溶剂热法制备一维锶磷灰石纳米棒及其发光性能研究(英文)

One-dimensional strontium hydroxyapatite(Sr-HAp) nanorods were successfully synthesized by a sim-ple solvothermal method.The products were characterized via X-ray diffraction(XRD),Fourier transform infrared(FT-IR),cold field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),photoluminescence(PL) excitation and emission spectra.The experimental results indicated that oleic acid as a surfactant played a key role in confining the growth of the Sr-HAp powders.A possible formation mechanism of the one-dimensional nanorod was proposed and elaborated.Moreover,the as-obtained Sr-HAp samples showed an in-tense and bright emission band centered at 460 nm under long-wavelength UV light excitation and the contents of NaOH used in the synthetic process had an obvious impact on the optical performance of Sr-HAp powders.The possible luminescent mechanism of the Sr-HAp samples was discussed.     

羟基磷灰石抗菌剂在涂料中的应用

通过共沉淀和离子交换的方法,将钛和锌离子共掺杂在羟基磷灰石上,制备了羟基磷灰石抗菌剂。研究了其与另外3种无机抗菌剂(锌型沸石抗菌剂、银型沸石抗菌剂、氧化钛光催化抗菌剂)在涂料中的应用。结果证明:锌型抗菌涂料对大肠杆菌和金黄色葡萄球菌的抗菌效果较差,其余3种类型抗菌涂料具有很好抗菌效果。但是,银型抗菌剂易引起涂料变色,氧化钛光催化抗菌剂在涂料中难分散且易加快涂料老化,而羟基磷灰石抗菌剂既具有良好的抗菌性能,且对涂料性能没有影响。还介绍了羟基磷灰石抗菌剂的抗菌机理。     

Synthesis,Characterization and In Vitro Antibacterial Activity of Coordination Polymers Based on Bis Bidentate Ligand

A novel bis (bidentate) ligand, namely 5, 5′- (2, 2′- (phenyl azanediyl) bis (ethane-2, 1 - diyl) bis (oxy) bis (methylene) diquinolin ?8 - ol) (PBEQ), was synthesized by condensation of 5 –chloromethyl ?8 - hydroxyquinoline hydrochloride with N, N – Di (2 - hydroxy ethyl) aniline in the presence of a base catalyst. This ligand was characterized by IR, ¹H-NMR, and elemental analysis. Coordination polymers of this bis-ligand (PBEQ) were prepared with Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) metal ions. All of these coordination polymers were characterized by elemental analyses, IR spectral and diffuse reflectance spectral studies. The thermal stability was evaluated by thermogravimetric analyses. In addition, all of the coordination polymers have been characterized by their magnetic susceptibilities. The microbicidal activity of all the samples has been monitored against plant pathogens.     

砷羟基磷灰石的水热合成与结构表征

以四水硝酸钙[Ca(NO3)2·4H2O]、磷酸氢二铵[(NH4)2HPO4]、十二水合砷酸钠[Na3AsO4·12H2O]为原料,在200℃下水热反应8h制得掺砷羟基磷灰石[Ca10(PO4)6-x(AsO4)x(OH)2].考察了反应液中不同砷含量对合成砷羟基磷灰石结构的影响.采用X射线衍射分析(XRD)、扫描电镜结合电子能谱分析(SEM/EDS)、傅立叶变换红外光谱分析(FTIR)等测试手段对产物的晶相、化学组成和形貌进行分析.结果表明:As取代部分磷(P)进入羟基磷灰石的晶格中,没有改变其晶体结构,但羟基磷灰石的晶胞参数发生了变化,随着As含量的增加,砷羟基磷灰石的晶体尺寸呈增大的趋势,晶体形状为短棒状.     

Bioactivity and Antibacterial Behaviors of Nanostructured Lithium-Doped Hydroxyapatite for Bone Scaffold Application

The material for bone scaffold replacement should be biocompatible and antibacterial to prevent scaffold-associated infection. We biofunctionalized the hydroxyapatite (HA) properties by doping it with lithium (Li). The HA and 4 Li-doped HA (0.5, 1.0, 2.0, 4.0 wt.%) samples were investigated to find the most suitable Li content for both aspects. The synthesized nanoparticles, by the mechanical alloying method, were cold-pressed uniaxially and then sintered for 2 h at 1250 °C. Characterization using field-emission scanning electron microscopy (FE-SEM) revealed particle sizes in the range of 60 to 120 nm. The XRD analysis proved the formation of HA and Li-doped HA nanoparticles with crystal sizes ranging from 59 to 89 nm. The bioactivity of samples was investigated in simulated body fluid (SBF), and the growth of apatite formed on surfaces was evaluated using SEM and EDS. Cellular behavior was estimated by MG63 osteoblast-like cells. The results of apatite growth and cell analysis showed that 1.0 wt.% Li doping was optimal to maximize the bioactivity of HA. Antibacterial characteristics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were performed by colony-forming unit (CFU) tests. The results showed that Li in the structure of HA increases its antibacterial properties. HA biofunctionalized by Li doping can be considered a suitable option for the fabrication of bone scaffolds due to its antibacterial and unique bioactivity properties.     

Surface Characterization and Biocompatibility of Selenium‐Doped Hydroxyapatite Coating on Titanium Alloy

Selenium‐doped hydroxyapatite (HA) was biomimetically coated on Ti6Al4V plates with the aim of combining the anticancer and antibacterial properties of selenium with the biocompatibility and bioactivity of HA. For the coating process, the composition of 1.5 × SBF (solution with ion concentrations at 1.5 times that of simulated body fluid, SBF) was modified to include 0.15 mM selenate (SeO₄^2?) ion. The selenium‐doped HA coating was characterized by several methods, such as scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy. The cytotoxicity of selenium on osteoblast and osteosarcoma cells was determined. The coating was shown to inhibit the growth of Staphylococcus epidermidis.     

Strontium Zirconate and Strontium Titanate Ceramics for High-Voltage Applications: Synthesis, Processing, and Dielectric Properties

The synthesis, processing, and electrical properties of SrZrO₃ and SrTiO₃ materials have been examined. Phase-pure powders of SrZrO₃ and SrTiO₃ materials were synthesized using the Pechini method. Powder processing routes that used water and 2-propanol as carrier fluids were developed to achieve high green densities, which resulted in sintered densities of >99% of the theoretical density. The relative permittivity and average breakdown strength for carefully processed SrZrO₃ were 60 and 40 V/μm; the corresponding values for SrTiO₃ were 400 and 35 V/μm. The higher breakdown strengths suggest that these materials can be used in high-voltage capacitor applications.     

硒化羧甲基壳聚糖的合成及表征

以亚硒酸钠和羧甲基壳聚糖为原料,合成了硒化羰甲基壳聚糖,产率为44.78%,硒含量为20.50 mg/g。利用紫外-可见光谱、红外光谱两种表征手段,证实了硒化羧甲基壳聚糖的合成。为研究低毒性、有效的有机补硒产品奠定了基础。     

溶胶-凝胶结合超临界流体干燥法制备纳米掺锶羟基磷灰石的研究

以硝酸钙、氯化锶、磷酸氢二氨等无机盐为原料,采用溶胶-凝胶结合超临界流体干燥法,制备了羟基磷灰石(HAP)纳米微粒、钙被半取代的掺锶羟基磷灰石(SrCaHAP)纳米微粒以及钙被全取代的掺锶羟基磷灰石(SrHAP)纳米微粒.通过元素含量分析、TEM、XRD、FT-IR等手段,对这些纳米微粒的结构进行了分析;探讨了锶的掺入对羟基磷灰石(HAP)的结构、晶形以及结晶度的影响.结果表明:采用溶胶-凝胶结合超临界CO2干燥法,在给定的反应条件下按Sr/[Sr Ca]原子比为0、0.5、1,锶可以按化学计量比掺入到HAP的分子结构中,可分别制备纯度较高、晶型结构较好的HAP、SrCaHAP和SrHAP纳米微粒.HAP掺入锶元素后,不仅降低SrCaHAP和SrHAP 中OH(,PO3(主要官能团的红外光谱吸收峰的振动频率,还改变了纳米微粒的晶形,从短棒状的HAP改变为针状的SrCaHAP,再改变为短棒状的SrHAP.HAP中钙被锶半取代后形成SrCaHAP,微粒结晶度降低,生物学性能改善;当钙被锶完全取代后形成不含钙的SrHAP,微粒结晶度增加,生物学性能变差.     

A Solid-State NMR Study of Selenium Substitution into Nanocrystalline Hydroxyapatite

The substitution of selenium oxyanions in the hydroxyapatite structure was examined using multinuclear solid-state resonance spectroscopy (ssNMR). The study was supported by powder X-ray diffractometry (PXRD) and wavelength dispersion X-ray fluorescence (WD-XRF). Samples of pure hydroxyapatite (HA₃₀₀) and selenate (HA₃₀₀-1.2SeO₄) or selenite (HA₃₀₀-1.2SeO₃) substituted hydroxyapatites were synthesized using the standard wet method and heated at 300 °C to remove loosely bonded water. PXRD data showed that all samples are single-phase, nanocrystalline hydroxyapatite. The incorporation of selenite and selenate ions affected the lattice constants. In selenium-containing samples the concentration of Se was very similar and amounted to 9.55% and 9.64%, for HA₃₀₀-1.2SeO₄ and HA₃₀₀-1.2SeO₃, respectively. PXRD and ssNMR data showed that the selenite doping significantly decreases the crystallite size and crystallinity degree. ³¹P and ¹H NMR experiments demonstrated the developed surface hydrated layer in all samples, especially in HA₃₀₀-1.2SeO₃. ¹H NMR studies showed the dehydroxylation of HA during the selenium oxyanions substitution and the existence of hydrogen bonding in structural hydroxyl group channels. ¹H→⁷⁷Se cross polarization NMR experiments indicated that selenites and selenates are located in the crystal lattice and on the crystal surface.     

In Vitro Corrosion and Cytocompatibility Properties of Nano-Whisker Hydroxyapatite Coating on Magnesium Alloy for Bone Tissue Engineering Applications

We report here the successful fabrication of nano-whisker hydroxyapatite (nHA) coatings on Mg alloy by using a simple one-step hydrothermal process in aqueous solution. The nHA coating shows uniform structure and high crystallinity. Results indicate that nHA coating is promising for improving the in vitro corrosion and cytocompatibility properties of Mg-based implants and devices for bone tissue engineering. In addition, the simple hydrothermal deposition method used in the current study is also applicable to substrates with complex shapes or surface geometries.     

Antibacterial and Cellular Behaviors of Novel Zinc-Doped Hydroxyapatite/Graphene Nanocomposite for Bone Tissue Engineering

Bacteria are one of the significant causes of infection in the body after scaffold implantation. Effective use of nanotechnology to overcome this problem is an exciting and practical solution. Nanoparticles can cause bacterial degradation by the electrostatic interaction with receptors and cell walls. Simultaneously, the incorporation of antibacterial materials such as zinc and graphene in nanoparticles can further enhance bacterial degradation. In the present study, zinc-doped hydroxyapatite/graphene was synthesized and characterized as a nanocomposite material possessing both antibacterial and bioactive properties for bone tissue engineering. After synthesizing the zinc-doped hydroxyapatite nanoparticles using a mechanochemical process, they were composited with reduced graphene oxide. The nanoparticles and nanocomposite samples were extensively investigated by transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Their antibacterial behaviors against Escherichia coli and Staphylococcus aureus were studied. The antibacterial properties of hydroxyapatite nanoparticles were found to be improved more than 2.7 and 3.4 times after zinc doping and further compositing with graphene, respectively. In vitro cell assessment was investigated by a cell viability test and alkaline phosphatase activity using mesenchymal stem cells, and the results showed that hydroxyapatite nanoparticles in the culture medium, in addition to non-toxicity, led to enhanced proliferation of bone marrow stem cells. Furthermore, zinc doping in combination with graphene significantly increased alkaline phosphatase activity and proliferation of mesenchymal stem cells. The antibacterial activity along with cell biocompatibility/bioactivity of zinc-doped hydroxyapatite/graphene nanocomposite are the highly desirable and suitable biological properties for bone tissue engineering successfully achieved in this work.     

Antibacterial and Cytocompatible: Combining Silver Nitrate with Strontium Acetate Increases the Therapeutic Window

Microbial infection and insufficient tissue formation are considered to be the two main causes of dental implant failure. Novel studies have focused on designing dual-functional strategies to promote antibacterial properties and improve tissue cell response simultaneously. In this study, we investigated the antibacterial properties and cytocompatibility of silver nitrate (AgNO₃) and strontium acetate (SrAc) in a mono-culture setup for dental application. Additionally, we defined the therapeutic window between the minimum inhibitory concentration against pathogenic bacteria and maximum cytocompatible dose in the case of combined applications in a co-culture setup. Antibacterial properties were screened using Aggregatibacter actinomycetemcomitans and cell response experiments were performed with osteoblastic cells (MC3T3) and fibroblastic cells (NIH3T3). The osteoinductive behavior was investigated separately on MC3T3 cells using alizarin red staining. A therapeutic window for AgNO₃ as well as SrAc applications could be defined in the case of MC3T3 cells while the cytocompatibility of NIH3T3 cells was compromised for all concentrations with an antibacterial effect. However, the combined application of AgNO₃/SrAc caused an enhanced antibacterial effect and opened a therapeutic window for both cell lines. Enhanced mineralization rates could be observed in cultures containing SrAc. In conclusion, we were able to demonstrate that adding SrAc to AgNO₃ not only intensifies antibacterial properties but also exhibits bone inductive characteristics, thereby offering a promising strategy to combat peri-implantitis and at the same time improve osseointegration in implant therapy.     

Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties

Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8–10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.     

羟丙基壳聚糖、壳聚糖铈/银的合成、表征和抗菌性能研究

以壳聚糖和硝酸铈铵为原料,并对壳聚糖进行改性,合成了两种新型的配合物。通过红外光谱、X射线光电子能谱、差热-热重分析、透射电镜等对合成物进行表征。由透射电镜照片发现合成物由分散的纳米颗粒组成。通过抗菌实验对其抑菌效果进行研究,结果表明这两种配合物对大肠杆菌和金黄色葡萄球菌均有较强的抑菌作用,最小抑菌浓度(MIC)分别为130μg/mL,70μg/mL和75μg/mL,60μg/mL,属于广谱抗菌剂,抗菌效果明显优于单独的壳聚糖、羟丙基壳聚糖、稀土化合物。     

聚丙烯基抗菌塑料的制备与性能研究

利用熔融挤出共混技术制备了聚丙烯(PP)基抗菌塑料。研究了抗菌母料Antim-PP对PP的抗菌性能和力学性能的影响。结果表明,当抗菌母料与PP的质量比为4:100时,抗菌PP塑料对大肠杆菌的抗菌率大于99%,抗菌母料的加入使共混物的冲击性能有明显改善,其他力学性能基本不受影响。     

羟基磷灰石空心纳米球的制备及表征

采用WOW复乳法制备羟基磷灰石,内水相为(NH4)2HPO4水溶液,中间油相为易挥发的环己烷,外水相为Ca(NO3)2.4H2O水溶液。分析了反应中传质机理为Ca2+扩散到内水相,在碱性下与内水相的HPO42-反应生成羟基磷灰石。通过XRD、FT-IR、SEM、TEM分析了产物的成分和形貌,证实产物为300nm左右的羟基磷灰石空心球。讨论了反应温度对纳米球形貌的影响,当温度为10℃时发生界面反应,得到空心的纳米球。     

碘化钆与乌洛托品配合物的合成、表征及抗菌活性研究

报道了配合物 Gd I3·C6 H1 2 N4 · HI· 1 4H2 O的新的合成方法 ,通过元素分析、X-射线粉末衍射、红外光谱、质谱、差热 -热重分析 ,确定了配合物的组成和结构 ,首次测定了配体和配合物的抗菌活性     

Synthesis of Antibacterial Hybrid Hydroxyapatite/Collagen/Polysaccharide Bioactive Membranes and Their Effect on Osteoblast Culture

Inspired by the composition and confined environment provided by collagen fibrils during bone formation, this study aimed to compare two different strategies to synthesize bioactive hybrid membranes and to assess the role the organic matrix plays as physical confinement during mineral phase deposition. The hybrid membranes were prepared by (1) incorporating calcium phosphate in a biopolymeric membrane for in situ hydroxyapatite (HAp) precipitation in the interstices of the biopolymeric membrane as a confined environment (Methodology 1) or (2) adding synthetic HAp nanoparticles (SHAp) to the freshly prepared biopolymeric membrane (Methodology 2). The biopolymeric membranes were based on hydrolyzed collagen (HC) and chitosan (Cht) or κ-carrageenan (κ-carr). The hybrid membranes presented homogeneous and continuous dispersion of the mineral particles embedded in the biopolymeric membrane interstices and enhanced mechanical properties. The importance of the confined spaces in biomineralization was confirmed by controlled biomimetic HAp precipitation via Methodology 1. HAp precipitation after immersion in simulated body fluid attested that the hybrid membranes were bioactive. Hybrid membranes containing Cht were not toxic to the osteoblasts. Hybrid membranes added with silver nanoparticles (AgNPs) displayed antibacterial action against different clinically important pathogenic microorganisms. Overall, these results open simple and promising pathways to develop a new generation of bioactive hybrid membranes with controllable degradation rates and antimicrobial properties.     

Chemical Synthesis and Characterization of Novel Antibacterial Polycyclic Polymer

Polyaniline (PAn) and poly(alkyl substituted anilines) were synthesized in aqueous media by chemical polymerization of alkyl substituted aniline in presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, and mechanism of polymerization with scanning electron microscope (SEM), transmission electron microscopy (TEM), fourier transform infrared (FTIR), and UV–visible spectroscopy (UV–vis), respectively. Results indicated that physicochemical properties of poly(alkyl substituted anilines) depend on substituent groups bonded to N-position. In general, alkyl-substituted PAn have similar chemical and optical properties to parent PAn and it seems that the substituted PAn follow the same polymerization mechanism as reported for PAn. The prepared polymers were then tested for the antibacterial properties against Gram-negative bacteria: Escherichia coli (E. coli). The antibacterial properties were assessed by measuring the zones of inhibition. The antimicrobial results showed clearly that PAn and poly(alkyl substituted anilines) exhibited excellent antibacterial activity against the growth of E. coli microorganism.