New iron-doped multilayer ceramic scaffold with noncontinuous bioactive behavior

New multilayer porous ceramic scaffolds, constituted by a core covered with external layers, are proposed as future bone tissue implants. The core with composition SiO₂ - 25P₂O₅ – 68CaO–6Li₂O (mol%) provided suitable compressive strength (0.9–1.6 MPa) to act as an initial support during bone tissue regeneration. The external layers with composition 29SiO₂ - 3P₂O₅ - (68-x) CaO - xFe₂O₃ (mol%) (x = 0.3 and 1) (samples C/EL-1Fe and C/EL-3Fe, respectively) conferred a bioactive character to scaffolds. The surfaces of both samples showed apatite precipitates after coming into contact with simulated body fluid (SBF). Sample C/EL-1Fe exhibited noncontinuous bioactive behavior, with precipitates of apatite that precipitated and dissolved between days 1 and 28. Sample C/EL-3Fe showed precipitates after 8 days that remained until the end of the study time. This variation in material, achieved by modifying the amounts of iron in external layers, represents an important advance in the ability to control an implant's bioactivity in line with requirements of future applications.     

Nanodispersions stabilized by β-cyclodextrin nanosponges: application for simultaneous enhancement of bioactivity and stability of sage essential oil

The aim of this work was to stabilize oil-in-water nanoemulsion containing sage (salvia officinalis) essential oil, for enhancing its physicochemical stability and enlarging its industrial applications. New β-cyclodextrin nanosponges were synthesized by polycondensation using naphthalene dicarboxylic acid as cross-linking agent, the latter system was characterized by FTIR spectroscopy, SEM, BET, and powder XRD. Nanoemulsions stabilized by free β-cyclodextrin or nanosponges were prepared, their physicochemical properties were determined (particles size, zeta potential, viscosity, turbidity, and essential oil content) and their stability was studied at different storage temperatures (4?°C, 20?°C, and 40?°C) during 3?months. Pharmaceutical application of prepared nanoemulsions was investigated in vitro by dissolution test study and in vivo by their antidiabetic activity evaluation in rats. Sage essential oil nanoemulsion stabilized by β-cyclodextrin-naphthalene dicarboxylic acid nanosponges presents very high stability and promising uses in pharmaceutical industry.     

Fabrication and properties of carbon fiber-Si3N4 nanowires-hydroxyapatite/phenolic resin composites for biological applications

Carbon fiber-Si₃N₄ nanowires-hydroxyapatite/phenolic resin (CF–Si₃N₄nws-HA/resin) composites were successfully fabricated by the combined methods of precursor impregnation-pyrolysis (PIP) and pulse electrochemical deposition (PED). The morphology, microstructure and element compositions of Si₃N₄nws and HA were characterized. The mechanical properties, biological friction performances and in-vitro bioactivity of CF-Si₃N₄nws-HA/resin composites were investigated. The results showed that the Si₃N₄nws induced the uniform growth of HA. The tensile strength of the CF-Si₃N₄nws-HA/resin composites increased by 41.7% compared with CF-HA/resin composites. The wear rate decreased by 85.8% compared with CF-HA/resin composites. CF-Si₃N₄nws-HA/resin composites showed good in-vitro bioactivity and have potential for applications in bone graft.     

Synthesis,Characterization, Speciation,and Biological Studies on Metal Chelates of Carbohydrates with Molecular Docking Investigation

The role of starch aerogel (St-AG) and carboxymethyl cellulose (CMC) as biolgical active compounds, when they subjected for complexation with metal ions, is assessed in this work. The complexation is carried out with palladium(II) and copper(II) ions, in solid state. Different tools of analysis are carried out to characterize and elucidate the structures of these complexes, namely: elemental analysis, IR, thermal analysis, magnetic measurement and molar conductance techniques. All synthesized complexes are formed with 1:2 (metal:ligand) stoichiometry except the case of aerogel starch 1:1 (Pd:starch). All isolated complexes show a satisfactory cytotoxic effect results against colon cancer cell lines HCT11. Additionally, these complexes are screened for their antibacterial activities against two types of Gram positive and negative bacteria. Molecular docking investigation confirmed the cytotoxicity and antibacterial results. Proton–ligands association constants and their complex formation constants with some bivalent metal ions, using potentiometric method show that the complexes formed in solution have a stoichiometry of 1:1 [metal:ligand]. The effects of metal ion, ionic radius, electronegativity and nature of ligand on the formation constants are discussed. The formation constants of the complexes with 3D transition metals followed the order Mn²⁺ < Co²⁺ < Ni²⁺ < Cu²⁺ > Zn²⁺.     

泥鳅多糖的研究进展

近年来随着泥鳅养殖及产业化的快速发展, 泥鳅资源的开发和高值化利用已成为研究热点。泥鳅是一种含有丰富优质蛋白、脂肪酸以及微量元素的营养健康食品, 具备多种保健功能和药用价值, 其中泥鳅多糖是从泥鳅中提取得到的一种游离中性多糖, 具有耐缺氧、抗肿瘤、抗氧化、调节免疫、降血糖、抗炎等功能。本文主要综述了泥鳅多糖的制备方法、分离提纯方法、结构表征、生物活性、精深加工等方面的研究进展,旨在为泥鳅多糖的高值化利用提供一些理论基础, 为泥鳅产业链的快速发展提供新的发展方向。     

Research advances in traditional and modern use of Nelumbo nucifera: phytochemicals,health promoting activities and beyond

Abstract

Nelumbo nucifera, or sacred lotus, has been valuable for us to use as vegetable, functional food, and herb medicine for over 2,000?years. The purpose of this article is to systematically review the traditional/modern uses, chemical compositions and pharmacological activities on different parts of N. nucifera. Traditionally, this plant has been used to treat chronic dyspepsia, hematuria, insomnia, nervous disorders, cardiovascular diseases, and hyperlipidemia. Now, phytochemical investigations on different parts of N. nucifera have indicated a wide spectrum of at least 255 constituents belonging to different chemical groups, including proteins, amino acids, polysaccharides, starch, flavonoids, alkaloids, essential oils, triterpenoids, steroids, and glycosides. Meanwhile, its pharmacological activities, including anti-obesity, antioxidant, anti-inflammatory, cardiovascular, hepatoprotective, hypoglycemic, hypolipidemic, antitumor, memory-improving and antiviral activities, have also been reviewed, together with its applications in health food industry and clinic uses of its single plant or herbal formulae. Herein, this review will provide state-of-the-art overview on its traditional and modern uses in food industry and medicines, together with the comprehensive profiles of phytochemicals, and health promoting bioactivities of this valuable plant. In addition, the new perspectives and future challenges in the research on lotus are also outlined.     

等离子活化烧结制备石墨烯/羟基磷灰石复相生物陶瓷

以羟基磷灰石(Hydroxyapatite, HAp)为基体, 石墨烯(Graphene, rGO)作为增强相, 利用等离子活化烧结制备了石墨烯/羟基磷灰石(rGO/HAp)复相生物陶瓷。系统研究了rGO添加量对HAp陶瓷基体物相结构、生物活性及断裂韧性的影响。结果表明, rGO的加入有利于提高HAp陶瓷的生物活性。同时, 复相生物陶瓷的硬度与断裂韧性随rGO添加量的增加均表现出先升高, 后显著降低的变化趋势。当rGO添加量为2wt%时, 样品的硬度与断裂韧性分别达到6.97 GPa和0.84 MPa•m^1/2, 较纯相HAp陶瓷提高了11.5%和37.3%。研究表明rGO的拔出效应是导致复相陶瓷力学性能提高的主要原因。     

微振动应力环境影响羟基磷灰石陶瓷生物活性及力学稳定性的体外评价

本研究考察微振动应力环境(MVS)下羟基磷灰石(HA)陶瓷的生物活性及力学稳定性, 探讨体内生理应力环境对HA陶瓷骨诱导性的影响。扫描电子显微镜(SEM)和钙离子释放结果均显示, MVS有利于具有较高微孔隙率((29±1.2)%, (26.4±0.3)%)HA材料的钙离子再沉积和类骨磷灰石层形成, 而对于微孔隙率较低((10.6±0.8)%)的HA材料则促进其钙离子释放。蛋白吸附结果显示40 Hz的MVS促进了HA的蛋白吸附, 60 Hz的MVS则显著抑制HA的蛋白吸附行为。抗压试验表明MVS应力环境并未影响HA多孔支架的力学稳定性。研究表明应力环境是影响HA陶瓷生物活性和骨诱导性的重要因素。     

硼硅酸盐生物玻璃的制备及其体外生物活性和降解性

采用熔融法制备了NaO-CaO-SiO2-P2O5-B2O3玻璃,用质量损失分析、pH值测定和X射线衍射、电子显微镜以及电感耦合等离子体离子浓度分析法表征玻璃与稀K2HPO4溶液的类生物反应,研究了这类玻璃的生物活性和生物降解性.结果表明:当玻璃中B2O3/SiO2的摩尔比为3:1时,生物活性较好.随着B2O3与SiO2的摩尔比减小,玻璃的降解速度变慢,获得的羟基磷灰石结晶度较低.利用此特性可控制生物玻璃的降解速度,从而与骨细胞生长速度相匹配.因此,此类硼硅酸盐生物活性玻璃有望在硬组织工程支架材料中得到应用.     

新型含氟三唑类化合物的合成及生物活性研究

以三氟氯乙烯、对羟基苯乙酮、三氮唑为主要原料,设计合成了6种新型含三氟乙氧基团的三唑类化合物,通过IR1、H NMR和EA确证其结构。通过生物活性测试表明,此类化合物均具有一定的杀菌活性。