Nanostructures

纳米结构
  • 文章类型: Journal Article
    Dental implant therapy, established as standard-of-care nearly three decades ago with the advent of microrough titanium surfaces, revolutionized clinical outcomes through enhanced osseointegration. However, despite this pivotal advancement, challenges persist, including prolonged healing times, restricted clinical indications, plateauing success rates, and a notable incidence of peri-implantitis. This review explores the biological merits and constraints of microrough surfaces and evaluates the current landscape of nanofeatured dental implant surfaces, aiming to illuminate strategies for addressing existing impediments in implant therapy. Currently available nanofeatured dental implants incorporated nano-structures onto their predecessor microrough surfaces. While nanofeature integration into microrough surfaces demonstrates potential for enhancing early-stage osseointegration, it falls short of surpassing its predecessors in terms of osseointegration capacity. This discrepancy may be attributed, in part, to the inherent \"dichotomy kinetics\" of osteoblasts, wherein increased surface roughness by nanofeatures enhances osteoblast differentiation but concomitantly impedes cell attachment and proliferation. We also showcase a controllable, hybrid micro-nano titanium model surface and contrast it with commercially-available nanofeatured surfaces. Unlike the commercial nanofeatured surfaces, the controllable micro-nano hybrid surface exhibits superior potential for enhancing both cell differentiation and proliferation. Hence, present nanofeatured dental implants represent an evolutionary step from conventional microrough implants, yet they presently lack transformative capacity to surmount existing limitations. Further research and development endeavors are imperative to devise optimized surfaces rooted in fundamental science, thereby propelling technological progress in the field.
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  • 文章类型: Journal Article
    Chirality, the property of molecules having mirror-image forms, plays a crucial role in pharmaceutical and biomedical research. This review highlights its growing importance, emphasizing how chiral drugs and nanomaterials impact drug effectiveness, safety, and diagnostics. Chiral molecules serve as precise diagnostic tools, aiding in accurate disease detection through unique biomolecule interactions. The article extensively covers chiral drug applications in treating cardiovascular diseases, CNS disorders, local anesthesia, anti-inflammatories, antimicrobials, and anticancer drugs. Additionally, it explores the emerging field of chiral nanomaterials, highlighting their suitability for biomedical applications in diagnostics and therapeutics, enhancing medical treatments.
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  • 文章类型: Journal Article
    Nanomaterials are becoming important tools for vaccine development owing to their tunable and adaptable nature. Unique properties of nanomaterials afford opportunities to modulate trafficking through various tissues, complement or augment adjuvant activities, and specify antigen valency and display. This versatility has enabled recent work designing nanomaterial vaccines for a broad range of diseases, including cancer, inflammatory diseases, and various infectious diseases. Recent successes of nanoparticle vaccines during the coronavirus disease 2019 (COVID-19) pandemic have fueled enthusiasm further. In this review, the most recent developments in nanovaccines for infectious disease, cancer, inflammatory diseases, allergic diseases, and nanoadjuvants are summarized. Additionally, challenges and opportunities for clinical translation of this unique class of materials are discussed.
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  • 文章类型: Journal Article
    在本文中,相同的V形金纳米结构和可变V形金纳米结构的周期性阵列被设计在具有薄的二氧化钒(VO2)间隔层的镀金二氧化硅(SiO2)衬底的顶部,以实现多波长和宽带等离子体开关,分别。具有小的粒子间分离的相同V形纳米结构(IVNS)的周期性阵列导致V形纳米结构(VNS)的基本等离子体激元的耦合相互作用,当入射光在x方向上偏振时,在所提出的开关的反射光谱中产生具有两个纵向等离子体激元模式的混合等离子体激元响应。X方向沿着连接周期性阵列的一个单位单元中的所有VNS的V结的轴取向。暴露在温度下,电场,或者光学刺激,VO2层从其单斜半导体状态转变为金红石金属状态,导致从所提出的纳米结构获得的反射光谱的整体变化,并导致有效的多波长切换作用。采用有限差分时域(FDTD)模型来证明,通过采用相同的V形纳米结构的周期性阵列,可以通过采用所提出的开关来实现在两个波长处的消光比>12dB。Further,基于可变V形纳米结构(VVNS)的等离子体开关-即,提出了在周期性阵列的一个单位单元中具有可变臂长度的多个VNS,用于宽带开关。在宽带操作模式下,我们报告了一个消光比>5分贝的工作波长范围>1400nm在近红外光谱范围跨越所有光通信频带,即,O,E,S,C,L和U波段。Further,还证明了这些开关的操作波长可以通过改变所提出的开关的几何参数来调节。这些交换机具有在通信网络中使用的潜力,其中不可避免地需要具有多波长操作或在宽操作带宽上切换的超小型和超快交换机。
    In this paper, periodic arrays of identical V-shaped gold nanostructures and variable V-shaped gold nanostructures are designed on top of a gold-coated silicon dioxide (SiO2) substrate with a thin spacer layer of vanadium dioxide (VO2) to realize multi-wavelength and broadband plasmonic switches, respectively. The periodic array of identical V-shaped nanostructures (IVNSs) with small inter-particle separation leads to coupled interactions of the elementary plasmons of a V-shaped nanostructure (VNS), resulting in a hybridized plasmon response with two longitudinal plasmonic modes in the reflectance spectra of the proposed switches when the incident light is polarized in the x-direction. The x-direction is oriented along the axis that joins the V-junctions of all VNSs in one unit cell of the periodic array. On exposure to temperature, electric field, or optical stimulus, the VO2 layer transforms from its monoclinic semiconducting state to its rutile metallic state, leading to an overall change in the reflectance spectra obtained from the proposed nanostructures and resulting in an efficient multi-wavelength switching action. Finite difference time domain (FDTD) modelling is employed to demonstrate that an extinction ratio > 12 dB at two wavelengths can be achieved by employing the proposed switches by employing periodic arrays of identical V-shaped nanostructures. Further, plasmonic switches based on variable V-shaped nanostructures (VVNSs) - i.e., multiple VNSs with variable arm lengths in one unit cell of a periodic array - are proposed for broadband switching. In the broadband operation mode, we report an extinction ratio > 5 dB over an operational wavelength range > 1400 nm in the near-IR spectral range spanning over all optical communication bands, i.e., the O, E, S, C, L and U bands. Further, it is also demonstrated that the wavelength of operation for these switches can be tuned by varying the geometrical parameters of the proposed switches. These switches have the potential to be employed in communication networks where ultrasmall and ultrafast switches with multi-wavelength operation or switching over a wide operational bandwidth are inevitably required.
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  • 文章类型: Journal Article
    生物技术的一个新领域是纳米技术。纳米技术是一个新兴领域,旨在开发具有纳米尺寸的各种物质,这些物质可用于制药的各个领域,生物勘探,人类活动和生物医学应用。纳米技术发展的一个重要阶段是纳米粒子的创造。为了增加它们的生物用途,环保材料合成工艺变得越来越重要。近年来,由于与多晶对应物相比,它们具有有益和独特的特性,因此对纳米结构材料表现出了极大的兴趣。纳米材料在电子学中的迷人表现,光学,光子学引起了很多兴趣。为了克服传统技术的缺点,已经出现了一种创造纳米颗粒的环保方法。今天,通过使用各种微生物产生了广泛的纳米颗粒,并研究了它们在许多尖端技术领域的潜力。这些颗粒具有明确的化学成分,尺寸,和形态。纳米粒子的绿色生产主要使用植物和微生物。因此,微生物纳米技术在农业和植物科学中的应用是本综述的主要重点。本综述重点介绍了可用的纳米颗粒的生物合成方法,主要关注微生物合成的纳米颗粒,参数和涉及的生物化学。Further,它考虑到微生物纳米生物合成中涉及的基因工程和合成生物学来构建微生物纳米工厂。
    A new area of biotechnology is nanotechnology. Nanotechnology is an emerging field that aims to develope various substances with nano-dimensions that have utilization in the various sectors of pharmaceuticals, bio prospecting, human activities and biomedical applications. An essential stage in the development of nanotechnology is the creation of nanoparticles. To increase their biological uses, eco-friendly material synthesis processes are becoming increasingly important. Recent years have shown a lot of interest in nanostructured materials due to their beneficial and unique characteristics compared to their polycrystalline counterparts. The fascinating performance of nanomaterials in electronics, optics, and photonics has generated a lot of interest. An eco-friendly approach of creating nanoparticles has emerged in order to get around the drawbacks of conventional techniques. Today, a wide range of nanoparticles have been created by employing various microbes, and their potential in numerous cutting-edge technological fields have been investigated. These particles have well-defined chemical compositions, sizes, and morphologies. The green production of nanoparticles mostly uses plants and microbes. Hence, the use of microbial nanotechnology in agriculture and plant science is the main emphasis of this review. The present review highlights the methods of biological synthesis of nanoparticles available with a major focus on microbially synthesized nanoparticles, parameters and biochemistry involved. Further, it takes into account the genetic engineering and synthetic biology involved in microbial nanobiosynthesis to the construction of microbial nanofactories.
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  • 文章类型: Journal Article
    心肌梗塞,通常由动脉粥样硬化斑块破裂引起,导致数小时内不可逆的缺血性心肌细胞死亡,随后心脏功能受损甚至心力衰竭。随着心力衰竭的发展,目前心肌梗死的介入再灌注策略仍然面临着高死亡率。以纳米材料为基础的治疗在减少心肌梗死面积和促进心肌梗死后心脏修复方面取得了很大进展。尽管大多数研究都是临床前试验。这篇综述主要集中在各种纳米药物治疗心肌梗死的最新进展(2016年至今)。我们总结了这些应用的机制策略,包括抗心肌细胞死亡策略,激活新生血管,抗氧化剂策略,免疫调节,抗心脏重塑,和心脏修复。
    Myocardial infarction, usually caused by the rupture of atherosclerotic plaque, leads to irreversible ischemic cardiomyocyte death within hours followed by impaired cardiac performance or even heart failure. Current interventional reperfusion strategies for myocardial infarction still face high mortality with the development of heart failure. Nanomaterial-based therapy has made great progress in reducing infarct size and promoting cardiac repair after MI, although most studies are preclinical trials. This review focuses primarily on recent progress (2016-now) in the development of various nanomedicines in the treatment of myocardial infarction. We summarize these applications with the strategy of mechanism including anti-cardiomyocyte death strategy, activation of neovascularization, antioxidants strategy, immunomodulation, anti-cardiac remodeling, and cardiac repair.
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  • 文章类型: Journal Article
    背景:与牙髓封闭剂结合的Gutta-percha(GP)仍然是最广泛用于三维闭塞的核心材料。密封剂充当GP和牙根牙本质壁之间的粘合剂。然而,GP芯材料的主要缺点之一是缺乏对密封剂的粘附性。ZnO薄膜由于其相当大的结合强度而具有许多显著的特性,良好的光学质量,和优秀的压电,抗菌,和抗真菌特性,在各个领域提供许多潜在的应用。本研究旨在探讨纳米结构ZnO薄膜的GP表面功能化对其与牙髓密封剂粘附性的影响。
    方法:将常规GP样品随机分成三组:(a)未处理的GP(对照);(b)用氩等离子体(PT)处理的GP;(c)官能化的GP(PT,随后是ZnO薄膜沉积)。GP的表面功能化包括一个多步骤的过程。首先,低压氩气PT用于修饰GP表面,然后通过磁控溅射沉积ZnO薄膜。使用SEM和水接触角分析评估表面形态。进一步的综合测试包括拉伸粘合强度评估,评估Endoresin和AHPlus生物陶瓷密封剂对GP的附着力。使用ANOVA程序进行数据统计分析。
    结果:ZnO薄膜再现了PT产生的下层表面形貌。与对照相比,ZnO薄膜沉积降低了水接触角(p<0.001)。内皮树脂显示出统计学上高于AH+生物陶瓷的平均粘结强度值(p<0.001)。对照和ZnO官能化GP之间存在统计学上的显着差异(p=0.006),后者表现出最高的平均粘结强度值。
    结论:纳米结构ZnO薄膜在GP表面上的沉积诱导了向亲水性的转变以及GP对Endoresin和AH生物陶瓷密封剂的粘附性增加。
    BACKGROUND: Gutta-percha (GP) combined with an endodontic sealer is still the core material most widely used for tridimensional obturation. The sealer acts as a bonding agent between the GP and the root dentinal walls. However, one of the main drawbacks of GP core material is the lack of adhesiveness to the sealer. ZnO thin films have many remarkable features due to their considerable bond strength, good optical quality, and excellent piezoelectric, antibacterial, and antifungal properties, offering many potential applications in various fields. This study aimed to explore the influence of GP surface\'s functionalization with a nanostructured ZnO thin film on its adhesiveness to endodontic sealers.
    METHODS: Conventional GP samples were divided randomly into three groups: (a) Untreated GP (control); (b) GP treated with argon plasma (PT); (c) Functionalized GP (PT followed by ZnO thin film deposition). GP\'s surface functionalization encompassed a multi-step process. First, a low-pressure argon PT was applied to modify the GP surface, followed by a ZnO thin film deposition via magnetron sputtering. The surface morphology was assessed using SEM and water contact angle analysis. Further comprehensive testing included tensile bond strength assessment evaluating Endoresin and AH Plus Bioceramic sealers\' adhesion to GP. ANOVA procedures were used for data statistical analysis.
    RESULTS: The ZnO thin film reproduced the underlying surface topography produced by PT. ZnO thin film deposition decreased the water contact angle compared to the control (p < 0.001). Endoresin showed a statistically higher mean bond strength value than AH Plus Bioceramic (p < 0.001). There was a statistically significant difference between the control and the ZnO-functionalized GP (p = 0.006), with the latter presenting the highest mean bond strength value.
    CONCLUSIONS: The deposition of a nanostructured ZnO thin film on GP surface induced a shift towards hydrophilicity and an increased GP\'s adhesion to Endoresin and AH Bioceramic sealers.
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  • 文章类型: Journal Article
    开发了一种用于细胞内miRNA成像和自给自足饥饿疗法(ST)和化学动力学疗法(CDT)的联合治疗的癌症靶向谷胱甘肽(GSH)门控治疗探针(CGT探针)。CGT探针是使用MnO2纳米片(MS)作为载体材料构建的,以吸附精心设计的功能DNA。它可以通过AS1411适体和核仁素之间的特异性识别被癌细胞内化。CGT探针进入癌细胞后,过度表达的GSH,作为栅极控制,可以通过类Fenton反应将MS降解为可用于CDT的Mn2。同时,Mn2+介导的CDT可以进一步与CGT探针的酶样活性(过氧化氢酶样活性和葡萄糖氧化酶样活性)级联,实现自给自足的ST/CDT协同治疗。同时,锚定的DNA被释放,通过miR-21的双取代催化发夹组装(DCHA)和FRET(荧光共振能量转移)成像实现原位信号放大。体外和体内实验表明,使用CGT探针可以实现准确和灵敏的miRNA检测。总的来说,巧妙的CGT探针为早期临床诊断和癌症治疗的发展开辟了新途径。
    A cancer-targeted glutathione (GSH)-gated theranostic probe (CGT probe) for intracellular miRNA imaging and combined treatment of self-sufficient starvation therapy (ST) and chemodynamic therapy (CDT) was developed. The CGT probe is constructed using MnO2 nanosheet (MS) as carrier material to adsorb the elaborately designed functional DNAs. It can be internalized by cancer cells via specific recognition between the AS1411 aptamer and nucleolin. After CGT probe entering the cancer cells, the overexpressed GSH, as gate-control, can degrade MS to Mn2+ which can be used for CDT by Fenton-like reaction. Simultaneously, Mn2+-mediated CDT can further cascade with the enzyme-like activities (catalase-like activity and glucose oxidase-like activity) of CGT probe, achieving self-sufficient ST/CDT synergistic therapy. Meanwhile, the anchored DNAs are released, achieving in situ signal amplification via disubstituted-catalytic hairpin assembly (DCHA) and FRET (fluorescence resonance energy transfer) imaging of miR-21. The in vitro and in vivo experiments demonstrated that accurate and sensitive miRNA detection can be achieved using the CGT probe. Overall, the ingenious CGT probe opens a new avenue for the development of early clinical diagnosis and cancer therapy.
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  • 文章类型: Journal Article
    伤口愈合是一个复杂的过程,协调各种细胞的协调行动,细胞因子和生长因子。纳米技术通过提供新的材料和方法将生物活性分子输送到伤口部位,为增强愈合过程提供了令人兴奋的新可能性。本文阐述了利用纳米粒子的最新进展,用于伤口愈合的纳米纤维和纳米片。它全面讨论了每种材料的优点和局限性,以及它们在各种类型伤口中的潜在应用。这些材料中的每一种,尽管共享公共属性,可以表现出不同的实际特征,使它们对于愈合各种类型的伤口特别有价值。在这次审查中,我们的主要重点是全面概述当前纳米粒子的最新应用,纳米纤维,纳米片和它们的组合对伤口愈合,作为指导研究人员在伤口愈合研究中适当利用这些纳米材料的宝贵资源。需要进一步的研究以深入了解这种类型的纳米材料在临床环境中的应用。
    Wound healing is a complex process that orchestrates the coordinated action of various cells, cytokines and growth factors. Nanotechnology offers exciting new possibilities for enhancing the healing process by providing novel materials and approaches to deliver bioactive molecules to the wound site. This article elucidates recent advancements in utilizing nanoparticles, nanofibres and nanosheets for wound healing. It comprehensively discusses the advantages and limitations of each of these materials, as well as their potential applications in various types of wounds. Each of these materials, despite sharing common properties, can exhibit distinct practical characteristics that render them particularly valuable for healing various types of wounds. In this review, our primary focus is to provide a comprehensive overview of the current state-of-the-art in applying nanoparticles, nanofibres, nanosheets and their combinations to wound healing, serving as a valuable resource to guide researchers in their appropriate utilization of these nanomaterials in wound-healing research. Further studies are necessary to gain insight into the application of this type of nanomaterials in clinical settings.
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  • 文章类型: Journal Article
    Nintedanib(NTB)是一种多种酪氨酸激酶抑制剂,被调查了许多疾病,如特发性肺纤维化(IPF),系统性硬化症间质性肺病(SSc-ILD)和非小细胞肺癌(NSCLC)。NTB可作为口服胶囊配方,但是它能够检测通过氧化形成的降解物,光解和水解过程使其难以量化。在目前的工作中,开发并验证了一种新的反相高效液相色谱(RP-HPLC)方法。
    开发的方法很简单,精确,可重复,稳定和准确。使用提出的分析方法方法评估了NTB的固有稳定性,并进行了力降解研究。NTB在ShimadzuC18色谱柱上作为固定相(250×4.6mm,5µm)使用等度洗脱方法,在HPLC级水和乙腈(ACN)中使用0.1%v/v的三乙胺(TEA),比例为35:65%v/v。流动相以1.0ml/min的恒定流速泵送,洗脱剂在390nm波长处检测。
    NTB在保留时间(tR)为6.77±0.00min时洗脱,相关系数为0.999,所开发的方法在0.5µg/ml至4.5µg/ml的浓度范围内呈线性。发现对于1.5µg/ml浓度,回收率在99.391±0.468%的范围内。六个重复标准品被确定为具有0.04的%RSD。
    配方辅料不会干扰NTB的测定,证明了所开发方法的特异性。所开发的分析方法的建议方法可用于量化原料药和药物制剂中存在的NTB的量。
    UNASSIGNED: Nintedanib (NTB) is a multiple tyrosine kinase inhibitor, been investigated for many disease conditions like idiopathic pulmonary fibrosis (IPF), systemic sclerosis interstitial lung disease (SSc-ILD) and non-small cell lung cancer (NSCLC). NTB is available as oral capsule formulation, but its ability to detect degradants formed through oxidative, photolytic and hydrolytic processes makes it difficult to quantify. In the current work, a novel reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated.
    UNASSIGNED: The developed method is simple, precise, reproducible, stable and accurate. The inherent stability of NTB was evaluated using the proposed analytical method approach and force degradation studies were carried out. NTB was separated chromatographically on the Shimadzu C 18 column as stationary phase (250 ×4.6 mm, 5 µm) using an isocratic elution method with 0.1% v/v triethyl amine (TEA) in HPLC grade water and acetonitrile (ACN) in the ratio 35:65% v/v. The mobile phase was pumped at a constant flow rate of 1.0 ml/min, and the eluent was detected at 390 nm wavelength.
    UNASSIGNED: NTB was eluted at 6.77±0.00 min of retention time (t R) with a correlation coefficient of 0.999, the developed method was linear in the concentration range of 0.5 µg/ml to 4.5 µg/ml. The recovery rate was found to be in the range of 99.391±0.468% for 1.5 µg/ml concentration. Six replicate standards were determined to have an % RSD of 0.04.
    UNASSIGNED: The formulation excipients didn\'t interfere with the determination of NTB, demonstrating the specificity of the developed method. The proposed approach of the analytical method developed can be used to quantify the amount of NTB present in bulk drugs and pharmaceutical formulations.
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