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Melanoma is a type of skin cancer that can be challenging to treat, especially in advanced stages. Radiotherapy is one of the main treatment modalities for melanoma, but its efficacy can be limited due to the radioresistance of melanoma cells. Recently, there has been growing interest in using high-Z metal nanoparticles (NPs) to enhance the effectiveness of radiotherapy for melanoma. This review provides an overview of the current state of radiotherapy for melanoma and discusses the physical and biological mechanisms of radiosensitization through high-Z metal NPs. Additionally, it summarizes the latest research on using high-Z metal NPs to sensitize melanoma cells to radiation, both in vitro and in vivo. By examining the available evidence, this review aims to shed light on the potential of high-Z metal NPs in improving radiotherapy outcomes for patients with melanoma. Graphical Abstract Article highlights Melanoma, a lethal skin cancer from melanocytes, causes 75% of skin cancer-related deaths worldwide. Rising incidence necessitates urgent interventions. Traditional treatments like surgery, chemotherapy, immunotherapy and radiotherapy (RT) have limitations. Nanomedicine, using nanoparticles (NPs) sized 1–100 nm, shows promise in enhancing cancer treatment, especially high-Z metal NPs (e.g., gold, platinum, gadolinium) in improving RT outcomes for melanoma. Radiotherapy for melanoma RT is vital for melanoma management, especially when surgery is not viable or cancer has spread. Combining RT with immune checkpoint inhibitors (ICI) improves outcomes in brain metastases. Fractionated RT enhances T cell responses, similar to vaccines. Studies suggest higher radiation doses may be more effective, with clinical studies indicating a median total dose of 30 Gy and BED >39.0 Gy10. High-Z metal NPs can enhance RT by targeting cancer cells precisely while sparing healthy tissue. High-Z metal NPs for radiotherapy of melanoma High-Z metal NPs like gold, magnetic iron oxide, gadolinium, copper-cysteamine and platinum enhance RT efficacy while preserving healthy tissue. Gold NPs enhance RT through unique properties like surface plasmon resonance. mIONs offer RT combined with hyperthermia, enhancing therapeutic outcomes. Gadolinium enhances MRI and RT, with AGuIX® NPs allowing precise imaging and targeted therapy. Other high-Z metals like copper-cysteamine and platinum enhance ROS production, improving treatment outcomes. Nanoparticle physicochemistry & radiosensitization Key design factors include material, size, shape, surface coating and charge. NP size affects biodistribution and clearance, with optimal sizes for tumor uptake being 20–60 nm. NP concentration and surface charge impact RT enhancement and cytocompatibility. Synthesis methods, including chemical, physical and green, ensure biocompatibility and reduced toxicity. Coatings improve stability and targeting, essential for passive and active strategies, enhancing treatment efficacy. Mechanisms of High-Z Metal NPs radiosensitization Radiosensitization involves physical, chemical and biological phases. High-Z metal NPs enhance RT through the photoelectric effect and sary electron production, increasing local radiation doses. They modulate chemical reactions, enhancing DNA damage and ROS production. Biologically, NPs disrupt cell cycles, delay DNA repair and induce oxidative stress, increasing tumor cell radiosensitivity. Conclusion High-Z metal nanoparticles show significant promise in enhancing radiotherapy for melanoma. Benefits include efficient x-ray absorption, targeted delivery and induction of oxidative stress. Key challenges like ensuring biocompatibility, understanding mechanisms and optimizing NP design need addressing before clinical translation. Continued research is essential for developing effective and safe NP-based therapies. Future perspectives Future prospects include using NPs for targeted radiation doses to melanoma cells, optimizing delivery strategies and conducting preclinical and clinical studies to validate efficacy and safety. Continued innovations in nanomedicine could lead to more targeted, effective and personalized cancer treatments, transforming oncology. [ABSTRACT FROM AUTHOR]

Background: Salmonella, is one of the most important pathogens causing foodborne illnesses worldwide. The early detection of Salmonella is essential to minimize the risk. Herein, the nanoprobe (CS-AuNPs@phage-T156) for Salmonella was obtained by functionalizing cysteamine (CS) stabilized gold nanoparticles (CS-AuNPs) with phage T156. Results: In the presence of target Salmonella, the CS-AuNPs@phage-T156 specifically recognized and adsorbed on the surface of Salmonella, then induced the aggregation of gold nanoparticles and the color changes from red to purple, which enabled visual detection. The concentration of Salmonella was quantified by the absorption ratio (A680/A526), with a wide linear range from 1.2 × 101 CFU/mL to 1.2 × 106 CFU/mL. Under the optimal experimental conditions, this assay possessed a potent selectivity characteristic quickly toward Salmonella, with a detection limit of 12 CFU/mL. Conclusion: This simple and rapid detection method is expected to provides a novel identification element for the detection of Salmonella by intuitive visualization judgment and quantitative analysis. [ABSTRACT FROM AUTHOR]

Gold nanoparticles are extensively used across various industries, particularly in biomedical fields, due to their high biocompatibility, stability, and low toxicity. The rising use of gold nanoparticles in biomedical applications has increased the demand for more sustainable synthesis methods that reduce costs and environmental impacts compared to traditional chemical processes. This study presents a green synthesis approach utilizing leaf extracts from Pterospermum canescens and Vernonia elaeagnifolia. The synthesized nanoparticles were characterized using UV‐VIS, XRD, HRTEM‐SAED, FESEM‐EDX, XPS, and FTIR analyses. These characterizations confirmed the formation, size, shape, and morphological features of the nanoparticles, as well as the involvement of secondary plant metabolites in their synthesis. The nanoparticles were found to be less than 50 nm in size, with P.C AuNPs averaging 27.48 nm and V.E AuNPs averaging 14.79 nm. The particles predominantly exhibited spherical or distorted spherical shapes. In cytotoxicity assays using C6 rat glioma cells, both types of nanoparticles demonstrated significant effects. V.E AuNPs induced apoptosis in 78 % of the cells, while P.C AuNPs induced apoptosis in 50 %, confirming their cytotoxic efficacy. Gene expression studies further revealed that V.E AuNPs significantly upregulated caspase‐3 and downregulated BCL‐2, indicating a potent apoptotic response, while P.C AuNPs showed a similar but less pronounced effect. Additionally, in collagen‐induced platelet aggregation studies, V.E AuNPs exhibited substantial anti‐platelet activity with increasing dosages, reducing platelet aggregation to less than 10 % at a concentration of 30 μg/ml, compared to minimal inhibition by P.C AuNPs. Overall, the study demonstrates that gold nanoparticles synthesized from Vernonia elaeagnifolia and Pterospermum canescens are effective and offer promising applications in biomedicine. The results confirm the potential of these green‐synthesized nanoparticles for use in cancer treatment and sustainable anti‐platelet drug development [ABSTRACT FROM AUTHOR]

Background: The SARS-CoV-2 pandemic has highlighted niclosamide (NIC) as a promising treatment for COVID-19. However, its clinical application is limited due to its poor water solubility, resulting in low bioavailability. Methods: To address this issue, we developed a AuNP-HA-NIC system, which combines gold nanoparticles with hyaluronic acid to enhance drug delivery. Our comprehensive characterization of the system revealed that hyaluronic acid with specific molecular weights, particularly those exposed to electron-beam irradiation between 2 and 20 kGy, produced the most stable nanoparticles for efficient drug loading and delivery. Results: Additionally, the AuNP-HA-NIC system exhibits a significant sensitivity to pH changes, which is a critical feature for targeted drug release. Under acidic conditions mimicking the stomach and small intestine, minimal drug release was observed, indicating the effective prevention of premature drug release in the gastrointestinal tract. Furthermore, the integration of a targeting aptamer established specific binding abilities towards the SARS-CoV-2 spike protein, distinguishing it from other coronaviruses. Conclusions: As research progresses, and with further in vivo testing and optimization, the AuNP-HA-NIC–aptamer system holds great promise as a game-changer in the field of antiviral therapeutics, particularly in the battle against COVID-19. [ABSTRACT FROM AUTHOR]

Microfluidic‐assisted synthesis of nanoparticles has generated significant interest for its precise control and high throughput capabilities. Among various nanomaterials, gold nanoparticles (AuNPs) have shown remarkable potential in numerous applications, such as disease detection, photothermotherapy, drug delivery, and even defense applications. Recent synthesis strategy of peptide‐mediated method has sparked greater interest by offering unique chiroptical properties and their applications in biomedical applications. In this study, the use of droplet microfluidics is explored for the synthesis of peptide‐mediated AuNPs, aiming to accelerate automated production via flow chemistry. This method leads to the formation of anisotropic gold particles, with sizes ranging from hundreds of nanometers to the micron scale. The interfacial energy is identified at the water/oil interface as a critical factor influencing this outcome, with L‐glutathione (L‐GSH) playing a significant role in the development of hyper‐branched structures. These results demonstrate the capability of droplet microfluidics in producing anisotropic gold particles at micron scales, presenting new possibilities for the advancement of nanoparticle synthesis techniques. [ABSTRACT FROM AUTHOR]

The basis of most neurological syndromes is the accumulation of free radical molecules. Quercetin is a polyphenolic bioflavonoid molecule and it has a very strong antioxidant effect by maintaining oxidative balance. There are many difficulties in the clinical use of quercetin due to its hydrophobic structure, low solubility, instability, poor oral bioavailability, and limited tissue-barrier penetration. Its synergistic use in complex with gold nanoparticles (AuNPs) could overcome these problems. AuNPs have recently emerged as an attractive candidate for delivery applications of various biomolecules and drugs. The aim of this study was to synthesize two different sized gold nanoparticles (AuNP 20 and AuNP 50) modified with polyethyleneimine (PEI) and quercetin, evaluate their potential neuroprotective effects on the in vitro oxidative stress model using DRG primary sensory neurons. It was shown that the antioxidant and anti-apoptotic ability of the bioflavonoid was preserved after exposure to the designed quercetin modified AuNPs. The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. It also potentially enables additional surface functionalization. This study indicates that designed nanoparticles (AuNP-Q-PEI) with different sizes could be a useful potential platform for the treatment of neurodegenerative syndromes or cancer diseases. Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. Designed nanoplatform (AuNPs-Q-PEI) increased stability and biocompatibility. After nanomaterial exposure in the oxidative stress model of the DRG sensory neurons, the level of ROS and apoptosis was significantly reduced. [Display omitted] • Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. • The antioxidant property of the bioflavonoid was preserved after exposure to designed Q-coated AuNPs in the DRG neurons. • The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. • The designed gold nanoconjugates could be a useful potential nanoplatform for the treatment of neurodegenerative syndromes. [ABSTRACT FROM AUTHOR]

Fluorescent molecules have enabled single-molecule detection of toxins, biomarkers, and pollutants under controlled conditions. Unfortunately, these fluorophores are typically organic molecules that degrade or become photobleached when applied to non-ideal systems. Noble metal nanoclusters, in particular gold nanoclusters (AuNCs), pose a solution to the problems of degradation and photobleaching. Despite the low fluorescence quantum yield of AuNCs without thiolated ligands, labeling these clusters with fluorescent ligands allows enhancement of the fluorescence intensity and manipulation of the emission wavelength. In this work, we explore the labeling of the bi-icosahedron Au25 (bi-Au25) nanocluster. The bi-Au25 nanocluster has unique stability and electrochemical properties making it an attractive, yet poorly studied, candidate for fluorescent labeling. In order to demonstrate its potential as a near-IR emitting nanocluster we synthesized and labeled the bi-Au25 with the novel fluorophore 6-(9-Anthryl)-5-hexyne-1-thiol, or simply anthracenethiol. Two common ligands used in the synthesis of bi-Au25 are hexanethiol and phenylethanethiol, and we spectroscopically verify the ability for the straight-chain alkane hexanethiol to block the labeling of bi-Au25, while the aromatic phenylethanethiol enables the labeling of the complex. These products are characterized with square wave voltammetry, UV-vis and fluorescence spectrophotometry, and NMR spectrometry. The fluorescently labeled bi-Au25 nanocluster demonstrates a 25x increase in NIR photoluminescence at ~ 810 nm when originally capped with phenylethanethiol, and not the long-chain alkanethiol. The quantum yield of this cluster has been improved from 0.0786% in the unlabeled cluster to 1.97% in the labeled product. [ABSTRACT FROM AUTHOR]

Cancer is one of the major threats to human health and lives. However, effective cancer treatments remain a great challenge in clinical medicine. As a common approach for cancer treatment, chemotherapy has saved the life of millions of people; however, patients who have gone through chemotherapy often suffer from severe side effects owing to the inherent cytotoxicity of anti-cancer drugs. Stabilizing the blood concentration of an anti-cancer drug will reduce the occurrence or severity of side effects, and relies on using an appropriate drug delivery system (DDS) for achieving sustained or even on-demand drug delivery. However, this is still an unmet clinical challenge since the mainstay of anti-cancer drugs is small molecules, which tend to be diffused rapidly in the body, and conventional DDSs exhibit the burst release phenomenon. Here, we establish a class of DDSs based on biodegradable core–shell microspheres with encapsulated doxorubicin hydrochloride-loaded gold nanoparticles (DOX@Au@MSs), with the core–shell microspheres being made of poly(lactic-co-glycolic acid) in the current study. By harnessing the physical barrier of the biodegradable shell of core–shell microspheres, DOX@Au@MSs can provide a sustained release of the anti-cancer drug in the test duration (which is 21 days in the current study). Thanks to the photothermal properties of the encapsulated gold nanoparticle carriers, the core–shell biodegradable microspheres can be ruptured through remotely controlled near-infrared (NIR) light, thereby achieving an NIR-controlled triggered release of the anti-cancer drug. Furthermore, the route of the DOX-Au@MS-enabled controlled release of the anti-cancer drug can provide durable cancer cell ablation for the long period of 72 h. [ABSTRACT FROM AUTHOR]

Achieving electronic/steric control and realizing selectivity regulation in nanocatalysis remains a formidable challenge, as the dynamic nature of metal‐ligand interfaces, including dissolution (metal leaching) and structural reconstruction, poses significant obstacles. Herein, we disclose carboranyls (CBs) as unprecedented carbon‐bonded functional ligands (Eads.CB‐Au(111)=−2.90 eV) for gold nanoparticles (AuNPs), showcasing their exceptional stabilization capability that is attributed by strong Au−C bonds combined with B−H⋅⋅⋅Au interactions. The synthesized CB@AuNPs exhibit core(Aun)‐satellite(CB2Au−) structure, showing high stability towards multiple stimuli (110 °C, pH=1–12, thiol etchants). In addition, different from conventional AuNP catalysts such as triphenylphosphine (PPh3) stabilized AuNPs, dissolution of catalytically active gold species was suppressed in CB@AuNPs under the reaction conditions. Leveraging these distinct features, CB@AuNPs realized outstanding p : o selectivities in aromatic bromination. Unbiased arenes including chlorobenzene (up to >30 : 1), bromobenzene (15 : 1) and phenyl acrylate were examined using CB@AuNPs as catalysts to afford highly‐selective p‐products. Both carboranyl ligands and carboranyl derived counterions are crucial for such regioselective transformation. This work has provided valuable insights for AuNPs in realizing diverse regioselective transformations. [ABSTRACT FROM AUTHOR]

Metal and metal oxide nanocomposites have unique properties and are promising for antibacterial and anticancer applications. In this work, we aimed to highlight the relationship between the biosynthesis ways of silver and gold-doped zinc oxide nanocomposites and their functions as anticancer on cell lines (MCF-7 and HepG2). The propolis was used to biosynthesize four different nanoparticles with the same components, including zinc, gold and silver. The nanocomposites were characterized using various techniques, including ultraviolet–visible spectroscopy (UV–Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray analysis (EDX) and cytotoxicity assays. The result of this study showed that formed nanocomposites have a similar level of Zn, Au, and Ag, ranging from 23–34%, 2–6%, and 2–3%, respectively. In addition, adding the components simultaneously produces the fastest color change, and the fabricated nanoparticles have spherical shapes with different layers. In addition, the prepared nanoparticles influenced the cell viability of the cancer cell lines, with the most effective one when Zn, Au, and Ag were added spontaneously to form a nanocomposite called (All) with IC50 of 24.5 µg/mL for MCF7 cells and 29.1 µg/mL for HepG2 cells. Thus, the study illustrates that the preparation of nanocomposite generated through green synthesis with different methods significantly affects the structure and function and may improve the synthesis of nanocomposite to be developed into an efficacious therapeutic agent for cancers. In addition, this study opens the door toward a novel track in the field of nanocomposites as it links the synthesis with structure and function. Further anti-cancer properties, as well as animal testing are needed for those nanocomposites. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (Au NPs) are unique catalysts due to their increased coordination unsaturation via nanoparticulation. Effective functioning requires an appropriate support to maintain particle dispersion without compromising nanoscale properties. Cross‐linked hydrophilic polymer‐derived hydrogels are ideal supports, particularly for biological and biomedical reactions, due to their aqueous affinity and biocompatibility. However, applications in confined spaces, such as in vivo environments, necessitate hydrogel micronization. This study introduces microsized DNA hydrogels as support for Au catalysts. DNA motif‐composed hydrogel particles exhibit high crosslinking density and produce small Au NPs owing to short DNA strands. This system significantly enhances catalytic efficiency compared to similar‐sized Au NP gel‐supported catalysts and requires minimal gold catalyst. Modulating DNA hydrogel crosslinking density allows easy control of Au NP size and catalytic activity, further improved by increased hydrogel surface area through microparticulation. These findings demonstrate DNA nanotechnology's versatility in tailoring DNA hydrogel properties and Au NP catalytic behavior. Computer‐aided design enables precise particle property and motif arrangement manipulation, offering promising customizable catalytic systems. [ABSTRACT FROM AUTHOR]

The investigation of blood flow into curved arteries is fascinating and essential to prevent the advancement of vascular disease. Motivated by electro-kinetic manipulation, gold nanoparticles, and their size applications, a mathematical model is developed to explain blood flow, entropy generation, and electro-kinetic energy conversion (EKEC) efficiency in curved arterial flow. To make this study more realistic, a patient-specific overlapped stenosis condition and non-Newtonian (power-law fluid) blood flow model have been considered. The effects of a magnetic field, external heating, and chemical reactions are also included. The Stone's strongly implicit scheme has been considered to solve the system of non-linear partial differential equations (PDE's) in the" MATLAB" software. In this numerical investigation, an error tolerance of 10 − 6 has been considered for every iteration step under Stone's scheme. The significance of various physical parameters, such as nanoparticle volume fraction (m), their size (dp), magnetic field intensity (M), inverse Debye length ( κ ¯ ), flow behavior index (Sc), heat source (H), and chemical reaction parameter (ξ) on the blood flow velocity, temperature, concentration, EKEC efficiency, and entropy generation have been explained graphically. This study also developed stream function contours to describe flow trapping patterns. The findings of this study conclude that the blood flow EKEC efficiency reduces with the presence of nanoparticles and stenosis in the artery. In addition, both flow velocity and entropy enhance by adopting large-size nanoparticles instead of small diametric nanoparticles. Clinical researchers and biologists may use the results of this computational study to forecast endothelial cell damage and plaque deposition in curved arteries with WSS profiles, by which the severity of these conditions can be reduced. [ABSTRACT FROM AUTHOR]

Adrenaline (AD) is important in information transmission through the human central nervous system. Considering the significant biochemical functions of AD, the development of electrochemical sensors capable of detecting AD levels in living organisms has attracted considerable interest. In this study, AD was detected using electrochemical sensors developed based on Au nanoparticles/ionic liquids/N‐ and P‐co‐doped carbon nanotubes‐modified carbon cloth (AuNPs/ILs/N,P‐MWCNTs/CC) electrodes. AuNPs/ILs/N,P‐MWCNTs/CC composites were prepared on carbon cloth (CC) substrates using ionic liquids (ILs), N‐ and P‐co‐doped multi‐walled carbon nanotubes (N,P‐MWCNTs), and Au nanoparticles (AuNPs) as modified materials. The effects of pH and scanning speed were optimized and tested on the prepared composites. The results of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) experiments showed that the modified ILs, N,P‐MWCNTs, and AuNPs effectively improved the oxidation performance of AD. In addition, the linear range obtained from the DPV scans of the AuNPs/ILs/N,P‐MWCNTs/CC composite material was 30–505 μmol/L, with a detection limit of 0.31 μmol/L. The fabricated sensors have good sensitivity (6.9 μA·mM−1·cm−2) for AD of 30–505 μM. Therefore, the electrochemical sensing method based on the AuNPs/ILs/N,P‐MWCNTs/CC composite material is a promising and reliable AD detection technology that also exhibits good selectivity in the presence of interfering substances such as folic acid and ibuprofen. In practical applications, this material can help realize real‐time AD detection to determine whether athletes use doping and other illegal drugs before competitions and to perform synchronous detection. [ABSTRACT FROM AUTHOR]

In observing the electrocatalytic current of nanoparticles (NPs) using single-entity electrochemistry (SEE), the surface state of the NPs significantly influences the SEE signal. This study investigates the influence of capping agents on the electrocatalytic properties of gold (Au) NPs using SEE. Two inner-sphere reactions, hydrazine oxidation and glucose oxidation, were chosen to explore the SEE characteristics of Au NPs based on the capping agent presence. The results revealed that "capping agent-free" Au NPs exhibited signal magnitudes and frequencies consistent with theoretical expectations, indicating superior stability and catalytic performance in electrolyte solutions. In contrast, citrate-capped Au NPs showed signals varying depending on the applied potential, with larger magnitudes and lower frequencies than expected, likely due to an aggregation of NPs. This study suggests that capping agents play a crucial role in the catalytic performance and stability of Au NPs in SEE. By demonstrating that minimizing capping agent presence can enhance effectiveness in SEE, it provides insights into the future applications of NPs, particularly highlighting their potential as nanocatalysts in energy conversion reactions and environmental applications. [ABSTRACT FROM AUTHOR]

Androgenetic alopecia (AGA) is a non-fatal disease prevalent worldwide. However, mixed efficacy has been observed among different therapies for hair regrowth in AGA patients. Thus, a nano-platform with synergistic treatments based on a hybrid extracellular vesicle encapsulating gold nanoparticles (AuNPs) and finasteride (Hybrid/Au@Fi) was constructed through membrane fusion between hair follicle stem cell (HFSC)-derived extracellular vesicles and liposomes. These hybrid vesicles (HVs) not only fuel hair regrowth by providing cellular signals in extracellular vesicles, but also improve storage stability, follicle retention, and drug encapsulation efficiency (EE%) for finasteride inhibiting 5α-reductase, and nano-size AuNPs that simulate low-level laser therapy (LLLT) with similar photothermal effects in vitro. The EE% of finasteride in these HVs reached 45.33%. The dual administration of these extracellular vesicles and finasteride showed a strong synergistic effect on HFSCs in vitro. In an AGA mouse model, once-daily topical Hybrid/Au@Fi (115.07 ± 0.32 nm, −7.50 ± 1.68 mV) gel led to a faster transition of hair follicles (HFs) from the catagen to the anagen, increased hair regrowth coverage, and higher quality of regrowth hair, compared to once-daily 5% minoxidil treatment. Compared to topical minoxidil, the multifaceted synergistic therapy of Hybrid/Au@Fi through topical administration offers a new option for intractable AGA patients with low side effects. [Display omitted] • These hybrid vesicles improved storage stability for cargos, follicle retention, and drug encapsulation efficiency (EE%) for finasteride. • The Hybrid/Au@Fi (115.07 ± 0.32 nm, −7.50 ± 1.68 mV) facilitated simulated in vitro layered dermal papilla cell (DPC) migration and angiogenesis with favorable cell dynamic behavior and no cytotoxicity. • In an AGA mouse model, once-daily topical application of Hybrid/Au@Fi gel exhibited a faster transition of hair follicles from the catagen to the anagen, higher hair regrowth coverage, and improved quality of regrowth hair, compared to once-daily 5% minoxidil treatment. [ABSTRACT FROM AUTHOR]

Worldwide, two million two hundred thousand new cases of breast cancer were diagnosed in 2020. Traditional breast cancer treatments have several side effects, such as poisoning of the heart and lung during chemotherapy and cardiovascular disease during radiotherapy. Moreover, many patients suffer from acute and chronic pain, loss of breast shape, and limited arm mobility after surgery. Researchers strive to reduce adverse effects by finding more effective strategies. Sonodynamic therapy is a newly developed cancer treatment that offers safety, high penetration depth into soft tissues, accessibility, affordability, etc. In addition to these benefits, sonodynamic therapy also enhances chemotherapy effectiveness. Therefore, the combination of sonodynamic therapy and chemotherapy along with a multifunctional sensitizer can enhance treatment effectiveness while minimizing side effects. In this study, PEGylated gold nanoparticles (PEG-GNPs) were synthesized and loaded with an anticancer agent, Gemcitabine (Gem-PEG-GNPs). The synthesized Gem-PEG-GNPs act as sonosensitizers and nanocarriers, which improve the efficacy of sonodynamic therapy and chemotherapy as well as reduce harmful effects. Ultrasound waves combined with Gem-PEG-GNPs increased apoptosis and decreased survival rates in MCF-7 cells. When Gem-PEG-GNPs and ultrasound waves were combined, a significant synergistic effect was observed compared to ultrasound waves alone. In conclusion, Gem-PEG-GNPs have the potential to be effective sonosensitizers and drug delivery agents in treatment of breast cancer. [ABSTRACT FROM AUTHOR]

Protein glycation a non-enzymatic protein modification, alters the structure of biomolecule leading to several neurodegenerative and other disorders. As onset of disorders due to protein glycation is primarily driven by the development of advanced glycation end products (AGEs), therapeutic intervention against related disorders by inhibiting AGEs production is imperative. Nanoparticles have recently gained more prominence as therapeutic agents in biological field such as medicine, drug discovery and diagnosis. In present study, we extensively investigated the effect of chemically synthesized polyvinylpyrrolidone conjugated gold nanoparticles (PVP-AuNP) on D-ribose induced glycation of hen egg white lysozyme (HEWL) under physiological conditions employing several biophysical and biochemical methods like absorption and fluorescence spectroscopy, static and dynamic light scattering, circular dichroism, alongwith fluorescence, and Atomic Force Microscopy. Our finding shows that AGEs formation was inhibited by PVP-AuNP at 37 °C, pH 7.4 over the period of 20 days. Interaction of gold nanoparticles prevented glycation induced misfolding and aggregation of lysozyme by stabilizing its native structure, which was evident with static light scattering, ThT, Congo red and ANS fluorescence coupled with CD spectroscopy. Further, by estimating carbonyl content and thiol group, our study suggests that PVP-AuNP possesses antioxidant property thus prevent the HEWL against glycation driven oxidative damage. Present study therefore elucidates that PVP-AuNP a significant antiglycation agent can be used against wide range of disorders induced by AGEs. [ABSTRACT FROM AUTHOR]

DNA is fundamental for storing and transmitting genetic information. Analyzing DNA or RNA base sequences enables the identification of genetic disorders, monitoring gene expression, and detecting pathogens. Traditional detection techniques like polymerase chain reaction (PCR) and next-generation sequencing (NGS) have limitations, including complexity, high cost, and the need for advanced computational skills. Therefore, there is a significant demand for enzyme-free and amplification-free strategies for rapid, low-cost, and sensitive DNA detection. DNA biosensors, especially those utilizing plasmonic nanomaterials, offer a promising solution. This study introduces a novel DNA-functionalized waveguide-enhanced nanoplasmonic optofluidic biosensor using a nanogold-linked sorbent assay for enzyme-free and amplification-free DNA detection. Integrating plasmonic gold nanoparticles (AuNPs) with a glass planar waveguide (WG) and a microfluidic channel, fabricated through cost-effective, vacuum-free methods, the biosensor achieves specific detection of complementary target DNA sequences. Utilizing a sandwich architecture, AuNPs labeled with detection DNA probes enhance sensitivity by altering evanescent wave distribution and inducing plasmon resonance modes. The biosensor demonstrated exceptional performance in DNA detection, achieving a limit of detection (LOD) of 33.1 fg/mL (4.36 fM) with a rapid response time of approximately 8 min. This ultrasensitive, rapid, and cost-effective biosensor exhibits minimal background nonspecific adsorption, making it highly suitable for clinical applications and early disease diagnosis. The innovative design and fabrication processes offer significant advantages for mass production, presenting a viable tool for precise disease diagnostics and improved clinical outcomes. [ABSTRACT FROM AUTHOR]

Abstract The globalization of food distribution has made it necessary to ensure the delivery of fresh food to the consumers. Protein‐rich foods produce a significant amount of tyramine when spoiled. Therefore, it was envisaged to develop localized surface plasmon resonance (LSPR)—sensor for monitoring tyramine content in beef, mackerel, and cheese. For this purpose, the sensors were developed by coating the LSPR chip with gold nanoparticles (AuNPs) followed by conjugation of tyramine‐specific peptide (TYR1). The TYR1 was synthesized and screened by phage display and binding efficiency was evaluated by DockThor. The optimized LSPR sensor showed highest binding efficiency at TYR1 concentration of 20 µg/mL with reaction time of 40 min. The sensor also showed an excellent detection range for beef, mackerel, and cheese were 0.01–10 ppb, 0.01–10 ppm, and 0.01–10 ppb, respectively, in comparison to standard. These findings indicated that this sensor can be used as a promising tool for on‐site monitoring of food quality.

Abstract Metal and metal oxide nanocomposites have unique properties and are promising for antibacterial and anticancer applications. In this work, we aimed to highlight the relationship between the biosynthesis ways of silver and gold-doped zinc oxide nanocomposites and their functions as anticancer on cell lines (MCF-7 and HepG2). The propolis was used to biosynthesize four different nanoparticles with the same components, including zinc, gold and silver. The nanocomposites were characterized using various techniques, including ultraviolet–visible spectroscopy (UV–Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy Dispersive X-ray analysis (EDX) and cytotoxicity assays. The result of this study showed that formed nanocomposites have a similar level of Zn, Au, and Ag, ranging from 23–34%, 2–6%, and 2–3%, respectively. In addition, adding the components simultaneously produces the fastest color change, and the fabricated nanoparticles have spherical shapes with different layers. In addition, the prepared nanoparticles influenced the cell viability of the cancer cell lines, with the most effective one when Zn, Au, and Ag were added spontaneously to form a nanocomposite called (All) with IC50 of 24.5 µg/mL for MCF7 cells and 29.1 µg/mL for HepG2 cells. Thus, the study illustrates that the preparation of nanocomposite generated through green synthesis with different methods significantly affects the structure and function and may improve the synthesis of nanocomposite to be developed into an efficacious therapeutic agent for cancers. In addition, this study opens the door toward a novel track in the field of nanocomposites as it links the synthesis with structure and function. Further anti-cancer properties, as well as animal testing are needed for those nanocomposites.

الملخص: اهداف البحث: هدفت هذه الدراسة إلى تقييم التأثيرات السامة على الخلايا الحية لمستخلص من أوراق نبات العطرة وجسيمات الذهب النانوية الحيوية المصنعة بطريقة التوليف الاخضر لتكوين غسول الفم لاستخدامه كبديل لغسولات الفم التجارية. تم استخدام (الخلايا الليفية الجلدية البشرية من الاجنة) في هذه الدراسة التي أجريت في المختبر، لأن خصائصها كانت متطابقة تقريبًا مع خصائص الخلايا الليفية اللثوية البشرية. طرق البحث: في هذه الدراسة، تم دراسة التوليف الأخضر لـجسيمات الذهب النانوية الحيوية باستخدام مقتطفات من أوراق نبات العطرة كوسيلة مستدامة واقتصادية. بعد ذلك، وباستخدام مجموعة من التقنيات التحليلية، تم تقييم الخواص الفيزيائية والكيميائية، مثل المجهر الإلكتروني النافذ و حيود الأشعة السينية و ومطياف الامتصاص المرئي فوق البنفسجي، وبالتالي استغرقت الاستعدادات والتقنيات التحليلية لتكوين جسيمات الذهب النانوية وقتًا قصيرًا يبلغ حوالي عشرة أيام. وقد استخدمت الدراسة الحالية ٣-[٤,٣-ثنائي ميثيل ثيازول-٢-ييل]-٢,٥ بروميد ثنائي فينيل-تترازوليوم (سمية التترازوليوم لموسمان) لدراسة التأثيرات السامة للخلايا لمستخلص أوراق نبات العطرة مع جسيمات الذهب النانوية الحيوية لنفس النبات باستخدام خط الخلايا القياسية المشتقة من الخلايا الليفية البشرية. النتائج: تم استخدام جرعات مختلفة (١٠٠٠، ٥٠٠، ٢٥٠، ١٠٠، ٥٠، ٢٥، ١٢,٥، ٦,٢٥، و ٣,١٢٥ ميكروجرام/مل) من جسيمات الذهب النانوية لنبات العطرة لتقييم السمية الخلوية، وقد دلت النتائج على تأثيرات سامة خلوية قليلة (أقل من ٢٠٪ سمية تقريبًا). وقد لوحظ مستوى عالٍ من التوافق الحيوي بين جسيمات الذهب النانوية لنبات العطرة والخلايا الليفية البشرية الطبيعية. الاستنتاجات: أظهر غسول الفم المصنوع باستخدام جزيئات الذهب النانوية الحيوية من مستخلص أوراق نبات العطرة المصنع بطريقة التوليف الاخضر, مستوى عالٍ من التوافق البيولوجي وله سمية خلوية منخفضة. لذلك، يمكن أن تكون تركيبات غسول الفم العشبية بمثابة بديل قابل للتطبيق لغسولات الفم الكيميائية. Abstract: Objective: This study aimed to assess the cytotoxic effects of an extract from Pelargonium graveolens leaves and green-synthesized gold nanoparticles (AuNPs) in a mouthwash when used as a substitute for commercial mouthwashes. Human dermal fibroblasts from neonates (HDFn) were used in this study that done in vitro, because their characteristics were nearly identical to those of human gingival fibroblasts. Method: In this study, the green synthesis of AuNPs using extracts from P. graveolens leaves was investigated as a sustainable and economical method. Then, using a range of analytical techniques, the physicochemical properties were evaluated, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and ultraviolet visible absorption spectroscopy (UV–Vis), so the preparations and analytical techniques of P. graveolens gold nanoparticles (AuNPs) take little time is about 10 days. The current study used the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl-tetrazolium bromide Mosmann's Tetrazolium Toxicity (MTT) to study the cytotoxic effects of P. graveolens leaf extract with P. graveolens gold nanoparticles (AuNPs) utilizing a human fibroblast-derived standard cell line. Results: Various doses (1000, 500, 250, 100, 50, 25, 12.5, 6.25, and 3.125 μg/mL) of P. graveolens AuNPs were used to assess cytotoxicity, demonstrating little cytotoxic effects (approximately below 20% toxicity). A high level of biocompatibility was observed between the P. graveolens AuNPs and normal human fibroblasts. Conclusion: The mouthwash made using green synthetic AuNPs obtained from P. graveolens leaf extract show high level of biocompatibility and has low cytotoxicity. Therefore, herbal mouthwash formulations can serve as a viable substitute for chemical mouthwashes.

Abstract Global public health confronts a pressing challenge in antimicrobial resistance (AMR), necessitating urgent intervention strategies due to the low success rate of new antibiotic development. Bacterial motility, beyond conventional antibiotic usage, significantly influences resistance evolution and ecological dynamics. Our recent study marks a breakthrough, revealing the unexplored ability of ultrafine gold nanosystems (UGNs) to inhibit bacterial resuscitation using a motile Escherichia coli (E.coli) K12 strain. We aim to deepen our comparative understanding of UGNs’ efficacy and resuscitation propensity against a non-motile E. coli K12 strain to assess the role of motility. Through UGN application, we identified heritable resistance in both strains, with motile strains exhibiting notably higher mutation rates. Resuscitation experiments unveiled faster recovery in motile strains, attributable to virulence factors, compared to non-motile strains. Additionally, our investigation into aggregation dynamics highlighted the role of protein-mediated aggregation in resistance development to nano-antimicrobials. Overall, the study reveals that the non-motile strains are more susceptible against UGNs, which shows promise in combating AMR.

Abstract Radiation therapy and phototherapy are commonly used cancer treatments that offer advantages such as a low risk of adverse effects and the ability to target cancer cells while sparing healthy tissue. A promising strategy for cancer treatment involves using nanoparticles (NPs) in combination with radiation and photothermal therapy to target cancer cells and improve treatment efficacy. The synthesis of gold NPs (AuNPs) for use in biomedical applications has traditionally involved toxic reducing agents. Here we harnessed dopamine (DA)-conjugated alginate (Alg) for the facile and green synthesis of Au NPs (Au@Alg-DA NPs). Alg-DA conjugate reduced Au ions, simultaneously stabilized the resulting AuNPs, and prevented aggregation, resulting in particles with a narrow size distribution and improved stability. Injectable Au@Alg-DA NPs significantly promoted ROS generation in 4T1 breast cancer cells when exposed to X-rays. In addition, their administration raised the temperature under a light excitation of 808 nm, thus helping to destroy cancer cells more effectively. Importantly, no substantial cytotoxicity was detected in our Au@Alg-DA NPs. Taken together, our work provides a promising route to obtain an injectable combined radio enhancer and photothermally active nanosystem for further potential clinic translation.

Global public health confronts a pressing challenge in antimicrobial resistance (AMR), necessitating urgent intervention strategies due to the low success rate of new antibiotic development. Bacterial motility, beyond conventional antibiotic usage, significantly influences resistance evolution and ecological dynamics. Our recent study marks a breakthrough, revealing the unexplored ability of ultrafine gold nanosystems (UGNs) to inhibit bacterial resuscitation using a motile Escherichia coli (E.coli) K12 strain. We aim to deepen our comparative understanding of UGNs' efficacy and resuscitation propensity against a non-motile E. coli K12 strain to assess the role of motility. Through UGN application, we identified heritable resistance in both strains, with motile strains exhibiting notably higher mutation rates. Resuscitation experiments unveiled faster recovery in motile strains, attributable to virulence factors, compared to non-motile strains. Additionally, our investigation into aggregation dynamics highlighted the role of protein-mediated aggregation in resistance development to nano-antimicrobials. Overall, the study reveals that the non-motile strains are more susceptible against UGNs, which shows promise in combating AMR. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) exhibit excellent plasmonic properties, including bright color and generation of localized electric field, hot carriers, and heat. These properties are widely applied in biology, sensing, spectroscopy, catalysis, and medicine. More attractive is that these properties are tremendously enhanced when AuNPs are assembled and form nanogaps between the particles. Therefore, assembling AuNPs in a controlled fashion is a key step for the study and applications of plasmonic properties. In this Account, I will introduce my group's collective efforts that have been made for a decade to develop the best assembly method. I will describe the assembly procedure in detail and demonstrate the various nanoassemblies produced by the method. The controlled assembly allows us to systematically examine the relationship between the plasmonic properties and structural parameters of the nanogaps. Among many properties, I focus on plasmon coupling. To conclude, I will discuss the prospects of nanoassembly plasmonics. [ABSTRACT FROM AUTHOR]

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The evolution of engineered nanoparticles (NPs); particularly metallic NPs have played an indispensable role in the development of nanotechnology. Among these NPs, gold nanoparticles (AuNPs) have attracted significant attention and are highly being utilized in several fields due to their exceptional properties. Gold nanoparticles were an emerging subject of intensive research due to their spherical shape, large specific surface area, and quick modification by functional groups. As the demand for AuNPs continuously increases; therefore, there is a pressing need to optimize the scientific approach to fully comprehend and exploit their potential. The effect of AuNPs on plant growth and development can either be beneficial or harmful, depending on the plant species and the concentration of NPs. Moderate concentrations of AuNPs have been found to induce primary and lateral roots, reduce oxidative stress, and elongate rosette diameter, while a higher concentration showed negative effects on plant growth and development. Gold nanoparticles also exhibit potent antibacterial, antiviral, and anticancer properties, making them most beneficial in various sectors, especially in the biomedical field. AuNPs are extensively being utilized across various sectors, but their application in the biomedical field is noteworthy, particularly in bioimaging, biosensing, targeted gene and drug delivery, theranostics, regenerative medicine, and tissue engineering. This review emphasizes the potential applications of AuNPs in diverse sectors including agriculture and biomedical, highlighting their potential impact (positive and negative) on plant growth. Furthermore, the review also aims to signify the mechanism of action of AuNPs and their efficacy against bacteria, viruses, and cancer cells. [ABSTRACT FROM AUTHOR]

Metabolic acidosis‐induced kidney injury (MAKI) is asymptomatic and lack of clinical biomarkers in early stage, but rapidly progresses to severe renal fibrosis and ultimately results in end‐stage kidney failure. Therefore, developing rapid and noninvasive strategies direct responsive to renal tubular acidic microenvironment rather than delayed biomarkers are essential for timely renoprotective interventions. Herein, we develop pH‐responsive luminescent gold nanoparticles (p‐AuNPs) in the second near‐infrared emission co‐coated with 2,3‐dimethylaleic anhydride conjugated β‐mercaptoethylamine and cationic 2‐diethylaminoethanethiol hydrochloride, which showed sensitive pH‐induced charge reversal and intrarenal self‐assembly for highly sensitive and long‐time (~24 h) imaging of different stages of MAKI. By integrating advantages of pH‐induced intrarenal self‐assembly and enhanced interactions between pH‐triggered positively charged p‐AuNPs and renal tubular cells, the early‐ and late‐stage MAKI could be differentiated rapidly within 10 min post‐injection (p.i.) with contrast index (CI) of 3.5 and 4.3, respectively. The corresponding maximum CI could reach 5.1 and 9.2 at 12 h p.i. respectively. Furthermore, p‐AuNPs were demonstrated to effectively real‐time monitor progressive recovery of kidney injury in MAKI mice after therapy, and also exhibit outstanding capabilities for drug screening. This pH‐responsive strategy showed great promise for feedback on kidney dysfunction progression, opening new possibilities for early‐stage diagnosis of pH‐related diseases. [ABSTRACT FROM AUTHOR]

Cortisol is a key stress biomarker in humans and animals, including fishes. In aquafarming, stress monitoring using cortisol quantification can help to optimize aquaculture practices for welfare and productivity enhancement. However, most current methods for cortisol detection rely on invasive tissue sampling. In this work, we developed a gold nanoparticle (AuNP)-based cortisol sensor to address the demand of detecting picomolar ranges of cortisol from complex fish tank water matrices as a non-invasive alternative for more effective stress monitoring. We first identified a DNA aptamer with effective binding to cortisol and then conjugated the thiol-labelled aptamer to AuNPs together with a blocker molecule (CALNN) to form an Au-Apt-CALNN conjugate that is stable in fish tank water. The cortisol detection principle is based on magnesium chloride (MgCl2)-induced particle aggregation, where the cortisol-bound aptamer on the AuNPs folds into a tertiary structure and provides greater protection for Au-Apt-CALNN against MgCl2-induced aggregation due to steric stabilization. At an optimum MgCl2 concentration, the differential stability of particles with and without cortisol binding offers a limit of detection (LOD) of 100 pM for cortisol within a 35 min reaction. The aptasensor has been validated on recirculating aquaculture system (RAS) fish tank water samples by the HPLC method and was able to detect changes in water cortisol induced by two different stress paradigms. This on-site deployable and non-invasive sensor offers opportunities for more efficient and real-time fish stress monitoring for the optimization of aquaculture practices. [ABSTRACT FROM AUTHOR]

In recent years, the examination of blood flow in diseased arteries has been an essential field of research. Atherosclerosis is one of the most common arterial diseases, usually known as stenosis. The current work investigates the combination impact of electric and magnetic fields of the unsteady, two-dimensional and laminar pulsatile non-Newtonian flow of blood in an axisymmetrically inclined tapered porous stenotic artery containing gold nanoparticles with different shapes subject to body acceleration and slip effect at the wall. Heat source and thermal radiation are also considered. The phenomenon of the imposed electric field is described by the Poisson–Boltzmann equation. To immobilize the effect of the vessel wall, a transformation of the radial coordinates is used. The adoption of gold nanoparticles as nanomaterials for drug delivery is mainly due to their stability, inert nature, absence of cytotoxicity, high disparity and biocompatibility. An explicit scheme of finite differences is employed for solving the nonlinear partial differential equations that govern the current problem, as well as the prescribed boundary conditions. The applied magnetic and electric fields have significant effects on the flow field and heat transfer. [ABSTRACT FROM AUTHOR]

Because of the possible harm that drugs may cause to the environment and public health, the discovery of pharmaceuticals in drinking water sources has drawn increasing attention. Pharmaceuticals such as atezolizumab (ATZ), a monoclonal antibody used to treat liver cancer, can enter water sources through a number of different routes. The design and development of a new electrochemical sensor for the detection of ATZ in water sources are presented in this research study. Gold nanoparticles (Au NPs) and an anti-Atezolizumab antibody (Ab) on a glassy carbon electrode (GCE) were used to develop the immunosensor. Differential pulse voltammetry was used to comprehensively examine the immunosensor's electrochemical characteristics. The immunosensor showed a broad concentration range of 0.001 to 2000 µg/mL and a low detection limit of 0.6 ng/mL. When the performance of the sensor was compared to other documented ATZ immunoassays, it demonstrated better performance because of its wide analytical range and low detection limit. The immunosensor's repeatability and stability were assessed as well; results revealed a significant 40-day stability period and a relative standard deviation of 4.13%. The immunosensor's distinct capacity to recognize ATZ validated its selectivity. Recovery experiments using human serum, urine, and drinking water samples were used to assess the immunosensor's feasibility; the range of recoveries was 90.00 to 99.40%. The results showed a strong correlation with the ATZ ELISA Assay Kit that is sold commercially. All things considered, the creation of this unique electrochemical sensor marks a substantial breakthrough in the fields of drug detection and environmental monitoring. This sensor could be used to quickly and accurately identify ATZ in water sources, assisting in maintaining the security of our water supply and safeguarding public health and the environment. [ABSTRACT FROM AUTHOR]

Inhaled colistin is used to treat pneumonia and respiratory infections through nebulization or dry powder inhalers. Nevertheless, the development of a metered-dose inhaler (MDI) for colistin, which could enhance patient convenience and treatment efficacy, has not yet been developed. Colistin is known for its ability to induce cellular toxicity. Gold nanoparticles (AuNPs) can potentially mitigate colistin toxicity. Therefore, this study aimed to evaluate the antimicrobial effectiveness of colistin conjugated with chitosan-capped gold nanoparticles (Col-CS-AuNPs) and their potential formulation for use with MDIs to deliver the aerosol directly to the deep lung. Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and elemental analysis were used to characterize the synthesized Col-CS-AuNPs. Drug release profiles fitted with the most suitable release kinetic model were evaluated. An MDI formulation containing 100 µg of colistin per puff was prepared. The aerosol properties used to determine the MDI performance included the fine particle fraction, mass median aerodynamic diameter, and geometric standard deviation, which were evaluated using the Andersen Cascade Impactor. The delivered dose uniformity was also determined. The antimicrobial efficacy of the Col-CS-AuNP formulation in the MDI was assessed. The chitosan-capped gold nanoparticles (CS-AuNPs) and Col-CS-AuNPs had particle sizes of 44.34 ± 1.02 and 174.50 ± 4.46 nm, respectively. CS-AuNPs effectively entrapped 76.4% of colistin. Col-CS-AuNPs exhibited an initial burst release of up to 60% colistin within the first 6 h. The release mechanism was accurately described by the Korsmeyer–Peppas model, with an R2 > 0.95. The aerosol properties of the Col-CS-AuNP formulation in the MDI revealed a high fine particle fraction of 61.08%, mass median aerodynamic diameter of 2.34 µm, and geometric standard deviation of 0.21, with a delivered dose uniformity within 75–125% of the labeled claim. The Col-CS-AuNP MDI formulation completely killed Escherichia coli at 5× and 10× minimum inhibitory concentrations after 6 and 12 h of incubation, respectively. The toxicity of CS-AuNP and Col-CS-AuNP MDI formulations in upper and lower respiratory tract cell lines was lower than that of free colistin. The stability of the Col-CS-AuNP MDI formulation was maintained for at least 3 months. The Col-CS-AuNP MDI formulation effectively eradicated bacteria over a 12-h period, showing promise for advancing lung infection treatments. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) is the most aggressive sub-type of breast cancer, mainly affecting premenopausal women. As it neither expresses hormone receptors nor overexpresses HER2 receptors, it is difficult to tackle this deadly disease effectively. It is a well-known fact that phytochemicals have remarkable therapeutic potential in the prevention and treatment of different disorders. One of the well-known phytochemicals, ellagic acid (EA) has shown better efficacy in the prevention and treatment of cancer in many preclinical and clinical settings. Therefore, in this study, ellagic acid gold nanoparticles (EA-AuNp) were synthesized and characterized to passively target TNBC cells through EPR effect. EA-AuNp were prepared using the direct reduction method and characterized by UV–Visible spectroscopy, DLS, XRD, EDX, TEM and FT-IR spectra. We found that it significantly suppressed the TNBC cell proliferation (IC 5 0 12 μ g/ml) compared to EA alone (IC 5 0 36 μ g/ml). Flow cytometry and live and dead assays revealed that EA-AuNp induced more cell death in TNBC cells compared to EA alone. Further, western blot analysis substantiated that EA-AuNp induced apoptosis by regulating the expression of Bcl-2, survivin, caspase 3 and caspase 9. In conclusion, EA-AuNp has high anti-cancer potential and additional preclinical and clinical studies are highly recommended. [ABSTRACT FROM AUTHOR]

Fentanyl (FTN) and synthetic analogs of FTN continue to ravage populations across the globe, including in the United States where opioids are increasingly being used and abused and are causing a staggering and growing number of overdose deaths each year. This growing pandemic is worsened by the ease with which FTN can be derivatized into numerous derivatives. Understanding the chemical properties/behaviors of the FTN class of compounds is critical for developing effective chemical detection schemes using nanoparticles (NPs) to optimize important chemical interactions. Halogen bonding (XB) is an intermolecular interaction between a polarized halogen atom on a molecule and e−-rich sites on another molecule, the latter of which is present at two or more sites on most fentanyl-type structures. Density functional theory (DFT) is used to identify these XB acceptor sites on different FTN derivatives. The high toxicity of these compounds necessitated a "fragmentation" strategy where smaller, non-toxic molecules resembling parts of the opioids acted as mimics of XB acceptor sites present on intact FTN and its derivatives. DFT of the fragments' interactions informed solution measurements of XB using 19F NMR titrations as well as electrochemical measurements of XB at self-assembled monolayer (SAM)-modified electrodes featuring XB donor ligands. Gold NPs, known as monolayer-protected clusters (MPCs), were also functionalized with strong XB donor ligands and assembled into films, and their interactions with FTN "fragments" were studied using voltammetry. Ultimately, spectroscopy and TEM analysis were combined to study whole-molecule FTN interactions with the functionalized MPCs in solution. The results suggested that the strongest XB interaction site on FTN, while common to most of the drug's derivatives, is not strong enough to induce NP-aggregation detection but may be better exploited in sensing schemes involving films. [ABSTRACT FROM AUTHOR]

The current study exemplifies the synthesis of novel gold nanoformulations loaded with dioxepine derivative a secondary metabolite from lichen Parmotrema reticulatum utilizing a green approach proving an insight into the impregnation method. The characteristic features of synthesized dioxepine-derived gold NPs (Dd-AuNPs) were analyzed using FT-IR (Fourier Transform Infrared Spectroscopy); it elaborates on the presence of diverse groups with broadband at 3461 cm−1 indicating the presence of the –OH group and the small dip at 2928 cm−1 corresponds to the stretching vibrations of –CH of carbohydrates. The crystallinity of synthesized Dd-AuNPs displayed three distinctive peaks in the 2θ range based on the XRD (X-ray diffraction) pattern. The surface zeta potential of Dd-AuNPs was + 58 mV, which shows the prepared nanoparticle surface has high positive charges and also showed an average hydrodynamic diameter of 661 nm with a peak intensity of 88% using the dynamic light scattering technique. The study elaborates its characterization with SEM (scanning electron microscope) analysis which indicates that AuNPs were dispersed in the solution; as supplementary, the results of HRTEM (high-resolution transmission electron microscopy) were shown at different magnifications along with selected area electron diffraction (SAED) pattern with several morphologies such as spherical, triangular, and hexagonal which particle size ranges from 20 to 30 nm. The synthesized Dd-AuNPs effectively scavenged free radicals in a dose-dependent manner with 21–45% and 12–71% of DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric ion reducing antioxidant power) assay respectively. In addition, in vitro studies exhibited high cytotoxic activity against the human lung cancer cell line (A549) with IC50 value of 12 μg/mL using MTT (3-(4,5-dimethylthiozol-2-yl)-3,5- diphenyl tetrazolium bromide) assay and accompanied by AO/EtBr (acridine orange (AO) and ethidium bromide (EtBr)) and DAPI (4′,6-diamidino-2-phenylindole) staining methods to confirm the apoptosis, nuclear condensation, and fragmentation. Similarly, flow cytometry analysis results provide greater shreds of evidence demonstrating that apoptosis occurred during the S phase, which was further confirmed using caspase assay proving the occurrence of apoptosis. These results highlight the intriguing potential of synthesized Dd-AuNPs as an effective source of bioactive compounds with antioxidant and anticancer abilities, necessitating additional research into their potential therapeutic potential in lung cancer cell lines. [ABSTRACT FROM AUTHOR]

A simple, eco-friendly method for the synthesis of gold nanoflowers using a non-proteinogenic amino acid is discussed in the present work. Gold nanostructure with unique morphology was synthesized, with the assistance of ornithine amino acid. Ornithine-stabilised gold nanoflowers were found to be highly sensitive towards mercury ions (Hg2+) due to Au–Hg amalgamate formation. Due to amalgamate formation, an evolution in morphology of ornithine-stabilised gold nanoflowers happens which can be monitored by the red shift in surface plasmon resonance. Under optimum conditions, our sensor shows a dynamic response range with a detection limit of 6 nM. This developed nanosensor can be used as Hg2+ ion sensor in polluted water/waste water by a one-step assay protocol. [ABSTRACT FROM AUTHOR]

Loop-mediated isothermal amplification (LAMP) is a molecular diagnosis technology with the advantages of isothermal reaction conditions and high sensitivity. However, the LAMP reactions are prone to producing false-positive results and thus are usually less reliable. This study demonstrates a gold nanoparticle (AuNP)-assisted colorimetric LAMP technique for diagnosing SARS-CoV-2, which aims to overcome the false-positive results. The AuNPs were functionalized with E gene probes, specifically tailored to bind to the amplified E-gene LAMP product, using the freezing method. Varied salt concentration and AuNP/probe combinations were tested for the highest visual performance. The experiments were conducted on synthetic SARS-CoV-2 RNA (Omicron variant), as well as on clinical samples. The assay showed an exceptional sensitivity of 8.05 fg of LAMP amplicon mixture (0.537 fg/µL). The average reaction time was ~ 30 min. In conclusion, AuNP-assisted LAMP detection will not identify any potential unspecific amplification, which helps to improve the efficiency and reliability of LAMP assays in point-of-care applications. The freezing method to functionalize the AuNPs with probes simplifies the assay, which can be utilized in further diagnostic studies. [ABSTRACT FROM AUTHOR]

[Display omitted] Triple-negative breast cancer (TNBC) is insensitive to conventional therapy due to its highly invasive nature resulting in poor therapeutic outcomes. Recent studies have shown multiple genes associated with ferroptosis in TNBC, suggesting an opportunity for ferroptosis-based treatment of TNBC. However, the efficiency of present ferroptosis agents for cancer is greatly restricted due to lack of specificity and low intracellular levels of H 2 O 2 in cancer cells. Herein, we report a nano-theranostic platform consisting of gold (Au)-iron oxide (Fe 3 O 4) Janus nanoparticles (GION@RGD) that effectively enhances the tumor-specific Fenton reaction through utilization of near-infrared (NIR) lasers, resulting in the generation of substantial quantities of toxic hydroxyl radicals (•OH). Specifically, Au nanoparticles (NPs) converted NIR light energy into thermal energy, inducing generation of abundant intracellular H 2 O 2 , thereby enhancing the iron-induced Fenton reaction. The generated •OH not only lead to apoptosis of malignant tumor cells but also induce the accumulation of lipid peroxides, causing ferroptosis of tumor cells. After functionalizing with the activity-targeting ligand RGD (Arg-Gly-Asp), precise synergistic treatment of TNBC was achieved in vivo under the guidance of Fe 3 O 4 enhanced T 2 -weighted magnetic resonance imaging (MRI). This synergistic treatment strategy of NIR-enhanced ferroptosis holds promise for the treatment of TNBC. [ABSTRACT FROM AUTHOR]

Acidity-activated gold nanoparticles (AuNPs) with self-complementary zwitterionic peptide decoration are developed for photothermal eradication of drug-resistant biofilm infections. The self-complementary zwitterionic peptide with longer charge domains and a polyethylene glycol oligomer spacer endow AuNPs with greater photothermal antimicrobial and biofilm eradication. [Display omitted] Drug-resistant biofilm infection is an extremely serious clinical problem, that easily leads to failure of antibiotic treatment. Although gold nanoparticles (AuNPs) as photothermal agents have been widely used in biofilm eradication, there are still challenges to be addressed, such as insignificantly redshifted absorption and slow assembly process of aggregated AuNPs. Herein, we developed an acidity-activated dispersion-to-aggregation transition to enhance the accumulation of self-complementary zwitterionic peptide-decorated AuNPs for photothermal eradication of drug-resistant biofilm infections. AuNPs were decorated with self-complementary zwitterionic peptides (ZP1 and ZP2) coupled with pH-sensitive anhydride (DMA) and pH-insensitive anhydride (SA), respectively. ZP2-decorated AuNPs with DMA modification (AuNP@ZP2(DMA)) exhibited prolonged blood circulation and enhanced accumulation in acidic biofilm microenvironment. Moreover, the electrostatic attraction between self-complementary ligands drove AuNPs to form closely packed aggregates with strong near-infrared absorption, leading to in vivo photoacoustic imaging ability and photothermal effect against drug-resistant bacteria and fungus, as well as microbial biofilms. AuNP@ZP2(DMA) with longer charge domains and a polyethylene glycol oligomer spacer showed greater photothermal antimicrobial and biofilm resistance in vitro and in vivo. This study develops an innovative acidity-activated AuNP photothermal agent, which provides an effective approach for treatment of biofilm infections. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) possess attractive electronic, optical, and catalytic properties, enabling many potential applications. Poly(N-isopropyl acrylamide) (PNIPAAm) is a temperature-responsive polymer that changes its hydrophilicity upon a slight temperature change, and combining PNIPAAm with AuNPs allows us to modulate the properties of AuNPs by temperature. In a previous study, we proposed a simpler method for designing PNIPAAm–AuNP hybrid microgels, which used an AuNP monomer with polymerizable groups. The size of AuNPs is the most important factor influencing their catalytic performance, and numerous studies have emphasized the importance of controlling the size of AuNPs by adjusting their stabilizer concentration. This paper focuses on the effect of AuNP size on the catalytic activity of PNIPAAm–AuNP hybrid microgels prepared via the copolymerization of N-isopropyl acrylamide and AuNP monomers with different AuNP sizes. To quantitatively evaluate the catalytic activity of the hybrid microgels, we monitored the reduction of 4-nitrophenol to 4-aminophenol using the hybrid microgels with various AuNP sizes. While the hybrid microgels with an AuNP size of 13.0 nm exhibited the highest reaction rate and the apparent reaction rate constant (kapp) of 24.2 × 10−3 s−1, those of 35.9 nm exhibited a small kapp of 1.3 × 10−3 s−1. Thus, the catalytic activity of the PNIPAAm–AuNP hybrid microgel was strongly influenced by the AuNP size. The hybrid microgels with various AuNP sizes enabled the reversibly temperature-responsive on–off regulation of the reduction reaction. [ABSTRACT FROM AUTHOR]

Gold nanoparticle (AuNP) fabrication via the oxidation of D-glucose is applied for detecting two foodborne pathogens, Enterococcus faecium (E. faecium) and Staphylococcus aureus (S. aureus). D-glucose is used as a reducing agent due to its oxidation to gluconic acid by sodium hydroxide (NaOH), resulting in the formation of AuNPs. Based on this mechanism, we develop AuNP-based colorimetric detection in conjunction with loop-mediated isothermal amplification (LAMP) for accurately identifying the infectious bacteria. Here, Au+ ions bind to the base of double-stranded DNA. In the presence of D-glucose and NaOH, the LAMP amplicon-Au+ complex maintains its bound state at 65 °C for 10 min while it is reduced to AuNPs in a dispersed form, exhibiting a red color. We aimed to pre-mix D-glucose with LAMP reagents before amplification and induce successful colorimetry without inhibiting amplification to simplify the experimental process and decrease the reaction time. Therefore, the entire process, including LAMP and colorimetric detection, is accomplished in approximately 1 h. The limit of detection of E. faecium and S. aureus is confirmed using the introduced method as 101 CFU/mL and 100 fg/μL, respectively. We expect that colorimetric detection using D-glucose-mediated AuNP synthesis offers an application for simple and immediate molecular diagnosis. [ABSTRACT FROM AUTHOR]

The accurate and effective detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential to preventing the spread of infectious diseases and ensuring human health. Herein, a nanobody-displayed whole-cell biosensor was developed for colorimetric detection of SARS-CoV-2 spike proteins. Serving as bioreceptors, yeast surfaces were genetically engineered to display SARS-CoV-2 binding of llama-derived single-domain antibodies (nanobodies) with high capture efficiency, facilitating the concentration and purification of SARS-CoV-2. Gold nanoparticles (AuNPs) employed as signal transductions were functionalized with horseradish peroxidase (HRP) and anti-SARS monoclonal antibodies to enhance the detection sensitivity. In the presence of SARS-CoV-2 spike proteins, the sandwiched binding will be formed by linking engineered yeast, SARS-CoV-2 spike proteins, and reporter AuNPs. The colorimetric signal was generated by the enzymatic reaction of HRP and its corresponding colorimetric substrate/chromogen system. At the optimal conditions, the developed whole-cell biosensor enables the sensitive detection of SARS-CoV-2 spike proteins in a linear range from 0.01 to 1 μg/mL with a limit of detection (LOD) of 0.037 μg/mL (about 4 × 108 virion particles/mL). Furthermore, the whole-cell biosensor was demonstrated to detect the spike protein of different SARS-CoV-2 variants in human serum, providing new possibilities for the detection of future SARS-CoV-2 variants.

Per- and polyfluoroalkyl substances (PFASs) are emerging contaminants detected ubiquitously and have negative impacts on human health and ecosystem; thus, developing in-situ sensing technique is important to ensure safety. Herein, we report a novel colorimetric-based sensor with perfluoroalkyl receptor attached to citrate coated gold nanoparticles (Citrate-Au NPs) that can detect several PFASs including perfluorocarboxylates with different chain lengths (PFHxA, PFOA, PFNA, PFDA), perfluorooctanoic sulfonate (PFOS), and perfluorooctanoic phosphonate (PFOPA). The sensor detects PFASs utilizing fluorous interaction between PFASs and the perfluoroalkyl receptor of Citrate-Au NPs in a solution at a fixed salt concentration, inducing changes in nanoparticle dispersity and the solution color. The rate of spectrum shift was linearly dependent on PFASs concentrations. Citrate-Au NPs with size between 29 – 109 nm were synthesized by adjusting citrate/Au molar ratios, and 78 nm showed the best sensitivity to PFOA concentration (with level of detection of 4.96 µM). Citrate-Au NPs only interacted with PFASs with perfluoroalkyl length > 4 and not with non-fluorinated alkyl compound (nonanoic acid). The performance of Citrate-Au NP based sensor was strongly dependent on the chain length of the perfluoroalkyl group and the head functional group; higher sensitivity was observed with longer chain over shorter chain, and with sulfonate functional group over carboxylate and phosphonate. The sensor was tested using real water samples (i.e., tap water, filtered river water), and it was found that the sensor is capable of detecting PFASs in these conditions if calibrated with the corresponding water matrix. While further optimization is needed, this study demonstrated new capability of Citrate-Au NPs based sensor for detection of PFASs in water.

The invasive plant, Sphagneticola trilobata (L.) J. F. Pruski, has been known for its bioactivities and used to synthesize gold nanoparticles (AuNPs). Nonetheless, previous research has not directly compared the effectiveness of the plant parts in producing the AuNPs. The objective of this study was to compare the effectiveness of the flower and leaf of S. trilobata in synthesizing AuNPs. S. trilobata leaves and flowers were separately extracted using distilled water at 60°C for 30 min. The leaf and flower extracts were mixed with the HAuCl. 3H2O and heated to 60°C for 30 min to yield AuNPs-ALSt and AuNPs-AFSt, respectively. AuNPs were also prepared using trisodium citrate (Na3C6H5O7) as a control. The resultant AuNPs were characterized using an ultraviolet-visible spectrophotometer, particle size analyzer, and scanning electron microscope. Antioxidant activity was evaluated based on 1-diphenyl-2-picrylhydrazyl (DPPH) inhibition and anticancer activity– 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay against MCF-7 cells. The AuNPs-ALSt and AuNPs-AFSt were revealed to have better stability and smaller particle diameters. AuNPs-ALSt and AuNPs-AFSt had average particle diameters of 11.86 ± 3.37 and 34.86 ± 23.56 nm, respectively. Agglomeration was predominantly observed in AuNPs synthesized using the flower or leaf extract as stipulated to be affected by the insufficient capping agent and intense hydrolytic reaction. AuNPs-AFSt had higher DPPH antioxidant activity than AuNPs-ALSt with half-maximal inhibitory concentrations of IC50 123.44 and 168.83 ppm, respectively. Both AuNPs-ALSt and AuNPs-AFSt could inhibit 80% growth of the MCF-7; however, at lower concentrations, inhibitory effects were more pronounced in AuNPs-AFSt. Aqueous extracts of S. trilobata flowers and leaves could be used to synthesize AuNPs, whereas the former yielded AuNPs with higher biological activities.

Purpose: Gold nanoparticles (GNPs) as pharmaceutical and drug delivery tools exhibited harmful effects on human health and other living species. Quercetin (Qur) reveals various pharmacological effects specially antioxidant, anti-inflammatory and antiapoptotic. This study is directed to investigate hepatotoxicity of GNPs, in addition, to assess the impact of Qur in mitigating the toxicological effects of GNPs. Methods: Groups of rats were treated with or without sphere GNPs (10, 20 and 50 nm) and Qur (200 mg/kg b.wt.). Blood and liver samples from euthanized rats were subjected to biochemical, hematological, histopathological, and immunohistochemical investigations. Results: In comparison with 20 and 50 nm treated groups, the 10 nm GNPs significantly increased serum hepatic enzymes, aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and bilirubin. These 10 nm GNPs were associated with oxidative stress and markedly decreased antioxidant enzymes: catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase (SOD). Immunohistochemically, 10 nm GNPs expressed intense positive signals in nuclei of hepatocytes when stained with anti-caspase-3 antibody confirming extensive apoptosis. Pre-cotreatment with Qur decreased all tested hepatic enzymes and increased serum level of antioxidant enzymes compared to 10 nm GNPs. Qur treatment strongly exhibited anti-Ki67 antibody (proliferative marker) indicating high proliferation of hepatic parenchyma. Histopathologically, 10 nm GNPs revealed diffuse hydropic degenerations, severe sinusoidal congestion, coagulative necrosis, sever steatosis and diffuse hemosiderosis within the hepatic parenchyma. Qur treatment ameliorated most of these pathological effects. Conclusion: The smaller diameters of GNPs induce potential oxidative stress, cytotoxic, and apoptotic effects in hepatic tissues rather than larger ones. In addition, Qur demonstrated a significant prophylactic role against hepatotoxicity of GNPs.

A novel localized surface plasmon resonance (LSPR) system based on the coupling of gold nanomushrooms (AuNMs) and gold nanoparticles (AuNPs) is developed to enable a significant plasmonic resonant shift. The AuNP size, surface chemistry, and concentration are characterized to maximize the LSPR effect. A 31 nm redshift is achieved when the AuNMs are saturated by the AuNPs. This giant redshift also increases the full width of the spectrum and is explained by the 3D finite-difference time-domain (FDTD) calculation. In addition, this LSPR substrate is packaged in a microfluidic cell and integrated with a CRISPR-Cas13a RNA detection assay for the detection of the SARS-CoV-2 RNA targets. Once activated by the target, the AuNPs are cleaved from linker probes and randomly deposited on the AuNM substrate, demonstrating a large redshift. The novel LSPR chip using AuNP as an indicator is simple, specific, isothermal, and label-free; and thus, provides a new opportunity to achieve the next generation multiplexing and sensitive molecular diagnostic system.

BACKGROUND: Gold nanoparticles are of great significance in the development of multifunctional transdermal drug delivery systems. Smaller gold nanoparticles can penetrate the dermis through the intercellular pathway, but are limited to their easy agglomeration and colloidal morphology, which makes it difficult to exert effects on low delivery efficiency. OBJECTIVE: To develop an ultrasound-optimized hydrogel delivery system by combining phase change nanodroplets with bio-adhesive hydrogel for percutaneous delivery of gold nanoparticles. METHODS: The ultrasound-responsive nanodroplets loaded with gold nanoparticles were prepared by the emulsion solvent evaporation method and loaded into the polydopamine-modified methylacryloyl gelatin hydrogel to prepare a composite hydrogel scaffold. The structure and chemical composition of the ultrasound-responsive nanogold carrier were characterized. The microstructure, porosity, permeability, rheology, in vitro hemostasis, and antibacterial properties of the composite hydrogel were characterized. The cell compatibility of the hydrogel scaffold was evaluated by live/dead staining, and the optimization effects of low-intensity pulsed ultrasound on the permeability, porosity, and mechanical properties of hydrogel were evaluated. RESULTS AND CONCLUSION: (1) Transmission electron microscopy and ultraviolet-visible spectroscopy proved the successful construction of nanogold carriers. The particle size and potential results demonstrated that the synthesized nanoscaled ultrasonic responsive carrier had good stability. (2) Live/dead cell staining proved that the prepared composite hydrogel scaffold had certain biocompatibility. (3) Scanning electron microscopy exhibited that the prepared composite hydrogel scaffold had a porous network structure, and numerous pores of about 2 μm appeared inside the macropores after the addition of nanodroplets and ultrasonic irradiation. The permeability experiment displayed that low-intensity pulsed ultrasound could optimize the porosity and permeability of hydrogel materials. The hemostatic performance of the composite hydrogel scaffold was better than that of the hemostatic sponge and polydopamine@ methylacrylylated gelatin hydrogel scaffold. Under the irradiation of low-intensity pulsed ultrasound, the composite hydrogel scaffolds had good antioxidant effects and antibacterial properties. (4) Thermal imaging results manifested that gold nanoparticles were encapsulated in ultrasound-responsive nanobubbles, and more uniform dispersion could be obtained under ultrasonic excitation. (5) The results of the mechanical property test demonstrated that the storage modulus of the hydrogel increased before and after loading gold nanoparticles-nanodroplets, which showed stronger mechanical properties. The elongation at break was 122%, and the ductility was better than that without gold nanoparticles-nanodroplets (P < 0.05). (6) These findings indicate that the composite hydrogel scaffold has good biocompatibility, antibacterial property, oxidation resistance, and hemostatic effect. [ABSTRACT FROM AUTHOR]