37 µM), renal adenocarcinoma 786.0 cells (IC50 = 27.34 + 0.6 µM), and hepatoma HepG2 cells (IC50 = 27.79 + 0.03 µM) when compared to the effect on the non-tumor human cells; skin fibroblast BJ cell line (IC50 = 40.13 + 0.7 µM) or epithelial breast MCF10A cells (IC50 = 33.2 + 0.89 µM). A high selectivity indices (SI) were observed in GNRs-treated PC3 and HL60 cells with values ranging from 1.69 to 4.83, whereas moderate SIs were observed in GNRs-treated HeLa, 786.0, and HepG2 cells with values ranging from 1.19 to 1.63. Other cells did not show a similar selective effect, including human laryngeal HEp2 cells, colon HCT116, metastatic renal adenocarcinoma ACHN cells, and human breast cancer cells (MCF7, MDA-MB-231, and MDA-MB-468 cells). The effect of GNRs was confirmed using the colony formation assay and the effect was found to be cell cycle specific. Finally, it was shown that laser treatment can potentiate the cytotoxic effect of the 25-nm GNRs.

CONCLUSION

GNRs are selective cytotoxic agents and they have the potential to act as candidate anticancer agents.

Surface engineering strategies of gold nanomaterials and their applications in biomedicine and detection

Gold nanomaterials have potential applications in biosensors and biomedicine due to their controllable synthesis steps, high biocompatibility, low toxicity and easy surface modification. However, there are still various limitations including low water solubility and stability, which greatly affect their applications. In addition, some synthetic methods are very complicated and costly. Therefore, huge efforts have been made to improve their properties. This review mainly introduces the strategies for surface modification of gold nanomaterials, such as amines, biological small molecules and organic small molecules as well as the biological applications of these functionalized AuNPs. We aim to provide effective ideas for better functionalization of gold nanomaterials in the future.

Bioactive glass doped with noble metal nanoparticles for bone regeneration: in vitro kinetics and proliferative impact on human bone cell line

This work investigates the bioactivity of novel silver-doped (BG-Ag) and gold-doped (BG-Au) quaternary 46S6 bioactive glasses synthesized via a semi-solid-state technique. A pseudo-second-order kinetic model successfully predicted the in vitro uptake kinetic profiles of the initial ion-exchange release of Ca in simulated body fluid, the subsequent Si release, and finally, the adsorption of Ca and P onto the bioactive glasses. Doping with silver nanoparticles enhanced the rate of P uptake by up to approximately 90%; whereas doping with gold nanoparticles improved Ca and P uptake rates by up to about 7 and 2 times, respectively; as well as Ca uptake capacity by up to about 19%. The results revealed that the combined effect of Ca and Si release, and possibly the release of silver and gold ions into solution, influenced apatite formation due to their effect on Ca and P uptake rate and capacity. In general, gold-doped bioactive glasses are favoured for enhancing Ca and P uptake rates in addition to Ca uptake capacity. However, silver-doped bioactive glasses being less expensive can be utilized for applications targeting rapid healing. In vitro studies showed that BG, BG-Ag and BG-Au had no cytotoxic effects on osteosarcoma MG-63 cells, while they exhibited a remarkable cell proliferation even at low concentration. The prepared bioactive glass doped with noble metal nanoparticles could be potentially used in bone regeneration applications.

Biofabrication of Gold Nanoparticles Using Capsicum annuum Extract and Its Antiquorum Sensing and Antibiofilm Activity against Bacterial Pathogens

The intensive use of antimicrobial agents has led to the emergence of multidrug resistance (MDR) among microbial pathogens. Such microbial (MDR) infections become more problematic in chronic diseases in which the efficacy of chemotherapeutic agents is highly reduced. To combat the problem of drug resistance, inhibition of bacterial quorum sensing (QS) and biofilms are considered as promising strategies in the development of anti-infective agents. In this study, gold nanoparticles (AuNPs-CA) were biofabricated using Capsicum annuum aqueous extract and characterized. The AuNPs-CA were tested against the QS-controlled virulence factors and biofilms of Pseudomonas aeruginosa PAO1 and Serratia marcescens MTCC 97. AuNPs-CA were found to be crystalline in nature with average particle size 19.97 nm. QS-mediated virulent traits of P. aeruginosa PAO1 such as pyocyanin, pyoverdin, exoprotease activity, elastase activity, rhamnolipids production, and swimming motility were reduced by 91.94, 72.16, 81.82, 65.72, 46.66, and 46.09%, respectively. Similarly, dose-dependent inhibition of virulence factors of S. marcescens MTCC 97 was recorded by the treatment of AuNPs-CA. The biofilm development and exopolysaccharide (EPS) production also decreased significantly. Microscopic analysis revealed that the adherence and colonization of the bacteria on solid support were reduced to a remarkable extent. The findings indicate the possibility of application of green synthesized gold nanoparticles in the management of bacterial infection after careful in vivo investigation.

Silver Ion Release Accelerated in the Gastrovascular Cavity of Hydra vulgaris Increases the Toxicity of Silver Sulfide Nanoparticles

Silver nanoparticles (Ag-NPs) streamed into aquatic environments are chemically transformed into various forms, and one of the predominant forms is silver sulfide NPs (Ag₂ S-NPs). Because of the lower dissolution rate of silver ions (Ag⁺ ), the toxicity of Ag₂ S-NPs could be lower than that of Ag-NPs. However, the toxicity of Ag₂ S-NPs has been observed to be restored under oxidative or acidic conditions. In the present study, 4 aquatic organisms, Pseudokirchneriella subcapitata (algae), Daphnia magna (crustacean), Danio rerio (fish), and Hydra vulgaris (cnidarian), were exposed to Ag₂ S-NPs transformed from Ag-NPs using Na₂ S under anoxic conditions; and acute toxicity was evaluated. The acute toxicity of Ag₂ S-NPs was rarely observed in algae, crustaceans, and fish, whereas it was significantly restored in cnidarians. Although the dissolution rate was low in the medium exposed to Ag₂ S-NPs, high Ag⁺ was detected in H. vulgaris. To understand the mechanisms of Ag₂ S-NP toxicity in cnidarians, transcriptional profiles of H. vulgaris exposed to Ag-NPs, Ag₂ S-NPs, and AgNO₃ were analyzed. As a result, most of the genes that were significantly changed in the Ag₂ S-NPs group were also found to be significantly changed in the AgNO₃ group, indicating that the toxicity of Ag₂ S-NPs was caused by Ag⁺ dissolved by the acidic condition in the gastrovascular cavity of H. vulgaris. This finding is the first in an aquatic organism and suggests the need to reconsider the stability and safety of Ag₂ S-NPs in the aquatic environment. Environ Toxicol Chem 2021;40:1662-1672. © 2021 SETAC.

Silver nanoparticle induced toxicity and cell death mechanisms in embryonic zebrafish cells

Cell death is the process that regulates homeostasis and biochemical changes in healthy cells. Silver nanoparticles (AgNPs) act as powerful cell death inducers through the disruption of cellular signalling functions. In this study, embryonic zebrafish cells (ZF4) were used as a potential early-stage aquatic model to evaluate the molecular and cell death mechanisms implicated in the toxicity of AgNPs and Ag⁺. Here, a low, medium, and high concentration (2.5, 5, and 10 μg mL^-1) of three different sizes of AgNPs (10, 30 and 100 nm) and ionic Ag⁺ (1, 1.5 and 2 μg mL^-1) were used to investigate whether the size of the nanomaterial, ionic form, and mass concentration were related to the activation of particular cell death mechanisms and/or induction of different signalling pathways. Changes in the physicochemical properties of the AgNPs were also assessed in the presence of complex medium (cell culture) and reference testing medium (ultra-pure water). Results demonstrated that AgNPs underwent dissolution, as well as changes in hydrodynamic size, zeta potential and polydispersity index in both tested media depending on particle size and concentration. Similarly, exposure dose played a key role in regulating the different cell death modalities (apoptosis, necrosis, autophagy), and the signalling pathways (repair mechanisms) in cells that were activated in the attempt to overcome the induced damage. This study contributes to the 3Rs initiative to replace, reduce and refine animal experimentation through the use of alternative models for nanomaterials assessment.

Functionalized Silica Star-Shaped Nanoparticles and Human Mesenchymal Stem Cells: An In Vitro Model

The biomedical translational applications of functionalized nanoparticles require comprehensive studies on their effect on human stem cells. Here, we have tested neat star-shaped mesoporous silica nanoparticles (s-MSN) and their chemically functionalized derivates; we examined nanoparticles (NPs) with similar dimensions but different surface chemistry, due to the amino groups grafted on silica nanoparticles (s-MSN-NH2), and gold nanoseeds chemically adsorbed on silica nanoparticles (s-MSN-Au). The different samples were dropped on glass coverslips to obtain a homogeneous deposition differing only for NPs' chemical functionalization and suitable for long-term culture of human Bone Marrow-Mesenchymal stem cells (hBM-MSCs) and Adipose stem cells (hASCs). Our model allowed us to demonstrate that hBM-MSCs and hASCs have comparable growth curves, viability, and canonical Vinculin Focal adhesion spots on functionalized s-MSN-NH2 and s-MSN-Au as on neat s-MSN and control systems, but also to show morphological changes on all NP types compared to the control counterparts. The new shape was stem-cell-specific and was maintained on all types of NPs. Compared to the other NPs, s-MSN-Au exerted a small genotoxic effect on both stem cell types, which, however, did not affect the stem cell behavior, likely due to a peculiar stem cell metabolic restoration response.

Intracellular and extracellular targets as mechanisms of cancer therapy by nanomaterials in relation to their physicochemical properties

Cancer nanomedicine has evolved in recent years and is only expected to increase due to the ease with which nanomaterials (NMs) may be manipulated to the advantage of the cancer patient. The success of nanomedicine is dependent on the cell death mechanism, which in turn is dependent on the organelle initially targeted. The success of cancer nanomedicine is also dependent on other cellular mechanisms such as the induction of autophagy dysfunction, manipulation of the tumor microenvironment (TME) and secretome or induction of host immune responses. Current cancer phototherapies for example, photothermal- or photodynamic therapies as well as radio enhancement also form a major part of cancer nanomedicine. In general, cancer nanomedicine may be grouped into those NMs exhibiting inherent anti-cancer properties that is, self-therapeutic NMs (Group 1), NMs leading to localization of phototherapies or radio-enhancement (Group 2), and NMs as nanocarriers in the absence or presence of external radiation (Group 3). The recent advances of these three groups, together with their advantages and disadvantages as well as their cellular mechanisms and ultimate outcomes are summarized in this review. By exploiting these different intracellular mechanisms involved in initiating cell death pathways, it is possible to synthesize NMs that may have the desirable characteristics to maximize their efficacy in cancer therapy. Therefore, a summary of these important physicochemical characteristics is also presented that need to be considered for optimal cancer cell targeting and initiation of mechanisms that will lead to cancerous cell death. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials Toxicology and Regulatory Issues in Nanomedicine > Regulatory and Policy Issues in Nanomedicine.

Laser-induced optothermal response of gold nanoparticles: From a physical viewpoint to cancer treatment application

Gold nanoparticles (GNPs)-based photothermal therapy (PTT) is a promising minimally invasive thermal therapy for the treatment of focal malignancies. Although GNPs-based PTT has been known for over two decades and GNPs possess unique properties as therapeutic agents, the delivery of a safe and effective therapy is still an open question. This review aims at providing relevant and recent information on the usage of GNPs in combination with the laser to treat cancers, pointing out the practical aspects that bear on the therapy outcome. Emphasis is given to the assessment of the GNPs' properties and the physical mechanisms underlying the laser-induced heat generation in GNPs-loaded tissues. The main techniques available for temperature measurement and the current theoretical simulation approaches predicting the therapeutic outcome are reviewed. Topical challenges in delivering safe thermal dosage are also presented with the aim to discuss the state-of-the-art and the future perspective in the field of GNPs-mediated PTT.

An ecofriendly synthesized gold nanoparticles induces cytotoxicity via apoptosis in HepG2 cells

Microbes have long been used for the synthesis of a variety of nanoparticles. Hepatocellular carcinoma (HCC) is the primary liver cancer and it is the second leading cause of cancer-related mortality worldwide. In this study, we have synthesized Enterococcus mediated gold nanoparticles (AuNPs) and investigated their cytotoxic potential against human hepatocellular cancer cell line (HepG2). AuNPs were synthesized using Enterococcus sp. RMAA. HepG2 cells were treated with different concentrations of AuNPs for 24 hours and cytotoxicity was analyzed by MTT ((4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. AuNPs induced reactive oxygen species expression was analyzed by 2',7'-dichlorodihydrofluorescein diacetate staining. Morphological changes related to apoptosis was analyzed by annexin V/propidium iodide staining. Protein expression of proliferating cell nuclear antigen (PCNA) was done by western blotting analysis. Bacterial-mediated AuNPs caused significant cytotoxicity in HepG2 cells. AuNPs treatment also caused the significant expression of ROS and morphological damage related to apoptosis. AuNPs treatments were responsible for the dislocation of cytochrome c from mitochondria to cytosol. The protein expression of PCNA was significantly decreased upon AuNPs treatment. These findings suggest that Enterococcus-mediated AuNPs can inhibit the proliferation of HepG2 cells via intracellular ROS mediated apoptosis, decreased PCNA expressions, and it may have the potential to treat HCC.

Radiosensitizing and Phototherapeutic Effects of AuNPs are Mediated by Differential Noxa and Bim Gene Expression in MCF-7 Breast Cancer Cell Line

To compare the apoptotic efficiency of AuNPs, ionizing and non-ionizing radiotherapy, phototherapy, and AuNPs-ionizing-radiotherapy), MCF-7 cells were used as a model for luminal B subtypes of breast carcinoma. A mixture of AuNPs [66% of Au-nanospheres (AuNSs) and 34% of Au-nanorods (AuNRs)] was synthesized and characterized by optical spectroscopy, zeta potential, and transmission electron microscopy (TEM). MCF-7 were divided into six groups (triplicates); after each treatment, cell viability was tested by MTT assay and relative gene expression levels of Bim and Noxa proapoptotic markers were assayed by qRT-PCR. A dose-dependent significant reduction in cell viability of MCF-7 was detected by all examined treatment protocols. Lower viability detected at extended exposure (48 hours) to AuNPs ( [Formula: see text]/ml) was mediated by the upregulation of Noxa gene expression. AuNS and AuNR in vitro PTTs were mediated by differential expression of Bim and Noxa while AuNPs mixture had a combined effect on both Bim and Noxa. Cellular recovery was observed two days-post x-rays irradiation at does < 3 Gy. AuNPs showed dose enhancement factor (DEF) > 12 indicating a high radiosensitizing effect that was partially mediated by Noxa. In conclusion, AuNPs combined therapies exert better anti-proliferative effects via differential regulation of Noxa and Bim gene expressions.

Gold Nanoparticle-Based Platforms for Diagnosis and Treatment of Myocardial Infarction

In recent years, an increasing rate of mortality due to myocardial infarction (MI) has led to the development of nanobased platforms, especially gold nanoparticles (AuNPs), as promising nanomaterials for diagnosis and treatment of MI. These promising NPs have been used to develop different nanobiosensors, mainly optical sensors for early detection of biomarkers as well as biomimetic/bioinspired platforms for cardiac tissue engineering (CTE). Therefore, in this Review, we presented an overview on the potential application of AuNPs as optical (surface plasmon resonance, colorimetric, fluorescence, and chemiluminescence) nanobiosensors for early diagnosis and prognosis of MI. On the other hand, we discussed the potential application of AuNPs either alone or with other NPs/polymers as promising three-dimensional (3D) scaffolds to regulate the microenvironment and mimic the morphological and electrical features of cardiac cells for potential application in CTE. Furthermore, we presented the challenges and ongoing efforts associated with the application of AuNPs in the diagnosis and treatment of MI. In conclusion, this Review may provide outstanding information regarding the development of AuNP-based technology as a promising platform for current MI treatment approaches.

Relative expression of microRNAs, apoptosis, and ultrastructure anomalies induced by gold nanoparticles in Trachyderma hispida (Coleoptera: Tenebrionidae)

The extensive use of nanomaterials generates toxic effects on non-target species and the ecosystem. Although gold nanoparticles (Au-NPs) are generally expected to be safe, the recent study contains conflicting data regarding their cytotoxicity in the darkling beetles Trachyderma hispida. The study postulated cellular perturbation in the ovarian tissue of the beetles induced by a sublethal dose of Au-NPs (0.01 mg/g). When compared with the controls, a significant inhibition in the activities of the antioxidant enzymes selenium-dependent (GPOX) and selenium-independent (GSTP) glutathione peroxidases (GPx) was observed in the treated beetles. The study proposed microRNAs (miRNA-282 and miRNA-989) as genotoxic markers for the first time, reporting a significant suppression in their transcriptional levels in the treated beetles. Furthermore, TUNEL (Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) and flow cytometry assays (annexin V-Fitc) indicated a significant increase in ovarian cell apoptosis in the treated beetles. Additionally, an ultrastructure examination revealed pathological changes in the ovarian cells of the treated beetles. The resulting anomalies in the present study may interrupt the fecundity of the beetles and lead to the future suppression of beetle populations.

Effective targeting of breast cancer cells (MCF7) via novel biogenic synthesis of gold nanoparticles using cancer-derived metabolites

Biogenic synthesis of nanoparticles provides many advantages over synthetic nanoparticles including clean and non-toxic approaches. Nanoparticle-based application for the development of diagnostics and therapeutics is a promising field that requires further enrichment and investigation. The use of biological systems for the generation of gold nanoparticles (AuNPs) has been extensively studied. The search for a biocompatibility approach for the development of nanoparticles is of great interest since it can provide more targeting and less toxicity. Here, we reported a bio-reductive approach of gold to AuNPs using metabolites extracted from mammalian cells, which provided a simple and efficient way for the synthesis of nanomaterials. AuNPs were more efficiently synthesized by the metabolites extracted from breast cancer (MCF7) and normal fibroblasts (F180) cells when compared to metabolites extracted from cell-free supernatants. The metabolites involved in biogenic synthesis are mainly alcohols and acids. Spectroscopic characterization using UV-visible spectra, morphological characterization using electron microscopy and structural characterization using X-ray diffraction (XRD) confirmed the AuNPs synthesis from mammalian cells metabolites. AuNPs generated from MCF7 cells metabolites showed significant anticancer activities against MCF7 and low toxicity when compared to those generated from F180 cells metabolites. The results reflected the cytotoxic activities of the parent metabolites extracted from MCF7 versus those extracted from F180. Comparative metabolomics analysis indicated that MCF7-generated AuNPs harbored tetratetracontane, octacosane, and cyclotetradecane while those generated from F180 harbored a high percentage of stearic, palmitic, heptadecanoic acid. We related the variation in cytotoxic activities between cell types to the differences in AuNPs-harboring metabolites. The process used in this study to develop the nanoparticles is novel and should have useful future anticancer applications mainly because of proper specific targeting to cancer cells.

Mechanisms and pathogenesis underlying environmental chemical-induced necroptosis

Necroptosis is a regulated cell death that is governed by mixed lineage kinase domain-like, receptor-interacting serine-threonine kinase 3 and commonly displays with necrosis morphological characteristics. This study examined the molecular mechanisms involved in the chemical-induced necroptosis where a systematic evaluation of experimental studies addressing this issue is missing. We strictly reviewed all scientific reports related to our search terms including "necroptosis" or "programmed necrosis", "environmental chemicals" or "air pollutants" or "pesticides" or "nanoparticles" and "Medicines" from 2009 to 2019. Manuscripts that met the objective of this study were included for further evaluations. Studies showed that several pathological contexts like cancer, neurodegenerative disorders, and inflammatory diseases were related to necroptosis. Furthermore, multiple chemical-induced cytotoxic effects, such as DNA damage, mitochondrial dysregulation, oxidative damage, lipid peroxidation, endoplasmic reticulum disruption, and inflammation are also associated with necroptosis. The main environmental exposures that are related to necroptosis are air pollutants (airborne particulate matter, cadmium, and hydrogen sulfide), nanoparticles (gold, silver, and silica), pesticides (endosulfan, cypermethrin, chlorpyrifos, and paraquat), and tobacco smoke. To sum up, air pollutants, pesticides, and nanoparticles could potentially affect human health via disruption of cell growth and induction of necroptosis. Understanding the exact molecular pathogenesis of these environmental chemicals needs further comprehensive research to provide innovative concepts for the prevention approaches and introduce novel targets for the amelioration of a range of human health problems.