Effect of gold nanoparticles on glutathione depletion-induced hydrogen peroxide generation and apoptosis in HL7702 cells

Impacts of loading thymoquinone to gold or silver nanoparticles on the efficacy of anti-tumor treatments in breast cancer with or without chemotherapeutic cisplatin

BACKGROUND

Nanotechnology has been greatly examined for tumor medication, as nanoparticles (NPs) serve a crucial role in drug delivery mechanisms for cancer therapy. In contrast to traditional cancer therapies, NPs-based drug delivery offers several benefits, including increased stability and biocompatibility, improved retention capabilities and permeability, as well as precise targeting.

AIM

The objective of this study was to examine the tumor-targeting efficacy of Thymoquinone (TQ)-loaded gold NPs (AuNPs/TQ conjugate) or TQ-loaded silver NPs (AgNPs/TQ conjugate) in conjunction with the conventional chemotherapy agent cisplatin (CP) in Ehrlich ascites carcinoma (EAC)-bearing mice.

METHODS

The loading capacity of synthesized conjugates was characterized by UV-Vis spectra and transmission electron microscope (TEM). We used CD-1 mice with a peritoneal EAC tumor xenograft model that received oral administration of TQ, AuNPs, AgNPs, AuNPs/TQ conjugate, and AgNPs/TQ conjugate.

METHODS

EAC-bearing mice received daily oral administration of one of the following treatments for six consecutive days: TQ, AuNPs, AgNPs, AuNPs/TQ, AgNPs/TQ, AuNPs/TQ + CP, or AgNPs/TQ + CP conjugates. Eleven days after EAC inoculations, assessments were conducted to evaluate the total number of tumor cells, splenocytes, white blood cells (WBCs), C-reactive protein (CRP) levels, flow cytometric analysis of apoptosis in EAC cells, as well as the functionality of the kidney and liver.

RESULTS

EAC-bearing mice that received treatment with TQ, AuNPs, AgNPs, AuNPs/TQ, and AgNPs/TQ exhibited significantly enhanced anti-tumor activity and improved therapeutic efficacy. Our results further revealed that the combined synergistic approach of TQ's anti-tumor properties, along with the efficient penetration abilities of AuNPs or AgNPs, led to a significant inhibition of the growth of tumor cells in EAC tumor-bearing mice. Moreover, the incorporation of CP into the AuNPs/TQ or AgNPs/TQ conjugates substantially augmented the anti-proliferative effects against EAC tumor cells, effectively overcoming resistance to chemotherapeutic agents. Furthermore, our data revealed that this combination resulted in an elevation of leukocyte counts, along with an increase in the absolute quantities of lymphocytes, neutrophils, and monocytes, thereby activating the immune system and reducing the inflammatory marker CRP. However, the restoration of splenocyte levels, which had been reduced due to EAC cell inoculation, required an extended period to return to baseline. Furthermore, the results indicated moderate alterations in the functionality of both the liver and kidney.

CONCLUSION

To conclude, AuNPs, AgNPs, AuNPs/TQ, and AgNPs/TQ may hold great promise as potential nanoparticle-based therapies for cancer treatment. Additionally, provides numerous benefits compared to conventional cancer therapies, such as selectivity and minimal side effects. Additionally, AuNPs, AuNPs/TQ, AuNPs/TQ + CP, AgNPs, AgNPs/TQ, or AgNPs/TQ + CP can specifically target tumor tissues, suppress tumor growth, extend the lifespan of tumor-bearing mice, and minimize cytotoxic effects on normal tissues, relative to the administration of free CP alone. More research is needed to understand the mechanisms of these nanoparticle-based therapies in clinical and optimize their use as cancer therapies.

Targeted Nanoclusters for Intratracheal Delivery in Intraoperative Imaging of Lung Adenocarcinoma

Background

Computed tomography (CT) is widely used all over the world, and the detection rate of early lung adenocarcinoma is increasing. Minimally invasive thoracic surgery (MITS) has emerged as the preferred surgical approach for lung adenocarcinoma, but identifying small lung adenocarcinomas is difficult. Therefore, there is a need for a non-invasive, convenient and efficient way to localize lung adenocarcinomas.

Materials and Methods

A targeted gold nanocluster for intraoperative fluorescence imaging by intratracheal delivery has been designed. Au-GSH-anti Napsin A nanoclusters (NapA-AuNCs) were synthesized, and their physicochemical properties and optical properties were characterized. Target effect, cytotoxicity and fluorescence time curve of NapA-AuNCs, were tested in vivo and in vitro, and intratracheal delivery was also carried.

Results

NapA-AuNCs targeting lung adenocarcinoma with red fluorescence and good mucus penetration were synthesized, which had the targeting property of A549 and lung adenocarcinoma tissue, and also had very low toxicity to normal lung epithelial cells and organs. Intracheal delivery involves faster imaging of lung adenocarcinoma and less accumulation of other organs than intravenous administration.

Conclusion

NapA-AuNCs targeting lung adenocarcinoma were successfully conjugated, and intratracheal delivery is a safe, effective for lung adenocarcinoma intraoperative localization.

Surface-Enhanced Raman Spectroscopy for the Detection of Reactive Oxygen Species

Reactive oxygen species (ROS) play fundamental roles in various biological and chemical processes in nature and industries, including cell signaling, disease development and aging, immune defenses, environmental remediation, pharmaceutical syntheses, metal corrosion, energy production, etc. As such, their detection is of paramount importance, but their accurate identification and quantification are technically challenging due to their transient nature with short lifetimes and low steady-state concentrations. As a highly sensitive and selective analytical technique, surface-enhanced Raman spectroscopy (SERS) is promising for detecting ROS in real-time, enabling in situ monitoring of ROS-involved electrochemical and biochemical events with exceptional resolution. This review provides a comprehensive analysis of the state-of-the-art in the SERS-based detection of ROS. Herein, the principles and ROS sensing mechanisms of SERS have been critically evaluated, highlighting their emerging applications in direct and indirect ROS monitoring in electrochemical and biological systems. The developments and reaction schemes of selective SERS probes for superoxide (•O2-), hydroxyl radicals (•OH), nitric oxide (•NO), peroxynitrite (ONOO-), and hypochlorite (OCl-) are presented. Finally, technical challenges and future research directions are discussed to guide the design of SERS for ROS analysis.

Ti3C2 (MXene), an advanced carrier system: role in photothermal, photoacoustic, enhanced drugs delivery and biological activity in cancer therapy

In the realm of healthcare and the advancing field of medical sciences, the development of efficient drug delivery systems become an immense promise to cure several diseases. Despite considerable advancements in drug delivery systems, numerous challenges persist, necessitating further enhancements to optimize patient outcomes. Smart nano-carriers, for instance, 2D sheets nano-carriers are the recently emerging nanosheets that may garner attention for targeted delivery of bioactive compounds, drugs, and genes to kill cancer cells. Within these advancements, Ti3C2TX-MXene, characterized as a two-dimensional transition metal carbide, has surfaced as a prominent intelligent nanocarrier within nanomedicine. Its noteworthy characteristics facilitated it as an ideal nanocarrier for cancer therapy. In recent advancements in drug delivery research, Ti3C2TX-MXene 2D nanocarriers have been designed to release drugs in response to specific stimuli, guided by distinct physicochemical  parameters. This review emphasized the multifaceted role of Ti3C2TX-MXene as a potential carrier for delivering poorly hydrophilic drugs to cancer cells, facilitated by various polymer coatings. Furthermore, beyond drug delivery, this smart nanocarrier demonstrates utility in photoacoustic imaging and photothermal therapy, further highlighting its significant role in cellular mechanisms.

Nanoparticles for Creating a Strategy to Stimulate Liver Regeneration

Presently, there is a need in the developing new approaches to stimulate liver regeneration, which would make its recovery more effective after resection. Application of nanoparticles, loaded with small bioactive molecules, with their targeted delivery into the liver is a promising approach. The aim of the investigation is to study the interaction of nanoparticles with various types of hepatic cells on the models of liver slices and primary hepatic cell cultures using the methods of multiphoton microscopy with fluorescence lifetime imaging.

Materials and Methods

Nanoparticles have been synthetized from polylactide (PLA), gold (Au), and silicon (SiO2), and characterized using scanning and transmission electron microscopy. These types of particles were labeled with a fluorescent Cy5 dye for their visualization. Liver slices and a primary hepatocyte culture were used as models for biological testing of nanoparticles. Biodistribution of the nanoparticles in the tissue and cells, their cytotoxicity, and the effect on the cell metabolism were assessed using optical bioimaging methods.

Results

The silicon nanoparticles are accumulated mainly by macrophages, which generate reactive oxygen species in a large amount and impair the native metabolic state of hepatocytes. The gold nanoparticles accumulate in all types of the liver cells but possess a marked toxic effect, which is indicated by the appearance of necrotic and apoptotic cells and a sharp change in the hepatocyte metabolic state. The polylactide nanoparticles accumulate most effectively in the liver cells, preferably in hepatocytes, do not change their native metabolic state, making this type of nanoparticles most promising for creating the bioactive molecule delivery systems to stimulate liver regeneration.

Current Advancements in Anti-Cancer Chimeric Antigen Receptor T Cell Immunotherapy and How Nanotechnology May Change the Game

Chimeric antigen receptor (CAR)-T cell immunotherapy represents a cutting-edge advancement in the landscape of cancer treatment. This innovative therapy has shown exceptional promise in targeting and eradicating malignant tumors, specifically leukemias and lymphomas. However, despite its groundbreaking successes, (CAR)-T cell therapy is not without its challenges. These challenges, particularly pronounced in the treatment of solid tumors, include but are not limited to, the selection of appropriate tumor antigens, managing therapy-related toxicity, overcoming T-cell exhaustion, and addressing the substantial financial costs associated with treatment. Nanomedicine, an interdisciplinary field that merges nanotechnology with medical science, offers novel strategies that could potentially address these limitations. Its application in cancer treatment has already led to significant advancements, including improved specificity in drug targeting, advancements in cancer diagnostics, enhanced imaging techniques, and strategies for long-term cancer prevention. The integration of nanomedicine with (CAR)-T cell therapy could revolutionize the treatment landscape by enhancing the delivery of genes in (CAR)-T cell engineering, reducing systemic toxicity, and alleviating the immunosuppressive effects within the tumor microenvironment. This review aims to explore how far (CAR)-T cell immunotherapy has come alone, and how nanomedicine could strengthen it into the future. Additionally, the review will examine strategies to limit the off-target effects and systemic toxicity associated with (CAR)-T cell therapy, potentially enhancing patient tolerance and treatment outcomes.

Gold Nanoparticles (AuNPs)-Toxicity, Safety and Green Synthesis: A Critical Review

In recent years, the extensive exploration of Gold Nanoparticles (AuNPs) has captivated the scientific community due to their versatile applications across various industries. With sizes typically ranging from 1 to 100 nm, AuNPs have emerged as promising entities for innovative technologies. This article comprehensively reviews recent advancements in AuNPs research, encompassing synthesis methodologies, diverse applications, and crucial insights into their toxicological profiles. Synthesis techniques for AuNPs span physical, chemical, and biological routes, focusing on eco-friendly "green synthesis" approaches. A critical examination of physical and chemical methods reveals their limitations, including high costs and the potential toxicity associated with using chemicals. Moreover, this article investigates the biosafety implications of AuNPs, shedding light on their potential toxic effects on cellular, tissue, and organ levels. By synthesizing key findings, this review underscores the pressing need for a thorough understanding of AuNPs toxicities, providing essential insights for safety assessment and advancing green toxicology principles.

Effects of Spherical and Rod-like Gold Nanoparticles on the Reactivity of Human Peripheral Blood Leukocytes

Gold nanoparticles (GNPs) are widely used in the technological and biomedical industries, which is a major driver of research on these nanoparticles. The main goal of this study was to determine the influence of GNPs (at 20, 100, and 200 μg/mL concentrations) on the reactivity of human peripheral blood leukocytes. Flow cytometry was used to evaluate the respiratory burst activity and pyroptosis in monocytes and granulocytes following incubation with GNPs for 30 and 60 min. Furthermore, the concentration of interleukin-1β (IL-1β) in human blood samples was assessed using enzyme-linked immunosorbent assay (ELISA) after their incubation with GNPs for 24 h. Under the conditions tested in the study, the GNPs did not significantly affect the production of reactive oxygen species in the granulocytes and monocytes that were not stimulated using phorbol 12-myristate 13-acetate (PMA) in comparison to the samples exposed to PMA (p < 0.05). Compared to the control sample, the greatest significant increase in the mean fluorescence intensity of the granulocytes occurred in the samples incubated with CGNPs = 100 and 200 µg/mL for tinc = 30 and 60 min (p < 0.05). From our results, we conclude that the physicochemical properties of the nanoparticles, chemical composition, and the type of nanoparticles used in the unit, along with the unit and incubation time, influence the induced toxicity.

Cancer chemotherapy resistance: Mechanisms and recent breakthrough in targeted drug delivery

Conventional chemotherapy, one of the most widely used cancer treatment methods, has serious side effects, and usually results in cancer treatment failure. Drug resistance is one of the primary reasons for this failure. The most significant drawbacks of systemic chemotherapy are rapid clearance from the circulation, the drug's low concentration in the tumor site, and considerable adverse effects outside the tumor. Several ways have been developed to boost neoplasm treatment efficacy and overcome medication resistance. In recent years, targeted drug delivery has become an essential therapeutic application. As more mechanisms of tumor treatment resistance are discovered, nanoparticles (NPs) are designed to target these pathways. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation. Nano-drugs have been increasingly employed in medicine, incorporating therapeutic applications for more precise and effective tumor diagnosis, therapy, and targeting. Many benefits of NP-based drug delivery systems in cancer treatment have been proven, including good pharmacokinetics, tumor cell-specific targeting, decreased side effects, and lessened drug resistance. As more mechanisms of tumor treatment resistance are discovered, NPs are designed to target these pathways. At the moment, this innovative technology has the potential to bring fresh insights into cancer therapy. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation.

Omics approaches for the assessment of biological responses to nanoparticles

Nanotechnology has enabled the development of innovative therapeutics, diagnostics, and drug delivery systems. Nanoparticles (NPs) can influence gene expression, protein synthesis, cell cycle, metabolism, and other subcellular processes. While conventional methods have limitations in characterizing responses to NPs, omics approaches can analyze complete sets of molecular entities that change upon exposure to NPs. This review discusses key omics approaches, namely transcriptomics, proteomics, metabolomics, lipidomics and multi-omics, applied to the assessment of biological responses to NPs. Fundamental concepts and analytical methods used for each approach are presented, as well as good practices for omics experiments. Bioinformatics tools are essential to analyze, interpret and visualize large omics data, and to correlate observations in different molecular layers. The authors envision that conducting interdisciplinary multi-omics analyses in future nanomedicine studies will reveal integrated cell responses to NPs at different omics levels, and the incorporation of omics into the evaluation of targeted delivery, efficacy, and safety will improve the development of nanomedicine therapies.

Microenvironmental Behaviour of Nanotheranostic Systems for Controlled Oxidative Stress and Cancer Treatment

The development of smart, efficient and multifunctional material systems for diseases treatment are imperative to meet current and future health challenges. Nanomaterials with theranostic properties have offered a cost effective and efficient solution for disease treatment, particularly, metal/oxide based nanotheranostic systems already offering therapeutic and imaging capabilities for cancer treatment. Nanoparticles can selectively generate/scavenge ROS through intrinsic or external stimuli to augment/diminish oxidative stress. An efficient treatment requires higher oxidative stress/toxicity in malignant disease, with a minimal level in surrounding normal cells. The size, shape and surface properties of nanoparticles are critical parameters for achieving a theranostic function in the microenvironment. In the last decade, different strategies for the synthesis of biocompatible theranostic nanostructures have been introduced. The exhibition of therapeutics properties such as selective reactive oxygen species (ROS) scavenging, hyperthermia, antibacterial, antiviral, and imaging capabilities such as MRI, CT and fluorescence activity have been reported in a variety of developed nanosystems to combat cancer, neurodegenerative and emerging infectious diseases. In this review article, theranostic in vitro behaviour in relation to the size, shape and synthesis methods of widely researched and developed nanosystems (Au, Ag, MnOx, iron oxide, maghemite quantum flakes, La2O3-x, TaOx, cerium nanodots, ITO, MgO1-x) are presented. In particular, ROS-based properties of the nanostructures in the microenvironment for cancer therapy are discussed. The provided overview of the biological behaviour of reported metal-based nanostructures will help to conceptualise novel designs and synthesis strategies for the development of advanced nanotheranostic systems.

Monodisperse Gold Nanoparticles: A Review on Synthesis and Their Application in Modern Medicine

Gold nanoparticles (AuNPs) are becoming increasingly popular as drug carriers due to their unique properties such as size tenability, multivalency, low toxicity and biocompatibility. AuNPs have physical features that distinguish them from bulk materials, small molecules and other nanoscale particles. Their unique combination of characteristics is just now being fully realized in various biomedical applications. In this review, we focus on the research accomplishments and new opportunities in this field, and we describe the rising developments in the use of monodisperse AuNPs for diagnostic and therapeutic applications. This study addresses the key principles and the most recent published data, focusing on monodisperse AuNP synthesis, surface modifications, and future theranostic applications. Moving forward, we also consider the possible development of functionalized monodisperse AuNPs for theranostic applications based on these efforts. We anticipate that as research advances, flexible AuNPs will become a crucial platform for medical applications.

An Overview of Nanotechnologies for Drug Delivery to the Brain

Drug delivery to the brain has been one of the toughest challenges researchers have faced to develop effective treatments for brain diseases. Owing to the blood–brain barrier (BBB), only a small portion of administered drug can reach the brain. A consequence of that is the need to administer a higher dose of the drug, which, expectedly, leads to a variety of unwanted side effects. Research in a variety of different fields has been underway for the past couple of decades to address this very serious and frequently lethal problem. One area of research that has produced optimistic results in recent years is nanomedicine. Nanomedicine is the science birthed by fusing the fields of nanotechnology, chemistry and medicine into one. Many different types of nanomedicine-based drug-delivery systems are currently being studied for the sole purpose of improved drug delivery to the brain. This review puts together and briefly summarizes some of the major breakthroughs in this crusade. Inorganic nanoparticle-based drug-delivery systems, such as gold nanoparticles and magnetic nanoparticles, are discussed, as well as some organic nanoparticulate systems. Amongst the organic drug-delivery nanosystems, polymeric micelles and dendrimers are discussed briefly and solid polymeric nanoparticles are explored in detail.

Gold Nanoparticles: Biosynthesis and Potential of Biomedical Application

Gold nanoparticles (AuNPs) are extremely promising objects for solving a wide range of biomedical problems. The gold nanoparticles production by biological method ("green synthesis") is eco-friendly and allows minimization of the amount of harmful chemical and toxic byproducts. This review is devoted to the AuNPs biosynthesis peculiarities using various living organisms (bacteria, fungi, algae, and plants). The participation of various biomolecules in the AuNPs synthesis and the influence of size, shapes, and capping agents on the functionalities are described. The proposed action mechanisms on target cells are highlighted. The biological activities of "green" AuNPs (antimicrobial, anticancer, antiviral, etc.) and the possibilities of their further biomedical application are also discussed.

Visualizing and evaluating mitochondrial cysteine via near-infrared fluorescence imaging in cells, tissues and in vivo under hypoxia/reperfusion stress

Increasingly grim environmental pollutions are closely related with the occurrence and development of diseases. However, it's obscure how environmental stress disturbs the normal physiological process, and then how endogenous reactive species mend the cases. Hypoxia/reperfusion (H/R), a common and intractable injury in aquaculture and clinic, can induce oxidative stress and ultimately cause irreversible injury to organism. Cysteine (Cys) plays essential roles in maintaining transduction of numerous reactive species and redox homeostasis in subcellular structures, cells and organisms. A great deal of fluorescence research about Cys are focusing on development of selective probes but with poor exploration of the biofunction under environmental stress. Therefore, it is of great significance to examine the bio-effects of Cys against H/R stress. In the present work, we design a fluorescent probe BCy-AC for in situ detecting Cys, the unique Enol-Keto tautomerization of fluorophore BCy-Keto propels the reaction process which will improve the sensitivity and potential application performance of the probe. BCy-AC is conveniently applied to visualize Cys in HT-22 cells, zebrafish and mice tissues. Moreover, imaging results obtained from H/R models reveal that endogenous Cys changes with hypoxia and reperfusion time and Cys pretreatment effectively defend H/R injury in cells and in vivo.

Detection of Oxidative Stress Induced by Nanomaterials in Cells-The Roles of Reactive Oxygen Species and Glutathione

The potential of nanomaterials use is huge, especially in fields such as medicine or industry. Due to widespread use of nanomaterials, their cytotoxicity and involvement in cellular pathways ought to be evaluated in detail. Nanomaterials can induce the production of a number of substances in cells, including reactive oxygen species (ROS), participating in physiological and pathological cellular processes. These highly reactive substances include: superoxide, singlet oxygen, hydroxyl radical, and hydrogen peroxide. For overall assessment, there are a number of fluorescent probes in particular that are very specific and selective for given ROS. In addition, due to the involvement of ROS in a number of cellular signaling pathways, understanding the principle of ROS production induced by nanomaterials is very important. For defense, the cells have a number of reparative and especially antioxidant mechanisms. One of the most potent antioxidants is a tripeptide glutathione. Thus, the glutathione depletion can be a characteristic manifestation of harmful effects caused by the prooxidative-acting of nanomaterials in cells. For these reasons, here we would like to provide a review on the current knowledge of ROS-mediated cellular nanotoxicity manifesting as glutathione depletion, including an overview of approaches for the detection of ROS levels in cells.

Toxicity of gold nanoparticles (AuNPs): A review

Gold nanoparticles are a kind of nanomaterials that have received great interest in field of biomedicine due to their electrical, mechanical, thermal, chemical and optical properties. With these great potentials came the consequence of their interaction with biological tissues and molecules which presents the possibility of toxicity. This paper aims to consolidate and bring forward the studies performed that evaluate the toxicological aspect of AuNPs which were categorized into in vivo and in vitro studies. Both indicate to some extent oxidative damage to tissues and cell lines used in vivo and in vitro respectively with the liver, spleen and kidney most affected. The outcome of these review showed small controversy but however, the primary toxicity and its extent is collectively determined by the characteristics, preparations and physicochemical properties of the NPs. Some studies have shown that AuNPs are not toxic, though many other studies contradict this statement. In order to have a holistic inference, more studies are required that will focus on characterization of NPs and changes of physical properties before and after treatment with biological media. So also, they should incorporate controlled experiment which includes supernatant control Since most studies dwell on citrate or CTAB-capped AuNPs, there is the need to evaluate the toxicity and pharmacokinetics of functionalized AuNPs with their surface composition which in turn affects their toxicity. Functionalizing the NPs surface with more peculiar ligands would however help regulate and detoxify the uptake of these NPs.

Glutathione-Depleting Nanomedicines for Synergistic Cancer Therapy

Cancer cells frequently exhibit resistance to various molecular and nanoscale drugs, which inevitably affects the drugs' therapeutic outcomes. Overexpression of glutathione (GSH) has been observed in many cancer cells, and solid evidence has corroborated the resulting tumor resistance to a variety of anticancer therapies, suggesting that this biochemical characteristic of cancer cells can be developed as a potential target for cancer treatments. The single treatment of GSH-depleting agents can potentiate the responses of the cancer cells to different cell death stimuli; therefore, as an adjunctive strategy, GSH depletion is usually combined with mainstream cancer therapies for enhancing the therapeutic outcomes. Propelled by the rapid development of nanotechnology, GSH-depleting agents can be readily constructed into anticancer nanomedicines, which have shown a steep rise over the past decade. Here, we review the common GSH-depleting nanomedicines which have been widely applied in synergistic cancer treatments in recent years. Some current challenges and future perspectives for GSH depletion-based cancer therapies are also presented. With the understanding of the structure-property relationship and action mechanisms of these biomaterials, we hope that the GSH-depleting nanotechnology will be further developed to realize more effective disease treatments and even achieve successful clinical translations.

Engineering nanomedicine for glutathione depletion-augmented cancer therapy

Glutathione (GSH), the main redox buffer, has long been recognized as a pivotal modulator of tumor initiation, progression and metastasis. It is also implicated in the resistance of platinum-based chemotherapy and radiation therapy. Therefore, depleting intracellular GSH was considered a potent solution to combating cancer. However, reducing GSH within cancer cells alone always failed to yield desirable therapeutic effects. In this regard, the convergence of GSH-scavenging agents with therapeutic drugs has thus been pursued in clinical practice. Unfortunately, the therapeutic outcomes are still unsatisfactory due to untargeted drug delivery. Advanced nanomedicine of synergistic GSH depletion and cancer treatment has attracted tremendous interest because they promise to deliver superior therapeutic benefits while alleviating life-threatening side effects. In the past five years, the authors and others have demonstrated that numerous nanomedicines, by simultaneously delivering GSH-depleting agents and therapeutic components, boost not only traditional chemotherapy and radiotherapy but also multifarious emerging treatment modalities, including photodynamic therapy, sonodynamic therapy, chemodynamic therapy, ferroptosis, and immunotherapy, to name a few, and achieved decent treatment outcomes in a large number of rodent tumor models. In this review, we summarize the most recent progress in engineering nanomedicine for GSH depletion-enhanced cancer therapies. Biosynthesis of GSH and various types of GSH-consuming strategies will be briefly introduced. The challenges and perspectives of leveraging nanomedicine for GSH consumption-augmented cancer therapies will be discussed at the end.

UPLC-Q-Exactive-MS analysis for hepatotoxicity components of Evodiae Fructus based on spectrum-toxicity relationship

Evodiae Fructus (EF) is generally divided into three categories: small flower EF (SEF), medium flower EF (MEF) and big flower EF (BEF) in commodity circulation according to the size of the fruit. It is a well-known and frequently used herbal medicine for treating gastrointestinal disorder-related stomachache and headache, which has aroused wide attention for its hepatotoxicity. However, reports about hepatotoxicity is controversial and hepatotoxic components are inconclusive. The study aimed to explain the controversial hepatotoxicity of EF and screen the components associated with hepatotoxicity of EF based on the spectrum-toxicity relationship. UPLC fingerprints of 39 batches of EF collected from different regions were established. Combined with the results of L02 cell viability assays, the spectrum-toxicity relationship was investigated on the basic of orthogonal partial least squares (OPLS). The results of the research demonstrated that the toxicity of EF was obviously various among the different categories, in particularly, SEF was with less toxicity, MEF except for adulterants and BEF had mild toxicity and adulterants of MEF (A-MEF) produced more damage to L02 cell and no regions specificity in hepatotoxicity of EF. Thereinto, samples, the contents of which do not meet the requirements of Chinese Pharmacopoeia, were adulterants. It was worth noting that P11, P17, P20 and P25 were closely related to hepatotoxicity of EF and they were respectively identified as limonin (LIM), evodiamine (EVO), 1-methyl-2-nonyl-4(1H)-quinolone (MNQ), and 1-methyl-2-undecyl-4(1H)-quinolone (MUQ) by UPLC-Q-Exactive-MS. The hepatoprotection of P11 and hepatotoxicity of P17 were consistent with the results of spectrum-toxicity relationship. In summary, A-MEF was more toxic than other categories and SEF was less toxic than the others. It was noteworthy that EVO was the main hepatotoxic component of EF and LIM was the main hepatoprotective component of EF. The results provided worthy evidence for better utilization and development of EF.

The Effect of 6-gingerol on Growth Factors and Apoptosis Indices in Rats Exposed to Gold Nanoparticles

INTRODUCTION

Research has shown that gold nanoparticles (AuNPs) can damage the physiological processes of brain tissue. Given the antioxidant properties of Gingerol (GING), this study aimed to determine the protective effect of 6-gingerol on hippocampal levels of Brain-Derived Neurotrophic Factor (BDNF), Nerve Growth Factor (NGF), DNA oxidative damage, and the amount of Bax and Bcl2 apoptosis indices of rats exposed to AuNPs.

METHODS

A total of 42 male Wistar rats were divided into four groups: control (30 days 0.5 mL saline), AuNPs (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL saline), AuNPs+GING 50 (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL density of gingerol 50 mg/kg), and AuNPs+GING100 (one time injection of 0.5 mL AuNPs, 200 ppm and 60 Nm + 30 days 0.5 mL density of gingerol 100 mg/kg). At the end of the treatment period, the hippocampal levels of NGF, BDNF, 8-hydroxy-desoxyguanosine (8-HOdG), and apoptotic indices of Bax and Bcl-2 were assessed with the ELISA method.

RESULTS

Compared with the AuNPs group, hippocampal levels of BDNF, NGF, and Bcl-2 in rats in the AuNPs+GING 50 and AuNPs+GING 100 groups significantly increased dose-dependently. However, the hippocampal levels of Bax and 8-HOdG significantly decreased dose-dependently (P<0.05).

CONCLUSION

According to obtained results, gingerol may improve hippocampal BDNF and NGF levels in rats exposed to AuNPs, probably by reducing apoptosis and oxidative DNA damage.

Understanding and advancement in gold nanoparticle targeted photothermal therapy of cancer

The present communication summarizes the importance, understanding and advancement in the photothermal therapy of cancer using gold nanoparticles. Photothermal therapy was used earlier as a single line therapy, but using a combination of photothermal therapy with other therapies like immunotherapy, chemotherapy, photodynamic therapy; efficient therapy management can be achieved. As it was discussed in many studies that gold nanoparticles are treated as idyllic photothermal transducers due to their structural dimensions, which enables them to strongly absorb near infrared light. Gold nanoparticles which are mediated for photothermal therapy can warn cancer cells to chemotherapy, regulate genes and immunotherapy by enhancing the cell permeability and intracellular delivery. The necrosis process and apoptosis depend on the power of laser and temperature within the cancerous tissues which are reached during irradiation. Cells death mechanism is also important because the cells which died through the process of necrosis can endorse secondary tumor growth while the cells which died through apoptosis may provoke the immune response to inhibit the development of secondary tumor growth. To decrease the in vivo barriers, gold nanostructures are again modified with targeting ligand and bio-responsive linker. The manuscript summarizes that the use of gold nanoparticles is capable of inhibiting the growth of cancerous cells by using photothermal therapy which has lesser adverse effects compared to other line therapies.

Gold nanoparticle‑mediated delivery of paclitaxel and nucleic acids for cancer therapy (Review)

Paclitaxel is a potent antineoplastic agent, but poor solubility and resistance have limited its use. Gold nanoparticles (AuNPs) are widely studied as drug carriers because they can be engineered to prevent drug insolubility, carry nucleic acid payloads for gene therapy, target specific tumor cell lines, modulate drug release and amplify photothermal therapy. Consequently, the conjugation of paclitaxel with AuNPs to improve antiproliferative and pro‑apoptotic potency may enable improved clinical outcomes. There are currently a number of different AuNPs under development, including simple drug or nucleic acid carriers and targeted AuNPs that are designed to deliver therapeutic payloads to specific cells. The current study reviewed previous research on AuNPs and the development of AuNP‑based paclitaxel delivery.

Electrostatically bound lanreotide peptide - gold nanoparticle conjugates for enhanced uptake in SSTR2-positive cancer cells

Lanreotide peptide (LP) has high affinity to somatostatin receptors like SSTR2 and is commonly used in the treatment of neuro-endocrine tumors. The main objective of this study is to target gold nanoparticles (AuNPs) towards SSTR2-positive cancer cells using lanreotide peptide (LP) as the targeting agent for enhanced tumor uptake and antitumor activity. pH mediated changes in the surface potential of LP and AuNP is used to prepare electrostatically bound AuNP-LP complexes. AuNP-LP complex formation was demonstrated by UV-Visible spectroscopy, surface potential, dynamic light scattering (DLS), small angle X-ray scattering and HR-TEM. Confocal microscopy and flow cytometric studies show that AuNP-LP complex has higher cellular uptake in SSTR2 expressed cancer cells (MCF-7 and AR42J) than in CHO cells. The enhanced cellular uptake of LP coated AuNPs lead to ~1.5 to 2-fold GSH depletion and enhanced ROS generation in MCF-7 cells. The preferential cytotoxicity of the AuNP-LP complex towards MCF-7 and AR42J cells, as revealed by MTT assay, is consistent with the increased cellular uptake. Our studies demonstrate that LP coated AuNP can be used as an effective platform to selectively target SSTR2 positive cancer cells for combination therapy approaches involving gold nanoparticles.

Discriminatory alteration of carbohydrate homeostasis by gold nanoparticles ingestion in Drosophila

With the extensive usage of gold nanoparticles (AuNPs) in various industrial sectors and biomedical applications, evaluation of their possible effects on human health becomes imperative. Therefore, the present study was aimed toward assessing the dose-dependent impact of AuNPs ingestion on metabolic homeostasis using Drosophila melanogaster as a model system. We found that larval ingestion of higher dose of AuNPs significantly reduced body weight. Further analysis of the crucial energy reservoir showed selective alteration in carbohydrate levels without any change in the lipid and protein levels. Transcriptional downregulation of glycogen synthase further supported impaired glycogen metabolism in flies supplemented with higher dose of AuNPs. Additionally, ingestion of higher dose of AuNPs in larvae results in significantly increased levels of reactive oxygen species (ROS) in the peripheral tissues, suggestive of stress condition. Our findings clearly imply that supplementing higher doses of AuNPs at an early developmental stage can potentially cause weight loss, impair glycogen metabolism, and elevate ROS production. Therefore, determination of a biologically effective dose is critical for the safety of mankind and vulnerable populations at the workplace.

Targeted Manganese doped silica nano GSH-cleaner for treatment of Liver Cancer by destroying the intracellular redox homeostasis

Background: Glutathione (GSH), the primary antioxidant in cells, could fight against oxidative stress. Tumor cells display a higher GSH level than normal cells for coping with the hyperoxidative state, which meets the requirements of enhanced metabolism and vicious proliferation. Therefore, the consumption of GSH will lead to cell redox imbalance and impede life activities. Herein, targeted sorafenib (SFB) loaded manganese doped silica nanoparticle (FaPEG-MnMSN@SFB) was constructed, which could destroy the intracellular redox homeostasis by consuming GSH. Methods: In this study, MnMSN was prepared by an optimized one-pot Stober's method for loading SFB, and FaPEG chain was modified on the surface of MnMSN to achieve long circulation and targeted delivery. The anticancer efficacy and mechanism of the designed FaPEG-MnMSN@SFB were assessed both in vitro and in vivo.Results: FaPEG-MnMSN@SFB exhibited efficient antitumor activity by dual depleting intracellular GSH (the degradation of MnMSN would consume intracellular GSH and the SFB would inhibit the effect of Xc- transport system to inhibit GSH synthesis). Moreover, disruption of redox balance would lead to apoptosis and reactive oxygen species (ROS)-dependent ferroptosis of tumor cells. Conclusion: Such a GSH-starvation therapeutic strategy would cause multi-path programmed cell death and could be a promising strategy for cancer therapy.

Physical Properties of Nanoparticles That Result in Improved Cancer Targeting

The therapeutic efficacy of drugs is dependent upon the ability of a drug to reach its target, and drug penetration into tumors is limited by abnormal vasculature and high interstitial pressure. Chemotherapy is the most common systemic treatment for cancer but can cause undesirable adverse effects, including toxicity to the bone marrow and gastrointestinal system. Therefore, nanotechnology-based drug delivery systems have been developed to reduce the adverse effects of traditional chemotherapy by enhancing the penetration and selective drug retention in tumor tissues. A thorough knowledge of the physical properties (e.g., size, surface charge, shape, and mechanical strength) and chemical attributes of nanoparticles is crucial to facilitate the application of nanotechnology to biomedical applications. This review provides a summary of how the attributes of nanoparticles can be exploited to improve therapeutic efficacy. An ideal nanoparticle is proposed at the end of this review in order to guide future development of nanoparticles for improved drug targeting in vivo.

The Effects of Polymer Coating of Gold Nanoparticles on Oxidative Stress and DNA Damage

Gold nanoparticles (AuNPs) have been widely used in many biological and biomedical applications. In this regard, their surface modification is of paramount importance in order to increase their cellular uptake, delivery capability, and optimize their distribution inside the body. The aim of this study was to examine the effects of AuNPs on cytotoxicity, oxidant/antioxidant parameters, and DNA damage in HepG2 cells and investigate the potential toxic effects of different surface modifications such as polyethylene glycol (PEG) and polyethyleneimine (PEI; molecular weights of 2,000 (low molecular weight [LMW]) and 25,000 (high molecular weight [HMW]). The study groups were determined as AuNPs, PEG-coated AuNPs (AuNPs/PEG), low-molecular weight polyethyleneimine-coated gold nanoparticles (AuNPs/PEI LMW), and high-molecular weight polyethyleneimine-coated gold nanoparticles (AuNPs/PEI HMW). After incubating HepG2 cells with different concentrations of nanoparticles for 24 hours, half maximal inhibitory concentrations (the concentration that kills 50% of the cells) were determined as 166.77, 257.73, and 198.44 µg/mL for AuNPs, AuNPs/PEG, and AuNPs/PEI LMW groups, respectively. Later, inhibitory concentration 30 (IC30, the concentration that kills 30% of the cells) doses were calculated, and further experiments were performed on cells that were exposed to IC30 doses. Although intracellular reactive oxygen species levels significantly increased in all nanoparticles, AuNPs as well as AuNPs/PEG did not cause any changes in oxidant/antioxidant parameters. However, AuNPs/PEI HMW particularly induced oxidative stress as evidence of alterations in lipid peroxidation and protein oxidation. These results suggest that at IC30 doses, AuNPs do not affect oxidative stress and DNA damage significantly. Polyethylene glycol coating does not have an impact on toxicity, however PEI coating (particularly HMW) can induce oxidative stress.

Extra-Small Gold Nanospheres Decorated With a Thiol Functionalized Biodegradable and Biocompatible Linear Polyamidoamine as Nanovectors of Anticancer Molecules

Gold nanoparticles are elective candidate for cancer therapy. Current efforts are devoted to developing innovative methods for their synthesis. Besides, understanding their interaction with cells have become increasingly important for their clinical application. This work aims to describe a simple approach for the synthesis of extra-small gold nanoparticles for breast cancer therapy. In brief, a biocompatible and biodegradable polyamidoamine (named AGMA1-SH), bearing 20%, on a molar basis, thiol-functionalized repeat units, is employed to stabilize and coat extra-small gold nanospheres of different sizes (2.5, 3.5, and 5 nm in gold core), and to generate a nanoplatform for the link with Trastuzumab monoclonal antibody for HER2-positive breast cancer targeting. Dynamic light scattering, transmission electron microscopy, ultraviolet visible spectroscopy, X-ray powder diffraction, circular dichroism, protein quantification assays are used for the characterization. The targeting properties of the nanosystems are explored to achieve enhanced and selective uptake of AGMA1-SH-gold nanoparticles by in vitro studies against HER-2 overexpressing cells, SKBR-3 and compared to HER-2 low expressing cells, MCF-7, and normal fibroblast cell line, NIH-3T3. In vitro physicochemical characterization demonstrates that gold nanoparticles modified with AGMA1-SH are more stable in aqueous solution than the unmodified ones. Additionally, the greater gold nanoparticles size (5-nm) is associated with a higher stability and conjugation efficiency with Trastuzumab, which retains its folding and anticancer activity after the conjugation. In particular, the larger Trastuzumab functionalized nanoparticles displays the highest efficacy (via the pro-apoptotic protein increase, anti-apoptotic components decrease, survival-proliferation pathways downregulation) and internalization (via the activation of the classical clathrin-mediated endocytosis) in HER-2 overexpressing SKBR-3 cells, without eliciting significant effects on the other cell lines. The use of biocompatible AGMA1-SH for producing covalently stabilized gold nanoparticles to achieve selective targeting, cytotoxicity and uptake is completely novel, offering an important advancement for developing new anticancer conjugated-gold nanoparticles.

Artemisinin-Based Smart Nanomedicines with Self-Supply of Ferrous Ion to Enhance Oxidative Stress for Specific and Efficient Cancer Treatment

Though abundant researches report that artemisinin could inhibit cancer cell growth via generating toxic reactive oxygen species (ROS), the therapeutic efficiency of artemisinin for cancer treatment is still limited owing to the insufficient intracellular ferrous ion and defensive effect of intracellular glutathione. Herein, we report a cathepsin B-controllable smart nanomedicine based on the structural and pharmacodynamic characteristics of artemisinin, which employed transferrin-peptide-modified mesoporous silica to codeliver artemisinin and buthionine-sulfoximine, a glutathione scavenger, into cancer cells. As a gatekeeper, the transferrin-peptide can not only target the cancer cells but also supply the extra ferrous iron to catalyze artemisinin to produce excessive ROS to kill cancer cells efficiently. Once the designed nanomedicine attack into lysosome of tumor cells, the cargos of nanomedicine can be released in the presence of cathepsin B to immediately activate self-amplification of oxidative stress by simultaneously elevating the levels of ROS and weakening the levels of glutathione. We anticipate that this rational design strategy provides innovative opportunities for artemisinin in the clinical application of cancer.

Effects of chronic treatment with gold nanoparticles on inflammatory responses and oxidative stress in Mdx mice

Duchenne muscular dystrophy (DMD) is an X-linked recessive hereditary myopathy characterised by progressive muscle degeneration in male children. As a consequence of DMD, increased inflammation and oxidative stress occur in muscle tissue along with morphological changes. Several studies have reported anti-inflammatory and antioxidant effects of gold nanoparticles (GNP) in muscle injury models. The objective of this study was to evaluate these effects along with the impacts of the disease on histopathological changes following chronic administration of GNP to Mdx mice. Two-month-old Mdx mice were separated into five groups of eight individuals each, as follows: wild-type (WT), Mdx-modified without treatment, Mdx + 2.5 mg/kg GNP, Mdx + 7.0 mg/kg GNP and Mdx + 21 mg/kg GNP. GNP with a mean diameter of 20 nm were injected subcutaneously at concentrations of 2.5, 7.0 and 21 mg/kg. Treatments continued for 30 d with injections administered at 48-h intervals. Twenty-four hours after the last injection, the animals were killed and the central region of the gastrocnemius muscle was surgically removed. Chronic administration of GNP reduced inflammation in the gastrocnemius muscle of Mdx mice and reduced morphological alterations due to inflammatory responses to muscular dystrophy. In addition, GNP also demonstrated antioxidant potential by reducing the production of reactive oxygen and nitrogen species, reducing oxidative damage and improving antioxidant activity.

Necrotic, apoptotic and autophagic cell fates triggered by nanoparticles

Nanomaterials have gained a rapid increase in use in a variety of applications that pertain to many aspects of human life. The majority of these innovations are centered on medical applications and a range of industrial and environmental uses ranging from electronics to environmental remediation. Despite the advantages of NPs, the knowledge of their toxicological behavior and their interactions with the cellular machinery that determines cell fate is extremely limited. This review is an attempt to summarize and increase our understanding of the mechanistic basis of nanomaterial interactions with the cellular machinery that governs cell fate and activity. We review the mechanisms of NP-induced necrosis, apoptosis and autophagy and potential implications of these pathways in nanomaterial-induced outcomes. Abbreviations: Ag, silver; CdTe, cadmium telluride; CNTs, carbon nanotubes; EC, endothelial cell; GFP, green fluorescent protein; GO, graphene oxide; GSH, glutathione; HUVECs, human umbilical vein endothelial cells; NP, nanoparticle; PEI, polyethylenimine; PVP, polyvinylpyrrolidone; QD, quantum dot; ROS, reactive oxygen species; SiO2, silicon dioxide; SPIONs, superparamagnetic iron oxide nanoparticles; SWCNT, single-walled carbon nanotubes; TiO2, titanium dioxide; USPION, ultra-small super paramagnetic iron oxide; ZnO, zinc oxide.

Gold Nanoparticles in Diagnostics and Therapeutics for Human Cancer

The application of nanotechnology for the treatment of cancer is mostly based on early tumor detection and diagnosis by nanodevices capable of selective targeting and delivery of chemotherapeutic drugs to the specific tumor site. Due to the remarkable properties of gold nanoparticles, they have long been considered as a potential tool for diagnosis of various cancers and for drug delivery applications. These properties include high surface area to volume ratio, surface plasmon resonance, surface chemistry and multi-functionalization, facile synthesis, and stable nature. Moreover, the non-toxic and non-immunogenic nature of gold nanoparticles and the high permeability and retention effect provide additional benefits by enabling easy penetration and accumulation of drugs at the tumor sites. Various innovative approaches with gold nanoparticles are under development. In this review, we provide an overview of recent progress made in the application of gold nanoparticles in the treatment of cancer by tumor detection, drug delivery, imaging, photothermal and photodynamic therapy and their current limitations in terms of bioavailability and the fate of the nanoparticles.

Identification and Characterization of Key Charged Residues in the Cofilin Protein Involved in Azole Susceptibility, Apoptosis, and Virulence of Aspergillus fumigatus

Through some specific amino acid residues, cofilin, a ubiquitous actin depolymerization factor, can significantly affect mitochondrial function related to drug resistance and apoptosis in Saccharomyces cerevisiae; however, this modulation in a major fungal pathogen, Aspergillus fumigatus, was still unclear. Hereby, it was found, first, that mutations on several charged residues in cofilin to alanine, D19A-R21A, E48A, and K36A, increased the formation of reactive oxygen species and induced apoptosis along with typical hallmarks, including mitochondrial membrane potential depolarization, cytochrome c release, upregulation of metacaspases, and DNA cleavage, in A. fumigatus Two of these mutations (D19A-R21A and K36A) increased acetyl coenzyme A and ATP concentrations by triggering fatty acid β-oxidation. The upregulated acetyl coenzyme A affected the ergosterol biosynthetic pathway, leading to overexpression of cyp51A and -B, while excess ATP fueled ATP-binding cassette transporters. Besides, both of these mutations reduced the susceptibility of A. fumigatus to azole drugs and enhanced the virulence of A. fumigatus in a Galleria mellonella infection model. Taken together, novel and key charged residues in cofilin were identified to be essential modules regulating the mitochondrial function involved in azole susceptibility, apoptosis, and virulence of A. fumigatus.

Gold Nanoparticle-Induced Cell Death and Potential Applications in Nanomedicine

Cell death is crucial to human health and is related to various serious diseases. Therefore, generation of new cell death regulators is urgently needed for disease treatment. Nanoparticles (NPs) are now routinely used in a variety of fields, including consumer products and medicine. Exhibiting stability and ease of decoration, gold nanoparticles (GNPs) could be used in diagnosis and disease treatment. Upon entering the human body, GNPs contact human cells in the blood, targeting organs and the immune system. This property results in the disturbance of cell function and even cell death. Therefore, GNPs may act as powerful cell death regulators. However, at present, we are far from establishing a structure–activity relationship between the physicochemical properties of GNPs and cell death, and predicting GNP-induced cell death. In this review, GNPs’ size, shape, and surface properties are observed to play key roles in regulating various cell death modalities and related signaling pathways. These results could guide the design of GNPs for nanomedicine.

Metabolomics reveals the depletion of intracellular metabolites in HepG2 cells after treatment with gold nanoparticles

Studies on the safety of gold nanoparticles (GNPs) are plentiful due to their successful application in drug delivery and treatment of diseases in trials. Cytotoxicity caused by GNPs has been studied on the physiological and biochemical level; yet, the effect of GNPs (particularly gold nano-spheres) on the metabolome of living organisms remains understudied. In this investigation, metabolomics was used to comprehensively study the metabolic alterations in HepG2 cells caused by GNPs; and to investigate the role of representative GNP coatings. GNPs were synthesized, coated and characterized before use on HepG2 cell cultures. Cells were treated for 3 h with citrate-, poly-(sodiumsterene sulfunate)-, and poly-vinylpyrrolidone (PVP)-capped GNPs, respectively. The internalization of the different GNPs and their effect on mitochondrial respiration and the metabolome were studied. Results indicated that the PVP-capped GNPs internalized more and also caused a more observable effect on the metabolome. Conversely, it was the citrate- and poly-(sodiumsterene sulfunate) coated particles that influenced ATP production in addition to the metabolomic changes. A holistic depletion of intracellular metabolites was observed regardless of GNP coating, which hints to the binding of certain metabolites to the particles.

Visualization and Inhibition of Mitochondria-Nuclear Translocation of Apoptosis Inducing Factor by a Graphene Oxide-DNA Nanosensor

High concentrations of oxidized low density lipoprotein (oxLDL) induce aberrant apoptosis of vascular smooth muscle cells (VSMCs) in atherosclerotic plaques. This apoptosis cannot be blocked completely by the inhibition of caspase, and it eventually potentiates plaque disruption and risk for cardiovascular disease. Given the important role of apoptosis inducing factor (AIF) in caspase-independent apoptosis, here we develop an AIF-targeting nanosensor by the assembly of graphene oxide (GO) nanosheets and dye-labeled DNA hybrid structures. This nanosensor selectively localizes in the cytosol of VSMCs, where it exhibits a "turn-off" fluorescence signal. Under oxLDL stimuli, the release of AIF from mitochondria into cytosol liberates the DNA hybrid structures from the surface of GO and results in a "turn-on" fluorescence signal. This nanosensor is shown to possess rapid response, high sensitivity, and selectivity for AIF that enables real-time imaging of AIF translocation in VSMCs. Using this novel nanosensor, a better assessment of the apoptotic level of VSMCs and a more accurate evaluation of the extent of atherosclerotic lesions can be obtained. More importantly, the abundant binding between DNA hybrid structures and AIF inhibits the translocation of AIF into the nucleus and subsequent apoptosis in VSMCs. This inhibition may help stabilize plaque and reduce the risk of heart attack and stroke.

Phytofabricated gold nanoparticles and their biomedical applications

In a couple of decades, nanotechnology has become a trending technology owing to its integrated science collection that incorporates variety of fields such as chemistry, physics, medicine, catalytic processes, food processing industries, electronics and energy sectors. One of the emerging fields of nanotechnology that has gained momentous admiration is nano-biotechnology. Nano-biotechnology is an integrated combination of biology with nanotechnology that encompasses the tailoring, and synthesis of small particles that are less than 100nm in size and subsequent exploitation of these particles for their biological applications. Though the variety of physical techniques and chemical procedures are known for the nanoparticles synthesis, biological approach is considered to be the preferred one. Environmental hazards and concerns associated with the physical and chemical approaches of nanoparticles synthesis has added impetus and zenith to the biological approach involving the use of plants and microorganisms. The current review article is focused on the synthesis of plant-derived (phytochemical) gold nanoparticles alongside their scope in biomedical applications.

Intracellular Accumulation of Gold Nanoparticles Leads to Inhibition of Macropinocytosis to Reduce the Endoplasmic Reticulum Stress

Understanding the toxicity of nanomaterials remains largely limited to acute cellular response, i.e., short-term in vitro cell-death based assays, and analyses of tissue- and organ-level accumulation and clearance patterns in animal models, which have produced very little information about how these materials (from the toxicity point of view) interact with the complex intracellular machinery. In particular, understanding the mechanism of toxicity caused by the gradual accumulation of nanomaterials due to prolonged exposure times is essential yet still continue to be a largely unexplored territory. Herein, we show intracellular accumulation and the associated toxicity of gold nanoparticles (AuNPs) for over two-months in the cultured vascular endothelial cells. We observed that steady exposure of AuNPs at low (non-lethal) dose leads to rapid intracellular accumulation without causing any detectable cell death while resulting in elevated endoplasmic reticulum (ER) stress. Above a certain intracellular AuNP threshold, inhibition of macropinocytosis mechanism ceases further nanoparticle uptake. Interestingly, the intracellular depletion of nanoparticles is irreversible. Once reaching the maximum achievable intracellular dose, a steady depletion is observed, while no cell death is observed at any stage of this overall process. This depletion is important for reducing the ER stress. To our knowledge, this is the first report suggesting active regulation of nanoparticle uptake by cells and the impact of long-term exposure to nanoparticles in vitro.

The effect of particle size on the genotoxicity of gold nanoparticles

Despite the increasing biomedical applications of gold nanoparticles (AuNPs), their toxicological effects need to be thoroughly understood. In the present study, the genotoxic potential of commercially available AuNPs with varying size (5, 20, and 50 nm) were assessed using a battery of in vitro and in vivo genotoxicity assays. In the comet assay, 20 and 50 nm AuNPs did not induce obvious DNA damage in HepG2 cells at the tested concentrations, whereas 5 nm NPs induced a dose-dependent increment in DNA damage after 24-h exposure. Furthermore, 5 nm AuNPs induced cell cycle arrest in G1 phase in response to DNA damage, and promoted the production of reactive oxygen species (ROS). In the chromosomal aberration test, AuNPs exposure did not increase in the frequency of chromosomal aberrations in Chinese hamster lung (CHL) cells. In the standard in vivo micronucleus test, no obvious increase in the frequency of micronucleus formation was found in mice after 4 day exposure of AuNPs. However, when the exposure period was extended to 14 days, 5 nm AuNPs presented significant clastogenic damage, with a dose-dependent increase of micronuclei frequencies. This finding suggests that particle size plays an important role in determining the genotoxicity of AuNPs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 710-719, 2017.

The bright side of plasmonic gold nanoparticles; activation of Nrf2, the cellular protective pathway

Plasmonic gold nanoparticles (AuNPs) are widely investigated for cancer therapy, due to their ability to strongly absorb light and convert it to heat and thus selectively destroy tumor cells. In this study we shed light on a new aspect of AuNPs and their plasmonic excitation, wherein they can provide anti-oxidant and anti-inflammatory protection by stimulating the cellular protective Nrf2 pathway. Our study was carried out on cells of the immune system, macrophages, and on skin cells, keratinocytes. A different response to AuNPs was noted in the two types of cells, explained by their distinct uptake profiles. In keratinocytes, the exposure to AuNPs, even at low concentrations, was sufficient to activate the Nrf2 pathway, without any irradiation, due to the presence of free AuNPs inside the cytosol. In contrast, in macrophages, the plasmonic excitation of the AuNPs by a low, non-lethal irradiation dose was required for their release from the constraining vesicles. The mechanism by which AuNPs activate the Nrf2 pathway was studied. Direct and indirect activation were suggested, based on the inherent ability of the AuNPs to react with thiol groups and to generate reactive oxygen species, in particular, under plasmonic excitation. The ability of AuNPs to directly activate the Nrf2 pathway renders them good candidates for treatment of disorders in which the up-regulation of Nrf2 is beneficial, specifically for topical treatment of inflammatory skin diseases.

Highly Hybridizable Spherical Nucleic Acids by Tandem Glutathione Treatment and Polythymine Spacing

Gold nanoparticle (AuNP)-templated spherical nucleic acids (SNAs) have been demonstrated as an important functional material in bionanotechnology. Fabrication of SNAs having high hybridization capacity to their complementary sequences is critical to ensure their applicability in areas such as antisense gene therapy and cellular sensing. The traditional salt-aging procedure is effective but tedious, requiring 1-3 days to complete. The rapid low-pH assisted protocol is efficient, but causes concerns related to nonspecific DNA adsorption to the AuNP core. To address these issues, we systematically compared the SNAs prepared by these two methods (salt-aging method and low-pH protocol). In terms of the number of complementary DNA that each SNA can bind and the average binding affinity of each thiolated DNA probe to its complementary strand, both methods yielded comparable hybridizability, although higher loading capacity was witnessed with SNAs made using the low-pH method. Additionally, it was found that nonspecific DNA binding could be eliminated almost completely by a simple glutathione (GSH) treatment of SNAs. Compared to conventional methods using toxic mercapto-hexanol or alkanethiols to remove nonspecific DNA adsorption, GSH is mild, cost-effective, and technically easy to use. In addition, GSH-passivated SNAs minimize the toxicity concerns related to AuNP-induced GSH depletion and therefore offer a more biocompatible alternative to previously reported SNAs. Moreover, rational design of probe sequences through inclusion of a polythymine spacer into the DNA sequences resulted in enhanced DNA loading capacity and stability against salt-induced aggregation. This work provides not only efficient and simple technical solutions to the issue of nonspecific DNA adsorption, but also new insights into the hybridizability of SNAs.