Beilstein Journal of Nanotechnology最新文献

It was recently shown that small bundles of linear carbon chains (LCC) encapsulated by double- and multi-wall carbon nanotubes (LCC@DWCNT and LCC@MWCNT, respectively) behave as Debye's materials for temperatures as high as 293 K with an estimate that such materials could still withstand such characteristics for even higher temperatures (≈700 K). Using the Debye model, thermodynamic observables (internal energy, coefficient of linear thermal expansion, specific heat, thermal strain, and Grüneisen parameter at constant pressure) were empirically determined for the first time in the range of temperatures 70 < T < 293 K. These observables were all correlated with the C-band frequency (ω_LCC) dependence on the temperature (T) and its first and second derivatives with relation to T, dω_LCC/dT, and d²ω_LCC/dT ². The C-band is a Raman spectroscopic signature for LCC, which is not only temperature-dependent but also dependent on the number of carbon atoms (N) constituting the LCC. In this present study, we extend these findings to temperatures ranging from 13 < T < 293 K, which provide more accurate values for both dω_LCC/dT and d²ω_LCC/dT ². The corrected values of these derivatives affect the Grüneisen parameters associated with the LCC, even though the other associated thermodynamic parameters remain essentially unchanged. Our measurements were performed in both isolated and small bundles of LCC@MWCNT, which allowed us to demonstrate that small bundles or isolated environments do not seem to influence the vibrational and thermodynamic properties measured.

Precise control of electrical conductivity, humidity sensitivity, and photocatalytic activity in polymeric and carbon-based materials is essential for advancing technologies in environmental sensing, flexible electronics, and photocatalytic systems. Conventional chemical modification methods often lack spatial precision, introduce impurities, and risk structural degradation. Ion implantation provides a controllable alternative for tuning surface properties at the nanoscale, enabling the targeted introduction of functional species without chemical reagents. This work investigates the effects of low-energy (20 keV) and medium-energy (1.5 MeV) Ag⁺ ion implantation on the electrical, sensory, and photocatalytic properties of graphene oxide (GO) and polyimide (PI). Implantations were carried out with fluences ranging from 3.75 × 10¹² cm^-2 to 1 × 10¹⁶ cm^-2. Silver ions offer excellent electrical, catalytic, and plasmonic characteristics, making them ideal for multifunctional enhancement of GO and PI. Elemental and structural changes induced by implantation were analyzed using Rutherford backscattering spectroscopy, elastic recoil detection analysis, Raman spectroscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Surface morphology was assessed via atomic force microscopy. Electrical properties as a function of air humidity were evaluated using a two-point method, and photocatalytic activity was tested by monitoring the UV-induced decomposition of rhodamine B. The results demonstrate that ion implantation significantly reduces surface resistivity and enhances both the photocatalytic activity and humidity sensitivity of GO and PI. The most pronounced improvements occurred at higher fluences, where defect generation and partial deoxygenation contributed to optimal performance. Ion implantation thus represents an effective approach for tuning the multifunctional behavior of polymer systems.

Polymers play a pivotal role in various drug delivery systems due to their versatility, with polymeric nanoparticles showing significant potential to overcome physiological barriers associated with oral administration. This review examines the current advancements in the application of polymers as oral nanocarriers, emphasizing key natural and synthetic polymers that enhance stability, bioavailability, and release. The physicochemical properties, biodegradability, and chemical modifications of these polymers, which promote mucoadhesion and epithelial permeability, critical factors for effective oral drug delivery, are discussed in detail. Furthermore, nanoparticle synthesis methods that enable controlled release profiles, optimized biodistribution, and improved therapeutic efficacy are also explored. Thus, polymers represent a dynamic platform for developing diverse nanocarriers for oral applications, and this review provides a valuable theoretical foundation for understanding the strategies currently employed in this field.

Esophageal cancer (EC) is a common malignant tumor of the digestive tract with poor prognosis and high mortality. The early diagnosis of EC mainly depends on endoscopic diagnosis, which not only needs to bear certain economic pressure, but also needs patients to recognize the high risk factors of EC. Most EC patients are diagnosed at intermediate or late stages, often due to a lack of awareness regarding early symptoms and lifestyle-related risk factors. However, the discovery of aptamers and the development of nanocarriers bring great benefits to the diagnosis, treatment, and targeted drug delivery of EC. Aptamers or peptide aptamers as biosensors or therapeutic agents for the diagnosis or treatment of EC, aptamer-drug conjugates and aptamer-functionalized drug nanocarriers for targeted drug delivery in esophageal cancer are reviewed in this paper. In addition, we expect investigators to pay special attention to improving aptamer permeability and stability to accelerate aptamer clinical transformation. In conclusion, leveraging the high target specificity of well-selected aptamers may bring new breakthroughs in the diagnosis, treatment and drug delivery of EC.

The treatment of dry eye disease (DED) often requires frequent use of artificial tear products. Because of their low permeability and limited ocular bioavailability, repeated applications are required for therapeutic effectiveness. In contrast to traditional drug delivery systems (DDS), a functional ophthalmic nanoemulsion was specifically designed to alleviate symptoms of DED by leveraging its antioxidant and osmoprotective properties. The study evaluated the optimal concentration of lecithin required to produce nanoemulsions with a uniform particle size and incorporated a co-surfactant to enhance the stability of the nanoformulation. A straightforward method was proposed, involving the dilution of the preformulation in an ophthalmic vehicle, followed by homogenization through ultrasonication, resulting in OphtNE-3.70% with a droplet diameter of 173 nm and a zeta potential of -44.7 mV. The addition of Kolliphor^® HS15 in OphtNE-3.66%(K1%) initially reduced the droplet size to 70.8 nm and enhanced the antioxidant effect. Although the droplet size and polydispersity index increased after more than 60 days, the formulation remained physically quite stable without phase separation. Both nanoformulations contained 2.6% (w/v) linseed oil, providing a bioactive concentration compatible with ocular administration volumes (~50 µL). At a final concentration of 1.30 mg·mL^-1, OphtNE-3.66%(K1%) showed >75% cell viability in L929 cells and ~10% 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant effect. These findings support the multifunctional potential (cytocompatibility and antioxidant) of sterile OphtNE-3.66%(K1%) for the treatment of DED, emphasizing the need for in vivo studies to ensure its efficacy and safety for ocular administration.

The anisotropic hygroscopic behavior of pine cone scales and its effect on bending motion, with implications for bioinspired actuation, is investigated. Using gravimetric water uptake measurements, synchrotron radiation-based nano-holotomography, and digital volume correlation analysis, inter- and intra-tissue variations of hygroscopic swelling/shrinkage were observed. In addition, the moisture content of pine cone scale tissues was measured as a function of relative humidity. There were distinct differences between tissues and a pronounced hysteresis between sorption and desorption. Finite element analysis was performed on geometries ranging from simplified bilayer models to complex remodeled scales. Simulation results showed an underestimation of the bending of bilayer geometries due to an overestimated contribution of sclerenchyma fiber stiffness. Geometries with discrete fibers embedded in a brown tissue matrix more accurately reproduced the bending angles observed in experiments. This highlights the importance of the chosen material properties and tissue arrangements for predicting pine cone scale bending in silico. By contributing to a deeper understanding of pine cone scale biomechanics, these results also support the development of bioinspired technical applications. Future studies should refine tissue mechanical properties and integrate high-resolution computed tomography-based geometries to further elucidate the mechanisms underlying hygroscopic actuation. This integrative approach will bridge experimental findings with computational modeling and advance plant biomechanics and biomimetic transfer.

In this work we consider a spin model composed of a single spin and connected to an infinitely coordinated Ising chain. Theoretical models of this type arise from various fields of theoretical physics, such as theory of open systems, quantum control, and quantum computations. In the thermodynamic limit of an infinite chain, we map the chain Hamiltonian to the Hamiltonian of the Lipkin-Meshkov-Glik model, and the system as a whole is described by a generalized Rabi Hamiltonian. Next, the effective Hamiltonian is obtained using the Foulton-Gouterman transformation. In the thermodynamic limit we obtain the spectrum of the whole system and study the properties of the ground-state quantum phase transition.

Ambient pressure X-ray photoelectron spectroscopy (APXPS) has emerged as an important technique for investigating surface and interface chemistry under realistic conditions, overcoming the limitations of conventional XPS restricted to ultrahigh vacuum. This review highlights the capabilities and scientific impact of APXPS at the MAX IV Laboratory, the world's first fourth-generation synchrotron light source. With the APXPS beamlines SPECIES and HIPPIE, MAX IV offers state-of-the-art instrumentation for in situ and operando studies across a broad pressure range, enabling research in catalysis, corrosion, energy storage, and thin film growth. The high brilliance and small beam size of MAX IV's synchrotron light are essential for pushing the time-resolution boundaries of APXPS, especially in the soft X-ray regime. We discuss representative studies at MAX IV, including investigations of single-atom catalysts, confined catalysis, time-resolved catalysis, atomic layer deposition, and electrochemical interfaces, showcasing the role of APXPS in advancing material and surface science.

Nanotechnology is revolutionizing pharmaceutical industry and drug development by providing significant advantages in controlling drug release, enhancing stability, and reducing adverse effects. Concurrently, natural products are being extensively researched for their anticancer and immunomodulatory properties. This patent review aims to analyze publications that integrate nanotechnology with natural products to develop cancer treatments and immunotherapies. In this context, 17 patents were identified through the free online databases of the European Patent Office (EPO) and the World Intellectual Property Organization (WIPO). The review discusses various types of nanotechnology, including nanoparticles, nanocarriers, and nanocapsules, as well as bioactive compounds primarily extracted from plants. Among the most frequently identified natural products were ursolic acid, hyaluronic acid, and catechins. These bioactive compounds have been shown to promote cell cycle arrest, reduce tumor size, and exhibit synergistic effects with other anticancer agents. Consequently, the combination of natural products with nanotechnology holds significant therapeutic potential.

Reported accidents involving scorpion poisoning by Tityus serrulatus are the most frequent in Brazil. The only specific treatment for envenomation is the administration of antivenoms associated with traditional adjuvants. Novel adjuvants are studied to reduce or avoid side effects and potentialize the efficacy of conventional serum. In this study, poly(lactic acid) nanoparticles were functionalized with polyethylenimine for loading peptides and proteins of T. serrulatus venom, and their use as a potential immunoadjuvant was evaluated. The protein loading efficiency of about 100% and the polyacrylamide gel electrophoresis assay confirmed the success of venom loading. Dynamic light scattering and zeta potential analysis supported small and narrow-sized cationic functionalized nanoparticles. Atomic force microscopy and scanning electron microscopy images showed nanoparticles with a spherical and smooth shape. The stability of tested formulations was accessed for six weeks, and the sustained release of proteins controlled by diffusion mechanism was also measured. Finally, in vivo immunization in BALB/c mice showed superior efficacy of the T. serrulatus venom protein-loaded nanoparticles compared to the traditional aluminum hydroxide immunoadjuvant. Thus, the formulations shown are promising nanocarriers to be used as a biotechnological approach to immunotherapy against scorpion envenomation.