Cancer, a combination of haematological and neoplastic malignancies, is a dreadful disease accounting for major fatalities worldwide. The domain of innovative nanoparticle-based technology has revolutionized the field of cancer therapeutics and imaging. With an emphasis on various nano-immunotherapeutic approaches, this study highlights the most recent developments in nano-immune engineering for metastatic tumours. Nanotechnology-based cancer immunotherapy has powered the (i) activation of T-cells in the tumour microenvironment (TME), (ii) preparation of efficient nanovaccines via nano-carriers and (iii) generation of smart nanomaterials which change their size/shape (size range of 1 to 1000 nm) and functionality upon activation in TME. The tumour microenvironment has an important, albeit contentious, role in controlling nanoparticle (NP) dispersion and subsequent biological consequences. The current study promotes the harnessing of potential peripheral immune cells by avoiding the creation of a pre-metastatic niche and, thus, suppressing tumour recurrence. This review descriptively accounts for a wide array of nanomaterials based on their polymeric constituents. Moreover, the current article explores the obstacles of integrating nanoscale immunomodulators and presents a forward-looking view of the novel nanotechnology-based approaches that may eventually prove helpful in eliminating metastatic illnesses.

A lot of innovative methods to synthesize various kinds of nanoparticles having specific shape and size are being explored for targeting immense applications through nanotechnology. In this work, simple, eco-friendly and cost-effective method has been adopted for the synthesis of silver (Ag), gold (Au) and palladium (Pd) nanoparticles using tannic acid. The morphology and size of nanoparticles were determined by TEM study, which revealed that nanoparticles are spherical in shape and exhibit an average diameter of about 6.66 nm, 12.24 nm and 19.65 nm for tannic acid mediated silver, gold and palladium nanoparticles (TA-AgNPs, TA-AuNPs and TA-PdNPs), respectively. The application of these nanoparticles was then explored as catalyst for the degradation of methylene blue and congo red dyes. The presence of these dyes was found to be detrimental for the aquatic life, as these dyes can seep into the ecosystem from the industrial waste. The catalytic activity of nanoparticles was compared by determining rate constant values. For, both the dyes, the value of rate constant followed the order- kAg ˃ kPd ˃ kAu. The dye degradation potential of TA-AgNPs was higher than TA-Au and TA-PdNPs. This difference in catalytic activity was attributed to lower work function value of AgNPs as compared to AuNPs and PdNPs. Present study provides an environmentally benign pathway for synthesizing metallic nanoparticles and their utilization as catalyst for degradation of harmful dyes. Such kinetic studies of comparative catalytic analysis may be useful in selection of nanoparticles, which may be best suited for a specific purpose.Graphical abstract

AbstractCancer remains a serious health problem in terms of incidence and mortality worldwide. As a result, researchers are working to identify new chemotherapeutic therapies or, potentially, to use innovative drug delivery methods in existing therapies. Recently, there has been a lot of interest in using nanocarriers as drug delivery systems, particularly for the treatment of cancer. Several novel nanocarrier-mediated drug delivery systems are currently being used to deliver chemotherapeutic agents to specific sites. Polymeric nanoparticles, liposomes, polymeric micelles, carbon nanotubes, dendrimers, solid lipid nanoparticles, magnetic nanoparticles and quantum dots are all examples of important nanocarriers. One of the most often prescribed chemotherapeutics for first-line therapy is gemcitabine hydrochloride, which has a broad spectrum of effects. Gemcitabine hydrochloride is an intriguing example of a drug for which various nanostructured targeted delivery methods are being explored over history. Even though some of these systems already exist on the market, there is continued research on this topic and new solutions are continually sought. In this context, the present review examines gemcitabine not as a specific drug, but as a proof of concept study that has drawn upon a wide range of innovative nanotechnology approaches.Graphical Abstract

The hexavalent chromium-containing pollutants are seriously harmful to human living environment. Catalytic reduction of Cr(VI) to Cr(III) is an effective way to reduce the impact of pollutants. Uniform spherical Pd nanoparticles are synthesized onto PVP-functionalized graphene and sizes of the particles are adjusted. The obtained Pd/graphene catalyst with an average diameter 2.42 nm of Pd particles exhibits the superior catalytic activity in the reduction of Cr(VI) to Cr(III), with a much high turnover frequency of 132.8 min−1. Superparamagnetic Pd/graphene shows the good catalytic activity and easily separation for recycling. The present Pd catalysts have attractive stability in the reductive reaction under high temperature and low pH, which keep constant activities for many recycles. The PVP-functionalized graphene as a support not only favors the formation of well-dispersed Pd nanoparticles but also provides the high surface for the adsorption and mass transfer of reagents. This support is potential to be used for other metal nanoparticle catalysts.Graphical abstract

Porous silicon (PSi) gained a lot of significance lately as a biosensor due to its significantly high absorption capacity, easily modulable porosity, and its biocompatibility. In this work, the etching time dependence of the optical response of PSi-based calmodulin (CaM) surface-functionalized calcium detector is studied. PSi was fabricated on P-type silicon wafers by electrochemical etching process. Increase in electrochemical etching time significantly increases the porosity of the PSi substrate. Thus, the optical response of the PSi-based calcium detector is observed to be remarkably affected by the change in etching time. Studies were performed on both nano (structure size ranging from 6 to 19 nm) and macro (pore size ranging from 6 to 1.5 µm) PSi. Optical parameters such as reflectance, scattering, and absorptance of the PSi-based optical detector were analyzed and notable changes were recorded for changing etching time in both nano- and macro-PSi samples. This study helps to drastically improve the sensitivity of PSi-based optical calcium detector, and the concept may be incorporated in the designing of calcium or other ionic and chemical sensors with improved selectivity and sensitivity. Thus, the study is useful in the fabrication of PSi-based calcium sensors with optimized etching time so that highly sensitive and precise calcium detection can be possible using it.Graphical Abstract

Barium titanate-polystyrene polymer composite (BaTiO3/PS) was synthesized by the solvent evaporation method while filler barium titanate was synthesized by the solid-state reaction method. The prepared sample was characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The crystalline nature and phase of the prepared samples were confirmed by X-ray diffraction analysis. The average particle sizes of BaTiO3 and BaTiO3/PS were estimated as 161 nm and 119 nm by SEM morphographs. The Williamson–Hall (W–H), size–strain plot (SSP), and Halder–Wagner (H-W) techniques were employed to determine the crystallite size and inherent lattice strain using X-ray peak broadening analyses. The values of crystallite size computed using the modified Debye–Scherrer equation, W–H approach, and SSP are extremely similar and strongly correlated. It was also observed that crystallite size and lattice strain were not highly correlated.

In this work, an efficient mesoporous catalyst based on MCM-41 was successfully synthesized. The synthesized catalyst of Ni(II)-4-phenylthiosemicarbazide supported in to functionalized MCM-41 (MCM-41/Pr-PTSC-Ni(II)) was identified using FT-IR, TGA, XRD, EDX, AAS,TEM, N2 adsorption–desorption and SEM techniques. The hot filtration test was done to check of leaching of Ni in the reaction mixture and to confirm the heterogeneous nature of the catalyst. The TEM of recovered catalyst in comparison of fresh catalyst confirmed that change did not occur in surface morphologies during the reaction. This mesoporous catalyst was used as an efficient, heterogeneous, recyclable and environment friendly catalyst in the synthesis of tetrahydrobenzo[b]pyran and 1,4-dihydropyrano[2,3-c]pyrazole derivatives in high yields and short reaction times. Also, the synthesized catalyst can be able to reuse for five times.Graphical abstractIn this work, a new mesoporous catalyst of MCM-41/Pr-PTSC-Ni(II) was synthesized and characterized by several techniques. Also the catalytic activity of this new catalyst was investigated for synthesis of tetrahydrobenzo[b]pyran and 1,4-dihydropyrano[2,3-c]pyrazole.

In nano-cutting, an element with uncertainty like cutting tool material can intensively affect the surface strength of manufactured materials during the plastic deformation progress. Via the method of molecular dynamics (MD) simulations, the interaction principle is studied in this article, considering three different cutting factors including cutting tool size, cutting angle, and cutting tool shape. Nano-crystalline (NC) Cu-Ag alloys with grain boundary affect zone (GBAZ) segregation are selected as the cutting workpiece. The outcomes indicate that the compression between the cutting tool and workpiece causes the formation of dislocations and chips. Using a larger cutting tool leads to a shorter time for misshapen nucleation and movement within the NC Cu-Ag alloy, more plastic deformation, and more average tangential forces. The cutting angle has a conspicuous effect on the dislocation domain and chip volume. Sharp tools can cause plastic deformation of the workpiece more easily. This study provides a theoretical basis for the design of nano-cutting workmanship to obtain suitable mechanical properties.

In this paper, we report the magneto-caloric properties of the Graphdiyne structure with mixed 3/2 and 1 spins investigated by Monte Carlo simulations. Such calculations were performed under the Metropolis algorithm. We illustrate the magnetizations and dM/dT of the Graphdiyne system with these mixed spins. It is found that the magnetic entropy of the Graphdiyne changes when varying the temperature values for several values of the external magnetic field. The maximum magnetic entropy variations of the system are deduced. The relative cooling power (RCP) coefficient of the Graphdiyne system has been estimated for several values of the external magnetic field. To complete this work, we have illustrated the magnetic hysteresis cycles of the Graphdiyne for fixed values of the other physical parameters.

Employing the isothermal molecular dynamics and the embedded atom method, we simulated melting of metallic nanoparticles (Au, Ag, Cu, Ni, and Pb ones). In more detail, the results for Au and Ag nanoparticles are presented and discussed. At first, we analyzed the behavior of the temperature dependences for the potential (cohesive) term into the specific (per atom) internal energy and for the degree of crystallinity in the course of heating nanoparticles. We have found that the results obtained for nanoparticles of about 4 and 8 nm in size (containing 2093 and 20,113 atoms, respectively) demonstrate the continuous melting. Employing the dependence of the specific potential energy on the distance to the nanoparticle center of mass and the common neighbor analysis, we showed that the continuous melting occurs via the surface pre-melting mechanism. Then, we evaluated the self-diffusion coefficient in the surface disordered layers of Au and Ag nanoparticles and found that our results agree in order of magnitude (10−9 m2/s) with the values of the self-diffusion coefficient for the bulk Au and Ag melts at the corresponding bulk melting temperatures. Finally, combining in our molecular dynamics experiments continuous heating Au nanoparticles with annealing them at some constant selected temperatures, we have shown that the liquid nucleation and growth mechanism should be most adequate to the melting behavior of metallic nanoparticles.

Catalytic reactions, with iron species as the active phase, require a specific structural organization to achieve good activity and selectivity. Thus, the presence of isolated Fe3+ ions or nanoclusters, the capacity to produce Fe3+/Fe2+ couples, or certain chemisorb reactive molecules are necessary for different reactions. Therefore, if the presence of these structural properties can be demonstrated, it could be inferred that the system could be active in a determined reaction avoiding the screening of catalytic tests. In the present work, using Mössbauer spectroscopy, we have verified that exchanged Fe in hydroxyapatite can produce Fe3+/Fe2+ redox couples which are necessary to achieve good catalytic performances in the NOx, N2O, and NH3 abatement reactions. Besides, this technique allowed us to verify that isolated Fe3+ sites and Fe(III)xOy nanoclusters were able to chemisorb CO molecules. Therefore, it could be thought that Fe/hydroxyapatite system might be active in catalytic reactions in which adsorption and dissociation of CO are necessary.Graphical Abstract

Cancer tops the list of most life-threatening diseases worldwide, recording around 10 million deaths annually. Implementation of microneedles (MNs) as a therapeutic delivery vehicle has revolutionized anticancer therapy, thanks to MNs’ minimally invasive and painless delivery aspect, high therapeutic efficacy, low cost, and relative biosafety. In this review, we overview the application of MNs for the delivery of different anticancer therapeutic and diagnostic modalities, including drugs, peptides, antibodies, gene, and vaccines. We further highlighted the fabrication strategies, materials, and therapeutic release patterns from MNs. Finally, we discussed biosafety concerns, translational aspects, limitations, and future perspective of MNs as an efficient anticancer theranostic system.Graphical Abstract

We perform full-wave electromagnetic simulations to investigate the formation of higher-order localized surface plasmons (LSP) in a multilayered Au-Si-Au nanodisk architecture and their evolution with the doping level and thickness of the semiconducting layer. We show that higher-order LSP modes can be efficiently excited and controlled not only by changing the thickness of the intermediate Si layer but also by optically tuning its doping level. We provide a detailed study of the nature and origin of the hybrid modes resulting from the hybridization of nanodisk primitive LSP modes. This approach substantially improves the functionality of the nanodisk stack structure and opens up a new practical pathway for the active control of the optical response of plasmonic-based and semiconducting-based devices.

The surface plasmon resonance property of silver nanoparticles (AgNPs) makes them a top-notch material for developing sensors, especially in surface-enhanced Raman scattering (SERS). The multi-shape silver nanoparticles decorated on cellulose fiber of paper provide flexible paper-based SERS substrates with different sensitivity. The isotropic and anisotropic morphology of AgNPs on filter paper has been controlled by weak and strong reducing agents: sodium borohydride (NaBH4), ascorbic acid (L-AA), glucose, formaldehyde (HCHO). The capping agent’s chitosan and the reaction conditions like the ratio of precursors and stirring speed also influence the shape, size, stability, and dispersity of AgNPs on filter paper. Multi-shape AgNPs on paper are obtained as spherical shapes (about 50–100 nm), rods (size 100–500 nm in length, 50-nm wide), or thin wings. Depending on the reduction condition, these AgNPs can be single-dispersed or stuck together to form corals on paper. The fabricated paper-based SERS substrates were investigated the optical characterization and used to detect melamine in an aqueous solution with detection limits as low as 10−8 M with the EF = 2.3 × 109.

Simple and quick techniques for assembling nanoparticles in topographically designed Poly(dimethylsiloxane) moulds of nanosized shapes have great potential in many spectroscopic and sensing tools. Close-packed particles pose rich plasmonic resonances, enabling the optical response to be tailored on both the nano- and macroscale. Template-assisted self-assembly (TASA) is a method that creates colloidal aggregates with controlled sizes formed by dewetting aqueous dispersions of NPs across surfaces. We present rapid TASA (rTASA), a modified version with an overall process time of under 10 min, improving speed and user-friendliness. Depending on the array pitch distance and average number of NPs per trap, the transmission through the template drops by between 20 and 80%, enabling them to be detected with even the simplest spectroscopic solutions. This rapid method is useful as a building block to generate self-assembled systems that exhibit exciting optical properties in crucial areas, particularly in building a fast test for size-selective NP detection.Graphical abstract

This study focused on a new functionalized magnetic graphene oxide (NH2/β-CD/NH2/β-CD MGO) nanoparticle with size in 31–47 nm and nearly spherical by the chemical precipitation method for the uptake of Pb (II) ions from aqueous media. The adsorption capacity was 296.16 mg g−1 under optimum conditions. The study indicated that the optimum conditions for lead (II) ions sequestration were pH = 6.5, nanoparticle dose = 17.75 mg L−1, and contact time = 75 min at room temperature. These results could be useful for the sequestration of lead (II) ions from wastewater. A central composite design (CCD) was employer for performing the experiments and the response surface methodology (RSM) was utilized for the analysis of these experiments. RSM was also used to model and improve the adsorption of lead (II) ions by the adsorbent. Based on the obtained results from different operating parameters, a maximum adsorption capacity of Pb (II) ions was 296.16 mg g−1 in pH = 6.5; at 75 min, a 17.75 mg L−1 adsorbent amount and a 55 mg L−1 initial concentration of Pb (II) ions. The RSM is practical for the optimization of MGO nanoadsorbent and improves the adsorption ability of MGO nanoadsorbent to remove Pb(II) ions from aqueous solutions. Pb(II) adsorption kinetics were conformed from the pseudo-second-order model (R2 > 0.9964) and the Freundlich isotherm model displayed the finest correlation with the equilibrium data (R2 > 0.9788). Basis as all of obtained data, the MGO-NH2/β-CD/NH2/β-CD with five times reusability was favorable adsorbent for purification of water pollution contains heavy metal ions.Graphical Abstract

Early diagnosis of lung cancer has gained much attention in the last few years due to its high incidence and fatality rate. In this paper, Sc-doped SnS2 (Sc − SnS2) monolayer is proposed as a promising biosensor to diagnose lung cancer in the early stage. Employing DFT-based investigation, the adsorption mechanism of three prominent biomarkers C3H4O, C3H6O, and C5H8 in the exhaled breath of lung cancer patients is analyzed. The effect of Sc-doping on pristine SnS2 is studied first followed by an investigation of the adsorption mechanism via. structural, magnetic, and electronic properties. Based on binding energy calculations, a single Sc atom adsorbs on the Sn-site of the SnS2 surface and is chosen as a molecular model for adsorption analysis. The findings revealed that the Sc-SnS2 monolayer had exceptional adsorption ability for three common volatile organic compounds (VOCs) found in lung cancer patients, resulting in a significant change in the physicochemical parameters of the sensing Sc-SnS2 system. The results projected Sc − SnS2 monolayer as a promising biosensor to diagnose lung cancer at an early stage and provide a way for experimentalists to explore it in the real application. Moreever, the charge-transfer behavior under the effect of electric field is also examined in order to explicate the expediency of Sc-doped SnS2 monolayer as a field-effect-transistor sensor.

Nanotechnology is increasingly being used in several application areas for deriving material properties through nanostructure control. Most nanoparticle images are obtained using high-magnification electron microscopy. However, processing numerous nanoparticle images and improving accuracy requires considerable time and labor. A number of studies focused on precisely assessing the overlapping features of nanoparticle images. For correlation and reliable discrimination of overlapped nanoparticles, this study proposed a framework using a deep-learning-based encoder and centroid-to-contour distance analysis. In the proposed framework, specialized preprocessing was used to divide an image into many images, and a convolutional neural network (CNN)-based encoder was used to derive the properties of nanoparticles included in the image. The resulting characteristics were used to estimate the center point of each nanoparticle through the proposed centroid-to-contour distance approach. Then, a nanoparticle spatial structure graph was generated using this analysis. The nanoparticle structure graph of the proposed framework clearly maps the overlapping relationship between nanoparticles. Experiments proved that the proposed framework more accurately assesses the nanoparticle structure than conventional algorithms do.

Reactant adsorption sites of novel metal catalysts are difficult to characterize precisely, which is vital for understanding heterogeneous reactions and designing efficient catalytic systems. However, even at cryogenic temperatures, a complete atomic understanding of catalytic reaction sites remains elusive, such as the variation in reactant molecule adsorption sites on metal nanoclusters (NCs). Here, we studied CO adsorption on the Pd NC of an Al2O3/NiAl(110) surface with atomic resolution by noncontact atomic force microscopy and Kelvin probe force microscopy at room temperature. We found that CO molecules are preferentially adsorbed on the Pd NC (~2 nm) on line defects. We investigated the consecutive scanning topographic AFM images of CO molecules on the Pd/Al2O3/NiAl surface and found the most stable adsorption site of CO molecules on bridge site and the most unstable adsorbed site on step_110, which are supported by density functional theory (DFT) calculations. This result reveals that the electronic and geometric properties of Pd NCs and CO molecules are expected to provide insight into the mechanism of Pd-based heterogeneous catalysis.Graphical abstract

MnOx, CeO2, and MnCe-O (Mn/Ce = 1) solids have been prepared via the citrate complexation and combustion method using citrate and urea precursors. The solids have been characterized by XRD, SEM-EDX, N2-adsorption-desorption, UV-Vis spectroscopy, TPR, O2-TPD, and XPS techniques. The catalytic reactivity of the manganese oxides was not affected by the preparation protocol. In the case of ceria and mixed oxides, the synthesis method greatly affected the structural and chemical properties, ultimately altering their reactivity. The citrate complexation method produced the most homogeneous and active mixed oxide, whereas the urea combustion method resulted in less active solids. The mixed oxide prepared via urea combustion was less active than the manganese single oxide; the decrease in activity was attributed to phase separation and the formation of Mn3O4 domains on the surface of ceria. In contrast, citrate complexation resulted in solids with the lowest particle size (~ 3 nm), the highest oxidation state for manganese, and the highest proportion of oxygen vacancies, which promote the oxidation reaction.