Nanoscale Research Letters最新文献

Wearable sensors have attracted considerable interest due to their ability to detect a variety of information generated by human physiological activities through physical and chemical means. The performance of wearable sensors is limited by their stability, and endowing wearable sensors with superhydrophobicity is one of the means to enable them to maintain excellent performance in harsh environments. This review emphasizes the imperative progress in flexible superhydrophobic sensors for wearable devices. Besides, the wettability principle and the mechanism of wearable sensors are briefly introduced to propose the combination of superhydrophobicity and wearable sensors. Next, superhydrophobic substrates for wearable sensors, including but not limited to, polydimethylsiloxane, polyurethane, gel, rubber, and fabric, are described in depth, and also the respective fabrication processes and performances. Moreover, the utility of superhydrophobic wearable sensors in a normal intelligent environment is described, highlighting their application in monitoring physiological signals, such as physical movement, pulse, vibration, temperature, perspiration, respiration, and so on. Finally, this review evaluates the challenges and dilemmas that wearable sensors must be overcome for further development and improve the functional performance of wearable sensors, paving the way for their expansion into advanced wearable sensing systems.

Paclitaxel (PTX), a naturally occurring diterpenoid isolated from Taxus brevifolia, is a first-line drug for the treatment of glioblastoma; however, it suffers from the disadvantages of poor water solubility and nonspecific biodistribution, which cause serious side effects in the human body. The marketed formulation suffers from serious side effects, such as allergic reactions, neutropenia, and neuropathy, which require safe and effective formulations of PTX. In the present study, PTX was entrapped in a solid–liquid lipid mixture with the aid of a surfactant using a modified solvent evaporation technique. Higher entrapment of the impressive stability of the formulation was achieved by employing quality design-based strategies. Optimized levels by employing a numerical optimization technique for each factor, that is, surfactant concentration (X1), lipid concentration (X2), and amount of organic solvent (X3) were 0.3%, 0.76% & 8.3 ml respectively. The resultant formulation exhibited a particle size of 121.44 nm, entrapment efficiency of 94.27%, and zeta potential of −20.21 mV with unimodal size distribution. A reduction in the % crystalline index from 48 to 3.4% ensured the amorphous form of the entrapped drug inside the formulation, which precludes the fear of leakage and instability of the formulation. Cell line studies conducted on U87MG Cell lines also suggested that the NLC of paclitaxel are more effective than those of pure PTX. In summary, PTXNLC seem to be a superior alternative carrier system for the formulation industry to obtain higher entrapment with excellent stability.

Malnutrition is one of the greatest challenges faced by humanity, which may be addressed by improving crop productivity to ensure food security. However, extensive use of synthetic fertilizers can lead to soil fertility degradation. This study highlights the potential of combining nanotechnology with biotechnology to enhance the germination rates of commercially important crop seeds. Bacterial biosurfactant extracted from a newly isolated Klebsiella sp. strain RGUDBI03 was used as a reducing and capping agent for the synthesis of zinc oxide nanoparticles (ZnO NPs) through a simple method. Extensive characterization of ZnO NPs through electron microscopic analysis showed well-dispersed, homogeneous NPs with a size range of 2–10 nm. High-resolution transmission electron microscopy (HR-TEM) images also revealed molecular fringes of 0.26 nm in single crystal ZnO NPs, with approximately 50% of the NPs exhibiting a size range of 2–4 nm. X-ray diffraction (XRD) results of ZnO NPs indicated the presence of (100), (002), (101), (102), (200), and (112) planes, confirming their crystalline nature. The presence of C = C–H, C = C, C–H, and C = C groups in both the bacterial biosurfactant and ZnO NPs, as depicted by Fourier-transform infrared spectroscopy (FTIR) spectra, confirmed the function of the biosurfactant as a reducing and capping agent. The nano-primed chickpea (Cicer arietinum) and rice (Oryza sativa) seeds showed an increase in water uptake rate, 89% and 92% respectively, compared to the control (73% and 44%), leading to an enhanced germination rate of 98% and 76%, compared to their respective controls (80% and 30%) under optimized conditions. Additionally, the nano-primed seeds exhibited higher levels of α-amylase activity in both seeds (0.37 mg/g for chickpea and 2.49 mg/g for rice) compared to the control. Notably, the ZnO NP priming solution exhibited no cytotoxicity on red blood cells and earthworms (Eudrilus eugeniae), indicating their non-cytotoxic and eco-friendly nature for future field trials.

Multiple sclerosis (MS) is a neuroimmunological disorder which causes axonal damage, demyelination and paralysis. Although numerous therapeutics have been developed for the effective treatment of MS and a few have been approved in recent decades, complete remission and treatment of MS remain a matter of concern. Nanotechnology is a potential approach for manipulating the properties of materials at the molecular level to attain desired properties. This approach is effective in the treatment of several CNS disorders by enhancing drug delivery, bioavailability and efficacy. We have briefly discussed the neuroimmunological disorders with a particular emphasis on MS. We also explored nanoengineered drug delivery systems, describing several nano-formulations for the treatment of MS, challenges and future of nanotechnology.

Nanoparticles synthesized from green sources have attracted great recognition in the present times, which can be ascribed to their distinctive attributes and diversified applicability. Therefore, the present study employed Ocimum basilicum seed extract to synthesize silver nanoparticles. UV–vis spectrophotometry revealed strenuous peaks for different concentrations of silver nanoparticles ranging between 400 and 430 nm. The average crystal size calculated using X-ray diffraction analysis was 6.7 nm. Energy-dispersive X-ray analysis clearly displayed the presence of silver ions in the elemental structure of the synthesized nanoparticles. The morphology of synthesized nanoparticles revealed by scanning electron microscopy was documented in terms of spherical shape surrounded by an organic layer and nanoparticle size was estimated to be in between 10 and 80 nm. The nanoparticles exhibited substantial antibacterial activity against 46 foodborne bacterial isolates and 15 clinical isolates of Klebsiella pneumoniae, with the largest inhibition zones measuring 24 and 13 mm, respectively. Minimum inhibitory concentration values ranged between 500 and 800 µl/ml for various isolates. The antibacterial effect of all antibiotics revealed considerable enhancement when combined with nanoparticles. The calculated fractional inhibitory concentration index values were < 1 validating excellent synergism between nanoparticles and all antibiotics except ciprofloxacin against the majority of bacterial isolates. Interestingly, the biogenic nanoparticles showed significant antioxidant potential with IC₅₀ value of 165 µg/ml as well as anti-inflammatory activity with an IC₅₀ value of 82 µg/ml. Conclusively, the seed extract of Ocimum basilicum can be prospected for the development of antibacterial silver nanoparticles against pathogenic bacteria.

Graphical abstract

In this work, we reported the synthesis of honey bee (Apis mellifera) venom-derived nanoparticles via a hydrothermal method. This method not only ensures the preservation of the bee venom’s bioactive components but also enhances their potential stability, thus broadening the scope for their applications in the biomedicinal field. The synthesis method started with the homogenization suspension of bee venom, followed by its hydrothermal process to synthesize bee venom nanoparticles (BVNPs). The successful synthesis of BVNPs was characterized using various characteristic techniques such as Ultraviolet–visible (UV–Vis) spectroscopy, Fourier Transforms Infrared (FTIR) Spectroscopy, Zeta Potential (ZP), Liquid Chromatography-Mass Spectrometry (LCMS), and Transmission Electron Microscopy (TEM). The synthesis of BVNPs through biosynthesis is shown by the visible violet-brown color development at 347 nm by UV–Vis spectroscopy. FTIR analysis revealed the presence of several functional groups in the BVNPs, including alcohols (–OH), phenols (C₆H₅–), carboxylic acids (–COOH), amines (–NH₂, –NH–), aldehydes (–CHO), ketones (–CO–), nitriles (–CN), amides (–CO–N–), imines (–CNH–), esters (–COO–), and polysaccharides. These functional groups, as confirmed by their specific stretching and bending vibrational modes, contribute to the diverse biological activities of BVNPs, including cytotoxicity against MCF-7 breast cancer cells. The ZP of the BVNPs indicated good colloidal stability at − 45 mV. LCMS analysis confirmed the presence of major bioactive molecules, including melittin & apamin and TEM analysis shows the BVNPs exhibited a quasi-spherical shape with good dispersion, the average size was approximately 25 nm, with some being smaller (quantum dots) and interplanar spacing of 0.236 nm indicated a highly ordered crystalline structure. Moreover, the anticancer efficacy of the BVNPs was ascertained through in vitro assays against MCF-7 breast cancer cells, showing a dose-dependent cytotoxic effect. The findings of this study underscore the viability of hydrothermal synthesis in producing biologically active and structurally stable BVNPs, with a significant potential for anticancer activities.

Graphical Abstract

The integration of green synthesis methods and advanced nanostructure designs holds significant promise for the development of innovative nanomaterials with diverse biomedical applications. This commentary delves into the use of barley grains for the eco-friendly synthesis of silver and gold nanoparticles, highlighting their potential as biocompatible agents with potent antibacterial properties. The barley-mediated synthesis approach not only offers a sustainable and cost-effective method for producing these nanoparticles but also underscores their remarkable efficacy against pathogenic bacteria. The barley-mediated approach not only offers a sustainable and cost-effective method for producing biocompatible nanoparticles but also demonstrates remarkable antibacterial efficacy against pathogenic bacteria. By critically evaluating the strengths and potential gaps in this synthesis approach, this commentary emphasizes the importance of integrating green synthesis techniques with advanced nanoparticle applications. Future research directions should aim at optimizing synthesis processes, ensuring enhanced stability and biocompatibility, and exploring the full potential of biologically synthesized nanoparticles in medical treatments and environmental sustainability. This focus on sustainable synthesis and application could pave the way for the next generation of nanomaterials, offering significant advancements in both healthcare and ecological preservation. By examining the strengths, gaps, and potential synergies between these two approaches, this commentary underscores the importance of sustainable synthesis techniques and the development of multifunctional nanoparticles. This integrated approach could lead to the creation of next-generation nanomaterials, offering significant advancements in medical treatments and environmental sustainability.

Hydroxyapatite (HA) is an extensively used biomaterial for dental and orthopaedic applications because of its biocompatibility and biomimetic nature. HA is extensively used as a bone-graft substitute. HA bone graft substitutes of bovine or synthetic origins have been extensively studied. However, caprine-based HA has not been explored. In this study, we aimed to determine the utilization of goat bone-derived HA for commercial applications. HA from caprine bone and teeth was isolated using thermal calcination. The developed HA can be used as a bone graft substitute. Chemical characterization of the isolated HA was carried out using Fourier transform infrared spectroscopy, X-Ray Diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The biocompatibility and apatite formation of isolated HA were assessed using MG-63 cells, MC3T3-E1, L929 cells, MSCs, adipose derived stem cells, human dermal tissue derived fibroblast cells and osteoblast-like cell line, The studies demonstrate that HA support cell adhesion and osteogenic properties. To improve sheep, lamp, or caprine bone-derived HA, several other composites have been developed with MgO₂, ZrO_2, ZnO_2, and other polymeric substances. 3D printed technology was used to develop a bioink using sheep-derived HA and printed the composite scaffold as a bone graft substitute. Furthermore, the biomedical applications of sheep-derived HA been studied in terms of their antimicrobial activity, bone-forming ability, and wound healing applications. Sheep-, goat-, and caprine-derived HA are still underutilized and require further research to develop commercial possibilities and sustainable raw materials for HA-based bone graft substitutes.

Dynamic random-access memory (DRAM) has been scaled down to meet high-density, high-speed, and low-power memory requirements. However, conventional DRAM has limitations in achieving memory reliability, especially sufficient capacitance to distinguish memory states. While there have been attempts to enhance capacitor technology, these solutions increase manufacturing cost and complexity. Additionally, Silicon-based capacitorless memories have been reported, but they still suffer from serious difficulties regarding reliability and power consumption. Here, we propose a novel Schottky barrier memory (SBRAM), which is free of the complex capacitor structure and features a heterojunction based on bandgap engineering. SBRAM can be configured as vertical cross-point arrays, which enables high-density integration with a 4F² footprint. In particular, the Schottky junction significantly reduces the reverse leakage current, preventing sneak current paths that cause leakage currents and readout errors during array operation. Moreover, the heterojunction physically divides the storage region into two regions, resulting in three distinct resistive states and inducing a gradual current slope to ensure sufficient holding margin. These states are determined by the holding voltage (V_hold) applied to the programmed device. When the V_hold is 1.1 V, the programmed state can be maintained with an exceptionally low current of 35.7 fA without a refresh operation.