Nanoscale Research Letters最新文献

The need for understanding the low-frequency noise (LFN) of metal oxide semiconductor thin-film transistors (TFTs) is increasing owing to the substantial effects of LFN in various circuit applications. A focal point of inquiry pertains to the examination of LFN amidst bias stress conditions, known to compromise TFT reliability. In this study, we investigate the effects of hot carrier stress (HCS) on zinc tin oxide (ZTO) TFTs by low-frequency noise (LFN) analysis. Asymmetric damage caused by HCS is analyzed by measuring the power spectral density at the source and drain sides. The excess noise generated by the HCS is analyzed with consideration of trap density of states (DOS). It is revealed that the needle defects are generated during the HCS, significantly affecting the LFN characteristics of the ZTO TFTs. Additionally, we observe a self-recovery behavior in the devices and demonstrate the relevant changes in the LFN characteristics following this phenomenon. This study provides valuable insights into the LFN characteristics of ZTO TFTs under HCS conditions and sheds light on the underlying mechanisms.

Low-frequency noise (LFN) characteristics of semiconductor devices pose a significant importance for understanding their working principle, particularly concerning material imperfections. Accordingly, substantial research endeavors have focused on characterizing the LFN of devices. However, the LFN characteristics of the ambipolar transistors have been rarely demonstrated. Herein, we investigate the effects of ambipolar carrier transport and CYTOP-induced p-type doping on low-frequency noise characteristics of MoTe₂ transistors. The source of the 1/f noise differs between the n-type (electron transport) and p-type (hole transport) modes. Notably, the influence of contact resistance is more pronounced in the n-type mode. CYTOP doping suppresses the n-type mode by introducing hole doping effects. Furthermore, CYTOP doping mitigates the impact of contact resistance on excess noise.

Brain cancer pose significant life-threats by destructively invading normal brain tissues, causing dysneuria, disability and death, and its therapeutics is limited by underdosage and toxicity lying in conventional drug delivery that relied on passive delivery. The application of nanorobots-based drug delivery systems is an emerging field that holds great potential for brain cancer active targeting and controllable treatment. The ability of nanorobots to encapsulate, transport, and supply therapies directly to the lesion site through blood–brain barriers makes it possible to deliver drugs to hard-to-reach areas. In order to improve the efficiency of drug delivery and problems such as precision and sustained release, nanorobots are effectively realized by converting other forms of energy into propulsion and motion, which are considered as high-efficiency methods for drug delivery. In this article, we described recent advances in the treatment of brain cancer with nanorobots mainly from three aspects: firstly, the development history and characteristics of nanorobots are reviewed; secondly, recent research progress of nanorobots in brain cancer is comprehensively investigated, like the driving mode and mechanism of nanorobots are described; thirdly, the potential translation of nanorobotics for brain diseases is discussed and the challenges and opportunities for future research are outlined.

Background

Malaria, a tropical neglected disease, imposes a significant burden on global health, leading to the loss of thousands of lives annually. Its gold standard treatment is a combination therapy of lumefantrine (LUM) and artemether (ART). Nanotechnology holds significant potential for improving drug bioavailability and potency while reducing adverse effects.

Objectives

This study aimed to develop lipid-core nanocapsules containing ART and LUM and evaluate their effects in an experimental cerebral malaria model (ECM).

Methods

The polymeric interfacial deposition method was used to develop lipid-core nanocapsules (LNCs) containing ART and LUM (LNC_ARTLUM) and were characterized using micrometric and nanometric scales. Male C57BL/6 mice were infected with Plasmodium (P.) berghei ANKA (PbA, 1 × 10⁵ PbA-parasitized red blood cells, intraperitoneally). On day 5 post-infection, PbA-infected mice were orally administered with ART + LUM, LNC_ARTLUM, blank nanocapsules (LNC_BL), or ethanol as a control. Parasitemia, clinical scores, and survival rates were monitored throughout the experiment. Organ-to-body weight ratios, cytokine quantification, and intravital microscopy analyses were conducted on day 7 post-infection.

Results

LNCs were successfully developed and characterized. The treatment with LNC_ARTLUM in ECM resulted in complete clearance of parasitemia at 10 dpi, decreased clinical scores, and maintained 100% survival rates. Thereated mice exhibited splenomegaly and reduced TNF-α, IL-1β, and MCP1 levels in the brain. Furthermore, the LNC_ARTLUM treatment protected the brain microvasculature, reducing the number of cells in the rolling process and adherent to the microvasculature endothelium.

Conclusion

Nanoformulations can potentially improve the efficacy of antimalarial drugs and be considered a promising approach to treat malaria.

We propose a novel design for multi-junction photonic crystal surface emitting lasers (PCSELs) operating in higher-order waveguide modes to minimize internal losses. This paper details the design and simulation of a 2-junction PCSEL, including calculations of confinement factors, coupling coefficients, radiation loss, and threshold currents. We compare the performance of 2 J-PCSELs and 1 J-PCSELs, demonstrating the potential for highly efficient multi-junction PCSELs with improved power conversion efficiency and output power.

Due to their excellent properties, blue CsPbBr₃ quantum dots show great promise for full-colour display and lighting applications. This study used acetonitrile, a polar solvent, to post-treat CsPbBr₃ quantum dots, resulting in a blue shift to 453 nm. To enhance stability, these quantum dots were encapsulated within the pore structure of mesoporous silica. A flexible luminescent fiber material was prepared using poly (lactic acid) (PLA) as the substrate, demonstrating improved hydrophobicity and stable optical properties. The material exhibited a contact angle of 99.7° and maintained 82.2% of its fluorescence intensity after 30 days at room temperature. These findings highlight its significant potential for optical applications.

Nanomaterials play a pivotal role in food preservation and its safety, offering ingenious solutions for sustainable food packaging. Nanomaterials enable the creation of packaging materials having unique functional properties. It not only extends the shelf life of the foods by releasing preservatives but also enhances food safety by preventing microbial contamination or food spoilage. In this review, we aim to provide an overview of the various applications of nanotechnology in food packaging, highlighting its key advantages. We also delve into the safety considerations and regulatory issues involved in developing nanotechnology-based food packaging materials. Additionally, advancements in the field of nanotechnology-based packaging have the potential to create safer, more sustainable, and high-quality packaging with greater functionality that delivers essential benefits to manufacturers and consumers.

Upconversion nanoparticles (UCNPs), capable of converting near-infrared (NIR) light into high-energy emission, hold significant promise for bioimaging applications. However, the presence of tissue barriers poses a challenge to the effective delivery of nanoparticles (NPs) to target organs. In this study, we demonstrate the core–shell UCNPs modified with cationic biopolymer, i.e., N, N-trimethyl chitosan (TMC), can overcome endothelial barriers. The core–shell UCNP is composed of NaGdF₄: Yb³⁺,Tm³⁺ (16.7 ± 2.7 nm) as core materials and silica (SiO₂) shell. The average particle size of UCNPs@SiO₂ is estimated at 26.1 ± 3.7 nm. X-ray diffraction (XRD), transmission electron microscopy (TEM) and element mapping shows the formation of hexagonal crystal structure of β-NaGdF₄ and elements doping. The surface of UCNPs@SiO₂ has been modified with poly(ethylene glycol) (PEG) to enhance water dispersibility and colloidal stability, and further modified with TMC with the zeta potential increasing from -2.1 ± 0.96 mV to 26.9 ± 12.6 mV. No significant toxic effect is imposed to HUVECs when the cells are treated with core–shell UCNPs with surface modification up to 250 µg/mL. The transport ability of the core–shell UCNPs has been evaluated by using the in vitro endothelial barrier model. Transepithelial electrical resistance (TEER) and immunofluorescence staining of tight junction proteins have been employed to verify the integrity of the in vitro endothelial barrier model. The results indicate that the transport percentage of the UCNPs@SiO₂ with PEG and TMC through the model is up to 4.56%, which is twice higher than that of the UCNPs@SiO₂ with PEG but without TMC and six times that of the UCNPs@SiO₂.

Among the numerous driving forces that cause the atherosclerotic cardiovascular disease (ASCVD), pathogenic bacterial extracellular membrane nanovesicles (BEMNs) containing toxins and virulence factors appear to be the key trigger of inflammation and atherogenesis, the major processes involved in the pathogenesis of ASCVD. Since BEMNs are the carriers of nanosized biomolecules to distant sites, they are now being considered as a novel drug delivery system. Nowadays, many therapeutic strategies are used to treat ASCVD. However, the conventional anti-atherosclerotic therapies are not effective enough. This primarily due to the inefficiency of non-targeted drug delivery systems to tissue affected areas, which, in turn, leads to numerous side effects, as well as faulty pharmacokinetics. In this regard, nanomedicine methods using nanoparticles (NPs) as targeted drug delivery vehicles proved to be extremely useful. Bioengineered BEMNs equipped with disease-specific ligand moieties and loaded with corresponding drugs represent a promising tool in nanomedicine, which can be used as a novel drug delivery system for a successful therapy of ASCVD. In this review, we outline the involvement of pathogenic BEMNs in the triggering of ASCVD, the conventional therapeutic strategies for the treatment of ASCVD, and the recent trends in nanomedicine using BEMNs and NPs as a vehicle for targeted drug delivery.

Breast cancer (BC) bone metastasis poses a significant clinical challenge due to its impact on patient prognosis and quality of life. Curcumin (CUR), a natural polyphenol compound found in turmeric, has shown potential in cancer therapy due to its anti-inflammatory, antioxidant, and anticancer properties. However, its metabolic instability and hydrophobicity have hindered its clinical applications, leading to a short plasma half-life, poor absorption, and low bioavailability. To enhance the drug-like properties of CUR, nanotechnology-based delivery strategies have been employed, utilizing polymeric, lipidic, and inorganic nanoparticles (NPs). These approaches have effectively overcome CUR’s inherent limitations by enhancing its stability and cellular bioavailability both in vitro and in vivo. Moreover, targeting molecules with high selectivity towards bone metastasized breast cancer cells can be used for site specific delivery of curcumin. Alendronate (ALN), a bone-seeking bisphosphonate, is one such moiety with high selectivity towards bone and thus can be effectively used for targeted delivery of curcumin loaded nanocarriers. This review will detail the process of bone metastasis in BC, elucidate the mechanism of action of CUR, and assess the efficacy of nanotechnology-based strategies for CUR delivery. Specifically, it will focus on how these strategies enhance CUR’s stability and improve targeted delivery approaches in the treatment of BC bone metastasis.

Graphical abstract