贵金属-磁性异质结构纳米材料及其生物医学应用

异质结构纳米颗粒不仅可以同时拥有多种单组分纳米颗粒不同的性能,实现多功能化,还可能因组分间的相互耦合作用而产生单组分颗粒不具备的新性能,因而在化学化工、生物医学、能源催化等领域引起广泛关注.贵金属具有特殊的光学性质和催化活性;磁性纳米颗粒拥有优异的磁性能,因而备受研究人员关注.贵金属-磁性异质结构纳米材料集合了两种材料优异的性能,能通过不同的异质结构展现出不同的性质.本文根据异质结构的类型,将贵金属-磁性异质结构纳米材料分为核壳结构、蛋黄-壳结构和哑铃结构3种,总结了不同贵金属-磁性异质结构纳米颗粒的特性、制备方法及应用,并重点论述了其在诊疗一体化探针、多模态成像探针和刺激响应型药物载体生物医学领域上的应用.     

Influence of phytochemicals on the biocompatibility of inorganic nanoparticles: a state-of-the-art review

Inorganic nanoparticles (NPs) are among the most produced NPs that could be used in consumer products and as healthcare materials, however, the intrinsic toxicity particularly through the mechanism associated oxidative stress raises the health concern about inorganic NP exposure. Phytochemicals are bioactive metabolites derived from plants as well as non-pathogenic microorganisms living within plants and have been shown to be beneficial to human health with their anti-aging, anti-cancer, anti-inflammation and anti-oxidant properties. In the present review, the influence of on the biocompatibility of inorganic NPs was discussed. It has been shown that phytochemicals could be used as bio-friendly capping agents for green synthesis of inorganic NPs, and phytochemical coated inorganic NPs were remarkable stable and biocompatible with high therapeutic efficiency. Meanwhile, the presence of phytochemicals was also able to reduce the side effects and enhance the therapeutic abilities of inorganic NPs, which is likely attributed to the anti-oxidative properties of phytochemicals. Thus, using phytochemicals could be a promising and plausible way to reduce side effects and increase the biocompatibility of inorganic NPs for biomedical applications.     

Vital roles of sustainable nano-fertilizers in improving plant quality and quantity-an updated review

Nanotechnology has received much attention because of its distinctive properties and many applications in various fields. Nanotechnology is a new approach to increase agricultural production with premium quality, environmental safety, biological support, and financial stability. Ecofriendly technology is becoming progressively important in modern agricultural applications as alternatives to traditional fertilizers and pesticides. Nanotechnology offers an alternative solution to overcome the disadvantages of conventional agriculture. Therefore, recent developments in using nanoparticles (NPs) in agriculture should be studied. This review presented a novel overview about the biosynthesis of NPs, using NPs as nano-fertilizers and nano-pesticides, the applications of NPs in agriculture, and their role in enhancing the function of biofactors. We also, show recent studies on NPs-plant interactions, the fate and safety of nanomaterials in plants, and NPs' function in alleviating the adverse effects of abiotic stress and heavy metal toxicity. Nano-fertilizers are essential to reduce the use of inorganic fertilizers and reduce their antagonistic effects on the environment. Nano-fertilizers are more reactive, can penetrate the epidermis allowing for gradual release, and targeted distribution, and thus reducing nutrients surplus, enhancing nutrient use efficiency. We also, concluded that NPs are crucial in alleviating abiotic stress and heavy metal toxicity. However, some studies reported the toxic effects of NPs on higher plants by induction of oxidative stress signals via depositing NPs on the cell surface and in organelles. The knowledge in our review article is critical in defining limitations and future perspectives of using nano-fertilizers as an alternative to conventional fertilizers.     

A review of cardiovascular toxicity of TiO<Subscript>2</Subscript>, ZnO and Ag nanoparticles (NPs)

To ensure the safe use of nanoparticles (NPs) in modern society, it is necessary and urgent to assess the potential toxicity of NPs. Cardiovascular system is required for the systemic distribution of NPs entering circulation. Therefore, the adverse cardiovascular effects of NPs have gained extensive research interests. Metal based NPs, such as TiO₂, ZnO and Ag NPs, are among the most popular NPs found in commercially available products. They may also have potential applications in biomedicine, which could increase their contact with cardiovascular systems. This review aimed at providing an overview about the adverse cardiovascular effects of TiO₂, ZnO and Ag NPs. We discussed about the bio-distribution of NPs following different exposure routes. We also discussed about the cardiovascular toxicity of TiO₂, ZnO and Ag NPs as assessed by in vivo and in vitro models. The possible mechanisms and contribution of physicochemical properties of metal based NPs were also discussed.     

Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems

For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble protein from wheat and corn; legumin is a casein-like protein from leguminous seeds such as peas; lectins are glycoproteins naturally occurring in many plants that recognize specific carbohydrate residues. NPs formed from these proteins show good biocompatibility, possess the ability to enhance solubility, and provide sustained release of drugs and reduce their toxicity and side effects. The effects of preparation methods on the size and loading capacity of these NPs are also described in this review.     

Bioengineered silver nanoparticles using Curvularia pallescens and its fungicidal activity against Cladosporium fulvum

Microorganisms based biosynthesis of nanomaterials has triggered significant attention, due to their great potential as vast source of the production of biocompatible nanoparticles (NPs). Such biosynthesized functional nanomaterials can be used for various biomedical applications. The present study investigates the green synthesis of silver nanoparticles (Ag NPs) using the fungus Curvularia pallescens (C. pallescens) which is isolated from cereals. The C. pallescens cell filtrate was used for the reduction of AgNO₃ to Ag NPs. To the best of our knowledge C. pallescens is utilized first time for the preparation of Ag NPs. Several alkaloids and proteins present in the phytopathogenic fungus C. pallescens were mainly responsible for the formation of highly crystalline Ag NPs. The as-synthesized Ag NPs were characterized by using UV–Visible spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The TEM micrographs have revealed that spherical shaped Ag NPs with polydisperse in size were obtained. These results have clearly suggested that the biomolecules secreted by C. pallescens are mainly responsible for the formation and stabilization of nanoparticles. Furthermore, the antifungal activity of the as-prepared Ag NPs was tested against Cladosporium fulvum, which is the major cause of a serious plant disease, known as tomato leaf mold. The synthesized Ag NPs displayed excellent fungicidal activity against the tested fungal pathogen. The extreme zone of reduction occurred at 50 μL, whereas, an increase in the reduction activity is observed with increasing the concentration of Ag NPs. These encouraging results can be further exploited by employing the as synthesized Ag NPs against various pathogenic fungi in order to ascertain their spectrum of fungicidal activity.     

Preparation and usage of nanomaterials in biomedicine

Nanotechnology is one of the most promising and decisive technologies in the world. Nanomaterials, as the primary research aspect of nanotechnology, are quite different from macroscopic materials because of their unique optical, electrical, magnetic, thermal properties, and more robust mechanical properties, which make them play an essential role in the field of materials science, biomedical field, aerospace field, and environmental energy. Different preparation methods for nanomaterials have various physical and chemical properties and are widely used in different areas. In this review, we focused on the preparation methods, including chemical, physical, and biological methods due to the properties of nanomaterials. We mainly clarified the characteristics, advantages, and disadvantages of different preparation methods. Then, we focused on the applications of nanomaterials in biomedicine, including biological detection, tumor diagnosis, and disease treatment, which provide a development trend and promising prospects for nanomaterials.     

综述——新型纳米生物材料的研发：纳米酶的发现与应用

自2007年发现四氧化三铁纳米材料具有类似辣根过氧化物酶的催化特性以来,纳米酶研究领域迅速崛起．不同形貌、尺度和材料各异的纳米酶相继出现,同时其催化机制逐渐被认识．由于纳米酶具有催化效率高、稳定、经济和规模化制备的特点,它在医学、化工、食品、农业和环境等领域的应用研究便应运而生．纳米酶的发现,不仅推动了纳米科技的基础研究,还拓展了纳米材料的应用．本文将介绍纳米酶研究领域的最新研究进展．     

Aptamer-functionalized quantum dots as theranostic nanotools against cancer and bacterial infections: A comprehensive overview of recent trends

Aptamers (Apts) are synthetic nucleic acid ligands that can be engineered to target various molecules, including amino acids, proteins, and pharmaceuticals. Through a series of adsorption, recovery, and amplification steps, Apts are extracted from combinatorial libraries of synthesized nucleic acids. Using aptasensors in bioanalysis and biomedicine can be improved by combining them with nanomaterials. Moreover, Apt-associated nanomaterials, including liposomes, polymeric, dendrimers, carbon nanomaterials, silica, nanorods, magnetic NPs, and quantum dots (QDs), have been widely used as promising nanotools in biomedicine. Following surface modifications and conjugation with appropriate functional groups, these nanomaterials can be successfully used in aptasensing. Advanced biological assays can use Apts immobilized on QD surfaces through physical interaction and chemical bonding. Accordingly, modern QD aptasensing platforms rely on interactions between QDs, Apts, and targets to detect them. QD-Apt conjugates can be used to directly detect prostate, ovarian, colorectal, and lung cancers or simultaneously detect biomarkers associated with these malignancies. Tenascin-C, mucin 1, prostate-specific antigen, prostate-specific membrane antigen, nucleolin, growth factors, and exosomes are among the cancer biomarkers that can be sensitively detected using such bioconjugates. Furthermore, Apt-conjugated QDs have shown great potential for controlling bacterial infections such as Bacillus thuringiensis, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Campylobacter jejuni, Staphylococcus aureus, and Salmonella typhimurium. This comprehensive review discusses recent advancements in the design of QD-Apt bioconjugates and their applications in cancer and bacterial theranostics.     

Impact of labile metal nanoparticles on cellular homeostasis. Current developments in imaging,synthesis and applications

BackgroundThe use of nanomaterials is constantly increasing in electronics, cosmetics, food additives, and is emerging in advanced biomedical applications such as theranostics, bio-imaging and therapeutics. However their safety raises concerns and requires appropriate methods to analyze their fate in vivo.Scope of reviewIn this review, we describe the current knowledge about the toxicity of labile metal (ZnO, CuO and Ag) nanoparticles (NPs) both at the organism and cellular levels, and describe the pathways that are triggered to maintain cellular homeostasis. We also describe advanced elemental imaging approaches to analyze intracellular NP fate. Finally, we open the discussion by presenting recent developments in terms of synthesis and applications of Ag and CuO NPs.Major conclusionsLabile metal nanoparticles (MeNPs) release metal ions that trigger a cellular response involving biomolecules binding to the ions followed by regulation of the redox balance. In addition, specific mechanisms are set up by the cell in response to physiological ions such as Cu(I) and Zn(II). Among all types of NPs, labile MeNPs induce the strongest inflammatory responses which are most probably due to the combined effects of the NPs and of its released ions. Interestingly, recent developments in imaging technologies enable the intracellular visualization of both the NPs and their ions and promise new insights into nanoparticle fate and toxicity.General significanceThe exponential use of nanotechnologies associated with the difficulties of assessing their impact on health and the environment has prompted scientists to develop novel methodologies to characterize these nanoobjects in a biological context.     

Tree gum-based renewable materials: Sustainable applications in nanotechnology,biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as ‘green’ bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal–hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.     

Variable antibody-dependent activation of complement by functionalized phospholipid nanoparticle surfaces

A wide variety of nanomaterials are currently being developed for use in the detection and treatment of human diseases. However, there is no systematic way to measure and predict the action of such materials in biological contexts. Lipid-encapsulated nanoparticles (NPs) are a class of nanomaterials that includes the liposomes, the most widely used and clinically proven type of NPs. Liposomes can, however, activate the complement system, an important branch of innate immunity, resulting in undesirable consequences. Here, we describe the complement response to lipid-encapsulated NPs that are functionalized on the surface with various lipid-anchored gadolinium chelates. We developed a quantitative approach to examine the interaction of NPs with the complement system using in vitro assays and correlating these results with those obtained in an in vivo mouse model. Our results indicate that surface functionalization of NPs with certain chemical structures elicits swift complement activation that is initiated by a natural IgM antibody and propagated via the classical pathway. The intensity of the response is dependent on the chemical structures of the lipid-anchored chelates and not zeta potential effects alone. Moreover, the extent of complement activation may be tempered by complement inhibiting regulatory proteins that bind to the surface of NPs. These findings represent a step forward in the understanding of the interactions between nanomaterials and the host innate immune response and provide the basis for a systematic structure-activity relationship study to establish guidelines that are critical to the future development of biocompatible nanotherapeutics.     

Exploring the therapeutic potential of Hibiscus rosa sinensis synthesized cobalt oxide (Co3O4-NPs) and magnesium oxide nanoparticles (MgO-NPs)

Herein, we present a green, economic and ecofriendly protocol for synthesis of cobalt oxide (Co₃O₄-NPs) and magnesium oxide nanoparticles (MgO-NPs) for multifaceted biomedical applications. In the study, a simple aqueous leaf extract of Hibiscus rosa sinensis, was employed for the facile one pot synthesis of Co₃O₄-NPs and MgO-NPs. The well characterized NPs were explored for multiple biomedical applications including bactericidal activity against urinary tract infection (UTI) isolates, leishmaniasis, larvicidal, antidiabetic antioxidant and biocompatibility studies. Our results showed that both the NPs were highly active against multidrug resistant UTI isolates as compared to traditional antibiotics and induced significant zone of inhibition against Proteus Vulgaris, Pseudomonas Aurigenosa and E.coli. The NPs, in particular Co₃O₄-NPs also showed significant larvicidal activity against the Aedes Aegypti, the mosquitoes involve in the transmission of Dengue fever. Similarly, excellent leishmanicidal activity was also observed against both the promastigote and amastigote forms of the parasite. Furthermore, the particles also exhibited considerable antidiabetic activity by inhibiting α-amylase and α-glucosidase enzymes. The biosynthesized NPs were found to be excellent antioxidant and biocompatible nanomaterials. Owing to ecofriendly synthesis, non-toxic and biocompatible nature, the Hibiscus rosa sinensis synthesized Co₃O₄-NPs and MgO-NPs can be exploited as potential candidates for multiple biomedical applications.     

综述与专论: 贵金属和碳纳米酶分子机制的理论研究

2007年四氧化三铁类过氧化物酶活性的发现催生了纳米酶这一新兴多学科交叉研究方向,多种基于金属、金属氧化物和碳纳米材料的纳米酶被发现,并在环境,食品安全,化工,生物医学等领域获得应用。相应的,纳米酶催化分子机制的理论研究也取得了进展。本文将回顾化学催化的基本原理,重点总结贵金属和碳纳米酶分子机制的理论研究进展。     

Preparation and biomedical application of a non-polymer coated superparamagnetic nanoparticle

We report the preparation of a non-polymer coated superparamagnetic nanoparticle that is stable and biocompatible both in vitro and in vivo. The non-polymer, betaine, is a natural methylating agent in mammalian liver with active surface property. Upon systemic administration, the nanoparticle has preferential biodistribution in mammalian liver and exhibits good reduction of relaxivity time and negative enhancement for the detection of hepatoma nodules in rats using MRI. Our data demonstrate that the non-polymer coated superparamagnetic nanoparticle should have potential applications in biomedicine.     

Toxicity of gold nanoparticles (AuNPs): A review

Gold nanoparticles are a kind of nanomaterials that have received great interest in field of biomedicine due to their electrical, mechanical, thermal, chemical and optical properties. With these great potentials came the consequence of their interaction with biological tissues and molecules which presents the possibility of toxicity. This paper aims to consolidate and bring forward the studies performed that evaluate the toxicological aspect of AuNPs which were categorized into in vivo and in vitro studies. Both indicate to some extent oxidative damage to tissues and cell lines used in vivo and in vitro respectively with the liver, spleen and kidney most affected. The outcome of these review showed small controversy but however, the primary toxicity and its extent is collectively determined by the characteristics, preparations and physicochemical properties of the NPs. Some studies have shown that AuNPs are not toxic, though many other studies contradict this statement. In order to have a holistic inference, more studies are required that will focus on characterization of NPs and changes of physical properties before and after treatment with biological media. So also, they should incorporate controlled experiment which includes supernatant control Since most studies dwell on citrate or CTAB-capped AuNPs, there is the need to evaluate the toxicity and pharmacokinetics of functionalized AuNPs with their surface composition which in turn affects their toxicity. Functionalizing the NPs surface with more peculiar ligands would however help regulate and detoxify the uptake of these NPs.     

纳米材料生物效应研究进展

随着纳米技术的快速发展,纳米材料在医学成像、疾病诊断、药物传输、癌症治疗、基因治疗等领域的应用和基础研究也在飞速发展.同时,纳米材料的这些有益应用使得人体通过吸入、经口、皮肤吸收和静脉注射等不同方式受到暴露.当纳米材料与生物体系发生相互作用时,有可能产生负面生物学效应,而这些潜在的毒理效应都是未知的.综述了纳米材料在生物医学领域巨大的应用前景,关注其对心血管系统、呼吸系统及转运到其他器官可能造成的负面效应,并探讨了纳米颗粒在引起心血管疾病及肺部炎症方面的可能机理与作用途径.最后对纳米材料的安全性评估和研究重点进行了总结.     

硫化铜纳米粒子应用于肿瘤诊断和治疗的研究进展

癌症是当今威胁人类健康的主要疾病之一。近年来提出的近红外光介导的光热治疗,能够对肿瘤组织进行定点清除并且对正常组织具有较低的毒副作用,为肿瘤的治疗提供了新的方法。开发具有良好生物相容性的高效光热偶联剂是发展光热治疗的首要条件。随着纳米技术的飞速发展,一些金属纳米结构由于具有独特的光学特性作为光热偶联剂被广泛应用到肿瘤的光热治疗中。然而,成本高昂、制备过程繁琐以及光热稳定性较差等不足,限制了这些纳米材料的进一步应用。最新报道的新型光热偶联剂半导体硫化铜纳米粒子(copper sulfide nanoparticles,CuS NPs),由于其具有制备工艺简单、成本低廉、突出的光热稳定性和良好的生物相容性等优势,成为了当今纳米医学领域研究的热点。本文主要综述了CuS纳米粒子在肿瘤光热治疗和影像诊断方面的应用研究,并对CuS纳米粒子在生物医学领域应用中存在的问题和未来的研究方向进行了展望。     

硫化镉纳米粒子对原核生物的毒理作用

硫化镉纳米粒子（cadmium sulfide nanoparticles,CdS NPs）是一种重要的半导体,具有突出的光电特性、可调带隙和化学稳定性,在分析化学、生物医学、荧光成像和生物传感器等方面具有潜在应用价值。生物合成CdS NPs具有可控、低成本、环境友好等优势而被广泛研究。然而CdS NPs本身兼具纳米材料毒性及重金属硫化物毒性,其对原核微生物的毒性研究受到广泛关注。本文以大肠杆菌为例,对CdS NPs在原核生物细胞内的毒性机理研究进展进行了综述,包括CdS NPs的生物合成机制、CdS NPs对大肠杆菌的毒害作用以及大肠杆菌对该毒害作用的防御机制,着重论述了细菌在合成CdS NPs过程中Cd²⁺及CdS对合成细菌本身的毒理作用及该细菌所产生的相应应激机制。本文旨在更好、更全面地评估CdS NPs的毒性,促进抗CdS NPs的原核生物在相关领域的发展和应用。     

Sustainable approaches towards green synthesis of TiO2 nanomaterials and their applications in photocatalysis-mediated sensing to monitor environmental pollution

Nanomaterials are gaining enormous interests due to their novel applications that have been explored nearly in every field of our contemporary society. In this scenario, preparations of nanomaterials following green routes have attracted widespread attention in terms of sustainable, reliable, and environmentally friendly practices to produce diverse nanostructures. In this review, we summarize the fundamental processes and mechanisms of green synthesis approaches of TiO₂ nanoparticles (NPs). We explore the role of plants and microbes as natural bioresources to prepare TiO₂ NPs. Particularly, focus has been made to explore the potential of TiO₂-based nanomaterials to design a variety of sensing platforms by exploiting the photocatalysis efficiency under the influence of a light source. These types of sensing are of massive importance for monitoring environmental pollution and therefore for inventing advanced strategies to remediate hazardous pollutants and offer a clean environment.