Background Cerium oxide nanoparticles (CeO NPs) are showing neuroprotective effects in various experimental models of neurodegeneration. Doping of nanoparticles with magnetic resonance imaging (MRI) contrast agents (e.g., gadolinium) could enable simultaneous diagnosis and treatment of neurodegenerative diseases, a technology called theranostics that is used primarily in oncology but can also be successfully applied in the diagnosis and treatment of neurodegenerative diseases. Methods In this study, we doped polyacrylic acid conjugated cerium oxide nanoparticles with gadolinium (Gd-CeO) to create a theranostic agent with MRI capabilities and neuroprotective properties. These nanoparticles were evaluated for their physicochemical characteristics, magnetic resonance imaging potential, biosafety profile, cellular uptake, and neuroprotective effects compared to CeO nanoparticles (CeO) in a human neuronal model of Parkinson's disease employing undifferentiated and retinoic acid-differentiated SH-SY5Y cells. Results The synthesized Gd-CeO nanoparticles showed good stability, concentration-dependent T-1 and T-2 contrast features, and were not cytotoxic. The Gd-CeO nanoparticles were rapidly taken by cells and maintained neuroprotective potency against hydrogen peroxide (H2O2)- and 6-hydroxydopamine (6-OHDA)-induced cell damage to a similar extent as did CeO nanoparticles without Gd doping. Moreover, we demonstrated a protective effect of Gd-CeO and CeO nanoparticles on mitochondrial membrane potential, DNA fragmentation, and the number of necrotic cells in both models of cell injury, whereas at the level of caspase-3 activity, we showed an inhibitory effect of the studied NPs only in the 6-OHDA model. Finally, the protection mediated by Gd-CeO and CeO nanoparticles against H2O2 was confirmed in mouse primary cortical neurons. Conclusions Since the developed Gd-CeO nanoparticles showed promising contrast features, as well as maintaining biosafety and neuroprotective properties similar to those of nanoparticles without Gd doping, they could be further investigated as a potential theranostic probe for neurodegenerative diseases, including Parkinson's disease.

A series of multifunctional cationic surfactants comprising a tertiary amide linker in their structures and differing in their architecture, i. e. single head-single tail pattern with different hydrophobic tails ([(3-alka-noyilmethylamino)propyl] trimethylammonium bromides (CnBr, n =12, 14 or 16)), as well as double head-double tail (gemini) analog (dimethyl{{3-[N-(3-{N-[3-(dimethylammonium)propyl] dodecylamido}propyl} dodecylamido}propyl}}ammonium dibromide (2xC12BrG3)) and double head-single tail (dicephalic) (N,N-bis [3,3 '-(trimethylammonio)propyl]dodecanamide dibromide (C12(TAPABr)2)), both with the same alkyl chain length, were evaluated for their surface activity at the air/solution interface as well as wettability of the glass and/or polytetrafluoroethylene (PTFE) surfaces. The physicochemical behavior at the air-liquid interface was investigated. Surface tension isotherms of aqueous solutions of the studied multifunctional cationic surfactants were determined by pendant drop shape analysis and interpreted using the modified surface quasi-twodimensional electrolyte (mSTDE) model of ionic surfactant adsorption, previously developed in our group. The analysis was supported by the molecular dynamics simulations. The wetting properties of the above-mentioned surfactants were evaluated by measuring the advancing and receding contact angles of their aqueous solutions on a bipolar glass surface and the advancing contact angle on an apolar PTFE surface. Based on these results, the influence of surfactants on the surface free energy (surface tension) of water, glass, and PTFE was examined. It was found that changes in the surface free energies of water and glass depend on both the alkyl chain length and the structure of the surfactant molecules. In the case of water, they are related to the reduction of only the acid-base component of this energy. These changes determine the wetting properties of the studied surfactants and indicate that single-chain, single-head surfactants and gemini-type surfactants have the highest wetting properties on hydrophobic solids and the lowest on hydrophilic solids.

Understanding how molecular additives modulate the interfacial structure and foaming behaviour of natural surfactants is essential for the design of high-performance, sustainable formulations. Here, we investigate how hydrogen-bond donor and acceptor additives - glycerol, choline chloride, and urea - modify the interfacial architecture of Quillaja saponin extract solutions. A multi-technique approach combining surface tension, interfacial dilational rheology, foam stability measurements, vibrational sum-frequency generation (SFG) spectroscopy, electrokinetic analysis, and atomistic molecular dynamics (MD) simulations reveals distinct additive-specific mechanisms at the molecular level. Using SFG spectroscopy, we resolved the additive-induced reorganisation of interfacial saponins and interfacial water molecules. Glycerol reduces the fraction of more strongly hydrogen-bonded interfacial water without altering surface tension, indicating interfacial insertion and reorientation while the overall macroscopic surface activity remains largely unchanged. In contrast, urea redistributes spectral weight toward strongly hydrogen-bonded interfacial water without significantly altering the overall surface excess of saponin, while decreasing headgroup-water contributions, thereby impairing the formation of lateral hydrogen bonds between neighbouring saponins and reducing the elasticity of the surface layer. Choline chloride induces pronounced suppression of the OH stretching band from interfacial water, consistent with charge screening and a substantial reduction of the interfacial net charge. MD simulations corroborate these findings by revealing that glycerol has more frequent contacts with the saccharide region of saponin, supporting strong interfacial cohesion. The high propensity of urea to interact with the polar residues of saponin explains the redistribution of interfacial water and headgroup hydroxyls observed in SFG spectra.

Polyelectrolyte-surfactant complexes (PESCs) have emerged as versatile soft-matter systems, offering unique opportunities for the design of multifunctional delivery platforms. Therefore, this study investigates the design, formation, and characterization of novel PESCs based on antimicrobial-functionalized poly(acrylic acid) (PAA) derivatives and a newly synthesized cationic dicephalic surfactant, 2-dodecyl-N,N,N,N',N',N'-hexamethyl-propan-1,3-ammonium dibromide (C12-DCNMe3Br). Building on our previous work on antimicrobial-decorated PAAs grafted with thymol (PAA-THY-15), menthol (PAA-MEN-15), and carvacrol (PAA-CAR-15), these polyanions were combined with the oppositely charged surfactant to construct multipurpose carrier systems. The designed PESCs were loaded with curcumin (CUR), a model hydrophobic drug with therapeutic properties, to evaluate their potential applicability as drug delivery systems (DDSs). A variety of physicochemical techniques were applied to gain insight into the complexation processes, self-assembly behavior, and functional properties of the resulting PESCs. Surface activity of new complexes was assessed by goniometric measurements, while their colloidal stability over time was studied using the turbidimetric method. Dynamic light scattering (DLS) provided information on particle size, polydispersity, and surface charge. Encapsulation efficiency (EE) and release kinetics were assessed by UV-vis spectrophotometry to evaluate the ability of the complexes to effectively entrap CUR and provide sustained release. The integration of antibacterial PAA derivatives with dicephalic surfactants highlights the versatility of PESCs as tunable, multifunctional carriers that combine antimicrobial protection with controlled drug delivery. These findings demonstrate that the designed complexes are promising candidates for advanced DDSs and pave the way for further development of functional colloidal materials tailored for biomedical applications.

Printed electronics is an emerging technology that has already transformed the world around us by enabling the fabrication of flexible, lightweight, and large-area electronic devices. However, achieving simultaneous optimization of electrical conductivity, environmental stability, mechanical flexibility, and cost efficiency remains a critical challenge. Nanowires (NWs) have gained prominence in various applications due to their high surface area to volume ratio. Silver NWs (Ag NWs) in particular have established themselves as leading platforms for transparent conductive electrodes (TCE), however their high cost and material consumption limit widespread adoption. While copper NWs (Cu NWs) offer cost advantages and comparable conductivity to silver; rapid oxidation and corresponding increase in resistivity in ambient conditions restrict their widespread adoption. Cu@Ag core-shell NWs (Cu@Ag NWs) are a promising solution, combining the cost efficiency of copper with the oxida0074ion resistance of silver through a strategic thin-shell design. This mini-review focuses on recent advances in Cu@Ag NWs synthesis, focusing particularly on kinetically controlled approaches that achieve conformal silver shells lowering the consumption of silver. We examine synthesis methodologies, including galvanic displacement and chemical reduction, discuss mechanisms underlying long-term environmental stability, and evaluate integration pathways for printed electronics applications including, transparent conductive films, flexible displays, wearable devices, and electromagnetic interference (EMI) shielding. Challenges and future considerations, including shell uniformity control, ink formulation optimization, and multi-functional coating systems incorporating protective oxide layers, are also addressed. This review provides a comprehensive framework for advancing Cu@Ag NWs technology toward practical commercial implementation in next-generation flexible and printed electronics.

Copper@silver (Cu@Ag) core–shell nanowires (NWs) were synthesized using a controlled galvanic displacement approach designed to suppress the oxidation typically observed in copper nanostructures. The procedure included a Diethylhydroxylamine (DEHA) based pretreatment to remove native surface oxides from the Cu NWs, improving the uniformity of subsequent silver deposition. Addition of Ascorbic Acid at a delayed rate enhanced homogeneous shell formation was the enabling even surface adsorption of silver ions prior to reduction. This timing minimized premature nucleation and facilitated the growth of smooth, continuous Ag shells. Inks formulated from these Cu@Ag NWs displayed low percolation thresholds (∼0.14 vol%) and high conductivity at only 1 vol% loading. The resulting films retained more than 90% of their initial conductivity after 28 days and very low Oxygen presence in EDX mapping spectrum peaks after 90 days ambient exposure, demonstrating enhanced environmental stability compared to uncoated Cu NW systems. This synthesis protocol offers a reproducible, solution processable route for preparing conductive inks suited to applications in flexible and large area printed electronics.

A series of multicharged surfactants with magnetic counterions (Mag-D-Surfs) containing one hydrophobic tail and two hydrophilic groupings, and comprising exclusively carbon atoms in the hydrophobic part, i.e., 2-alkyl-N,N,N,N',N',N'-hexamethylpropan-1,3-ammonium salts (ferrates; alkyl: decyl, dodecyl, and tetradecyl, abbreviated, respectively, as C10-DCMe3Mag, C12-DCNMe3Mag, and C14-DCNMe3Mag), were first synthesized and characterized by FT-IR, Raman, X-ray fluorescence (XRF), and FIR spectra as well as elemental analyses. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), supported by optical polarization microscopy, showed that the coexistence of isotropic and anisotropic subphases depended on cooling rates. Surface activity of Cn-DCNMe3Mag at the air/water interface was evaluated by measuring the surface tension of their solutions by the pendant drop technique and compared with surfactants without magnetic function. Moreover, surface tensiometry in a magnetic field demonstrated that the studied Mag-D-Surfs exhibited magnetically induced changes in the drop shape. Their magnetic behavior in the solid state was determined by superconducting quantum interference device magnetometry (SQUID). All findings related to the aforementioned double-headed Mag-D-Surfs were compared to linear magnetic ionic liquids surfactants (MILSs), i.e., alkyltrimethylammonium halogenoferrates (alkyl: dodecyl [DTA][FeClxBr4-x-], tetradecyl [TTA][FeClxBr4-x-], and cetyl [CTA][FeClxBr4-x-]). Magnetic tests confirm the paramagnetic nature of the studied compounds and the 1:1 molar ratio (surface active cation:Fe3+) for all the studied surfactants. Their unique physicochemical properties demonstrate exceptional performance, particularly in the development of new stimuli-responsive materials.

We explored the physicochemical aspects of the problem of a rising air bubble in an aqueous surfactant solution, where saturated n-hexane vapor is present within the bubble. The rising velocity profiles of these bubbles were measured in pure water and salt-free solutions of a nonionic (n-octanol) or cationic (dodecyltrimethylammonium bromide, C12TAB) surfactant at various concentrations. They were compared with the results for corresponding hexane-free systems. Additionally, dynamic surface tension for stationary bubbles was measured using bubble profile analysis tensiometry. To support these experimental data, we conducted an investigation using molecular dynamics (MD) simulations. For pure water, both surface tension measurements and MD simulations confirmed the adsorption of n-hexane molecules from the vapor phase to the stationary water interface, which is consistent with the literature reports. However, the rising bubble velocity was not affected by n-hexane vapor. We discuss this intriguing finding within the context of hydrodynamic forces. In the surfactant systems, a strong effect of coadsorption of surfactant from the solution and n-hexane from the vapor phase was observed in all investigations. The surface tension isotherms were theoretically described using a modified Frumkin adsorption model, additionally accounting for the ionic nature of C12TAB and the coadsorption of n-hexane from the vapor. The free energy of adsorption exhibited a strong correlation with the free energy profiles at the interface, as determined by MD simulations. The rising bubble data were theoretically analyzed in terms of the drag coefficient and the extent of bubble deformation. However, studies of the bubble velocity profiles revealed some unusual features, particularly during the dynamic layer formation phase.

Polyelectrolyte multilayers (PEMs) are widely utilized in membrane technologies, biosensing, and drug delivery, where precise control over permeability, which refers to the ease of transport through the multilayer, is essential. While the influence of anions on PEMs is well-documented, the role of countercations in regulating transport properties through films remains underexplored. Here, we investigate the effects of sodium (Na+) and potassium (K+) countercations on the formation, structure, permeability, and transport properties of PAH/PSS and PDADMAC/PSS multilayers. Using a quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy, we demonstrate that K+-assembled films exhibit higher mass, denser packing, and significantly reduced permeability compared to Na+-assembled films. Extended characterizations reveal selected permeability toward ionic probes and frequency-dependent impedance behavior in K+, underscoring the potential of the films as tunable barriers. We further demonstrate their application in a model drug release system, highlighting controlled release profiles influenced by countercation choice. These findings provide insights into cation-mediated tuning of PEM properties, offering a robust strategy for designing advanced materials for separation, sensing, and biomedical applications.

The construction of multipurpose particles with functional coatings of varying structure and composition provides the opportunity to modify their physicochemical and biological characteristics. In accordance with the aforementioned, new polyelectrolytes (PEs) decorated with an antimicrobial function (PEs-DAF) were designed and prepared to apply them as building blocks of a various carrier systems. A series of hydrogel nano- and microparticles were developed and coated with an outer PE shell with antimicrobial functionality. To this end, poly-(acrylic acid) (PAA) was grafted with different degrees of substitution (DS) of antimicrobial essential oils such as thymol (THY), menthol (MEN), and carvacrol (CAR) (abbreviated as PAA-X-DS% (X = THY, MEN, CAR; DS = 5,15)) using Steglich esterification under mild reaction conditions. Their structures were confirmed by 1H NMR and FTIR spectroscopy. The particles' morphology and mean diameter were determined by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The physicochemical properties of the novel functional coatings were characterized using quartz crystal microbalance with a dissipation (QCM-D) analysis and spectroscopic ellipsometry. The antimicrobial properties of the functionalized PAA and the alginate microgel particles decorated with these PEs were evaluated against Staphylococcus aureus and Escherichia coli using the agar disc diffusion assay and minimal inhibitory concentration evaluation. The particles exhibited satisfactory antimicrobial activity, and some examples showed higher bioactivity than the functionalized PAAs. Moreover, the designed systems were loaded with resveratrol (RES), a model chemotherapeutic substance, to assess their potential applicability as drug carriers. The analysis proved the effective RES encapsulation and its release in a controlled manner depending on the coating properties. The results found in our study indicate potential therapeutic applications of the new antimicrobial-decorated carrier systems in the treatment of multidrug-resistant pathogenic infections.

Inefficient delivery of neuroprotective drugs to their target sites remains a major impediment in the treatment of neurodegenerative disorders. Therefore, our research was focused on a new strategy for the preparation of polymeric-based theranostic nanocarriers of neuroprotective drugs. Polymeric theranostic nanocarriers of calcineurin inhibitors, Cyclosporin A (CsA) and Tacrolimus (FK506), as potential neuroprotective agents, were prepared via the self-emulsification solvent evaporation (SESE) method with the combination of a layer-by-layer technique. For magnetic resonance imaging, gadolinium-labeled poly-l-lysine (PLL-Gd) was used, while for optical imaging, rhodamine-labeled poly-l-lysine (PLL-ROD) was used. Developed nanocarriers were characterized for their properties: the size was below 250 nm, the encapsulation efficiency was ∼100%, and they could serve as transport devices for therapeutic cargo and imaging compounds, e.g., distribution assessment. Developed nanocarriers were safe for tested cells (human neuroblastoma cells, primary neuronal cell cultures, and brain microvascular endothelial cells). Equally important, they willingly traversed the artificial blood-brain barrier. Our study demonstrated that the newly designed polymeric-based theranostic nanocarriers possess favorable physicochemical and biological properties and may serve as a useful platform for neuroprotective compound delivery.

Metallic nanoparticles are widely used to enhance the electrical conductivity of functional materials. However, despite extensive experimental and theoretical research, further improvement of their conductive performance and the development of low-temperature fabrication processes remain necessary. In this work, we report a UV-Vis-assisted, low-temperature sintering strategy for conductive coatings composed of nickel@silver (Ni@Ag) core-shell nanoparticles and size-controlled silver nanoparticles. The hybrid paste formulation enabled a significant reduction in electrical resistivity, with smaller Ag nanoparticles (10 nm) providing the highest conductivity due to enhanced particle coalescence and improved film densification. An optimal Ag nanoparticle content of 1.5 wt% resulted in coatings with a resistivity of 16 mu Omegacm, corresponding to 46% of the bulk conductivity of nickel and exceeding the performance of undoped Ni@Ag films. This scalable and non-destructive approach offers an effective route for fabricating high-conductivity coatings at low processing temperatures. This scalable, non-destructive process offers a viable route for printed conductive circuits on heat-sensitive substrates.

Polyelectrolyte multilayers (PEMs) are very promising systems in the field of material science, intensively developed and broadly examined with constantly increasing interest in applications such as sensors, coatings, membranes, and biomedical interfaces. While the impact of ionic strength on PEM formation is well established, the influence of specific counterions remains underexplored. In this study, we systematically examine the effect of six monovalent cations-NH4*, Li*, Na*, K*, Rb*, and Cs*-on the build-up, morphology, permeability, and surface wettability of PDADMAC/PSS multilayers assembled via the layer-by-layer technique. Using a combination of quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), cyclic voltammetry, and contact angle measurements, we demonstrate that the physicochemical properties of PEMs are strongly influenced by cation identity. Larger, chaotropic cations (Rb*, Cs*) produce thicker, smoother, and more compact films with reduced permeability, consistent with enhanced charge screening and interchain packing. In contrast, smaller, kosmotropic cations (Li*, Na*) lead to thinner, rougher, and more permeable films, suggesting weaker chain interactions and looser film structures. K* induces exceptionally high surface hydrophobicity and blocking efficiency, while NH4* shows distinct behavior likely due to its hydrogen-bonding capabilities. A clear odd-even alternation in contact angle was observed, driven by the chemical nature of the terminating layer (PDADMAC vs. PSS), highlighting the importance of surface composition in wetting behavior. These findings demonstrate that even subtle differences in ion type can modulate film growth kinetics, surface morphology, and functional performance. The results offer new insights into the design of PEMs with tailored permeability, roughness, and surface energy, with direct implications for their optimization in electrochemical sensors, antifouling coatings, and controlled-release systems.

Investigating the adsorption properties of emulsifiers at water-oil interfaces enables advances in the comprehension of the mechanisms governing emulsion ageing and stabilization. The utilization of natural compounds in emulsion formulations is increasingly relevant for those applications where it is challenging to maintain a low impact on the environment and health. We report here a study on saponin and chitosan at the interface between water and medium-chain triglycerides (MCT) oil in relation to the properties of the corresponding emulsions. Complementary experimental approaches have been adopted to investigate interfacial properties and emulsion evolution, relying on drop tensiometry, optical and confocal microscopy, and light transmission/scattering analysis. In addition, molecular dynamics simulation has been undertaken as support for the interpretation of the experimental results. The multi-technique investigation adopted here enabled a better understanding of saponin adsorption properties and of the role of chitosan in emulsion evolution. In particular, the results evidence the formation of amphiphilic saponin-chitosan complexes, which adsorb at the liquid-liquid interface and improve the stability of oil-in-water emulsions. Since the system investigated mainly consists of natural compounds, the results of this work can contribute to the development of new and efficient low-impact formulations.

The interfacial behavior of aqueous solutions of newly synthesized 2-alkyl-N,N,N,N',N',N'-hexamethylpropan-1,3-ammonium dibromides with decyl, dodecyl, and tetradecyl alkyl chains was investigated both experimentally and theoretically. The results of the surface tension measurements were described using the modified surface quasi-two-dimensional electrolyte (mSTDE) model of ionic surfactant adsorption, which was supported by molecular dynamics simulations. Our contribution encompasses the design, synthesis, and characterization of a novel class of dicephalic-type cationic surfactants, branched on a methine motif, possessing two symmetric trimethylammonium groups, which constitute a double-head extension of the standard alkyltrimethylammonium salts of the single-head, single-tail structure. The convenient synthetic route and final purification steps allowed for the high-yield, high-purity production of the surfactants. Dicephalic-type surfactants demonstrated lower surface activity and higher critical micelle concentration values when compared with their single head-single tail counterparts. That can be attributed primarily to the presence of strong electrostatic repulsive forces within the bulky, double-charge headgroups and significant counterion condensation. Furthermore, molecular dynamics simulations demonstrated a propensity for the desorption of surfactants from the interface, even in diluted solutions, which constrained the attainable surface concentration and resulted in a lower reduction in surface tension. The mSTDE model of adsorption provided an excellent description of the experimental surface isotherms with a concise set of parameters. The model's predictive power was demonstrated by the studies of the effect of inorganic salts on the surface activity of investigated surfactants. Our unique approach enabled us to gain a theoretical explanation of the newly devised surfactants' behavior at the water/air interface.

Oxidative stress and neuroinflammation play a pivotal role in pathomechanisms of brain ischemia. Our research aimed to formulate a nanotheranostic system for delivering carnosic acid as a neuroprotective agent with anti-oxidative and anti-inflammatory properties to ischemic brain tissue, mimicked by organotypic hippocampal cultures (OHCs) exposed to oxygen–glucose deprivation (OGD). In the first part of this study, the nanocarriers were formulated by encapsulating two types of nanocores (nanoemulsion (AOT) and polymeric (PCL)) containing CA into multilayer shells using the sequential adsorption of charged nanoobjects method. The newly designed nanoparticles possessed favorable physicochemical characteristics as reflected by zeta potential and other parameters. Next, we demonstrated that the newly designed gadolinium-containing nanoparticles were not toxic to OHCs and did not affect the detrimental effects of OGD on the viability of the hippocampal cells. Importantly, they readily crossed the artificial blood–brain barrier based on the human cerebral microvascular endothelial (hCMEC/D3) cell line. Furthermore, the PCL-Gd carnosic acid–loaded nanoparticles displayed anti-inflammatory potential, expressed as decreased OGD-induced HIF-1α and IL-1β levels. Results of the molecular study revealed a complex mechanism of the nanoformulation on ischemia-related neuroinflammation in OHCs, including anti-inflammatory protein A20 stimulation and moderate attenuation of the NFκB signaling pathway. Summing up, this study points to acceptable biocompatibility of the newly designed CA-containing theranostic nanoformulation and emphasizes their interaction with inflammatory processes commonly associated with the ischemic brain.

The food industry is actively seeking innovative approaches to enhance food quality and extend shelf life. To this end, we developed novel micro/nanoemulsion formulations that combine commercial essential oils (oregano, lemongrass, thyme, rosemary) with bio-polysaccharides (cationic chitosan and anionic furcellaran). These ingredients were chosen for their inherent antimicrobial properties, which are crucial for developing new preservation methods. The primary objective was to conduct a comprehensive physicochemical characterization of these novel nanoformulations, which integrate essential oils, polysaccharides, and antimicrobial peptides (RW4, LL37). The interfacial tension measurements indicated the absence of slowly adsorbing, surface active contaminants. The nanoemulsion droplets, prepared via ultrasonication, had sizes ranging from 150 to 400 nm, which appeared to correlate with the essential oils' interfacial tension. The IR spectra analysis supported by the Density Functional Theory computation confirmed that the main components of the commercial essential oils were carvacrol for oregano, thymol for thyme, 1,8-cineole for rosemary, and citral for lemongrass. The negative surface charge determined by the electrokinetic measurements of nanoemulsion drops can result from the dissociation of carboxylic groups at the interface, which could be evidenced by the presence of bands in the region 1700-1740 cm-1. The nanoformulations exhibited stability for 44-60 days, and their potential antimicrobial properties were enhanced by the addition of peptides RW4 and LL37 without impairing the stability. These developed nanoformulations present a promising solution for food preservation applications.

This study investigates the effects of varying concentrations of TiO2 NPs (from 0.00512 to 51.2 mu g/mL) on the self-organisation of biohybrid systems formed by them and photosystem II-enriched photosynthetic membranes (PSII BBY). The superfine TiO2 NPs with diameters of similar to 1 nm (quantum dots, QDs) can easily penetrate the membrane, modifying its lipid-protein matrix. Topographical changes to the PSII BBY-TiO2 QDs system were monitored by atomic force microscopy (AFM) in a liquid environment to ensure the physiological activity of PSII BBY. Membrane roughness increased with NP concentration, with root mean square roughness (Rq) ranging from 0.26 nm to 0.40 nm. Minkowski functionals revealed that TiO2 concentrations >= 0.1 mu g/mu g induced significant topographical changes, with surfaces transitioning from valley-dominated to rough peaks and holes. Fractal and multifractal analysis confirmed the presence of self-affine structures, with fractal dimensions (FD) ranging from 2.201 to 2.283 and Hurst coefficients (H) below 0.5 for TiO2-treated samples, indicating short-range correlations. The PSII BBY control exhibited the highest multifractality, with a Delta alpha of 1.372. The observed changes in the organisation of PSII BBY membranes under the influence of TiO2 QDs show that this is an important factor that, along with the high reactivity of the QDs surface in forming covalent bonds with biomolecules, will influence the modulation of the efficiency of light energy assimilation and water oxidation in this type of biohybrid system. Furthermore, our results demonstrate the potential dangers of altering cell membranes at a molecular level when living organisms are exposed to nanoparticles of this size. In our study, the TiO2 QDs were of anthropogenic origin, derived from commercially available TiO2 powder.

Cerium oxide nanoparticles (CeONPs) exhibiting antioxidant properties are investigated as potential tools for neurodegenerative diseases. Here, we synthesized polyacrylic acid conjugated cerium oxide (CeO) nanoparticles, and further to enhance their neuroprotective effect, Eu3+ was substituted at different concentrations (5, 10, 15 and 20 mol%) to the CeO, which can also impart fluorescence to the system. CeONPs and Eu-CeONPs in the size range of 15–30 nm were stable at room temperature. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed the chemical state of Eu and Ce components, and we could conclude that all Eu3+ detected on the surface is well integrated into the cerium oxide lattice. The emission spectrum of Eu-CeO arising from the 7F0 → 5D1 MD and 7F0 → 5D2 transitions indicated the Eu3+ ion acting as a luminescence center. The fluorescence of Eu-CeONPs was visualized by depositing them at the surface of positively charged latex particles. The developed nanoparticles were safe for human neuronal-like cells. Compared with CeONPs, Eu-CeONPs at all concentrations exhibited enhanced neuroprotection against 6-OHDA, while the protection trend of Eu-CeO was similar to that of CeO against H2O2 in SH-SY5Y cells. Hence, the developed Eu-CeONPs could be further investigated as a potential theranostic probe.

The design of novel polymeric carrier systems with functional coatings is of great interest for delivering various bioactive molecules. Microcapsules coated with polyelectrolyte (PE) films provide additional functionality and fine-tuning advantages essential for controlled drug release. We developed hydrogel microcarriers coated with functional PE films with encapsulated substances of natural origin, resveratrol (RES), curcumin (CUR), and epigallocatechin gallate (EGCG), which have cytotoxic and chemopreventive properties. Alginate (ALG) based microparticles were loaded with phytopharmaceuticals using the emulsification method, and then their surface was modified with PE coatings, such as chitosan (CHIT) or poly(allylamine hydrochloride) (PAH). The morphology and mean diameter of microcarriers were characterised by scanning electron microscopy, encapsulation efficiency was determined by UV-Vis spectroscopy, whereas the physicochemical properties of functional PE layers were studied using quartz crystal microbalance with dissipation monitoring and streaming potential measurements. The release profiles of active compounds from the hydrogel microparticles were described using the Peppas-Sahlin model. The cytotoxic effect of designed delivery systems was studied by evaluating their impact on the proliferation, mitochondrial metabolic function, and lipid peroxidation level of 5637 human bladder cancer cells. The present work demonstrates that the physicochemical and biological features of fabricated microcarriers can be controlled by the type of encapsulated anti-cancer agent and PE coating.