Surface Of Nanoparticles Research Articles

Enhancing the Mechanical Properties of Injectable Nanocomposite Hydrogels by Adding Boronic Acid/Boronate Ester Dynamic Bonds at the Nanoparticle-Polymer Interface.

Incorporating nanoparticles into injectable hydrogels is a well-known technique for improving the mechanical properties of these materials. However, significant differences in the mechanical properties of the polymer matrix and the nanoparticles can result in localized stress concentrations at the polymer-nanoparticle interface. This situation can lead to problems such as particle-matrix debonding, void formation, and material failure. This work introduces boronic acid/boronate ester dynamic covalent bonds (DCBs) as energy dissipation sites to mitigate stress concentrations at the polymer-nanoparticle interface. Once boronic acid groups were immobilized on the surface of SiO2 nanoparticles (SiO2-BA) and incorporated into an alginate matrix, the nanocomposite hydrogels exhibited enhanced viscoelastic properties. Compared to unmodified SiO2 nanoparticles, introducing SiO2 nanoparticles with boronic acid on their surface improved the structural integrity and stability of the hydrogel. In addition, nanoparticle-reinforced hydrogels showed increased stiffness and deformation resistance compared to controls. These properties were dependent on nanoparticle concentration. Injectability tests showed shear-thinning behavior for the modified hydrogels with injection force within clinically acceptable ranges and superior recovery.

Circularly Polarized Light-Induced Chiral Growth of Achiral Plasmonic Nanoparticles Dispersed in a Solution.

Plasmonic nanoparticles (NPs) with chiral geometries have wide applications from chiral molecular sensing to enantioselective catalysis. The synthesis of chiral plasmonic nanoparticles using circularly polarized light (CPL) has attracted a considerable amount of attention because it eliminates the need for chiral molecules. However, NPs need to be immobilized on a solid substrate during synthesis. Here, we successfully synthesized colloidal chiral plasmonic NPs by depositing silver on the surface of achiral gold nanoparticles dispersed in a solution using CPL. Circular dichroism (CD) signals corresponding to the handedness of the irradiated CPL were observed when gold nanorods or gold nanotriangles were used. In contrast, no clear CD signal was observed when gold nanospheres were used. The morphological anisotropy of the gold nanoparticles was a key factor in the synthesis of chiral plasmonic nanoparticles using CPL. Furthermore, we demonstrated the tuning of chiroptical properties according to the CPL wavelength.

Synthesis of Pd-decorated ZnO nanocomposites with improved gas-sensitive properties for acetone detection

ZnO/Pd nanocomposites containing 0.5–3.0 mol.% palladium and possessing improved gas-sensitive properties for VOC’s detection were prepared using solvothermal synthesis. The synthesised powders have been characterised using various methods of physicochemical analysis (DSC/TGA, XRD, SET/TEM, XPS). It is shown that Pd@PdO nanoparticles (4–7 nm in diameter) are localised on the surface of ZnO nanoparticles (40–50 nm in size). According to the combined XRD and XPS data, it was found that palladium is in partially oxidised state, and the nanocomposite has a structure close to "core@shell": Pd@PdO. The influence of palladium concentration in the ZnO/Pd composite on the complex of chemoresistive gas-sensitive properties was studied. It is shown that at 250 °C the obtained nanocomposites demonstrate a high (up to 57.8 a.u.) response to 100 ppb–20 ppm acetone, which can be used as a part of supersensitive devices for noninvasive diagnostics of diseases.

A Thin Polymer Layer Enables Peptide-Polycation Complexes with Ultrahigh Efficient Encapsulation.

A monolayer encapsulation is a new opportunity for engineering a system with high drug loading, but immobilizing polymer molecules on the surface of individual peptide nanoparticles is still an ongoing challenge. Herein, an individual peptide nanoparticle encapsulation strategy is proposed via surface adsorption, in which peptide molecules undergo granulation and subsequently aggregate with polymer molecules, forming a network via electrostatic interactions. Under the water phase, surplus polymer molecules dissolve, leading to a single nanoparticle encapsulation with a core-shell structure. As expected, the dense interfacial layer on the peptide nanoparticle surface achieves a superior loading degree of up to 95.4%. What's more, once the core-shell structure is established, the peptide mass fraction in individual encapsulation always exceeds 90% even under fierce external force. Following the individual nanoparticle encapsulation, the insulin-polycation complex (InsNp@PEI) reduces the inflammation from polymer and displays an effective glycemic control in type 1 diabetes. Overall, the newly developed single surface decoration encapsulates peptides with ultrahigh efficiency and opens up the possibility for further encapsulation.

Nickel-decorated ZnO nanoparticles for effective solar reduction of hexavalent chromium and removal of selected pharmaceuticals

The efficient visible light driven photocatalytic reduction of hexavalent chromium, Cr(VI) was demonstrated using ZnO nanoparticles (NPs) decorated with oxo-clusters of transition metals. The ZnO NPs were synthesized by a facile one-pot solvothermal synthesis followed by a fast microwave-assisted (MW) grafting of transition metals on the surface of NPs. Nickel was found to be the most active transition metal for photocatalytic activity as demonstrated by reduction of Cr(VI) to Cr(III). The optimally grafted samples contained 0.5 wt% Ni and increased photocatalytic activity by almost one-fold. The oxo-clusters did not enter the lattice of ZnO but rather resided on the surface and their efficient bonding to the ZnO surface was proved by Raman, TEM and X-Ray absorption techniques. Influence of MW power was studied and shown that excessive power load leads to formation of elongated structures of ZnO which decreases the photocatalytic activity. It was demonstrated by measuring fluorescent radical products that electrons, efficiently transferred via oxygen, were the main active species in combination with the unchanged oxidation power of holes and •OH in the grafted samples. The applicability of the materials was tested in immobilized plug flow photoreactor system degrading five pharmaceuticals simultaneously where their long-term use was shown.

Features of synthesis of ZnSe ceramics from nanopowders obtained using a high-power laser

The reasons for the occurrence of optical inhomogeneities in ZnSe or Fe:ZnSe ceramics, which were made from nanoparticles, obtained using a continuous wave ytterbium fiber laser, were investigated. Evaporation of ZnSe at T ≤ 900 ˚С results in formation of large pores (0.5 - 10µm) in the ceramics. When the material is oxidized by means of oxygen adsorbed from air onto the surface of nanoparticles, such refractory phases as ZnO and ZnSeO3 are formed. Even a low content of these phases ( < 1wt. %) results in formation of accumulations of small crystallites ( 0.2 - 3 μm) in the ceramics. Numerous pores and extended accumulations of small crystallites are optical non-uniformities that scatter and absorb light. Changes in the chemical composition and contamination of ZnSe during the production of nanopowders and ceramics turned out to be too small for such inhomogeneities to form.

Protein absorption alters the cellular targeting of glycopolymeric nanoparticles

Glycopolymeric nanoparticles are widely employed in biomedical applications due to their high targeting ability, biocompatibility, and biodegradability. The pendant saccharides serve as targeting ligands to be explicitly coordinated to receptors on cell membrane surfaces. However, proteins in the blood often absorb onto the nanoparticle surface, potentially impacting the exposure and effectiveness of the saccharide ligands for targeted delivery. To elucidate the protein absorption effects, we prepared micelles decorated with different percentages of fructose moieties and evaluated the bioactivity of nanoparticles using 2D cell culture, tumor spheroid, liver organoid, and coculture models. The 2D cell culture model did not show a significant difference in activity between protein-coated and non-coated micelles. However, a dramatic decrease in cellular uptake and penetration ability of micelles was observed in 3D tumor spheroids after protein absorption. Additionally, protein absorption notably increased micelle uptake in liver organoids. In the coculture model, protein absorption reduced micelle uptake in tumor spheroids while favoring uptake in liver organoids. Our work suggests that decreasing non-specific protein absorption of glycopolymeric nanoparticles could enhance their delivery efficiency. These findings underscore the importance of understanding protein interactions in nanoparticle applications for drug delivery.

Synthesis and in vitro study of surface-modified and anti-EGFR DNA aptamer -conjugated chitosan nanoparticles as a potential targeted drug delivery system

Nowadays, finding effective approaches for cancer therapy is one of the significant issues related to human health all over the world. Hence, in this research, we designed and synthesized a novel targeted DDS based on surface-modified chitosan (CS) for the effective delivery of noscapine (NO). As the surface of CS nanoparticles was firstly modified with carboxyl groups and followed by covalent conjugation of DNA-aptamer (Ap) as targeting and receptor blocker agent. Secondly, NO, as a chemotherapeutic agent, was loaded into prepared nano-complex and synthetics were effectively characterized via various analytical devices, including FT-IR, 1H NMR, DLS, Zeta potential analyzer, TGA, TEM, and SEM to verify quality and quantity of synthetics. Drug loading was obtained about 25 % and sustained drug release was observed for nano-complex at different pHs. Then, the cell viability assay was performed on MCF-7 (as breast cancer cell) and HFF-1 (as normal cell) cell lines to investigate cancer cell inhibition potency of nano-complex. Cell viability of cancer cells was 19.84 ± 1.87 % (for C-CS-Ap-NO) and 75.43 ± 2.64 % (for C-CS-Ap) after 72 h of treatment with 400 nM concentration. These results have been confirming the excellent potency of synthesized novel nano-complex as practical DDS in cancer therapy.

Growth of dendritic CuS nanostructures for photoacoustic image guided Chemo-Photothermal therapy

Herein, we report a unique method for design and development of carboxyl enriched dendritic CuS nanostructures (CuS NSs) for photoacoustic image guided chemo-photothermal therapy. The dendritic network was grown on the surface of CuS nanoparticles via layer-by-layer assembly of amino acid. XRD and TEM studies established the formation of crystalline well-spherical nanosized hexagonal covellite (CuS) phase. The successful growth of dendritic structure was apparent from the rise in surface charge, hydrodynamic diameter and characteristic vibrational band intensity of peptide bonds. The developed different generations of dendritic CuS NSs (D0-CuS NSs, D1-CuS NSs, D2-CuS NSs and D3-CuS NSs) displayed wide-ranging absorption band in near infrared (NIR) zone and exhibited good photothermal heating efficacy upon irradiation of 980 nm laser light. From in to vitro cellular studies, it has been found that the NIR irradiation effectively enhanced the photothermal toxicity of D3-CuS NSs towards cancer cells. Moreover, these negatively charged water-dispersible D3-CuS NSs were conjugated with positively charged anticancer drug, doxorubicin hydrochloride (DOX) through electrostatic interaction. The DOX loaded D3-CuS NSs (DOX@D3-CuS NSs) revealed pH dependent drug release behaviour and their considerable uptake in breast cancer cells (MCF-7). Further, DOX@D3-CuS NSs exhibited a much higher toxicity towards cancer cells upon NIR light over individual counterparts suggesting their strong ability for chemo-photothermal therapy. Moreover, these biocompatible CuS NSs have shown excellent concentration dependent photoacoustic properties at pulse laser excitation (850 nm) and thus, they can be found potential application in chemo-photothermal therapy.

Green-synthesized BiFeO3 nanoparticles for efficient photocatalytic degradation of organic dyes, antibiotic and catalytic reduction of 4-nitrophenol

Green-synthesized nanoparticles have recently emerged as promising catalysts for the removal of toxic dyes from water bodies. In this article, Bismuth ferrite (BiFeO3) nanoparticles were synthesized by a simple and low-cost method using Couroupita guianensis plant leaf extract. The particles were used as photocatalysts for degrading RhB, MO dyes, and TC antibiotics, as well as for reducing toxic 4-NP to useful 4-AP. The synthesized nanoparticles were characterized using several state-of-the-art tools. The formation of perovskite structure and the presence of biomolecules on the surface of BiFeO3 nanoparticles was confirmed by FTIR analysis. Raman spectrum revealed a rhombohedral structure of BiFeO3 nanoparticles, corroborating the XRD analysis. FESEM micrograph demonstrated irregularly shaped agglomerated nanoparticles. The average hydrodynamic diameter was estimated to be 51 nm using the DLS technique. The optical energy bandgap of the bismuth ferrite was estimated using Tauc’s relation for direct bandgap semiconductors. SQUID measurements revealed that these nanoparticles exhibit a weak ferromagnetic ordering. Furthermore, these nanomaterials degraded the cationic and anionic dyes effectively because of the formation of hydroxyl radicals, confirmed by the scavenger test. The photocatalytic degradation pathway of RhB dye was investigated through LC-MS analysis, and the intermediate degradation products were identified. The prepared material also exhibited excellent catalytic efficiency in a short duration of time. This study proclaims that these nanoparticles can be used as potential catalysts for the purification of water.

Synthesis of novel Ag-doped ZnFe based-oxides nanocomposite for wastewater treatment, self-cleaning, and corrosion resistance

To tackle the critical environmental and industrial challenges, this research endeavors to develop nanomaterial with enhanced photocatalytic function, corrosion resistance, self-cleaning capabilities, and optimal effluent treatment. This research successfully synthesized Ag@ZnFe2O4 nanocomposite to activate peroxymonosulfate (PMS) for the removal of Congo red from water. The structural composition and morphology of the materials were examined by the utilization of XRD, FTIR, XPS, SEM with EDS and TEM. The study examined the impacts of catalyst dosage, concentrations of PMS, pH, and simultaneous ions on the experiment, as well as the ability of the nanocomposites to be reused and their stability. The photocatalytic degradation process was hypothesized to operate using free radical trapping tests. Results indicated that the heterostructure junction flanked by ZnFe2O4 nanoparticles and Ag promoted charge transfer, reducing electron-hole recombination. By adding 5mg of Ag@ZnFe₂O₄ nanocomposite, Congo red degradation was optimized at 98.7% due to the huge surface area of Ag microflowers, which boosted active sites and CR elimination. Due to nanoparticle surface charge, PMS speciation, and radical interactions, CR degradation was most efficient at pH 7.3 and less efficient at pH 9.5. CR degradation rates rose with PMS concentration, reaching 34.7%, 67.9%, and 97.9% at 0.3, 0.6, and 1mM, respectively. The order of the inhibitory action was CO32− > H2PO4− > Cl− > NO3−. Free radical entrapment experiments show that hydroxyl (•OH) and sulfate radicals (•SO₄⁻) are key in CR photodegradation, with h+ and •O₂ being the main active species. ESR tests revealed radicals, while electron transfer between ZnFe₂O₄ and Ag boosted carrier migration, driving redox cycles and CR breakdown into stable byproducts like CO₂ and H₂O. Light-induced reaction eliminated 45.8% of TOC, indicating CR partial mineralization. Mechanism of PMS-based photodegradation of CR removal was proposed. This study underscores the promising potential of Ag@ZnFe2O4/nanocomposites for PMS activation in degrading Congo red-contaminated wastewater. Electrochemical impedance spectroscopy (EIS) showed that a polymeric nanocomposite coating greatly improves the ability to resist corrosion in steel substrates when exposed to a 3.5% NaCl solution. This is achieved by reducing the corrosion current density and boosting corrosion resistance. Superhydrophobic nanocomposite coatings repel water and pollutants, safeguarding various substrates from soil residues.

Fast identification of Baijius based on organic acid response colorimetric sensor array

Herein, a simple colorimetric sensor array sensitive to organic acids was designed by gold (Au) and silver (Ag) nanoparticles modified with four different compounds for the identification of 16 famous Baijius containing different organic acids. In detail, the sensing mechanism of the colorimetric sensor array was based on the charge transfer between the nanoparticle surface protectant and H+, which reduced the electrostatic force between the nanoparticles, leading to the aggregation and color change of the nanoparticles. The unique color change of the colorimetric array before and after the reaction was used as a unique fingerprint profile for each specific analyte, which can be identified by the naked eye. The generated digital database was analyzed using pattern recognition methods, including principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). All Baijius can be easily identified by fingerprint mapping or PCA scoring maps. 32 blind samples were tested by LDA and 30 samples were correctly classified. The HCA results showed that all samples were correctly classified and even very similar 1 % dilutions of the Baijiu can be easily distinguished, demonstrating the potential of the constructed colorimetric sensor array technology for quality control applications of Baijius and other beverages.

Abnormally narrow peaks in TPR-H2 over Pt/CeO2: Experiment and mathematical modelling

The application and development of methods using hydrogen as a gas for testing active surface sites is of great interest in the study of oxide catalysts. In this work a systematic study of Pt/CeO2 catalysts, depending on the platinum loading and calcination temperature was carried out using the method of temperature-programmed reduction by hydrogen (TPR-H2). Experimental TPR-H2 curves demonstrated a complex structure over a wide temperature range, including the presence of abnormally narrow consumption peaks (ANCP-H2) at low temperatures. To describe the kinetics, mathematical modeling of H2 consumption by various platinum active centers has been used, including isolated platinum ions (single atoms) and PtOx clusters of 2D and 3D structures on the surface of ceria nanoparticles. We proposed a criterion that makes it possible to extend the analysis of the TPR-H2 curves for reducible metal-supported oxide systems and unambiguously establish the action of the autocatalytic mechanism in hydrogen consumption. The kinetics of ANCP-H2 by cluster PtOx centers with a half-width of several degrees on the base of the autocatalysis mechanism was described on the base of the proposed model. The simulations show that ANCP-H2 are described by synchronous fast formation of metallic centers that provide a sharp acceleration of H2 consumption. In general, the obtained results establish the fundamental aspects of the H2 interaction with heterogeneous catalysts and are of particular interest in the light of various practical applications of hydrogen energy.

Oral delivery of solid lipid nanoparticles surface decorated with hyaluronic acid and bovine serum albumin: A novel approach to treat colon cancer through active targeting

The present study aims to prepare and evaluate solid lipid nanoparticles (SLNs) loaded with irinotecan (IRN) drug and daidzein (DZN) isoflavonoid and surface coated with ligand materials such as hyaluronic acid (HA) and bovine serum albumin (BSA) with additional coating of chitosan for active targeting to receptors present on colon surface epithelium for oral targeted delivery. The optimized batch was evaluated for particle size, zeta potential exhibiting nanometric size with good entrapment efficiency. Nanoparticles were found to be spherical. FTIR and DSC revealed that all the excipients and formulation were compatabile to each other and showed better encapsulation exhibiting amorphous and crystallinity forms. In vitro drug release of SLNs confirmed that initially a burst release, followed by sustained release pattern was exhibited. Cell lines studied performed on HT-29 cells showed demonstrated that conjugated SLNs inhibited cytotoxicity at 75 μg/ml, indicating that cells were taken up through a receptor-mediated endocytosis process. Cell cycle analysis showed that cell arrest was done at 67.8 % (G0/G1 phase) and inhibited apoptosis by 56 %. Further during In vivo studies, RT-PCR study revealed downregulation of Carcinoembryonic antigen (CEA), a non-specific serum biomarker overexpressed in tumor cells and upregulation of pro-inflammatory cytokine TNF-α. Histopathological study revealed that conjugated (HA-BSA) coated with chitosan SLNs restored normal mucosa and colon architecture, depicting all mucosal layers. Hence, these conjugated SLNs may serve as a novel combination for the treatment of colon cancer.

Nanoparticle Formulations for the Improvement of Symptomatic Treatments of Neurodegenerative Disorders

Neuronanomedicine merges nanotechnology and neuroscience in the pursuit of engineering therapeutic interventions for neurological disorders, including Alzheimer’s disease (AD) and Parkinson’s disease (PD). While no nanoparticle‐based drug delivery systems (NDDSs) are yet approved for use for targeting the central nervous system, this review critically analyses the development of NDDSs for the improvement of currently approved therapeutics for the symptomatic treatment of AD and PD. It showcases how NDDSs can help therapeutic payloads overcome existing limitations, such as insufficient drug accumulation in the brain and limited effectiveness, by enhancing their pharmacokinetics, bioavailability, brain penetration and accumulation, and overall therapeutic efficacy through drug encapsulation, manipulation of nanoparticle properties, and nanoparticle surface functionalisation. However, we also draw attention to widespread issues in the field that impede progress, including the poor selection of in vitro models and the inadequate design of pre‐clinical in vivo studies. We further advocate for greater standardisation of study design and reporting requirements in the future, which would likely enhance outcomes and expedite the translation of neuronanomedicines.

Room‐Temperature Lasing of Dual‐Metal Nanoparticle Surface Lattice Resonance with Monolithic InGaAs Multiple Quantum Wells on GaAs Substrates

This study demonstrates the surface lattice resonance (SLR) laser utilizing asymmetric dual‐metallic nanoparticle arrays, incorporating a high‐refractive‐index material, which exhibits a confinement factor of 16%, enhancing the coupling between metal and dielectric materials. Multiple quantum wells (MQWs) are integrated with plasmonic SLR in the proposed structure. Through theoretical design and experimental validation, the MQW plasmonic SLR laser exhibits excellent high Q‐factor and stable operation at room temperature. This demonstration enhances laser performance and achieves low‐threshold operation with a laser threshold as low as ≈2.39 MW cm−2. This study's design of plasmonic SLR lasers further advances the realization of optoelectronic device applications.

Nature of Charge Transfer Effects in Complexes of Dopamine Derivatives Adsorbed on Graphene-Type Nanostructures

Continuing the investigation started for dopamine (DA) and dopamine-o-quinone (DoQ) (see, the light absorption and charge transfer properties of the dopamine zwitterion (called dopamine-semiquinone or DsQ) adsorbed on the graphene nanoparticle surface is investigated using the ground state and linear-response time-dependent density functional theories, considering the ωB97X-D3BJ/def2-TZVPP level of theory. In terms of the strength of molecular adsorption on the surface, the DsQ form has 50% higher binding energy than that found in our previous work for the DA or DoQ cases (−20.24 kcal/mol vs. −30.41 kcal/mol). The results obtained for electronically excited states and UV-Vis absorption spectra show that the photochemical behavior of DsQ is more similar to DA than that observed for DoQ. Of the three systems analyzed, the DsQ-based complex shows the most active charge transfer (CT) phenomenon, both in terms of the number of CT-like states and the amount of charge transferred. Of the first thirty electronically excited states computed for the DsQ case, eleven are purely of the CT type, and nine are mixed CT and localized (or Frenkel) excitations. By varying the adsorption distance between the molecule and the surface vertically, the amount of charge transfer obtained for DA decreases significantly as the distance increases: for DoQ it remains stable, for DsQ there are states for which little change is observed, and for others, there is a significant change. Furthermore, the mechanistic compilation of the electron orbital diagrams of the individual components cannot describe in detail the nature of the excitations inside the complex.

The solid-solution HxPO4@Fe3O4 synthesized by irradiation enhances the adsorption capacity of tungsten(VI) and anti-interference of coexisting oxoanion in waste water: Surface oxolation interaction

Tungsten (W), mainly existing as hexavalent oxidation state in nature, has been considered as an increasingly prominent waterborne pollutant, but it is also a critical metal. Therefore, it is important to develop a material to adsorb W(VI) from the waste water containing W(VI) to realize the high-efficiency enrichment and recovery of W(VI). Inspired by self-assembly of phosphate and W(VI) ions in the acidic solutions to form phosphotungstic polyoxoanions (e.g., Keggin-type PW12O403−), in this work, we have loaded the phosphate ion to surface of the magnetic Fe3O4 nanoparticles (Fe3O4 NPs) by β particle irradiation to synthesize a composite adsorbent, HxPO4@Fe3O4 solid-solution (SS). This novel adsorbent is very efficient for W(VI) adsorption and recovery. The results of a batch of adsorption experiments indicate that HxPO4@Fe3O4 SS has a high adsorption efficiency for W(VI) in aqueous environments and strong anti-interference of coexist ions especially PO43−. Under room temperature conditions (∼25 °C), the maximum adsorption capacity reaches 88.44 mg g−1. This method not only ensures a substantial increase in W(VI) adsorption but also provides a facile means for adsorbent recovery, while minimizing additional environmental burdens. Based on the characterization results from Fourier transform infrared, Zeta potential, and X-ray photoelectron spectroscopies, we speculated that the possible mechanism of the adsorption process is that formed W(VI) polyoxoanions in acidic solutions are initially attracted by electrostatic attraction to the positively charged HxPO4@Fe3O4 surface, and then oxolation reaction occurs between W-OH of polyoxoanions and phosphate hydroxyl (P-OH) on the HxPO4@Fe3O4 surface to form P-O-W bridging oxygen group. This adsorption mechanism is also reflected in the adsorption kinetics, following a pseudo-second-order kinetic model, and adsorption thermodynamics, exhibiting a large enthalpy change (−76.3 kJ/mol) and a significant entropy reduction (−174.5 J/(mol K)).

The Adsorption of Chlorpromazine on the Surface of Gold Nanoparticles and Its Effect on the Toxicity to Selected Mammalian Cells

Chlorpromazine (CPZ) is a first-generation neuroleptic with well-established antitumor and antiviral properties. Currently, numerous studies are focused on developing new methods for CPZ delivery; however, the knowledge regarding its conjugates with metal nanoparticles remains limited. The aim of this study was to prepare CPZ conjugates with gold nanoparticles (AuNPs) and evaluate their biological activity on human lymphocytes (HUT-78 and COLO 720L), as well as human (COLO 679) and murine (B16-F0) melanoma cells, in comparison to the effects induced by unconjugated CPZ molecules and AuNPs with well-defined properties. During the treatment of cells with CPZ, AuNPs, and CPZ-AuNP conjugates, changes in mitochondrial activity, membrane integrity, and the secretion of lipid peroxidation mediators were studied using standard biological assays such as MTT, LDH, and MDA assays. It was found that positively charged CPZ-AuNP conjugates more effectively reduced cell viability compared to AuNPs alone. The dose-dependent membrane damage was correlated with oxidative stress resulting from exposure to CPZ-AuNP conjugates. The activity of the conjugates depended on their composition and the size of the AuNPs. It was concluded that conjugating CPZ to AuNPs reduced its biological activity, while the cellular response to the treatment varied depending on the specific cell type.

Investigating the effect of coating and synthesis parameters on La1-xSrxMnO3 based core-shell magnetic nanoparticles

Magnetic nanoparticles are an important class of functional materials that have unique magnetic properties due to their reduced size (<100 nm) and have the potential for use in many fields. In the preparation of magnetic nanoparticles, factors such as intrinsic magnetic properties, surface coating, size and shape of the particles, surface charge and stability are very important. In this regard, carefully determining the synthesis parameters of magnetic nanoparticles and particle coating materials is of critical importance in the application area chosen for the material. In this study, La1-xSrxMnO3 (x = 0.27, 0.30, 0.33) magnetic nanoparticles (MNPs), carbon-coated magnetic nanoparticles in core–shell structure (C@MNP) and their derivatives integrated into graphene oxide (GO-C@MNP) were synthesized and their properties were investigated in detail for their use in possible future application studies. The crystal structure of perovskite compounds with Pbnm symmetry remains unchanged after carbon coating but shrinks in volume due to its amorphous structure. The magnetic behavior of the uncoated and coated materials is almost identical, but the Curie temperature of the compounds shifts to a higher temperature. In the specific absorption ratio (SAR) measurements performed, it was found that the best SAR value for carbon-coated MNPs was 12.9 W/g at x = 0.27. By integrating the MNPs into graphene oxide, heat is easily distributed regionally, and this shows that the structures can be ideal candidates for applications such as hyperthermia, drug carriers, tissue repair, and cellular therapy including cell labeling and targeting.Perovskite-structured manganite materials were selected for their suitability in controlled production, where the Curie temperature can be tuned near the therapeutic temperature by adjusting the doping levels, making them ideal for magnetic hyperthermia applications. In this study, for the first time, the nanoparticle surfaces were coated with carbon, which was chosen not only due to carbon’s non-magnetic nature but also because it provides an ideal platform for future combined biomedical applications such as drug delivery systems.