Targeted polyethylene glycol gold nanoparticles for the treatment of pancreatic cancer: from synthesis to proof-of-concept in vitro studies

Polyoxometalate-Decorated Gold Nanoparticles Inhibit β-Amyloid Aggregation and Cross the Blood-Brain Barrier in a µphysiological Model

Alzheimer's disease is characterized by a combination of several neuropathological hallmarks, such as extracellular aggregates of beta amyloid (Aβ). Numerous alternatives have been studied for inhibiting Aβ aggregation but, at this time, there are no effective treatments available. Here, we developed the tri-component nanohybrid system AuNPs@POM@PEG based on gold nanoparticles (AuNPs) covered with polyoxometalates (POMs) and polyethylene glycol (PEG). In this work, AuNPs@POM@PEG demonstrated the inhibition of the formation of amyloid fibrils, showing a 75% decrease in Aβ aggregation in vitro. As it is a potential candidate for the treatment of Alzheimer's disease, we evaluated the cytotoxicity of AuNPs@POM@PEG and its ability to cross the blood-brain barrier (BBB). We achieved a stable nanosystem that is non-cytotoxic below 2.5 nM to human neurovascular cells. The brain permeability of AuNPs@POM@PEG was analyzed in an in vitro microphysiological model of the BBB (BBB-on-a-chip), containing 3D human neurovascular cell co-cultures and microfluidics. The results show that AuNPs@POM@PEG was able to cross the brain endothelial barrier in the chip and demonstrated that POM does not affect the barrier integrity, giving the green light to further studies into this system as a nanotherapeutic.

Improvement of the Effectiveness of HER2+ Cancer Therapy by Use of Doxorubicin and Trastuzumab Modified Radioactive Gold Nanoparticles

In the present article, we describe a multimodal radiobioconjugate that contains a chemotherapeutic agent (doxorubicin, DOX), a β-emitter (198Au), and a guiding vector (trastuzumab, Tmab) for targeted therapy of cancers overexpressing HER2 receptors. To achieve this goal, radioactive gold nanoparticles (198AuNPs) with a mean diameter of 30 nm were synthesized and coated with a poly(ethylene glycol) (PEG) linker conjugated to DOX and monoclonal antibody (Tmab) via peptide bond formation. In vitro experiments demonstrated a high affinity of the radiobioconjugate to HER2 receptors and cell internalization. Cytotoxicity experiments performed using the MTS assay showed a significant decrease in the viability of SKOV-3 cells. A synergistic cytotoxic effect due to the simultaneous presence of DOX and 198Au was revealed after 48 h of treatment with 2.5 MBq/mL. Flow cytometry analysis indicated that DOX-198AuNPs-Tmab mainly induced cell cycle arrest in the G2/M phase and late apoptosis. Dose-dependent additive and synergistic effects of the radiobioconjugate were also shown in spheroid models. Ex vivo biodistribution experiments were performed in SKOV-3 tumor-bearing mice, investigating different distributions of the 198AuNPs-DOX and DOX-198AuNPs-Tmab after intravenous (i.v.) and intratumoral (i.t.) administration. Finally, in vivo therapeutic efficacy studies on the same animal model demonstrated very promising results, as they showed a significant tumor growth arrest up to 28 days following a single intratumoral injection of 10 MBq. Therefore, the proposed multimodal radiobioconjugate shows great potential for the local treatment of HER2+ cancers.

Current status of nano-vaccinology in veterinary medicine science

Vaccination programmes provide a safe, effective and cost-efficient strategy for maintaining population health. In veterinary medicine, vaccination not only reduces disease within animal populations but also serves to enhance public health by targeting zoonoses. Nevertheless, for many pathogens, an effective vaccine remains elusive. Recently, nanovaccines have proved to be successful for various infectious and non-infectious diseases of animals. These novel technologies, such as virus-like particles, self-assembling proteins, polymeric nanoparticles, liposomes and virosomes, offer great potential for solving many of the vaccine production challenges. Their benefits include low immunotoxicity, antigen stability, enhanced immunogenicity, flexibility sustained release and the ability to evoke both humoral and cellular immune responses. Nanovaccines are more efficient than traditional vaccines due to ease of control and plasticity in their physio-chemical properties. They use a highly targeted immunological approach which can provide strong and long-lasting immunity. This article reviews the currently available nanovaccine technology and considers its utility for both infectious diseases and non-infectious diseases such as auto-immunity and cancer. Future research opportunities and application challenges from bench to clinical usage are also discussed.

Surface Functionalization of Gold Nanoparticles for Targeting the Tumor Microenvironment to Improve Antitumor Efficiency

Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.

Doxorubicin- and Trastuzumab-Modified Gold Nanoparticles as Potential Multimodal Agents for Targeted Therapy of HER2+ Cancers

Recently, targeted nanoparticles (NPs) have attracted much attention in cancer treatment due to their high potential as carriers for drug delivery. In this article, we present a novel bioconjugate (DOX–AuNPs–Tmab) consisting of gold nanoparticles (AuNPs, 30 nm) attached to chemotherapeutic agent doxorubicin (DOX) and a monoclonal antibody, trastuzumab (Tmab), which exhibited specific binding to HER2 receptors. The size and shape of synthesized AuNPs, as well as their surface modification, were analyzed by the TEM (transmission electron microscopy) and DLS (dynamic light scattering) methods. Biological studies were performed on the SKOV-3 cell line (HER2+) and showed high specificity of binding to the receptors and internalization capabilities, whereas MDA-MB-231 cells (HER2−) did not. Cytotoxicity experiments revealed a decrease in the metabolic activity of cancer cells and surface area reduction of spheroids treated with DOX–AuNPs–Tmab. The bioconjugate induced mainly cell cycle G2/M-phase arrest and late apoptosis. Our results suggest that DOX–AuNPs–Tmab has great potential for targeted therapy of HER2-positive tumors.

Glymphatic-assisted perivascular brain delivery of intrathecal small gold nanoparticles

Nanoparticles are ultrafine particulate matter having considerable potential for treatment of central nervous system (CNS) disorders. Despite their tiny size, the blood-brain barrier (BBB) restricts their access to the CNS. Their direct cerebrospinal fluid (CSF) administration bypasses the BBB endothelium, but still fails to give adequate brain uptake. We present a novel approach for efficient CNS delivery of ¹¹¹In-radiolabelled gold nanoparticles (AuNPs; 10-15 nm) via intra-cisterna magna administration, with tracking by SPECT imaging. To accelerate CSF brain influx, we administered AuNPs intracisternally in conjunction with systemic hypertonic saline, which dramatically increased the parenchymal AuNP uptake, especially in deep brain regions. AuNPs entered the CNS along periarterial spaces as visualized by MRI of gadolinium-labelled AuNPs and were cleared from brain within 24 h and excreted through the kidneys. Thus, the glymphatic-assisted perivascular network augment by systemic hypertonic saline is a pathway for highly efficient brain-wide distribution of small AuNPs.

Evaluation of the parameters affecting the loading of anticancer drug Paclitaxel on coated gold nanoparticles for breast cancer treatment

The purpose of this study is the design and synthesis of gold nanoparticles (GNPs) conjugated with paclitaxel and to investigate the parameters affecting the stability of synthesised nanoparticles with drug delivery capability. Here, synthesised GNPs were coated with polyethylene glycol. Then these particles were conjugated with paclitaxel under different conditions and the physical and structural characteristics, as well as the factors affecting the loading of paclitaxel on nanoparticles, were evaluated by ultraviolet spectrophotometer, fourier transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering and zeta potential apparatus. It was found that pegylated GNPs have a limited loading capacity at the time of 24 h of incubation and the Paclitaxel loading was observed to be pH dependent. The use of these particles in the treatment of breast cancer (MCF7) was also investigated using the MTT test. It was determined that the survival percentage of MCF7 cells in the presence of paclitaxel-bound nanoparticles decreases to about 55% at the maximum measured concentration (690 μM).

NFL-TBS.40-63 Peptide Gold Complex Nanovector: A Novel Therapeutic Approach to Increase Anticancer Activity by Breakdown of Microtubules in Pancreatic Adenocarcinoma (PDAC)

The role of the NFL-TBS.40-63 peptide is to destroy the microtubule network of target glioma cancer cells. Recently, we have conceived a gold-complex biotinylated NFL-TBS.40-63 (BIOT-NFL) to form a hybrid gold nanovector (BIOT-NFL-PEG-AuNPs). This methodology showed, for the first time, the ability of the BIOT-NFL-PEG-AuNPs to target the destruction of pancreatic cancer cells (PDAC) under experimental conditions, as well as detoxification and preclinical therapeutic efficacy regulated by the steric and chemical configuration of the peptide. For this aim, a mouse transplantation tumor model induced by MIA-PACA-2 cells was applied to estimate the therapeutic efficacy of BIOT-NFL-PEG-AuNPs as a nanoformulation. Our relevant results display that BIOT-NFL-PEG-AuNPs slowed the tumor growth and decreased the tumor index without effects on the body weight of mice with an excellent antiangiogenic effect, mediated by the ability of BIOT-NFL-PEG-AuNPs to alter the metabolic profiles of these MIA-PACA-2 cells. The cytokine levels were detected to evaluate the behavior of serum inflammatory factors and the power of BIOT-NFL-PEG-AuNPs to boost the immune system.

Metabolite Profiling and Biological Activity Assessment of Casuarina equisetifolia Bark after Incorporating Gold Nanoparticles

OBJECTIVE

Casuarina equisetifolia bark is rich in various active metabolites and selected to be studied due to limitation of the synthetic antioxidants that have adverse side effects. The present study aimed to enhance efficiency of the most effective extract by incorporating gold nanoparticles (Au-NPs).

METHODS

The phytochemical and biological measurements were carried out in total methanolic extract and its successive fractions. Moreover, these measurements were assayed in the most effective extract after incorporating Au-NPs.

RESULTS

The study revealed that total methanolic extract exhibited the highest biological and cytotoxic activities as compared to other fractions. Therefore, it is considered as good candidate for nano-extract preparation. The methanolic extract incorporated with Au-NPs showed higher antioxidant, scavenging and cytotoxic activities in addition to higher inhibitory effect against α-amylase activity as compared to native extract itself. To pinpoint active agents in total methanolic extract, the secondary metabolite profiling via HPLC-MS showed that 33 and 17 metabolites were annotated in the extract before and after incorporating Au-NPs, respectively. The median lethal dose (LD50) showed that gold total methanolic nano-extract is safer than total methanolic extract.

CONCLUSION

This study concluded that total methanolic C. equisetifolia bark extract is a valuable bioresource to synthesize an eco-friendly Au-NPs with health-enhancing effect as antioxidant, antidiabetic and cytotoxic agents. The present study is considered as the first report on utilization of C. equisetifolia bark in synthesis of Au-NPs by mean of green nanotechnology and investigation of its biological activity in relation to its metabolite fingerprint.

Gold nanoparticles: current and upcoming biomedical applications in sensing, drug, and gene delivery

Gold nanoparticles (AuNPs) present unique physicochemical characteristics, low cytotoxicity, chemical stability, size/morphology tunability, surface functionalization capability, and optical properties which can be exploited for detection applications (colorimetry, surface-enhanced Raman scattering, and photoluminescence). The current challenge for AuNPs is incorporating these properties in developing more sensible and selective sensing methods and multifunctional platforms capable of controlled and precise drug or gene delivery. This review briefly highlights the recent progress of AuNPs in biomedicine as bio-sensors and targeted nano vehicles.

Cell penetrating peptide (CPP) gold(iii) - complex - bioconjugates: from chemical design to interaction with cancer cells for nanomedicine applications

This study promotes an innovative synthesis of a nanotheragnostic scaffold capable of targeting and destroying pancreatic cancer cells (PDAC) using the Biotinylated NFL-TBS.40-63 peptide (BIOT-NFL), known to enter various glioblastoma cancer cells (GBM) where it specifically destroys their microtubule network. This recently proposed methodology (P7391FR00-50481 LIV) applied to other peptides VIM (Vimentin) and TAT (Twin-Arginine Translocation) (CPP peptides) has many advantages, such as targeted selective internalization and high stability under experimental conditions, modulated by steric and chemical configurations of peptides. The successful interaction of peptides on gold surfaces has been confirmed by UV-visible, dynamic light scattering (DLS), Zeta potential (ZP) and Raman spectroscopy analyses. The cellular internalization in pancreatic ductal adenocarcinoma (PDAC; MIA PACA-2) and GBM (F98) cells was monitored by transmission electron microscopy (TEM) and showed a better cellular internalization in the presence of peptides with gold nanoparticles. In this work, we also evaluated the power of these hybrid peptide-nanoparticles as photothermal agents after cancer cell internalization. These findings envisage novel perspectives for the development of high peptide-nanotheragnostics.

Gold nanoparticles and obese adipose tissue microenvironment in cancer treatment

The epidemiological correlation between obesity and cancer is well characterized, but the biological mechanisms which regulate tumor development and response to therapy in obese cancer patients remain unclear. The tumor microenvironment plays an important role in protecting cancer cells by altering the delivery of anticancer therapy to the tumor tissue, reducing the efficacy of treatment. Obese tumor microenvironment provides additional benefits to the survival of tumor cells against anticancer therapies by altering the extracellular matrix composition, angiogenesis processes and the immune cells profile. Nanotechnology, and in particular gold nanoparticles, are being researched as a theranostic strategy for cancer treatment due to their ability to sensitize cancer cells to radiation and photodynamic therapy, enhance delivery of drugs to tumor cells, and in diagnostic applications. Adipose tissue and the obese tumor microenvironment may alter the activity of nanotherapeutics. In this article, we reviewed the current state of our understanding about the mechanisms by which the obese tumor microenvironment may alter the delivery and efficacy of anti-cancer treatments, and why the use of gold nanoparticles may represent an interesting strategy for cancer treatment in the obesity setting.

Electrodeformation of White Blood Cells Enriched with Gold Nanoparticles

The elasticity of white blood cells (WBCs) provides valuable insight into the condition of the cells themselves, the presence of some diseases, as well as immune system activity. In this work, we describe a novel process of refined control of WBCs’ elasticity through a combined use of gold nanoparticles (AuNPs) and the microelectrode array device. The capture and controlled deformation of gold nanoparticles enriched white blood cells in vitro are demonstrated and quantified. Gold nanoparticles enhance the effect of electrically induced deformation and make the DEP-related processes more controllable.

Nanocarriers for pancreatic cancer imaging, treatments, and immunotherapies

Pancreatic tumors are highly desmoplastic and immunosuppressive. Delivery and distribution of drugs within pancreatic tumors are compromised due to intrinsic physical and biochemical stresses that lead to increased interstitial fluid pressure, vascular compression, and hypoxia. Immunotherapy-based approaches, including therapeutic vaccines, immune checkpoint inhibition, CAR-T cell therapy, and adoptive T cell therapies, are challenged by an immunosuppressive tumor microenvironment. Together, extensive fibrosis and immunosuppression present major challenges to developing treatments for pancreatic cancer. In this context, nanoparticles have been extensively studied as delivery platforms and adjuvants for cancer and other disease therapies. Recent advances in nanotechnology have led to the development of multiple nanocarrier-based formulations that not only improve drug delivery but also enhance immunotherapy-based approaches for pancreatic cancer. This review discusses and critically analyzes the novel nanoscale strategies that have been used for drug delivery and immunomodulation to improve treatment efficacy, including newly emerging immunotherapy-based approaches. This review also presents important perspectives on future research directions that will guide the rational design of novel and robust nanoscale platforms to treat pancreatic tumors, particularly with respect to targeted therapies and immunotherapies. These insights will inform the next generation of clinical treatments to help patients manage this debilitating disease and enhance survival rates.

Ligand Ratio Plays a Critical Role in the Design of Optimal Multifunctional Gold Nanoclusters for Targeted Gastric Cancer Therapy

Nanodrug delivery systems (NDDSs) based on water-soluble and atomically precise gold nanoclusters (AuNCs) are under the spotlight due to their great potential in cancer theranostics. Gastric cancer (GC) is one of the most aggressive cancers with a low early diagnosis rate, with drug therapy being the primary means to overcome its increasing incidence. In this work, we designed and characterized a set of 28 targeted nanosystems based on Au₁₄₄(p-MBA)₆₀ (p-MBA = para-mercaptobenzoic acid) nanocluster to be potentially employed as combination therapy in GC treatment. The proposed multifunctional AuNCs are functionalized with cytotoxic drugs (5-fluorouracil and epirubicin) or inhibitors of different signaling pathways (phosphatidylinositol 3-kinases (PI3K)/protein kinase B (Akt)/mammalian target of the rapamycin (mTOR), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor (HIF)) and RGD peptides as targeting ligands, and we studied the role of ligand ratio in their optimal structural conformation using peptide-protein docking and all-atom molecular dynamics (MD) simulations. The results reveal that the peptide/drug ratio is a crucial factor influencing the potential targeting ability of the nanosystem. The most convenient features were observed when the peptide amount was favored over the drug in most cases; however, we demonstrated that the system composition and the intermolecular interactions on the ligand shell are crucial for achieving the desired effect. This approach helps guide the experimental stage, providing essential information on the size and composition of the nanosystem at the atomic level for ligand tuning in order to increase the desired properties.

The use of HRM shifts in qPCR to investigate a much neglected aspect of interference by intracellular nanoparticles

Genetic molecular studies used to understand potential risks of engineered nanomaterials (ENMs) are incomplete. Intracellular residual ENMs present in biological samples may cause assay interference. This report applies the high-resolution melt (HRM) feature of RT-qPCR to detect shifts caused by the presence of gold nanoparticles (AuNPs). A universal RNA standard (untreated control) sample was spiked with known amounts of AuNPs and reverse transcribed, where 10 reference genes were amplified. The amplification plots, dissociation assay (melt) profiles, electrophoretic profiles and HRM difference curves were analysed and detected interference caused by AuNPs, which differed according to the amount of AuNP present (i.e. semi-quantitative). Whether or not the assay interference was specific to the reverse transcription or the PCR amplification step was tested. The study was extended to a target gene-of-interest (GOI), Caspase 7. Also, the effect on in vitro cellular samples was assessed (for reference genes and Caspase 7). This method can screen for the presence of AuNPs in RNA samples, which were isolated from biological material in contact with the nanomaterials, i.e., during exposure and risk assessment studies. This is an important quality control procedure to be implemented when quantifying the expression of a GOI from samples that have been in contact with various ENMs. It is recommended to further examine 18S, PPIA and TBP since these were the most reliable for detecting shifts in the difference curves, irrespective of the source of the RNA, or, the point at which the different AuNPs interacted with the assay.

Flavin-adenine-dinucleotide gold complex nanoparticles: chemical modeling design, physico-chemical assessment and perspectives in nanomedicine

Flavoproteins play an important role in the regulatory process of cell life, and they are involved in several redox reactions that regulate the metabolism of carbohydrates, amino acids, and lipids. The development of effective drug delivery systems is one of the major challenges in the fight against cancer. This study involves a nanomedicine pathway to encapsulate the cofactor flavin adenine dinucleotide (FAD) using polymeric gold nanoparticles (PEG-AuNPs) through two chemical methods of functionalization (chelation (IN); carbodiimide chemistry (ON)). These hybrid gold nanoparticles and their precursors were characterized by analytical techniques (Raman, UV-Vis, and H1-NMR spectroscopy and transmission electron microscopy (TEM)) which confirmed the grafting of the cofactor agent. The results of the computational studies (Density Functional Theory (DFT)) were in agreement with the experimental observations. We also monitored the interaction of our hybrid nanoparticle systems with small aptamers (APT) in order to validate the hypotheses on the biomolecular mechanisms and also investigate their biological efficiency on pancreatic cancer cells (MIAPaCa-2 cells).

Understanding the Adsorption of Peptides and Proteins onto PEGylated Gold Nanoparticles

Polyethylene glycol (PEG) surface conjugations are widely employed to render passivating properties to nanoparticles in biological applications. The benefits of surface passivation by PEG are reduced protein adsorption, diminished non-specific interactions, and improvement in pharmacokinetics. However, the limitations of PEG passivation remain an active area of research, and recent examples from the literature demonstrate how PEG passivation can fail. Here, we study the adsorption amount of biomolecules to PEGylated gold nanoparticles (AuNPs), focusing on how different protein properties influence binding. The AuNPs are PEGylated with three different sizes of conjugated PEG chains, and we examine interactions with proteins of different sizes, charges, and surface cysteine content. The experiments are carried out in vitro at physiologically relevant timescales to obtain the adsorption amounts and rates of each biomolecule on AuNP-PEGs of varying compositions. Our findings are relevant in understanding how protein size and the surface cysteine content affect binding, and our work reveals that cysteine residues can dramatically increase adsorption rates on PEGylated AuNPs. Moreover, shorter chain PEG molecules passivate the AuNP surface more effectively against all protein types.

Investigation of Nano-Bio Interactions within a Pancreatic Tumor Microenvironment for the Advancement of Nanomedicine in Cancer Treatment

Pancreatic cancer is one of the deadliest types of cancer, with a five-year survival rate of only 10%. Nanotechnology offers a novel perspective to treat such deadly cancers through their incorporation into radiotherapy and chemotherapy. However, the interaction of nanoparticles (NPs) with cancer cells and with other major cell types within the pancreatic tumor microenvironment (TME) is yet to be understood. Therefore, our goal is to shed light on the dynamics of NPs within a TME of pancreatic origin. In addition to cancer cells, normal fibroblasts (NFs) and cancer-associated fibroblasts (CAFs) were examined in this study due to their important yet opposite roles of suppressing tumor growth and promoting tumor growth, respectively. Gold nanoparticles were used as the model NP system due to their biocompatibility and physical and chemical proprieties, and their dynamics were studied both quantitatively and qualitatively in vitro and in vivo. The in vitro studies revealed that both cancer cells and CAFs take up 50% more NPs compared to NFs. Most importantly, they all managed to retain 70–80% of NPs over a 24-h time period. Uptake and retention of NPs within an in vivo environment was also consistent with in vitro results. This study shows the paradigm-changing potential of NPs to combat the disease.

Doxorubicin (DOX) Gadolinium-Gold-Complex: A New Way to Tune Hybrid Nanorods as Theranostic Agent

INTRODUCTION

In this paper, we have designed and formulated, a novel synthesis of doxorubicin (DOX) loaded bimetallic gold nanorods in which gold salt (HAuCl4) is chelated with anthracycline (DOX), diacid polyethylene-glycol (PEG-COOH) and gadolinium salt (GdCl3 * 6 H2O) to form DOX IN-Gd-AuNRs compared with DOX ON-Gd-AuNRs in which the drug was grafted onto the bimetallic pegylated nanoparticle surface by electrostatic adsorption.

MATERIAL AND METHOD

The physical and chemical evaluation was performed by spectroscopic analytical techniques (Raman spectroscopy, UV-Visible and transmission electron microscopy (TEM)). Magnetic features at 7T were also measured. Photothermal abilities were assessed. Cytotoxicity studies on MIA PaCa-2, human pancreatic carcinoma and TIB-75 hepatocytes cell lines were carried out to evaluate their biocompatibility and showed a 320 fold higher efficiency for DOX after encapsulation.

RESULTS

Exhaustive physicochemical characterization studies were conducted showing a mid size of 20 to 40 nm diameters obtained with low polydispersity, efficient synthesis using seed mediated synthesis with chelation reaction with high scale-up, long duration stability, specific doxorubicin release with acidic pH, strong photothermal abilities at 808 nm in the NIR transparency window, strong magnetic r1 relaxivities for positive MRI, well adapted for image guided therapy and therapeutical purpose in biological tissues.

CONCLUSION

In this paper, we have developed a novel theranostic nanoparticle composed of gadolinium complexes to gold ions, with a PEG biopolymer matrix conjugated with antitumoral doxorubicin, providing multifunctional therapeutic features. Particularly, these nano conjugates enhanced the cytotoxicity toward tumoral MIAPaCa-2 cells by a factor of 320 compared to doxorubicin alone. Moreover, MRI T1 features at 7T enables interesting positive contrast for bioimaging and their adapted size for potential passive targeting to tumors by Enhanced Permeability Retention. Given these encouraging antitumoral and imaging properties, this bimetallic theranostic nanomaterial system represents a veritable promise as a therapeutic entity in the field of medicinal applications.

Brij-stabilized zein nanoparticles as potential drug carriers

The current study was designed to provide a preliminary physico-chemical characterization of zein nanosystems prepared with various Brij surfactants (for the first time to the best of our knowledge) as a function of various external stimuli such as temperature, pH, serum incubation and the freeze-drying process. The results demonstrate that when Brijs are characterized by unsaturation (C18), considerable stabilization of the colloidal structure is promoted while the length of the polyethylene glycol fraction does not significantly modulate the physico-chemical properties of the nanosystems. Specifically, dynamic light scattering and nanoparticle tracking analysis demonstrated that the use of 0.2 % w/v of Brij O10 promoted the formation of stable zein nanosystems with mean sizes of ∼150 nm and a narrow size distribution, preserving their structures at various pHs and temperatures. The use of mannitol as cryoprotectant resulted in a formulation that can easily be re-suspended in water after the freeze-drying process. This nanoformulation demonstrated that it efficiently retained different amounts of both hydrophilic and lipophilic compounds and showed a prolonged release of the entrapped molecules. In addition, the nanosystems showed a favorable degree of in vitro safety on various cell lines when a concentration <50 μg/mL of protein was used, demonstrating the potential application of Brij O10-stabilized zein nanoparticles as innovative nanocarriers of several active compounds.

Idarubicin-Gold Complex: From Crystal Growth to Gold Nanoparticles

Idarubicin (IDA) is the analog of daunorubicin (DNR). The absence of the methoxy group at position 4 of IDA remarkably improved lipophilicity, which is responsible for extra cellular uptake, higher DNA-binding ability, and considerable cytotoxicity in correlation with doxorubicin (DOX) and DNR. In this paper, we conceived two principal objectives: we realized the crystal structure of IDA by X-ray diffraction measurements on single crystals at room temperature (monoclinic, space group P2₁, a = 5.1302(2) Å, b = 9.9122(5) Å, c = 24.8868(11) Å; β = 91.425(4)°; V = 1265.14(10) ų) with refinements of the structure converged to the final R = 3.87%. The second objective has been to develop gold nanoparticles encapsulated with idarubicin through an original methodology in which gold salt (HAuCl₄) is chelated with IDA and diacid polymer (PEG) to form hybrid nanoparticles called IDA IN PEG-AuNPs in which drug solubility was enhanced. The computational studies were in agreement with the experimental observations. These hybrid nanoparticles and their precursors were analyzed by Raman, UV-Vis, ¹H NMR, and transmission electron microscopy (TEM). The main results are completed by a theoretical approach to understand the whole process.

Voltage-Gated Potassium Channels as Regulators of Cell Death

Ion channels allow the flux of specific ions across biological membranes, thereby determining ion homeostasis within the cells. Voltage-gated potassium-selective ion channels crucially contribute to the setting of the plasma membrane potential, to volume regulation and to the physiologically relevant modulation of intracellular potassium concentration. In turn, these factors affect cell cycle progression, proliferation and apoptosis. The present review summarizes our current knowledge about the involvement of various voltage-gated channels of the Kv family in the above processes and discusses the possibility of their pharmacological targeting in the context of cancer with special emphasis on Kv1.1, Kv1.3, Kv1.5, Kv2.1, Kv10.1, and Kv11.1.

Peptide directed phthalocyanine-gold nanoparticles for selective photodynamic therapy of EGFR overexpressing cancers

Gold nanoparticles, covalently functionalised with the photosensitiser C11Pc and PEG, were actively targeted towards epidermal growth factor receptor overexpressing cancers using the peptide FITC-βAAEYLRK. Selective phototoxicity was observed at nanomolar concentrations with minimal dark toxicity.

CTL-doxorubicin (DOX)-gold complex nanoparticles (DOX-AuGCs): from synthesis to enhancement of therapeutic effect on liver cancer model

In this work, we bring back a rapid way to conceive doxorubicin (DOX) hybrid gold nanoparticles, in which DOX and Au(iii) ions were complexed with a hydrochloride-lactose-modified chitosan, named CTL and dicarboxylic acid-terminated polyethylene-glycol (PEG), leading to hybrid polymer-sugar-metal nanoparticles (DOX-AuGSs). All formulations were assessed by spectroscopic techniques (Raman and UV-Vis) and transmission electron microscopy (TEM). To estimate the therapeutic effect of DOX-AuGSs in liver cancer, murine HepG2 cells were used to induce a hepatic carcinoma model in nude mice. The survival time of the tumor-bearing mice, body weight and tumor volume were measured and recorded. The cytokines were used to detect the serum inflammatory factors, and the blood cell analyzer was used to determine the blood cell content of different groups of nude mice. The outcomes demonstrate that DOX-AuGCs significantly suppressed the tumor growth derived from human HepG2 injection and reduce the tumor index without affecting the body weight of mice. Moreover, DOX-AuGCs significantly reduced the serum levels of cytokines IL-6, TNF-α and IL-12 P70. Finally, a histological analysis of the heart tissue sections indicated that DOX-AuGCs significantly reduce the chronic myocardial toxicity of DOX during the period of treatment.

Lenalidomide (LENA) Hybrid Gold Complex Nanoparticles: Synthesis, Physicochemical Evaluation, and Perspectives in Nanomedicine

This paper proposes a fast methodology to synthesize hybrid lenalidomide gold nanoparticles. Gold (HAuCl₄) is chelated with an antiangiogenic compound (lenalidomide (LENA)) and diacid poly(ethylene glycol) (PEG) as capping agent and reagent. The suggested synthesis is rapid and results in gold nanoparticles (AuNPs) with enhanced drug solubility. The binding between LENA, PEG, and Au(III) ions forms hybrid nanovectors named LENA IN PEG-AuNPs, which were characterized by different spectroscopic techniques (Raman and UV-vis), transmission electron microscopy (TEM), and compared with LENA ON PEG-AuNPs, in which the drug was grafted onto gold surface by carbodiimide chemistry (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide, EDC/NHS). The effective drug delivery under pH conditions was also reached, combined with doxorubicin (DOX) to improve the synergic chemotherapy and stability under experimental conditions. For biomedical purposes, hybrid gold nanocarriers were conjugated with folic acid (FA), which is specifically overexpressed in cancer cells. This paper will be very important in the domain of therapeutic gold complex, paving the way for reaching progress of novel drug carrier synthesis in nanomedicine.

Active targeting of gold nanoparticles as cancer therapeutics

Gold nanoparticles (AuNPs) are of increasing interest for their unique properties and their biocompatability, minimal toxicity, multivalency and size tunability make them exciting drug carriers. The functionalisaton of AuNPs with targeting moieties allows for their selective delivery to cancers, with antibodies, proteins, peptides, aptamers, carbohydrates and small molecules all exploited. Here, we review the recent advances in targeted-AuNPs for the treatment of cancer, with a particular focus on these classes of targeting ligands. We highlight the benefits and potential drawbacks of each ligand class and propose directions in which the field could grow.

Neuroblastoma-targeted nanoparticles and novel nanotechnology-based treatment methods

Neuroblastoma is a complicated pediatric tumor, originating from the neural crest, which is the most prevalent in adrenal glands, but may rarely be seen in some other tissues as well. Studies are focused on developing new strategies through novel chemo- and immuno-therapeutic drug targets. Different types of oncogenes such as MYCN, tumor suppressor genes such as p53, and some structural genes such as vascular endothelial growth factor are considered as targets for neuroblastoma therapy. The individual expression patterns in NB cells make them appropriate for this purpose. The combined effect of nano-drug delivery systems and specific drug targets will result in lower systemic side effects, prolonged therapeutic effects, and improvements in the pharmacokinetic properties of the drugs. Some of these novel drug delivery systems with a focus on liposomes as carriers are also discussed. In this review, genes and protein products that are beneficial as drug targets in the treatment of neuroblastoma have been discussed.

Denaturant-Mediated Modulation of the Formation and Drug Encapsulation Responses of Gold Nanoparticles

The extensive and diversified applications of the well-known plasmonic nanoparticle systems along with their easy and environment-friendly synthesis strategies drive us to investigate in-depth this important research field. In the current scenario, our present study deals with an important plasmonic nanomaterial, i.e., globular protein, and human serum albumin (HSA)-conjugated gold nanoparticle (HSA-Au NP) system. The well-known chemical denaturants, urea and guanidine hydrochloride (GdnHCl or GnHCl), are investigated to show detrimental effects toward the formation of gold nanoparticles; however, the effect of GdnHCl is observed to be much prominent compared to that of urea. The synthesized nanoparticle system is found to be highly biocompatible from the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based cytotoxicity assay, and therefore, the applications of encapsulation of the well-known anticancer drug molecule, doxorubicin hydrochloride (Dox), in the nanoparticle system are further studied. In this drug encapsulation study, drug-metal complexation between Dox and HAuCl₄·3H₂O has been discussed elaborately. Similar to the nanoparticle formation, the effects of denaturants on drug encapsulation have also been discovered, and interestingly, it has been observed that urea plays a positive role, whereas GdnHCl plays a negative or detrimental role toward drug encapsulation in the synthesized gold nanoparticle system. The detailed photophysical mechanisms behind the drug encapsulation in the synthesized plasmonic nanosystem at every stage have also been explored. Overall, this study will conclusively explain the influences of the extensively used chemical denaturants on the synthesis and drug encapsulation behaviors of a well-known protein-conjugated gold nanoparticle, and as a consequence, it can be highly useful and acceptable to the biomedical and pharmaceutical research communities.

Temozolomide, Gemcitabine, and Decitabine Hybrid Nanoconjugates: From Design to Proof-of-Concept (PoC) of Synergies toward the Understanding of Drug Impact on Human Glioblastoma Cells

This paper emphasizes the synthesis of novel hybrid drug nanoparticles (Hyb-D-AuNPs) based on gold-temozolomide (TMZ) complexes combined with gemcitabine (GEM) and decitabine (DAC) to improve the efficiency and reduce the resistance of U87 malignant glial cells against TMZ. All products were evaluated by several spectroscopic techniques (Raman, UV-Vis) and transmission electron microscopy (TEM). Besides, for therapeutic purposes, the effect of these nanoparticles on cell proliferation and toxicity was evaluated, which clearly showed a synergic action of TMZ and GEM. Through the analysis of the exometabolome by nuclear magnetic resonance (NMR), the metabolic changes in the culture medium were measured in glial cells. Moreover, these nanoparticles are especially appropriated to the thermal destruction of cancer in the case of photothermal therapy due to their photothermal heating properties. This study presents an original chemical approach that it could play a central role in the field of nanomedicine, with novel perspectives for the development of new drugs and active targeting in glioblastoma multiforme (GBM) cancer therapy.

Aptamer-Gold(III) Complex Nanoparticles: A New Way to Detect Cu, Zn SOD Glycoprotein

Aptamers are small biomolecules composed of 20-100 nucleotides that recognize target molecules in three-dimensional structures. These natural targeting molecules have attracted interest in the biomedical field as biomarkers for cancer diagnostics. In this study, we investigated the interaction of a characteristic aptamer with its target protein, Cu, Zn superoxide dismutase (SOD 4), on a gold nanoparticle (AuNP) surface under experimental conditions. For this purpose, we applied two protocols to coat SOD 4 aptamer (APT) on the nanoparticle surface: carbodiimide chemistry (EDC/NHS) (Method ON) and a complexation methodology (Method IN). The nano-aptamer's interactions with SOD 4 were detected by UV-vis absorption and Raman spectroscopy in a range of protein concentrations (from 1 μM to 50 nM). We believe that the interaction is heavily dependent on the nature of the biomarker (SOD 4) and also on the steric arrangement of the aptamer on the gold nanoparticle surface. The lowest detectable concentration (limit of detection, LOD) was about 2 nM for APT IN PEG-AuNPs and 8 nM for APT ON PEG-AuNPs. For the first time, we demonstrated a very sensitive detection of SOD 4 in the nanomolar concentration range with new ways of biosensor synthesis (APT IN and ON), providing a very strong tool to understand the effect of aptamer conformation to detect SOD 4.

Polymer nanoparticle-assisted chemotherapy of pancreatic cancer

Pancreatic cancer is a lethal disease characterized by highly dense stroma fibrosis. Only 15-20% of patients with pancreatic cancer have resectable tumors, and only around 20% of them survive to 5 years. Traditional cancer treatments have little effect on their prognosis, and successful surgical resection combined with effective perioperative therapy is the main method for maximizing long-term survival. For this reason, chemotherapy is an adjunct treatment for resectable cancer and is the main therapy for incurable pancreatic cancer, including metastatic pancreatic adenocarcinoma. However, there are various side effects of chemotherapeutic medicine and low drug penetration because the complex tumor microenvironment limits the application of chemotherapy. As a novel strategy, polymer nanoparticles make it possible to target the tumor microenvironment, release cytotoxic agents through various responsive reactions, and thus overcome the treatment barrier. As drug carriers, polymer nanoparticles show marked advantages, such as increased drug delivery and efficiency, controlled drug release, decreased side effects, prolonged half-life, and evasion of immunogenic blockade. In this review, we discuss the factors that cause chemotherapy obstacles in pancreatic cancer, and introduce the application of polymer nanoparticles to treat pancreatic cancer.

Nanomedicines in Diagnosis and Treatment of Cancer: An Update

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Nanomedicine has revolutionized the field of cancer detection and treatment by enabling the delivery of imaging agents and therapeutics into cancer cells. Cancer diagnostic and therapeutic agents can be either encapsulated or conjugated to nanosystems and accessed to the tumor environment through the passive targeting approach (EPR effect) of the designed nanomedicine. It may also actively target the tumor exploiting conjugation of targeting moiety (like antibody, peptides, vitamins, and hormones) to the surface of the nanoparticulate system. Different diagnostic agents (like contrast agents, radionuclide probes and fluorescent dyes) are conjugated with the multifunctional nanoparticulate system to achieve simultaneous cancer detection along with targeted therapy. Nowadays targeted drug delivery, as well as the early cancer diagnosis is a key research area where nanomedicine is playing a crucial role. This review encompasses the significant recent advancements in drug delivery as well as molecular imaging and diagnosis of cancer exploiting polymer-based, lipid-based and inorganic nanoparticulate systems.

Thiol-Poly(Sodium Styrene Sulfonate) (PolyNaSS-SH) Gold Complexes: From a Chemical Design to a One-Step Synthesis of Hybrid Gold Nanoparticles and Their Interaction with Human Proteins

This study highlights recent advances in the synthesis of nanoconjugates based on gold (Au(III)) complex with a bioactive polymer bearing sulfonate groups called thiol-poly(sodium styrene sulfonate) (PolyNaSS-SH) with various molecular weights (5, 10, and 35 kDa). The three nanomaterials differ substantially in shape and structure. In particular, for PolyNaSS-SH of 35 kDa, we obtained a characteristic core-shell flower shape after chelation of the Au(III) ions and successively reduction with sodium borohydride (NaBH₄). The mechanism of formation of the hybrid nanoparticles (PolyNaSS-SH@AuNPs (35 kDa) and their interactions between plasmatic proteins (human serum albumin (HSA), collagen I (Col 1), and fibronectin (Fn)) were deeply studied from a chemical and physical point of view by using several analytical techniques such as Raman spectroscopy, UV-visible, transmission electron microscopy (TEM), ¹H NMR, and X-ray photoelectron spectroscopy (XPS).

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.

Sizing up the Next Generation of Nanomedicines

During the past two decades the nanomedicine field has experienced significant progress. To date, over sixty nanoparticle (NP) formulations have been approved in the US and EU while many others are in clinical or preclinical development, indicating a concerted effort to translate promising bench research to commercially viable pharmaceutical products. The use of NPs as novel drug delivery systems, for example, can improve drug safety and efficacy profiles and enable access to intracellular domains of diseased cells, thus paving the way to previously intractable biological targets. However, the measurement of their physicochemical properties presents substantial challenges relative to conventional injectable formulations. In this perspective, we focus exclusively on particle size, a core property and critical quality attribute of nanomedicines. We present an overview of relevant state-of-the-art technologies for particle sizing, highlighting the main parameters that can influence the selection of techniques suitable for a specific size range or material. We consider the increasing need, and associated challenge, to measure size in physiologically relevant media. We detail the importance of standards, key to validate any measurement, and the need for suitable reference materials for processes used to characterize novel and complex NPs. This perspective highlights issues critical to achieve compliance with regulatory guidelines and to support research and manufacturing quality control.

Design and Synthesis of Gold-Gadolinium-Core-Shell Nanoparticles as Contrast Agent: a Smart Way to Future Nanomaterials for Nanomedicine Applications

INTRODUCTION

The development of biopolymers for the synthesis of Gd(III) nanoparticles, as therapeutics, could play a key role in nanomedicine. Biocompatible polymers are not only used for complex monovalent biomolecules, but also for the realization of multivalent active targeting materials as diagnostic and/or therapeutic hybrid nanoparticles. In this article, it was reported for the first time, a novel synthesis of Gd(III)-biopolymer-Au(III) complex, acting as a key ingredient of core-shell gold nanoparticles (Gd(@AuNPs).

MATERIAL AND METHODS

The physical and chemical evaluation was carried out by spectroscopic analytical techniques (Raman spectroscopy, UV-visible and TEM). The theoretical characterization by DFT (density functional theory) analysis was carried out under specific conditions to investigate the interaction between the Au and the Gd precursors, during the first nucleation step. Magnetic features with relaxivity measurements at 7T were also performed as well as cytotoxicity studies on hepatocyte cell lines for biocompatibility studies. The in vivo detailed dynamic biodistribution studies in mice to characterize the potential applications for biology as MRI contrast agents were then achieved.

RESULTS

Physical-chemical evaluation confirms the successful design and reaction supposed. Viabilities of TIB-75 (hepatocytes) cells were evaluated using Alamar blue cytotoxic tests with increasing concentrations of nanoparticles. In vivo biodistribution studies were then accomplished to assess the kinetic behavior of the nanoparticles in mice and characterize their stealthiness property after intravenous injection.

CONCLUSION

We demonstrated that Gd@AuNPs have some advantages to display hepatocytes in the liver. Particularly, these nanoconjugates give a good cellular uptake of several quantities of Gd@NPs into cells, while preserving a T1 contrast inside cells that provide a robust in vivo detection using T1-weighted MR images. These results will strengthen the role of gadolinium as complex to gold in order to tune Gd(@AuNPs) as an innovative diagnostic agent in the field of nanomedicine.

Present Scenario of Bioconjugates in Cancer Therapy: A Review

Cancer is one of the deadliest diseases and poses a risk to people all over the world. Surgery, chemo, and radiation therapy have been the only options available until today to combat this major problem. Chemotherapeutic drugs have been used for treatment for more than 50 years. Unfortunately, these drugs have inherent cytotoxicities and tumor cells have started inducing resistance against these drugs. Other common techniques such as surgery and radiotherapy have their own drawbacks. Therefore, such techniques are incompetent tools to alleviate the disease efficiently without any adverse effects. This scenario has inspired researchers to develop alternative techniques with enhanced therapeutic effects and minimal side effects. Such techniques include targeted therapy, liposomal therapy, hormonal therapy, and immunotherapy, etc. However, these therapies are expensive and not effective enough. Furthermore, researchers have conjugated therapeutic agents or drugs with different molecules, delivery vectors, and/or imaging modalities to combat such problems and enhance the therapeutic effect. This conjugation technique has led to the development of bioconjugation therapy, in which at least one molecule is of biological origin. These bioconjugates are the new therapeutic strategies, having prospective synergistic antitumor effects and have potency to overcome the complications being produced by chemo drugs. Herein, we provide an overview of various bioconjugates developed so far, as well as their classification, characteristics, and targeting approach for cancer. Additionally, the most popular nanostructures based on their organic or inorganic origin (metallic, magnetic, polymeric nanoparticles, dendrimers, and silica nanoparticles) characterized as nanocarriers are also discussed. Moreover, we hope that this review will provide inspiration for researchers to develop better bioconjugates as therapeutic agents.

Galectin-1 protein modified gold (III)-PEGylated complex-nanoparticles: Proof of concept of alternative probe in colorimetric glucose detection

Galectins (Gal) are a family of dimeric lectins, composed by two galactoside-binding sites implicated in the regulation of cancer progression and immune responses. In this study, we report for the first time the synthesis and the physical-chemical characterization of galectin-1-complex-gold COOH-terminated polyethlenglicole (PEG)-coated NPs (Gal-1 IN PEG-AuNPs) and their ability to recognize glucose in an aqueous solution with a concentration varying from 10 mM to 100 pM. The chemical protocol consistsof three steps: (i) complexation between galectin-1Gal-1 and tetrachloroauric acid (HAuCl₄) to form gold-protein grains; (ii) staking process of COOH-terminated polyethlenglicole molecules (PEG) onto Gal-1-Au complex and (iii) reduction of hybrid metal ions to obtain a colloidal stable solution. During the complexation, the spectral signatures related to the Gal-1 orientation on the gold surface have been found to change due to its protonation state. The effective glucose monitoring was detected by UV-vis, Raman spectroscopy and Transmission Electron Microscopy (TEM). Overall, we observed that the interaction is strongly dependent on the Gal-1 conformation at the surface of gold nanoparticles.

Study of gold nanoparticles for mammography diagnostic and radiotherapy improvements

Aim

A study on the possibility to use gold nanoparticles in mammography, both for a better image diagnostics and radiotherapy, is presented and discussed. We evaluate quantitatively the increment of dose released to the tumor enriched with Au-NPs with respect to the near healthy tissues, finding that for X-rays the increase can reach two orders of greater intensity.

Background

Gold nanoparticles continue to be investigated for their potential to improve existing therapies and to develop novel therapies. They are simple to obtain, can be functionalized with different chemical approaches, are stable, non-toxic, non-immunogenic and have high permeability and retention effects in the tumor cells. The possibility to use these for breast calcified tumors to be better treated by radiotherapy is presented as a possible method to destroy the tumor.

Materials and methods

The nanoparticles can be generated in water using the top-down method, should have a size of the order of 10-20 nm and be treated to avoid their coalescence. Under diagnostic X-ray monitoring, the solution containing nanoparticles can be injected locally inside the tumor site avoiding injection in healthy tissues. The concentrations that can be used should be of the order of 10 mg/ml or higher.

Results

An enhancement of the computerized tomography diagnostics using 80-150 keV energy is expected, due to the higher mass X-ray coefficient attenuation with respect to other contrast media. Due to the increment of the effective atomic number of the biological tissue containing the gold nanoparticles, also an improvement of the radiotherapy effect using about 30 keV X-ray energy is expected, due to the higher photoelectric cross sections involved.

Conclusions

The study carried out represents a feasibility proposal for the use of Au-nanoparticles for mammographic molecular imaging aimed at radiotherapy of tumor nodules but no clinical results are presented.

Development of resveratrol-conjugated gold nanoparticles: interrelationship of increased resveratrol corona on anti-tumor efficacy against breast, pancreatic and prostate cancers

Background: As part of our continuing quest to enhance the efficacy of bioactive phytochemicals in cancer therapy, we report an innovative green nanotechnology approach toward the use of resveratrol for the production of biocompatible resveratrol-conjugated gold nanoparticles (Res-AuNPs). Our overarching aim is to exploit the inherent pro-apoptotic properties of gold nanoparticles (AuNPs) through synergistic anti-tumor characteristics of resveratrol, with the aim of developing a new class of green nanotechnology-based phytochemical-embedded AuNPs for applications in oncology.

Method: Resveratrol was used to reduce Au³⁺ to Au⁰ for the synthesis of Res-AuNPs at room temperature and gum arabic (GA) was used to further encapsulate the nanoparticulate surface to increase the overall stability of the AuNPs. This comprehensive study involves the synthesis, full characterization and in vitro stability of Res-AuNPs in various biological media for their ultimate applications as anti-cancer agents against human breast (MDAMB-231), pancreatic (PANC-1) and prostate (PC-3) cancers.

Results: This strategy to systematically increase the corona of resveratrol on AuNPs, in order to gain insights into the interrelationship of the phytochemical corona on the overall anti-tumor activities of Res-AuNPs, proved successful. The increased resveratrol corona on Res-AuNPs showed superior anti-cancer effects, attributed to an optimal cellular uptake after 24-hour incubation, while GA provided a protein matrix support for enhanced trans-resveratrol loading onto the surface of the AuNPs.

Conclusion: The approach described in this study harnesses the benefits of nutraceuticals and nanoparticles toward the development of Res-AuNPs. We provide compelling evidence that the increased corona of resveratrol on AuNPs enhances the bioavailability of resveratrol so that therapeutically active species can be optimally available in vivo for applications in cancer therapy.

Design and Synthesis of Hybrid PEGylated Metal Monopicolinate Cyclam Ligands for Biomedical Applications

In this study, we report, for the first time, the synthesis of two original nanosystems, based on gold Au(III) and copper Cu(II): simple gold-copper nanoparticles (Cu⁰AuNPs) and enriched monopicolinate cyclam (L1)-Cu(II)-Au(III)-complex (L1@Cu²⁺AuNPs). The two nanomaterials differ substantially by the chelation or not of the Cu(II) ions during the NPs synthesis process. The two hybrid nanoparticles (Cu⁰AuNPs; L1@Cu²⁺AuNPs) were deeply studied from the chemical and physical point of view, using many different analytical techniques such as Raman and UV-vis spectroscopy, electron transmission microscopy, and dynamic light scattering. Both nanosystems show morphological and good chemical stability at pH 4 values and in physiological conditions during 98 h. Undifferentiated and neural differentiated murine embryonic stem cells were used as a model system for in vitro experiments to reveal the effects of NPs on these cells. The comparative study between Cu⁰AuNPs and L1@Cu²⁺AuNPs highlights that copper chelated in its +2 oxidation state in the NPs is more functional for biological application.

A protein corona study by scattering correlation spectroscopy: a comparative study between spherical and urchin-shaped gold nanoparticles

The study of protein interactions with gold nanoparticles (GNP) is a key step prior to any biomedical application. These interactions depend on many GNP parameters such as size, surface charge, chemistry, and shape. In this work, we propose to use a sensitive technique named scattering correlation spectroscopy or SCS to study protein interactions with GNP. SCS allowed the investigation of the GNP hydrodynamic radius with a very high sensitivity before and after interaction with proteins. No labeling is needed. As a proof-of-concept, two of the most used morphologies of GNP-based nanovectors have been used within this work: spherical-shaped GNP (GNS) and branched-shaped GNP (GNU). The measurement of several parameters such as the number of proteins binding to one GNP, the binding affinity and the cooperativeness of binding for three different plasma proteins on the GNP surface was carried out. While GNS showed an increase in the hydrodynamic radius, indicating that each kind of protein binds on the GNS in a specific orientation, GNU showed different orientations of proteins due to their multi-oriented surfaces (tips) with a higher surface to volume area. Quantitative data based on the Hill model were extracted to obtain the affinity of the proteins to both GNS and GNU surfaces. Data variations can be understood in terms of the electrostatic properties of the proteins, which interact differently with the negatively charged GNP surfaces.

Doxorubicin and Anti-PD-L1 Antibody Conjugated Gold Nanoparticles for Colorectal Cancer Photochemotherapy

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The prognosis and overall survival of CRC are known to be significantly correlated with the overexpression of PD-L1. Since combination therapies can significantly improve therapeutic efficacy, we constructed doxorubicin (DOX) conjugated and anti-PD-L1 targeting gold nanoparticles (PD-L1-AuNP-DOX) for the targeted chemo-photothermal therapy of CRC. DOX and anti-PD-L1 antibody were conjugated to the α-terminal end group of lipoic acid polyethylene glycol N-hydroxysuccinimide (LA-PEG-NHS) using an amide linkage, and PD-L1-AuNP-DOX was constructed by linking LA-PEG-DOX, LA-PEG-PD-L1, and a short PEG chain on the surface of AuNP using thiol-Au covalent bonds. Physicochemical characterizations and biological studies of PD-L1-AuNP-DOX were performed in the presence of near-infrared (NIR) irradiation (biologic studies were conducted using cellular uptake, apoptosis, and cell cycle assays in CT-26 cells). PD-L1-AuNP-DOX (40.0 ± 3.1 nm) was successfully constructed and facilitated the efficient intracellular uptake of DOX as evidenced by pronounced apoptotic effects (66.0%) in CT-26 cells. PD-L1-AuNP-DOX treatment plus NIR irradiation significantly and synergistically suppressed the in vitro proliferation of CT-26 cells by increasing apoptosis and cell cycle arrest. The study demonstrates that PD-L1-AuNP-DOX in combination with synergistic targeted chemo-photothermal therapy has a considerable potential for the treatment of localized CRC.

Ion channels as therapeutic antibody targets

It is now well established that antibodies have numerous potential benefits when developed as therapeutics. Here, we evaluate the technical challenges of raising antibodies to membrane-spanning proteins together with enabling technologies that may facilitate the discovery of antibody therapeutics to ion channels. Additionally, we discuss the potential targeting opportunities in the anti-ion channel antibody landscape, along with a number of case studies where functional antibodies that target ion channels have been reported. Antibodies currently in development and progressing towards the clinic are highlighted.