Synthesis Of AuNPs Research Articles

Supported of gold nanoparticles on carboxymethyl lignin modified magnetic nanoparticles as an efficient catalyst for reduction of nitroarenes and treatment of human melanoma

This article represents the synthesis and characterizations of Au NPs immobilized and carboxymethyl lignin (CML) modified Fe3O4 nanoparticles (Fe3O4@CML/Au NPs) following a bio-inspired protocol without the participation of any toxic and harmful reductant or stabilizers. Following various physicochemical methodologies, such as FT-IR, FE-SEM, TEM, EDX, XRD, VSM, and ICP-OES, the textural characteristics and different structural aspects were evaluated. The Fe3O4@CML/Au NPs nanocomposite was subsequently explored towards the catalytic reduction of diverse aromatic nitro functions using green conditions. An excellent yield were achieved within very short reaction time. Nine recycling runs of the nanocatalyst were completed without a discernible loss of catalytic activity, thanks to its easy magnetic recovery. The DPPH assay was carried out to examine the antioxidant effectiveness. The Fe3O4@CML/Au NPs nanocomposite inhibited half of the DPPH in a 250 μg/mL solution. To measure the anti-human melanoma efficacy of Fe3O4@CML/Au NPs nanocomposite, MTT assay was applied on HT144, MUM2C, IPC-298 and SKMEL24 cell lines. Fe3O4@CML/Au NPs nanocomposite had high anti-human melanoma efficacy on above tumor cells. The best finding of anti-human melanoma properties of Fe3O4@CML/Au NPs nanocomposite was seen in the case of the SKMEL24 cell line. The IC50 of Fe3O4@CML/Au NPs nanocomposite was 137, 145, 185, and 125 μg/mL against HT144, MUM2C, IPC-298 and SKMEL24 cells, respectively. This research exhibited remarkable anti-human melanoma and antioxidant efficacies of Fe3O4@CML/Au NPs nanocomposite in the in vitro condition.

Green synthesis of gold nanoparticles using macroalgae Halimeda macroloba extract and their photocatalytic degradation of methylene blue and methyl orange

AbstractGreen synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical and environmental applications. This study reported the novel eco‐friendly synthesis of AuNPs using green macroalgae Halimeda macroloba (HM) extract and evaluate their photocatalytic potential. The green synthesized H. macroloba mediated gold nanoparticles (HM‐AuNPs) was characterized using UV–visible spectrophotometry, Fourier‐transform infrared (FT‐IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscope‐energy dispersive spectroscopy, x‐ray photoelectron spectroscopy (XPS), and particle size distribution (PSD) anlaysis. The UV–visible spectrum shows a sharp intense plasmonic resonance peak at 543 nm. The bioactive compounds present in HM were primarily responsible for the biological reduction of gold ions validated by FT‐IR analysis. XRD analysis proved the crystalline face centered cubic structure of the HM‐AuNPs. The average particle size of 18.72 nm and morphological evidences were obtained from the images from TEM. The metallic form of biosynthesised HM‐AuNPs was confirmed by XPS results with a distinctive binding energy. The photocatalytic degradation ability of the green synthesized HM‐AuNPs was investigated against the methylene blue (MB) and methylene orange (MO) dyes under sunlight irradiation. The HM‐AuNPs exhibited 97.23% and 89.91% photocatalytic activity against MB and MO after 90 min of exposure to sunlight, respectively. The overall results of this research indicate that H. macroloba mediated HM‐AuNPs can be used as an effective option for the degradation of industrial dyes.

Green synthesis of gold nanoparticles obtained from Punica granatum flower extract for phytochemical determination and antibacterial activity

Numerous biomedical applications such as biological detection, drug delivery, diagnostic imaging and tissue engineering, have incorporated nanotechnology. Parts of the pomegranate (Punica granatum) flower are known to have strong antibacterial properties. In this study, the anti-susceptibility test was used to look into the green synthesis of gold nanoparticles using Punica granatum and the inhibitory effect of these particles. According to the current study, prepared AuNPs were evaluated using a variety of methods including UV-visible spectrophotometry, FTIR, SEM and GC-MS to identify the phytochemicals. The bacterial and fungal species Candida albicans and Malassezia furfur that are inhibited by the synthetic colloidal gold nanoparticles made with Punica granatum flower extract include Escherichia coli, Pseudomonas, Staphylococcus, Klebsiella pneumoniae and Protea. In this work, we describe a simple, quick and reproducible method for the environmentally friendly synthesis of AuNPs without the need for expensive reducing agents. Simple incubation of a flower extract with aqueous gold ions at ambient temperature resulted in ‘medium monodisperse’ nanoparticles, suggesting that the plant extract acted as a strong reducing agent.

Dissolved black carbon mediated photo-reductive formation of colloidal-stable gold nanoparticles

Gold nanoparticles (AuNPs) have garnered attention as an emerging class of nanomaterials due to their wide range of applications across various sectors. This study reported that the dissolved black carbon (DBC) can mediate Au(III) photoreduction and form uniform and colloidal-stable AuNPs in aqueous solutions at room temperature under sunlight irradiation. Transmission electron microscopy images revealed that the average diameter of the photo-formed AuNPs was approximately 16 nm, and these nanoparticles maintained considerable colloidal-stability over time. Notably, no change in average size was observed following a 23-day storage period at 4°C in a light-free environment. The photo-formed superoxide (O2·-) is the crucial reductant in this reaction. O2·-, generated by DBC, reduces Au(III) to Au(I), which is then further reduced to Au(0), culminating in the formation of AuNPs. Furthermore, our findings illustrate that an increase in reaction pH shifts the predominant species of Au(III) in the solution toward forms with a lower redox potential, thereby decreasing the oxidizability of Au(III) and consequently decelerating the photoreduction process. A mildly acidic environment is more favorable for the DBC-mediated photoformation of AuNPs. This study elucidates that DBC can be observed as a novel reductant to complete the photo-reductive formation of AuNPs under low-cost conditions, opening up a new possibility for the green synthesis of AuNPs.

Abstract 5758: Gold nanoparticles with graphene quantum dots as drug delivery platforms for anticancer applications

Abstract Cancer is a global health challenge that has a profound impact on the lives of people worldwide, either directly affecting individuals or their loved ones. Among the various types of cancer, prostate cancer stands out as one of the most prevalent in men. Prostate cancer is primarily identified by symptoms related to urinary health. Conventional medical approaches often rely on drug-based treatments to address this form of cancer. However, like many treatments, drug therapy comes with its own set of challenges. In our research project, we propose an alternative approach for managing prostate cancer. Our innovative idea centers around utilizing nanoparticles as a means of drug delivery. Specifically, we are investigating the use of Taxol, also known as Paclitaxel, as the drug of interest. Taxol possesses a significant challenge due to its hydrophobic nature, which hinders its circulation within the bloodstream. Its solubility is extremely low, at 0.00025 mg per milliliter. To overcome this limitation, we have undertaken the synthesis and integration of AuNPs (gold nanoparticles) with GQDs (graphene quantum dots). This combination enhances the drug's hydrophilic properties, making it more effective in transportation. Our research has led us to conduct experiments on prostate cancer cells (specifically the PC3 cell line). We aim to compare the IC50 value, which represents the drug concentration required to kill 50% of the cancer cells, when using the drug alone versus when using the drug in conjunction with the nanoparticles. Taxol's IC50 value is determined to be 5.73nM. In addition to assessing the impact on cancer cells, we have also examined how the nanoparticles interact with blood, and how this interaction influences the morphology of red blood cells. Furthermore, we have characterized the system using various analytical techniques, including FTIR, NMR, Fluorescence, and UV-Vis spectroscopy. To pinpoint the accumulation sites of the drug and delivery agents, we have employed confocal microscopy on the cancer cells. Our ultimate objective is to equip the drug with the necessary components to facilitate its entry into prostate cancer cells effectively. Citation Format: Fabiola M. Rosa Suárez, Gerardo Morell, Brad Weiner, Nataniel Medina, Wenndy Pantoja. Gold nanoparticles with graphene quantum dots as drug delivery platforms for anticancer applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5758.

Green synthesis of silver and gold nanoparticles in Callistemon viminalis extracts and their antimicrobial activities.

In the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV-Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV-Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone of inhibition 15.5±0.75 and 15±0.85mm was observed for Ag NPs against E. coli and P. aeruginosa. Similarly, Trichoderma sp. and Aspergillus sp. were inhibited by Ag NPs up to 13.5±0.95 and 13±0.70mm. This work will open doors for the development of new antimicrobial agents using green chemistry.

Green synthesis, characterization, anti-cancer and antimicrobial activity of AuNPs extracted from Euphorbia antiquorum stem and flower: Experimental and theoretical calculations

Green nanoparticles derived from medicinal plants have attained popularity in recent years. Gold nanoparticles, with their distinct biological properties, are being investigated. Several studies have shown that gold nanoparticles are effective in anticancer treatments. In this study, Euphorbia antiquorum (EA) extract was used in the green synthesis of gold nanoparticles. The gold nanoparticles (EA-AuNps) were studied with ultraviolet–visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The antimicrobial and antioxidant activity of EA-AuNps were assessed and investigated. The EA-AuNps were tested against the MCF-7 breast cancer cell line. The main chemical components of the Euphorbia antiquorum plant include antiquol, camelliol, euphol, euphorbol, ingenol, isohelianol, and taraxerol. These molecules were optimized using density functional theory/B3LYP functional-6-311G** basis sets, and their physical and chemical properties were determined & discussed. Furthermore, the optimized molecules have been docked against Vascular endothelial growth factor receptor-2 (VGEFR-2), Extracellular signal-regulated kinase-2 (ERK-2), and Tumor necrosis factor receptor-1 (TNFR-1). The results suggest that euphol and euphorbol could be among the most potent macromolecule inhibitors.

Modulation of calcium-influx by carboxymethyl tamarind‑gold nanoparticles promotes biomineralization for tissue regeneration

Gold nanoparticles (AuNPs) have been reported to modulate bone tissue regeneration and are being extensively utilized in biomedical implementations attributable to their low cytotoxicity, biocompatibility and simplicity of functionalization. Lately, biologically synthesized nanoparticles have acquired popularity because of their environmentally acceptable alternatives for diverse applications. Here we report the green synthesis of AuNPs by taking the biopolymer Carboxymethyl Tamarind (CMT) as a unique reducing as well as a stabilizing agent. The synthesized CMT-AuNPs were analyzed by UV–vis spectrophotometer, DLS, FTIR, XRD, TGA, SEM and TEM. These results suggest that CMT-AuNPs possess an average size of 19.93 ± 8.52 nm and have long-term stability. Further, these CMT-AuNPs promote the proliferation together with the differentiation and mineralization of osteoblast cells in a “dose-dependent” manner. Additionally, CMT-AuNPs are non-toxic to SD rats when applied externally. We suggest that the CMT-AuNPs have the potential to be a suitable and non-toxic agent for differentiation and mineralization of osteoblast cells in vitro and this can be tested in vivo as well.

Gold nanoparticles synthesis mediated by fungus isolated from aerobic granular sludge: Process and mechanisms

Due to the low toxicity, biocompatibility and eco-friendliness, microorganisms have received a lot of attention for gold nanoparticles (AuNPs) synthesis. This work isolated a fungal strain capable of efficiently generating AuNPs from aerobic granular sludge, named XY3. Comparison of 18S rDNA sequence results showed that fungus XY3 belongs to Candida rugopelliculosa. AuNPs were synthesized by initiating an Au3+-induced stress response that prompted the reduction of Au3+ to Au0 by the fungus XY3. It is worth noting that the addition of nutritional substrates weakens the stress response induced by Au3+, resulting in a decrease in the yield of AuNPs. As evidenced by nystatin inhibition studies, the synthesis of AuNPs is based on biochemical reactions rather than purely physical changes. The XRD results suggested that XY3-secreted biomolecules were involved in the reduction of Au3+ and AuNPs synthesis. The results of the three variation patterns of reducing power, biomolecules, and AuNPs absorbance revealed that Au3+ reduction was mostly dependent on the reducing polysaccharides. In addition, extracellular proteins were shown to be involved in the synthesis of AuNPs, which is responsible for the uniform distribution of AuNPs. This work provided a wide and cost-effective seed source for AuNPs synthesis, and also offered a resourceful solution for residual sludge treatment of fungal type aerobic granular sludge.

Size-Dependent Surface Plasmon Resonance of Green Synthesized Gold Nanoparticles Using <i>Mangifera indica</i> Fruit Peel Extract

Gold nanoparticles (AuNPs) have been studied for various applications due to their adjustable surface plasmon resonance (SPR) properties and facile synthesis. AuNP production has predominantly relied on synthetic chemicals to reduce and stabilize gold precursors. There is an increasing demand for environmentally friendly synthesis methods due to ecological concerns. This work introduced a green synthesis approach using Mangifera indica fruit peel extract. Obtained through maceration of dried fruit peels, this extract served as a reducing agent for gold precursors at 80°C. We obtained varying sizes of AuNPs by manipulating the initial concentration of gold ions: 0.1mM, 0.25mM, and 0.5mM. The UV-vis spectroscopy results confirmed the signature SPR peak for AuNPs around 530 nm, with peak shifts highly dependent on the gold ion concentration. The dynamic light scattering (DLS) measurements revealed hydrodynamic diameters of 89.5 nm, 121.5 nm, and 144.5 nm for the various concentrations. The Fourier transform (FTIR) analysis identified the role of inherent phenols and flavonoids in gold precursor reduction. This study emphasizes the potential of Mangifera indica fruit peel extract as a viable alternative for AuNP synthesis. This study could possibly boost the utilization of gold nanoparticles towards applications in biology and medicine as well as environmental remediation.

Synthesis of AuNPs in microemulsion and nano-emulsion systems using aqueous extract of C. chayamansa leaves as reducing agent

This paper explores the synthesis and characterization of gold nanoparticles using various microemulsion and nano-emulsion systems. The pseudo-ternary system consists of an aqueous phase / Brij O10: 1,2-hexanediol (1:1) / castor oil; the aqueous phases include the aqueous extract of Chaya Maya (Cnidoscolus chayamansa) leaves or aqueous extract of Chaya maya leaves combined with the inorganic gold precursor. Chaya maya extract act as a reducing agent for gold (III) ions. The influence of aqueous phase content and surfactant concentration on gold nanoparticles size, morphology, and stability is investigated. Dynamic Light Scattering, Scanning Transmission Electron Microscopy, and UV-Vis spectroscopy are employed to analyze the synthesized gold nanoparticles. The sizes of the gold nanoparticles obtained were influenced by the system composition and are within the range of 19–40 nm. Results indicate that increasing the aqueous phase content generally leads to larger nanoparticle sizes, while higher surfactant concentrations yield smaller nanoparticles. A transition from microemulsion to nano-emulsion is observed at a specific aqueous phase content, marking a shift in nanoparticle size distribution and growth behavior. Additionally, microemulsion and nano-emulsion systems provide stability to gold nanoparticles, as evidenced by measured Zeta potentials indicating negatively charged surfaces conducting to colloidal stability. Also, remark that the use of organometallic precursors is no needed to obtain very good results on nanoparticle size and shape when O/W systems are used to this end. These findings highlight the potential of tailored microemulsion and nano-emulsion systems formulated with low-toxic components for controlling gold nanoparticles properties under mild conditions, contributing to the development of advanced gold nanoparticles-based materials with enhanced functionalities, with implications for diverse applications.

Green synthesis of Au Nps using Hemidesmus indicus root extract (Hire) and investigating its potential biomedical efficacies

Green synthesis of Au Nps using Hemidesmus indicus root extract (Hire) and investigating its potential biomedical efficacies

Plasmon-based colorimetric assay using green synthesized gold nanoparticles for the detection of bisphenol A.

Herein, we report a green synthesized gold nanoparticle (AuNPs) based colorimetric detection of bisphenol A (BPA). The AuNPs were synthesized using khat leaf extract as a reducing agent by optimizing factors affecting the AuNPs synthesis, including gold precursor concentration (1mM), and reaction temperature (60°C). The AuNPs characterization was carried out using ultraviolet-visible spectrophotometry and transmission electron microscopy, and it was found spherical with an average particle size of 17.3 ± 3.7nm. A colorimetric nanosensor was developed by conjugation of bio-inspired AuNPs with BPA-specific aptamer for a quick and easy detection of BPA in plastic bottled water. The colorimetric assay relies on the strong affinity of BPA for aptamer, which causes detachment of the aptamer from the AuNPs surface in the presence of BPA inducing AuNPs aggregation. To achieve the colorimetric detection of BPA, the concentrations of NaCl and aptamer were optimized. The detection of BPA was monitored visually using a naked eye, as well as quantitatively using an ultraviolet-visible spectrophotometer. The method visual limit of detection (LOD) was determined to be 0.1ng/mL and reached 0.09ng/mL using ultraviolet-visible spectrophotometer. The method demonstrated very good linearity (R2 = 0.9986) in the range of 0.1-100ng/mL. The proposed method showed high sensitivity to BPA detection in plastic bottled water with 86.7-98.0%, recovery. Therefore, the proposed colorimetric nanosensor can be used for determination of BPA in plastic bottled waters with reliable performance at lower concentrations.

The application of bacteria-derived dehydrogenases and oxidases in the synthesis of gold nanoparticles.

In this work the green synthesis of gold nanoparticles (Au-NPs) using the oxidoreductive enzymes Myriococcum thermophilum cellobiose dehydrogenase (Mt CDH), Glomerella cingulata glucose dehydrogenase (Gc GDH), and Aspergillus niger glucose oxidase (An GOX)) as bioreductants was investigated. The influence of reaction conditions on the synthesis of Au-NPs was examined and optimised. The reaction kinetics and the influence of Au ions on the reaction rate were determined. Based on the kinetic study, the mechanism of Au-NP synthesis was proposed. The Au-NPs were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). The surface plasmon resonance (SPR) absorption peaks of the Au-NPs synthesised with Mt CDH and Gc GDH were observed at 535nm, indicating an average size of around 50nm. According to the image analysis performed on a TEM micrograph, the Au-NPs synthesized with Gc GDH have a spherical shape with an average size of 2.83 and 6.63nm after 24 and 48h of the reaction, respectively. KEY POINTS: • The Au NPs were synthesised by the action of enzymes CDH and GDH. • The synthesis of Au-NPs by CDH is related to the oxidation of cellobiose. • The synthesis of Au-NPs by GDH was not driven by the reaction kinetic.

Amelioration of gold nanoparticles mediated through Ocimum oil extracts induces reactive oxygen species and mitochondrial instability against MCF-7 breast carcinoma.

Phytomedicines are potential immunity-boosting components with effective anticystic properties, minimal side effects, and biomedical applications, making them valuable for combating various diseases. India is renowned globally for Ayurveda, an ancient treatment methodology known for its holistic approach in identifying the root cause of diseases. Tulsi (Ocimum sanctum) is a common household medicine in India. While essential oils from plants like Tulsi have long been recognized for their medicinal properties, there is a gap in understanding their potential in synthesizing gold nanoparticles (AuNPs) and their efficacy against breast carcinoma, particularly in the context of immunosuppressive conditions. We investigated the potential application of essential oils isolated from O. sanctum in the synthesis of AuNPs and their efficacy against MCF-7 breast carcinoma. Gas chromatography-mass spectroscopy identified compounds with potential anticancer effects against breast cancer cells. Synthesised AuNPs displayed high hemocompatibility and antimicrobial activity against nosocomial Pseudomonas aeruginosa, Escherichia coli, Vibrio cholerae, and Bacillus subtilis strains. Os-AuNPs induced chromosomal instability and mitotic arrest in the G2/M cell cycle phase. Subsequent fluorescence and cell cytometry studies demonstrated the systemic release of ROS, depolarisation of mitochondrial membrane potential, and production of apoptotic bodies. DNA damage and comet assays confirmed the anticancer potential of synthesised AuNPs. This study illuminates the potential of O. sanctum-derived AuNPs in breast carcinoma treatment, paving the way for future AuNP-based therapies in biomedicine.

Detection and quantification of Cu2+ ion using gold nanoparticles via Smartphone-based digital imaging colorimetry technique

Heavy metals are the main pollutants in the environment because of their toxic effects on human health. One of the heavy metals in drinking water is copper ion (Cu2+). In this study, gold nanoparticles (AuNPs) were used to detect Cu2+ using a smartphone via the digital image colorimetry (DIC) method. The synthesis of AuNPs was carried out by chemical reduction method from HAuCl4 solution with sodium citrate as a reducing agent. The formation of AuNPs was confirmed using UV–vis spectroscopy, TEM, XRD, and FTIR. AuNPs (45 mM) which had a wine red color selectively changed color to blue after the addition of Cu2+ ions. The color change of AuNPs was monitored using a smartphone and validated with a UV–vis spectrophotometer. Particle size analysis concluded that the presence of Cu2+ ions could cause AuNPs to agglomerate, making the particle size larger. The standard curve for Cu2+ ions shows good linear results in the concentration range of 15–90 mM using the DIC method. The accuracy of the proposed DIC was tested by checking the actual concentration and an accuracy of 97.6% was obtained. This method also shows good results for sensitivity and selectivity, with a detection limit of 8.3 mM.

Toward environmentally favorable nano-sensing by production of reusable gold nanoparticles from gold nano-waste: life cycle and nanocircular economy implications

This study aids in the identification of environmentally friendly and sustainable applications of gold nanoparticles.

Optical Modulation of the Blood-Brain Barrier for Glioblastoma Treatment.

The blood-brain barrier (BBB) is a major obstacle to the diagnostics and treatment of many central nervous system (CNS) diseases. A prime example of this challenge is seen in glioblastoma (GBM), the most aggressive and malignant primary brain tumor. The BBB in brain tumors, or the blood-brain-tumor barrier (BBTB), prevents the efficient delivery of most therapeutics to brain tumors. Current strategies to overcome the BBB for therapeutic delivery, such as using hyperosmotic agents (mannitol), have impeded progress in clinical translation limited by the lack of spatial resolution, high incidences of complications, and potential for toxicity. Focused ultrasound combined with intravenously administered microbubbles enables the transient disruption of the BBB and has progressed to early-phase clinical trials. However, the poor survival with currently approved treatments for GBM highlights the compelling need to develop and validate treatment strategies as well as the screening for more potent anticancer drugs. In this protocol, we introduce an optical method to open the BBTB (OptoBBTB) for therapeutic delivery via ultrashort pulse laser stimulation of vascular targeting plasmonic gold nanoparticles (AuNPs). Specifically, the protocol includes the synthesis and characterization of vascular-targeting AuNPs and a detailed procedure of optoBBTB. We also report the downstream characterization of the drug delivery and tumor treatment efficacy after BBB modulation. Compared with other barrier modulation methods, our optical approach has advantages in high spatial resolution and minimally invasive access to tissues. Overall, optoBBTB allows for the delivery of a variety of therapeutics into the brain and will accelerate drug delivery and screening for CNS disease treatment. Key features • Pulsed laser excitation of vascular-targeting gold nanoparticles non-invasively and reversibly modulates the blood-brain barrier permeability. • OptoBBTB enhances drug delivery in clinically relevant glioblastoma models. • OptoBBTB has the potential for drug screening and evaluation for superficial brain tumor treatment.

Advances in Gold Nanoparticles: Synthesis, Functionalization Strategies, and Theranostic Applications in Cancer.

Cancer is among the leading causes of mortality and morbidity in the world. Metallic nanoparticles, especially gold nanoparticles (AuNPs) have emerged to be attractive systems to circumvent the associated adverse effects. By the virtue of their unique properties of tunable size, shape, composition, optical properties, biocompatibility, minimal toxicity, multivalency, fluorescence-luminescence property and surface plasmon resonance; AuNPs have the potential to be used as drug delivery systems. It is vital to ensure that the drug reaches the target site of action for selective kill of cancer cells without harm to healthy cells. These AuNPs can be easily functionalized with a wide array of ligands like peptides, oligonucleotides, polymers, carbohydrates for active targeting to ensure site specific delivery and reduced systemic effects. AuNPs have been in-vestigated as carriers for gene delivery, drug delivery with or without photothermal therapy, in diagnosis based on radiation or spectroscopy. They have emerged as attractive theranostic approach in the overall management of cancer with superior benefit to risk features. In this review, we have discussed synthesis of different AuNPs (nanorods, spherical nanoparticles, and hollow AuNPs), their functionalization strategies and their applications in biomedical domain. Various research studies and clinical trials on application of AuNPs in diagnosis and therapeutics are highlighted.

Biosynthesis and Characterizations of Gold Nanoparticles (AuNPs) Prepare Using Different Age Classes of <i>Marphysa moribidii </i>(Polychaetes) Extract as Biogenic Reducing Agents

The utilization of Marphysa moribidii, a local marine baitworm (Polychaeta), as a possible biogenic reducing agent in the synthesis of AuNPs was successfully performed. In this particular study, different age classes of M. moribidii based on their body widths that classified as Class I (3 – 5 mm), Class II (6 – 8 mm), and Class III (9 – 11 mm) were employed in the biosynthesis of AuNPs. The use of different age classes of M. moribidii for the biosynthesis of AuNPs is a fascinating approach that takes advantage of the varying metabolic activities of the different age groups. The colour changes of the solution from yellow to red ruby is the initial observation for the successful biosynthesis of AuNPs where AuNPs_II shows the fastest changes of colour after 2 h incubation and maintains stable for over 1 month of storage. Further confirmation was depicted from the existence of surface Plasmon resonance (SPR) absorption peaks in a range of 545 – 552 nm from UV-Vis spectroscopy. TEM analysis shows the formation of spherical-like shape of biosynthesis AuNPs with average particle size around 42 – 57 nm where AuNPs_II had the smaller particle size. Lastly, the antibacterial assessment of biosynthesized produced from different age classes of M. moribidii had good antibacterial activity against Gram-negative bacteria, but poor activity against Gram-positive bacteria. AuNPs produced from Class II M. moribidii (AuNPs_II) provide the highest ZOI value of 13 mm. The utilization of different age classes of M. moribidii for the biosynthesis of metal nanoparticles is an interesting pathway for designing a novel method that can be considered nature-friendly, safe, and hopeful for the future.