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Recent advances in the treatment of colorectal cancer (CRC) have highlighted the integration of metal-based nanoparticles into sophisticated therapeutic strategies. This examination delves into the potential applications of these nanoparticles, particularly in augmenting the effectiveness of photodynamic therapy (PDT) and targeted drug delivery systems. Metal nanoparticles, such as gold (Au), silver (Ag), and copper (Cu), possess distinctive characteristics that make them valuable in cancer treatment. Beyond their role as drug carriers, these nanoparticles actively engage in therapeutic processes like apoptosis induction, enhancement of photothermal effects, and generation of reactive oxygen species (ROS) crucial for tumor cell eradication. The utilization of metal nanoparticles in CRC therapy addresses significant challenges encountered with conventional treatments, such as drug resistance and systemic toxicity. For example, engineered Au nanoparticles enable targeted drug delivery, reducing off-target effects and maximizing therapeutic efficacy against cancerous cells. Their capacity to absorb near-infrared light allows for localized hyperthermia, effectively eliminating cancerous tissues. Similarly, Cu nanoparticles exhibit potential in overcoming drug resistance by enhancing the efficacy of traditional chemotherapeutic agents through ROS production and improved drug stability. This review underscores the significance of precision medicine in CRC care. Through the integration of metal nanoparticles alongside complementary biomarkers and personalized treatment strategies, a more efficient and tailored therapeutic approach can be achieved. The synergistic effect of PDT in combination with metal nanoparticles introduces a novel methodology to CRC treatment, offering a dual-action mechanism that enhances tumor targeting while minimizing undesirable effects. In conclusion, the integration of metal-based nanoparticles in CRC therapy marks a significant progress in oncological treatments. Continued research is imperative to comprehensively grasp their mechanisms, optimize their clinical utility, and address potential safety considerations. This thorough assessment aims to pave the way for future advancements in CRC treatment through the application of nanotechnology and personalized medicine strategies., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Background: Cathepsin B, a cysteine protease, is considered a potential biomarker for early diagnosis of cancer and inflammatory bowel diseases. Therefore, more feasible and effective diagnostic method may be beneficial for monitoring of cancer or related diseases., Results: A phage-display library was biopanned against biotinylated cathepsin B to identify a high-affinity peptide with the sequence WDMWPSMDWKAE. The identified peptide-displaying phage clones and phage-free synthetic peptides were characterized using enzyme-linked immunosorbent assays (ELISAs) and electrochemical analyses (impedance spectroscopy, cyclic voltammetry, and square wave voltammetry). Feasibilities of phage-on-a-sensor, peptide-on-a-sensor, and peptide-on-a-AuNPs/MXene sensor were evaluated. The limit of detection and binding affinity values of the peptide-on-a-AuNPs/MXene sensor interface were two to four times lower than those of the two other sensors, indicating that the peptide-on-a-AuNPs/MXene sensor is more specific for cathepsin B (good recovery (86-102%) and %RSD (< 11%) with clinical samples, and can distinguish different stages of Crohn's disease. Furthermore, the concentration of cathepsin B measured by our sensor showed a good correlation with those estimated by the commercially available ELISA kit., Conclusion: In summary, screening and rational design of high-affinity peptides specific to cathepsin B for developing peptide-based electrochemical biosensors is reported for the first time. This study could promote the development of alternative antibody-free detection methods for clinical assays to test inflammatory bowel disease and other diseases., (© 2023. The Author(s).)

This study developed a simple and rapid strategic technique to detect ractopamine (chemical growth-promoting agent) in pork. Two highly sensitive and specific gold nanoparticle-based portable sensors, i.e., localized surface plasmon resonance (LSPR) sensors, and lateral flow immunoassay (LFIA) strips were developed to detect veterinary drug residues in food products, that have detrimental effects on humans. Optimization studies were conducted on several sensor devices to improve sensitivity. Each sensor comprised functionalized gold nanoparticles conjugated with ractopamine antibodies. The LSPR sensor chip achieved excellent detection sensitivity = 1.19 fg/mL and was advantageous for quantitative analysis due to its wide dynamic range. On the other hand, LFIA strips provided visual test confirmation and achieved 2.27 ng/mL detection sensitivity, significantly less sensitive than LSPR. The complementary sensors help overcome each other's shortcomings with both the techniques offering ease of use, affordability and rapid diagnosis. Thus, these sensors can be applied on-site for routine screening of harmful drug residues in pork meat. They also provide useful direction for advanced technologies to enhance assay performance for detecting various other food drug contaminants.

Herein, we have developed peptide-coated gold nanoparticles (AuNPs) based on localized surface plasmon resonance (LSPR) sensor chips that can detect fipronil with high sensitivity and selectivity. The phage display technique has been exploited for the screening of highly specific fipronil-binding peptides for the selective detection of the molecule. LSPR sensor chips are fabricated initially by attaching uniformly synthesized AuNPs on the glass substrate, followed by the addition of screened peptides. The parameters, such as the peptide concentration of 20 µg mL -1 and the reaction time of 30 min, are further optimized to maximize the efficacy of the fabricated LSPR sensor chips. The sensing analysis is performed systematically under standard fipronil solutions and spike samples from eggs. The developed sensor has shown excellent sensitivity towards both standard solutions and spike samples with limit of detection (LOD) values of 0.01 ppb, respectively. Significantly, the developed LSPR sensor chips offer distinct features, such as a facile fabrication approach, on-site sensing, rapid analysis, cost-effectiveness, and the possibility of mass production, in which the chips can be effectively used as a promising and potential on-site detection tool for the estimation of fipronil.

The excessive use of food additives in manufactured food products negatively affects their quality and potentially impacts human health. In the present study, a composite consisting of gold nanoparticles decorated on tungsten carbide (AuNP-WC) was successfully fabricated using a facile and cost-effective ultrasonication technique. Compared to a bare glassy carbon electrode (GCE), AuNP-GCE, and WC-GCE, the AuNP-WC-GCE demonstrated excellent sensing performance for tert-butylhydroquinone (TBHQ) when used as an electrocatalyst in 0.05 M phosphate buffer solution (PBS), with a low working potential and a high peak current. In particular, the composite was able to detect the oxidation of TBHQ within a linear concentration range of 5 to 75 nM, with an extremely low detection limit of 0.20 nM. The practicability of the sensor was also assessed in the analysis of TBHQ in real samples of soybean oil, blended oil, and red wine, with satisfactory recovery rates obtained., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Meat is often wasted due to the perceived concerns of its shelf life and preservation. Specifically, in meat formation, biogenic amines (BAs) are the major agents to spoil them. Herein, we have developed a carbon disulfide (CS 2 ) added colloidal gold nanoparticles-based colorimetric sensor for the rapid and on-site detection of biogenic amines. Transmission electron microscopy is used to observe the morphological changes in colloidal gold nanoparticles and aggregation behavior of CS 2 added to the colloidal gold nanoparticles' solution. Raman spectroscopic analysis is further used to characterize the peaks of CS 2 , Cad and CS 2 -Cad molecules. Absorption spectroscopy is used to estimate the colorimetric differences and diffuse reflectance spectra of the samples. The sensing analysis is performed systematically in the presence and absence of CS 2 . CS 2 added colloidal gold nanoparticles colorimetric sensor detected the BAs with a limit of detection (LOD) value of 50.00 µM. Furthermore, the developed sensor has shown an LOD of 50.00 µM for the detection of multiple BAs at a single time. The observed differences in the colorimetric and absorption signals indicate that the structure of BAs is converted to the dithiocarbamate (DTC)-BA molecule, due to the chemical reactions between the amine groups of BAs and CS 2 . Significantly, the developed colorimetric sensor offers distinct features such as facile fabrication approach, on-site sensing strategy, rapid analysis, visual detection, cost-effective, possibility of mass production, availability to detect multiple BAs at a single time and appreciable sensitivity. The developed sensor can be effectively used as a promising and alternative on-site tool for the estimation of BAs.

Human health and environment have been continuously getting exposure to toxic chemicals including nanomaterial; therefore, nontoxicity has recently attracted huge amount of attention. In this study, RU-AgNPs were synthesized by a green synthesis procedure and evaluated for their toxicity in human umbilical vein endothelial cells (HUVECs) as well as on zebrafish embryos via apoptotic pathway. The synthesized RU-AgNPs were average in size (20-25 nm) with a negative surface charge of -13.43 mV. As a result, RU-AgNPs potentiated the formation of reactive oxygen species (ROS) in HUVECs as confirmed by the results of immunoblotting analysis using apoptotic markers, such as Bax, Bcl2, and cytochrome C. Moreover, the induction of apoptosis in HUVECs was also authenticated in a dose-dependent manner after the treatment with RU-AgNPs by the Incucyte analysis. In vivo trials conducted on zebrafish visualized the mortality, malformation, and imbalanced in the heart rate, and cell death of the whole embryo, including severe morphological changes in the yolk sac and the tail of zebrafish. Furthermore, the results of western blot analysis demonstrated the increasing intensity of apoptotic biomarkers such as Bax, Bcl2, and Cyto C, including enhanced production of ROS, validating the cell death in zebrafish larvae. In addition, chemically functionalized silver nanoparticles found to be more cytotoxic than biogenic functionalized silver nanoparticles. Above-mentioned findings clearly demonstrate that Ru-AgNPs cause the toxicity via ROS-induced apoptotic pathway. Therefore, it is necessary to decide RU-AgNPs toxicity levels before being used in any biomedical application., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We report a facile method for sample preparation and sensitive on-site detection of melamine in powdered infant formula and chocolate using Raman spectroscopy on sharp-edged gold nanostars (AuNSs). The aggregation of AuNSs by sodium chloride (1.2 M) facilitates the more sensitive detection of melamine in comparison with spherical gold nanoparticles (AuNPs). Density functional theory quantum mechanical calculations were performed to determine the energetic stability on gold cluster atoms. Our spectroscopic data indicated that AuNSs are an efficient platform for detecting melamine in food mixtures. The detection limits of melamine in powdered infant formula and chocolate were found to be ~0.1 mg/kg and ~1 mg/kg, respectively, on AuNPs, whereas they were observed to be ~0.01 mg/kg and ~0.1 mg/kg, respectively, on AuNSs. Using a handheld Raman spectrometer, a sub-mg/kg detection of melamine in both powdered infant formula and chocolate could be achieved within a few minutes.

This study aimed to develop a more sensitive method for the detection of hepatitis B surface antigen (HBsAg) using heteroassembled gold nanoparticles (AuNPs). A single layered localized surface plasmon resonance (LSPR) chip format was developed with antigen-antibody reaction-based detection symmetry using AuNPs, which detected HBsAg at 10 pg/mL. To further improve the detection limit, a modified detection format was fabricated by fixing a secondary antibody (to form a heteroassembled sandwich format) to the AuNP monolayer, which enhanced the detection sensitivity by about 100 times. The developed heteroassembled AuNPs sandwich-immunoassay LSPR chip format was able to detect as little as 100 fg/mL of HBsAg within 10-15 min. In addition, the heteroassembled AuNPs sandwich-immunoassay LSPR chip format did not show any non-specific binding to other tested antigens, including alpha fetoprotein (AFP), C-reactive protein (CRP), and prostate-specific antigen (PSA). These findings confirm that the proposed detection strategy of heteroassembled AuNPs sandwich-immunoassay LSPR chip format may provide a new platform for early diagnosis of various human diseases., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Curcumin-conjugated gold clusters (CUR-AuNCs) were synthesized using a "green" procedure and utilized as an anticancer and a bioimaging agent. Curcumin is a well-known anticancer agent, which forms a cluster when reacting with a gold precursor under mild alkali condition. A fluorescence spectroscopy analysis showed that the CUR-AuNCs emitted red fluorescence (650 nm) upon visible light (550) irradiation. Fourier transform infrared spectroscopy analysis confirmed the stretching and bending nature between the gold atoms and curcumin. Meanwhile, transmission electron microscopy analysis showed a cluster of approximately 1-3 nm with a uniform size. Time-resolved fluorescence analysis demonstrated that the red fluorescence was highly stable. Moreover, laser confocal imaging and atomic force microscopy analysis illustrated that a cluster was well distributed in the cell. This cluster exhibited less toxicity in the mortal cell line (COS-7) and high toxicity in the cervical cancer cell line (HeLa). The results demonstrated the conjugation of curcumin into the fluorescent gold cluster as a potential material for anticancer therapy and bioimaging applications.

Metal-organic frameworks are a novel class of organic-inorganic hybrid polymer with potential applications in bioimaging, drug delivery, and ROS therapy. NH 2 -MIL-125, which is a titanium-based metal organic framework with a large surface area of 1540m 2 /g, was synthesized using a hydrothermal method. The material was characterized by powder X-ray diffreaction (PXRD), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM), and N 2 isotherm analyses. The size of the polymer was reduced to the nanoscale using a high-frequency sonication process. PEGylation was carried out to improve the stability and bioavailability of the NMOF. The as-synthesized nano-NH 2 -MIL-125/PEG (NMOF/PEG) exhibited good biocompatibility over the (Cancer) MCF-7 and (Normal) COS-7 cell line. The interaction of NMOF/PEG with the breast cancer cell line (MCF-7) was examined by BIO-TEM analysis and laser confocal imaging. 2',7'-dichlorofluorescin diacetate (DCFDA) analysis confirmed that NMOF/PEG produced free radicals inside the cancer cell line (MCF-7) upon visible light irradiation. NMOF/PEG absorbed a large amount of DOX (20wt.% of DOX) and showed pH, and photosensitive release. This controlled drug delivery was attributed to the presence of NH 2 , Ti group in MOF and a hydroxyl group in PEG. This combination of chemo- and ROS-therapy showed excellent efficiency in killing cancer MCF-7 cells., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A non-labeled, portable plasmonic biosensor-based device was developed to enable the ultra-sensitive and selective detection of Salmonella typhimurium in pork meat samples. Specifically, a plasmonic sensor, using the self-assembly of gold nanoparticles (AuNPs) to achieve a regulated diameter of 20 nm for the AuNP monolayers, was used to conduct high-density deposition on a transparent substrate, which produced longitudinal wavelength extinction shifts via a localized surface plasmon resonance (LSPR) signal. The developed aptamers conjugated to the LSPR sensing chips revealed an ultra-sensitive upper limit of detection (LOD) of approximately 10 4 cfu/mL for S. typhimurium in pure culture under the optimal assay conditions, with a total analysis time of 30-35 min. When the LSPR sensing chips were applied on artificially contaminated pork meat samples, S. typhimurium in the spiked pork meat samples was also detected at an LOD of 1.0 × 10 4 cfu/mL. The developed method could detect S. typhimurium in spiked pork meat samples without a pre-enrichment step. Additionally, the LSPR sensing chips developed against S. typhimurium were not susceptible to any effect of the food matrix or background contaminant microflora. These findings confirmed that the developed gold nanoparticle-aptamer-based LSPR sensing chips could facilitate sensitive detection of S. typhimurium in food samples.

Two zinc-aminoclays [ZnACs] with functionalized primary amines [(-CH 2 ) 3 NH 2 ] were prepared by a simple sol-gel reaction using cationic metal precursors of ZnCl 2 and Zn(NO 3 ) 2 with 3-aminopropyl triethoxysilane [APTES] under ambient conditions. Due to the facile interaction of heavy metals with primary amine sites and Zn-related intrinsic antimicrobial activity, toxicity assays of ZnACs nanoparticles (NPs) prior to their environmental and human-health applications are essential. However, such reports remain rare. Thus, in the present study, a cell viability assay of in-vitro HeLa cells comparing ZnCl 2 , Zn(NO 3 ) 2 salts, and ZnO (~50nm average diameter) NPs was performed. Interestingly, compared with the ZnCl 2 , and Zn(NO 3 ) 2 salts, and ZnO NPs (18.73/18.12/51.49µg/mL and 18.12/15.19/46.10µg/mL of IC 50 values for 24 and 48h), the two ZnACs NPs exhibited the highest toxicity (IC 50 values of 21.18/18.36µg/mL and 18.37/17.09µg/mL for 24 and 48h, respectively), whose concentrations were calculated on Zn elemental composition. This might be due to the enhanced bioavailability and uptake into cells of ZnAC NPs themselves and their positively charged hydrophilicity by reactive oxygen species (ROS) generation, particularly as ZnACs exist in cationic NP's form, not in released Zn 2+ ionic form (i.e., dissolved nanometal). However, in an in-vivo embryotoxicity assay in zebrafish, ZnACs and ZnO NPs showed toxic effects at 50-100µg/mL (corresponding to 37.88-75.76 of Zn wt% µg/mL). The hatching rate (%) of zebrafish was lowest for the ZnO NPs, particularly where ZnAC-[(NO 3 ) 2 ] is slightly more toxic than ZnAC-[Cl 2 ]. These results are all very pertinent to the issue of ZnACs' potential applications in the environmental and biomedical fields., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In this study, we developed lateral flow assay (LFA) biosensors for the detection of hepatitis B surface antigens using well-controlled gold nanoparticles (AuNPs). To enhance colorimetric signals, a seeded growth method was used for the preparation of size-controlled AuNPs with a narrow size distribution. Different sizes of AuNPs in the range of 342-137.8 nm were conjugated with antibodies and then optimized for the efficient detection of LFA biosensors. The conjugation stability was investigated by UV-vis spectroscopy of AuNP dispersion at various pH values and concentrations of antibody. Based on optimized conjugation conditions, the use of 42.7 ± 0.8 nm AuNPs exhibited superior performance for the detection of LFAs relative to other sizes of AuNPs., Competing Interests: The authors declare no conflict of interest.

Although surface area metric was suggested as an appropriate dose metric for acute lung inflammation of NPs, it might not be effective for fast-dissolving NPs because they lose their reactive surface when dissolved in the phagolysosomes. Herein, we evaluated the dose metric for fast-dissolving NPs using a rat intratracheal instillation model. A panel of fast-dissolving NPs (CoO, CuO and ZnO) and their constituent metal ions (CoCl 2 , CuCl 2 and ZnCl 2 ) were compiled and each compound was intratracheally instilled into the lungs of female Wistar rats at the same molar concentrations in the NP doses (40, 100 and 400 μg/rat). The toxicity endpoints including cytological and biochemical data in bronchoalveolar lavage fluid were evaluated at 24 h after instillation. To evaluate the dose metric, each toxicity endpoint was plotted against the instilled dose (mass or surface area) or the equivalent dose (mass or surface area) that was weighted by the ratio of specific dose-generated responses between metal chlorides. Dose-response curves of fast-dissolving NPs about percentage of granulocytes, lactate dehydrogenase levels and total protein levels showed similar pattern but slightly less potential than those of their respective metal chlorides. When each toxicity endpoint was plotted against the equivalent mass dose, three types of NPs showed more overlapping dose-response curves than other dose metrics. In conclusion, this study implies that the equivalent mass dose is an appropriate dose metric for fast-dissolving NPs and the main factor determining the slope of the dose-response curve is the intrinsic toxicity of the their constituent ions.

Background: Instillation of highly soluble nanoparticles (NPs) into the lungs of rodents can cause acute eosinophilia without any previous sensitizations by the role of dissolved ions. However, whether gradually dissolving NPs can cause the same type of eosinophilia remains to be elucidated. We selected nickel oxide (NiO) as a gradually dissolving NP and evaluated the time course pulmonary inflammation pattern as well as its mechanisms., Methods: NiO NPs were intratracheally instilled into female Wistar rats at various concentrations (50, 100, and 200 cm(2)/rat) and the lung inflammation was evaluated at various time-points (1, 2, 3, and 4 days). As positive controls, NiCl2 and the ovalbumin-induced allergic airway inflammation model was applied. NiCl2 was instilled at 171.1 μg Ni/rat, which is equivalent nickel concentration of 200 cm(2)/rat of NiO NPs. Cytological analysis and biochemical analysis including lactate dehydrogenase (LDH), total protein, and pro-inflammatory cytokines were measured in bronchoalveolar lavage fluid (BALF). The levels of total immunoglobulin E (IgE) and anaphylatoxins (C3a and C5a) were measured in BALF and serum. The levels of eotaxin were measured in the alveolar macrophages and normal lung tissue before and after addition of cell lysis buffer to evaluate whether the direct lysis of cells can release intracellular eotaxin., Results: NiO NPs produced acute neutrophilic inflammation throughout the study. However, eosinophils were recruited at 3 and 4 days post-instillation of NiO NPs and the magnitude and pattern of inflammation was similar with NiCl2 at 24 h post-instillation. The eosinophil recruitment by NiO NPs was not related with either the levels of total IgE or anaphylatoxins. The lysis of alveolar macrophages and normal lung tissue showed high levels of intracellular eotaxin and the levels of LDH showed positive correlation with the levels of eotaxin., Conclusions: Instillation of NiO NPs produced neutrophilia at 1 and 2 days after instillation, while the mixed type of neutrophilic and eosinophilic inflammation was produced at 3 and 4 days post-instillation, which was consistent with NiCl2. The mechanism of the eosinophilia involves the direct release of intracellular eotaxin due to the rupture of cells by the accumulated solubilized nickel ions in the phagolysosome.

Here, we present a simple method for controlling the density of Au nanoparticles (Au NPs) on a modified silicon substrate, by destabilizing the colloidal Au NPs with 3-mercaptopropyltrimethoxylsilane (3-MPTMS) for microelectromechanical-system-based applications to reduce tribological issues. A silicon surface was pretreated with a 3-MPTMS solution, immediately after which thiolated Au NPs were added to it, resulting in their uniform deposition on the silicon substrate. Without any material property change of the colloidal Au NPs, we observed the formation of large clusters Au NPs on the modified silicon surface. Analysis by scanning electron microscopy with energy dispersive X-ray spectroscopy indicated that the addition of 3-MPTMS resulted in an alternation of the chemical characteristics of the solution. Atomic force microscopy imaging supported the notion that silicon surface modification is the most important factor on tribological properties of materials along with ligand-modified Au NPs. The density of Au NPs on a silicon surface was significantly dependent on several factors, including the concentration of colloidal Au NPs, deposition time, and concentration of 3-MPTMS solution, while temperature range which was used throughout experiment was determined to have no significant effect. A relatively high density of Au NPs forms on the silicon surface as the concentrations of Au NPs and 3-MPTMS are increased. In addition, the maximum deposition of Au NPs on silicon wafer was observed at 3 h, while the effects of temperature variation were minimal.

We have demonstrated the fabrication of the biosensor platforms by means of the integration of the genetically engineered fusion proteins and the uniform gold nanoparticle-deposited multi-walled nanotube hybrid (Au-MWNT-HB) films for the detection of C-reactive protein (CRP). Au-MWNT-HB films were used as a good electrochemical transducer due to their excellent electrical properties and large surface areas for the signal transduction, while the genetically engineered fusion proteins, or 6His-GBP-SpA fusion proteins, specifically bind onto the surface of the Au-MWNT-HB films and efficiently immobilize bioreceptors for the detection of CRP. As-obtained biosensor platforms were characterized by electrochemical and optical analysis and revealed better performance compared to conventional Au-based biosensors. The concept delineated herein opens a new insight into nanobiotechnology through the integration of genetically engineered biomaterials with carbon nanotube (CNT)-based nanohybrids for emerging applications., (Copyright 2010 Elsevier Inc. All rights reserved.)