纳米材料产生细胞毒性原因的研究进展

纳米颗粒通常指直径在100nm以下的颗粒物质。近年来随着纳米技术的飞速发展,纳米材料被医用于工程、信息技术、化妆品、医药卫生等许多领域。特别是在生物医学领域,纳米材料在组织工程、控释药物载体、介入治疗器械、生物大分子分离等方面呈现出广泛的应用前景。但在纳米材料的应用过程中,其毒性作用也逐渐引起人们的关注,纳米材料毒性作用的研究不仅为纳米材料和设备的安全性评价提供了理论依据,而且进一步扩展纳米技术的应用领域。目前,关     

碳纳米管和几种纳米颗粒材料的安全性研究进展

目的本文对产生纳米毒性的原理进行了分析,对该领域的研究给予展望和建议。方法综述了几种纳米材料(单壁碳纳米管、纳米颗粒、纳米磁性材料、纳米红色元素硒等)的现有生物效应和毒理学研究,分析了纳米材料粒径与剂量对纳米毒性的影响,当粒径减小到一定程度原本无毒或毒性较小的材料也显示出毒性或者毒性增强。结果纳米材料可以经过肺血屏障和皮肤进入体内,巨噬细胞的消除功能开始下降,造成纳米物质在体内的聚集可能导致毒性的产生,且粒径越小其吞噬能力越小,但是仅凭这些现象尚不能确定其真正原因。结论新的安全评价体系的建立对于纳米材料的应用至关重要。     

纳米沉淀法及其在纳米药物载体领域的应用研究进展

纳米材料在生物医学领域具有广泛的应用。纳米沉淀法通过控制溶质溶液与非溶剂的混合制备纳米颗粒,反应快速,适用于多种纳米颗粒的制备。近年来纳米沉淀法领域已取得大量研究进展,基于混合器的Flash纳米沉淀技术以及基于水动力聚焦的微流控纳米沉淀技术的出现,提高混合效率和对反应条件的控制性,为高质量纳米颗粒的规模化制备提供条件。纳米沉淀法被广泛用于各种纳米颗粒以及药物载体(姜黄素、紫杉醇、阿霉素、喜树碱、顺铂、青霉素等)的制备,对其近年来的研究进展进行总结归纳。     

上转换荧光材料的化学修饰及在免疫检测的应用

上转换纳米材料是近年来发展起来的新兴稀土荧光材料。在近红外光的激发下可将其转变成可见光这一光学特性,使其具有抗光漂白能力强、宽的反斯托克斯位移、低毒性以及无自体荧光干扰等优点,在免疫检测中可提高灵敏度和信噪比。上转换稀土纳米颗粒水溶性和分散性较差,因此要通过化学修饰成水溶性和分散性较好的上转换稀土颗粒,以进一步与生物分子偶联。本文主要在合成上转换纳米颗粒的基础上,对化学修饰的方法及荧光共振能量传递机制、基于磁分离富集的免疫检测技术、固相微孔板荧光标记技术、免疫传感技术和免疫层析技术的应用研究做一综述。上转换技术的成功应用解决了传统的纳米材料应用中低灵敏度的问题,在医学检测领域具有很大的应用潜力。     

纳米基因载体的研究现状

基因治疗正成为当今医学研究的热门课题,载体问题是制约基因治疗成功的关键.目前,常用的载体包括病毒载体和非病毒载体,后者以其无病毒毒性和免疫原性等优越性而倍受瞩目.随着纳米生物技术的发展和多种纳米材料的涌现,以纳米颗粒为基础的非病毒基因载体倍受研究者推崇.综述了纳米基因载体的研究现状,重点总结阐述了阳离子聚合物、无机纳米颗粒及磁性纳米颗粒载体系统,并探讨了其在应用研究方面的现状和前景.     

病毒纳米颗粒在医学领域的潜在应用

过去,对于病毒的研究主要集中在它的传染性和将其作为工具来加深对细胞生物学的理解,然而随着近年来对于病毒结构的研究深入,病毒在纳米科技领域的应用日益受到人们的关注。通过化学或基因方法修饰过的病毒纳米颗粒能够作为潜在的优秀载体应用到多个方面,例如:药物/基因输送载体、高级疫苗载体以及各种具有特殊功能的无机、有机纳米材料等。本文综述了近来病毒纳米颗粒在医学领域的应用情况。     

生物医用无机纳米颗粒的表面修饰研究进展

纳米材料由于其极小的尺寸,拥有许多常规材料所不具备的优良特性,如光学性能、电磁学性能、热力学性能、量子力学性能等,使其在诸多领域尤其是在生物医学领域具有广阔的应用前景。生物医用无机纳米颗粒是指纳米级的无机纳米核分散于溶剂中所形成的胶体分散系统。无机核的组成包括贵金属（如 Au、Ag、Pt、Pb等）,半导体材料（如 CdSe、CdS、ZnS、TiO2、PbS等）,磁性材料（如 Fe2O3或 Co纳米颗粒）以及复合材料（如 FePt、CoPt等）。依据其组成材料的不同,纳米颗粒可具有一系列独特性质,诸如高电子密度、强光学吸收性质、磷光或荧光性质及具有磁矩等。     

超顺磁性氧化铁纳米颗粒在药物靶向递送中的研究进展

超顺磁性氧化铁(SPIO)是一种新型的生物医学纳米材料,具有表面效应、小尺寸效应和宏观量子隧道效应,而较好的生物相容性及超顺磁性使其广泛用于疾病的靶向治疗.相比于其他纳米药物载体,超顺磁性氧化铁纳米颗粒(SPIONs)因其内在属性如固有磁性、良好的安全性及制备和表面修饰方法的可用性等在纳米药物领域中显示出巨大潜力,为其多样的生物医学应用铺平了道路.但研究人员对其不可预知的毒性、改变细胞信号转导和基因表达等方面仍有顾虑.对SPIONs在药物靶向递送中的研究进展作一综述.     

纳米水平分子成像与诊疗一体化研究进展与挑战

分子成像能以非侵入性的方式重现活体细胞的生理功能和生物学过程,提高疾病的早期和特异性诊断水平。纳米颗粒/材料具有物理性质可控性高、易于表面修饰、血液循环时间长和可功能化等优点,在疾病诊断与治疗中显示出巨大潜力。但如何阐明纳米材料多功能间的内在联系、解决其代谢及安全性等关键机制难题、实现纳米颗粒/材料多功能性到临床多功能...     

二氧化钛纳米颗粒解聚方法

目的:研究二氧化钛(TiO2)纳米颗粒解聚的方法.方法:以超声的方法在不同条件下对多种TiO2纳米材料进行处理,利用透射电镜观察解聚情况.结果:在一定温度、功率和时间条件下,利用超声法可以对不同粒径和性质的TiO2纳米颗粒进行解聚,解聚后的TiO2纳米颗粒能满足其生物学效应的研究.结论:超声波振荡法是纳米颗粒团聚体解聚的有效方法.     

纳米材料在医学检测与疾病诊断中的应用

纳米材料具有尺寸小、比表面积高的特点,在光、声、电、热、磁等性质上有着不同于其他传统材料的独特之处。随着纳米材料研究的不断进步,越来越多的功能化纳米材料以及相关器件凭借着高灵敏度、高特异性、准确、快速等优点,在医学检测领域得到了广泛应用。纳米材料的快速发展可以为临床诊断提供新的方法,为疾病的预防以及治疗提供更多的科学依据。纳米材料在多种疾病的诊断上均有着较大的发展潜力和广阔的应用前景。本文概述了纳米材料的特性及其用于医学检测的原理,介绍了纳米材料在传染病、恶性肿瘤、糖尿病、神经退行性疾病和心血管疾病等医学检测中的应用研究进展,并对未来的发展和应用做了展望与评述。     

Processing, properties, and in vitro bioactivity of polysulfone-bioactive glass composites

The mismatch between the mechanical properties of bioceramics and natural tissue has restricted in several cases a wider application of ceramics in medical and dental fields. To overcome this problem, polymer matrix composites can be designed to combine bioactive properties of some bioceramics with the superior mechanical properties of some engineering plastics. In this work, polymer particulate composites composed of a high mechanical-property polymer and bioactive glass particles were produced and both the in vitro bioactivity and properties of the system were investigated. Composites with different volume fraction and particle size were prepared. In vitro tests showed that hydroxy-carbonate-apatite can be deposited on the surface of a composite as early as 20 h in a simulated body fluid. Ionic evolution from a composite with 40% volume fraction of particles was demonstrated to be similar to bulk bioactive glasses. The mechanical properties of some of the obtained composites had values comparable with the ones reported for bone. Moreover, a physical model based on dynamical mechanical tests showed evidences that the interface of the composite was aiding in the stress transfer process.     

Non‐Volatile Glycerin Gel Enhanced by Sub‐5 nm Particles with Super Elasticity,Recoverability, and High Temperature Resistance

A gel material that can be applied to industry needs to fulfill two requirements: excellent mechanical properties and high temperature resistance. Previous research developed a hydrogel enhanced by sub‐5 nm particles, with excellent mechanical properties. While its application in the open environment is still limited by the volatilization of inner moisture, in this research, a non‐volatile gel (NV gel) enhanced by 5‐nm spherulites is manufactured. The NV gel remains stable after staying at 90 °C for 24 h. Meanwhile, being enhanced by sub‐5 nm nanospherulites, the NV gel shows good mechanical properties: with 200 ppm nanoparticle content, the tensile strength reaches 814 kPa and the compressive stress is 173.41 MPa at a recoverable 99% strain. The high temperature resistance is characterized by thermogravimetric analysis (TGA) and mechanical testing after thermal treatment. Transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, time of flight secondary ion mass spectrometry, and thermogravimetric analysis are used to evaluate the microstructure of NV gel. Possessing non‐volatile and good mechanical properties at the same time, this NV gel becomes very suitable for fulfilling the application requirement as an engineering material.     

A Mechatronic System for Quantitative Application and Assessment of Massage-Like Actions in Small Animals

Massage therapy has a long history and has been widely believed effective in restoring tissue function, relieving pain and stress, and promoting overall well-being. However, the application of massage-like actions and the efficacy of massage are largely based on anecdotal experiences that are difficult to define and measure. This leads to a somewhat limited evidence-based interface of massage therapy with modern medicine. In this study, we introduce a mechatronic device that delivers highly reproducible massage-like mechanical loads to the hind limbs of small animals (rats and rabbits), where various massage-like actions are quantified by the loading parameters (magnitude, frequency and duration) of the compressive and transverse forces on the subject tissues. The effect of massage is measured by the difference in passive viscoelastic properties of the subject tissues before and after mechanical loading, both obtained by the same device. Results show that this device is useful in identifying the loading parameters that are most conducive to a change in tissue mechanical properties, and can determine the range of loading parameters that result in sustained changes in tissue mechanical properties and function. This device presents the first step in our effort for quantifying the application of massage-like actions used clinically and measurement of their efficacy that can readily be combined with various quantitative measures (e.g., active mechanical properties and physiological assays) for determining the therapeutic and mechanistic effects of massage therapies.     

Mechanical behaviour of a new acrylic radiopaque iodine-containing bone cement

In total hip replacement, fixation of a prosthesis is in most cases obtained by the application of methacrylic bone cements. Most of the commercially available bone cements contain barium sulphate or zirconium dioxide as radiopacifier. As is shown in the literature, the presence of these inorganic particles can be unfavourable in terms of mechanical and biological properties. Here, we describe a new type of bone cement, where X-ray contrast is obtained via the introduction of an iodine-containing methacrylate copolymer; a copolymer of methylmethacrylate and 2-[4-iodobenzoyl]-oxo-ethylmethacrylate (4-IEMA) is added to the powder component of the cement. The properties of the new I-containing bone cement (I-cement) are compared to those of a commercially available bone cement, with barium sulphate as radiopacifier (B-cement). The composition of the I-cement is adjusted such that similar handling properties and radiopacity as for the commercial cement are obtained. In view of the mechanical properties, it can be stated that the intrinsic mechanical behaviour of the I-cement, as revealed from compression tests, is superior to that of B-cement. Concerning the fatigue behaviour it can be concluded that, though B-cement has a slightly higher fatigue crack propagation resistance than I-cement, the fatigue life of vacuum-mixed I-cement is significantly better than that of B-cement. This is explained by the presence of BaSO4 clumps in the commercial cement; these act as crack initiation sites. The mechanical properties (especially fatigue resistance) of the new I-cement warrant its further development toward clinical application.     

Study on Characteristics of Acellular Bovine Pericardium Crosslinked with Genipin

The study used a naturally occurring crosslinking reagent-genipin to chemically modify acellular bovine pericardium, prepare cardiac valve tissue engineering scaffold material,and evaluated genipin crosslinked acellular matrix of bovine pericardium by investigating the physical and chemical properties of the tissues, such as the surface properties, crosslinking characteristics, mechanical properties, resistance to enzymatic capacity in vitro, and hemolysis tests. The results showed that acellular bovine pericardium matrix crosslinked with genipin was strong hydrophilicity, high crosslinking index, and stable structure, which can maintain good mechanical properties. As a kind of scaffold material for valve tissue engineering, it has wide application prospect.     

3D Printed Multifunctional Self-Adhesive and Conductive Polyacrylamide/Chitosan/Sodium Carboxymethyl Cellulose/CNT Hydrogels as Flexible Sensors

3D printing of hydrogels with improved mechanical properties will play an important role in many fields in the future. Polyacrylamide with controllable reaction conditions and chitosan with increased mechanical strength are chosen to prepare hybrid hydrogels with high mechanical properties (elongation >2000%). The addition of sodium carboxymethyl cellulose enables this hydrogel system to have excellent rheological properties for 3D printing. The samples prepared by 3D printing technology have larger elongation (>1000%) and higher elastic modulus (141.99 kPa). Carbon nanotube-added composite hydrogels can be used to fabricate flexible electronic devices with diverse functions and structures. The prepared sensor can detect the signals of human movement (joint movement, breathing, drinking water), and has a sensitive signal response in the range of 12–67 °C. In addition, this sensor can also be extended to the application of NH₃ gas signal sensing. Due to the stable performance and long service life of conductive multifunctional hydrogels, the application potential of hydrogel sensors will be further increased. In conclusion, this simple-prepared 3D-printable high-mechanical-performance hydrogel with multiple network crosslinks has a favorable competitive advantage in future flexible material applications.     

Influence of the pore generator on the evolution of the mechanical properties and the porosity and interconnectivity of a calcium phosphate cement

Porosity and interconnectivity are important properties of calcium phosphate cements (CPCs) and bone-replacement materials. Porosity of CPCs can be achieved by adding polymeric biodegradable pore-generating particles (porogens), which can add porosity to the CPC and can also be used as a drug-delivery system. Porosity affects the mechanical properties of CPCs, and hence is of relevance for clinical application of these cements. The current study focused on the effect of combinations of polymeric mesoporous porogens on the properties of a CPC, such as specific surface area, porosity and interconnectivity and the development of mechanical properties. CPC powder was mixed with different amounts of PLGA porogens of various molecular weights and porogen sizes. The major factors affecting the properties of the CPC were related to the amount of porogen loaded and the porogen size; the molecular weight did not show a significant effect per se. A minimal porogen size of 40 μm in 30 wt.% seems to produce a CPC with mechanical properties, porosity and interconnectivity suitable for clinical applications. The properties studied here, and induced by the porogen and CPC, can be used as a guide to evoke a specific host-response to maintain CPC integrity and to generate an explicit bone ingrowth.     

材料生物力学2021年研究进展

机体组织具有复杂的三维动态结构,且受到多种形式的作用力。细胞从细胞外基质（extracellular matrix, ECM）中感受力学刺激,ECM构建的力学微环境调控细胞不同生物学功能。制备可模拟机体组织ECM力学微环境的生物材料是生物力学领域研究的热点和难点之一。生物材料的不同理化性质赋予材料特定的力学性能,进而影响细胞行为和功能。本文结合2021年材料生物力学领域的最新文献,特别关注新型材料生物力学对细胞生物学行为的调控和在组织工程中的应用,并探讨材料生物力学研究领域的未来发展方向。     

Resilin: Protein-based elastomeric biomaterials

Resilin is an elastomeric protein found in insect cuticles and is remarkable for its high strain, low stiffness, and high resilience. Since the first resilin sequence was identified in Drosophilia melanogaster (fruit fly), researchers have utilized molecular cloning techniques to construct resilin-based proteins for a number of different applications. In addition to exhibiting the superior mechanical properties of resilin, resilin-based proteins are autofluorescent, display self-assembly properties, and undergo phase transitions in response to temperature. These properties have potential application in designing biosensors or environmentally responsive materials for use in tissue engineering or drug delivery. Furthermore, the capability of resilin-based biomaterials has been expanded by designing proteins that include both resilin-based sequences and bioactive domains such as cell-adhesion or matrix metalloproteinase sequences. These new materials maintain the superior mechanical and physical properties of resilin and also have the added benefit of controlling cell response. Because the mechanical and biological properties can be tuned through protein engineering, a wide range of properties can be achieved for tissue engineering applications including muscles, vocal folds, cardiovascular tissues, and cartilage.