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The article presents a simple expression of the power transferred from the electromagnetic field (EMF) to a biological nanomachine (NM) embedded in a background medium (BM). The expression is useful to analyse the interaction mechanism and test the hypothesis on its nature. Furthermore, it should represent a helpful tool to design remotely controlled NMs for bio-medical applications and the relative electromagnetic control apparatuses. Finally, to show its practical usefulness, we used it to discuss the hypothesis on the energy transfer mechanism proposed in the literature to explain intriguing experimental phenomena referring to the remotely controlled dehybridization of DNA molecules attached to gold nanocrystals. 相似文献
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Dong Hwan Wang Jason Seifter Jong Hyeok Park Dae‐Geun Choi Alan J. Heeger 《Liver Transplantation》2012,2(11):1319-1322
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Dong Hwan Wang Jason Seifter Jong Hyeok Park Dae‐Geun Choi Alan J. Heeger 《Liver Transplantation》2012,2(11):1282-1282
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目的 为模拟肌腱组织的显微结构和力学性能,促进肌腱组织的再生修复,制备负载不同质量分数纳米氧化锌且同时具备取向结构的左旋聚乳酸（PLLA）纤维膜,对其进行理化表征和生物性能评价,探讨其对肌腱细胞增殖分化的影响。方法 利用静电纺丝技术制备PLLA纤维支架及含不同质量分数纳米ZnO的PLLA/ZnO纤维支架。通过扫描电镜、力学拉伸、能谱仪（EDS）图谱表征支架的理化性能,并将支架与小鼠肌腱细胞共培养检测其生物相容性及对细胞增殖、分化的调控作用。结果 纤维支架均呈取向性排列,锌元素在纤维中均匀分布,PLLA/0.1%ZnO纤维支架拉伸强度和杨氏模量均显著高于PLLA组。PLLA/0.1%ZnO纤维支架表面细胞数量显著高于PLLA组,且活性更好;小鼠肌腱细胞沿纤维排列方向呈定向性黏附和生长。结论 取向PLLA/0.1%ZnO纤维支架具有优良的理化性能,并可显著促进肌腱细胞定向生长和增殖分化,未来有望用于肌腱组织的再生修复。 相似文献
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Rotaru AE Jiang W Finster K Skrydstrup T Meyer RL 《Biotechnology and bioengineering》2012,109(8):1889-1897
The use of microorganisms as support for reduction of dissolved Pd(II) to immobilized Pd(0) nanoparticles is an environmentally friendly approach for Pd recovery from waste. To better understand and engineer Pd(0) nanoparticle synthesis, one has to consider the mechanisms by which Pd(II) is reduced on microbial surfaces. Escherichia coli, Shewanella oneidensis, and Pseudomonas putida were used as model organisms in order to elucidate the role of microbial cells in Pd(II) reduction under acidic conditions. Pd(II) was reduced by formate under acidic conditions, and the process occurred substantially faster in the presence of cells as compared to cell-free controls. We found no difference between native (untreated) and autoclaved cells, and could demonstrate that even a non-enzymatic protein (bovine serum albumin) stimulated Pd(II) reduction as efficiently as bacterial cells. Amine groups readily interact with Pd(II), and to specifically test their role in surface-assisted Pd(II) reduction by formate, we replaced bacterial cells with polystyrene microparticles functionalized with amine or carboxyl groups. Amine-functionalized microparticles had the same effect on Pd(II) reduction as bacterial cells, and the effect could be hampered if the amine groups were blocked by acetylation. The interaction with amine groups was confirmed by infrared spectroscopy on whole cells and amine-functionalized microparticles. In conclusion, bio-supported Pd(II) reduction on microbial surfaces is possibly mediated by a non-enzymatic mechanism. We therefore suggest the use of amine-rich biomaterials rather than intact cells for Pd bio-recovery from waste. 相似文献
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Engel G. Vrieling Theo P. M. Beelen Rutger A. van Santen Winfried W. C. Gieskes 《Journal of biotechnology》1999,70(1-3):39-51
The demand for new materials and products is still growing and the interest in naturally formed biopolymers and biominerals, such as chitin, calcium precipitates and silica is increasing. Photosynthesizing microalgae of the family Bacillariophyceae (diatoms) produce silica exoskeletons with a potential to be used in specific industrial or technological processes, they also are an excellent model in studies of silicon biomineralization. In contrast to geologically aged diatomaceous earth, the freshly prepared silica of cultured or harvested natural diatoms has been characterized insufficiently with respect to the properties (e.g. purity, specific surface area, porosity) required for technological and industrial application. In this contribution we summarize aspects of cellular processes that are involved in silicon biomineralization of diatoms and the current knowledge of the characterization of diatomaceous silica, following methods used for synthetically derived silica-based materials. 相似文献
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Zhi Chen 《Luminescence》2016,31(4):965-971
Zinc oxide nanoparticles doped with bovine serum albumin were used to determine histidine in aqueous solutions using a fluorescence spectroscopic technique. The results showed that histidine effectively quenched the fluorescence of the modified ZnO nanoparticles, whereas other amino acids did not significantly affect the light emission, thereby allowing selective and sensitive histidine detection in amino acid mixtures. Under optimal conditions (pH 7.0, 25 °C, 10 min preincubation), the detection limit for histidine was ~ 9.87 × 10–7 mol/L. The high value of the determined quenching rate constant Kq (3.30 × 1013 L/mol/s) was consistent with a static quenching mechanism. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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目的:探讨纳米氧化锌经口染毒60 d对C57BL/6J小鼠多种外周脏器的损伤作用。方法:20只雄性C57BL/6J小鼠随机分为对照组和实验组,每组10只,实验组将纳米氧化锌溶液以20 mg/kg体重的剂量连续灌胃染毒60 d,对照组给予相应量的生理盐水;小鼠每周称重一次,染毒结束后,眼球取血,检测血糖、血脂、肝功能和肾功能相关指标,以及血清中炎症因子PAF、IL-6和TNF-α含量;取心脏、肝脏、脾脏、肺、肾脏和小肠组织制备病理切片,HE染色后,观察组织形态学变化。结果:实验组和对照组之间的体重无显著性差异;与正常对照组比较,实验组大鼠血中白蛋白(ALB)、白蛋白/球蛋白比值(A/G)、碱性磷酸酶(ALP)、谷草/谷丙转氨酶比值(S/L)、尿酸(UA)和尿素氮(BUN)含量明显升高(P＜0.05或 P＜0.01);两组间血清中炎症因子含量无显著差异。病理学检查发现,实验组心肌中部分区域出现浊肿,肝脏出现轻度炎性病变(灶性或小灶性坏死),脾脏色素沉着减少,肺部出现轻或中度间质性炎症,肾脏和小肠未见明显病理改变。结论:纳米氧化锌经口染毒60 d未引起C57BL/6J小鼠血液系统炎症,但可诱导心脏、肝脏、脾脏和肺脏出现轻度的病理变化,并导致肝脏和肾脏的功能异常。 相似文献
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S Aravind Kumar s Rajeshkumar SP Saravana Dinesh Ashwin Mathew George Ravindra Kumar Jain 《Bioinformation》2020,16(11):863
The nanoparticles such as hydroxyapatite, zinc oxide, titanium dioxide and zirconium nanoparticles have application in dentistry. Therefore, it is of interest to document the antimicrobial activity of silymarin mediated zinc oxide and hydroxy apatite nanoparticles against oral pathogens. Hence, we synthesized hydroxyapatie and zinc oxide nanoparticles with silymarin and characterized by UV-visible spectrophotometer. Data shows that silymarin mediated HAP and ZnO nanoparticles have antimicrobial activity against oral pathogens such as Pseudomonas sp, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Candida albicans. 相似文献
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The use of bio‐nanotechnology for the fabrication of diverse functional nanomaterials with precisely controlled morphologies and microstructures is attracting considerable attention due to its sustainability and renewability. As one of the key energy storage devices, supercapacitor (SC) requires the active electrode material to have high specific surface area, interconnected porous structure, excellent electronic conductivity, and appropriate heteroatom doping for promoting the transfer of electrons and electrolyte ions. The combination of bio‐technology and SC will open up a new avenue for the large‐scale fabrication of high performance functional energy storage devices. In this review, the most state‐of‐the‐art research progress in bio‐nanotechnological fabrication of different nanomaterials, including carbon materials, metal oxides, conducting polymers, and their corresponding composites are reviewed with the following three bio‐nanotechnical approaches covered: (1) biomass carbonization technologies; (2) bio‐template methods; and (3) bio‐complex technologies, while also highlighting their applications as functional SC electrodes. 相似文献
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Novel luminescent dense nano‐silica hybrid materials (DNSS) modified with different amounts of (3‐aminopropyl)triethoxysilane (APTES) and 1,8‐naphthalic anhydride (NA) were successfully synthesized via two steps combined with post‐grafting methods. Powder X‐ray diffraction (XRD), N2‐sorption analysis, Fourier transform infrared (FT‐IR) spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), photoluminescence (PL) spectroscopy and elemental analysis, as well as time‐resolved decays were employed to characterize the resultant hybrid materials. The results revealed that luminescent organic molecules had been successfully loaded onto the amine‐modified surface of nano‐silica spheres. In addition, their fluorescence intensity and characteristic peak of emission spectra changed with increasing amount of APTES and NA additive. In particular, the characteristic peak showed a red shift from 390 to 450 nm, however, this was inconsistent with results calculated on the basis of the elemental analysis data, most probably because of the dispersion behaviors of NA molecules from the aggregating to the monolayer state. These observations demonstrated the existence of a quantum confinement effectiveness of NA–DNSS samples, and therefore a possible mechanism was put forward. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Hosseinkhani B Søbjerg LS Rotaru AE Emtiazi G Skrydstrup T Meyer RL 《Biotechnology and bioengineering》2012,109(1):45-52
Bimetallic nanoparticles are considered the next generation of nanocatalysts with increased stability and catalytic activity. Bio-supported synthesis of monometallic nanoparticles has been proposed as an environmentally friendly alternative to the conventional chemical and physical protocols. In this study we synthesize bimetallic bio-supported Pd-Au nanoparticles for the first time using microorganisms as support material. The synthesis involved two steps: (1) Formation of monometallic bio-supported Pd(0) and Au(0) nanoparticles on the surface of Cupriavidus necator cells, and (2) formation of bimetallic bio-supported nanoparticles by reduction of either Au(III) or Pd(II) on to the nanoparticles prepared in step one. Bio-supported monometallic Pd(0) or Au(0) nanoparticles were formed on the surface of C. necator by reduction of Pd(II) or Au(III) with formate. Addition of Au(III) or Pd(II) to the bio-supported particles resulted in increased particle size. UV-Vis spectrophotometry and HR-TEM analyses indicated that the previously monometallic nanoparticles had become fully or partially covered by Au(0) or Pd(0), respectively. Furthermore, Energy Dispersive Spectrometry (EDS) and Fast Fourier Transformation (FFT) analyses confirmed that the nanoparticles indeed were bimetallic. The bimetallic nanoparticles did not have a core-shell structure, but were superior to monometallic particles at reducing p-nitrophenol to p-aminophenol. Hence, formation of microbially supported nanoparticles may be a cheap and environmentally friendly approach for production of bimetallic nanocatalysts. 相似文献
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Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early cancer is a great challenge. Herein, we choose the visible‐light emitting zinc oxide non–core/shell type nanoparticle (NP) fluorophores (ZHIE) as prototypical materials. We have reported on these materials previously. The results showed that the ZHIE NPs exhibited good water solubility and good biocompatibility. This study was conducted to investigate the toxicity of ZHIE NPs when intravenously administered to mice repeatedly at the dose required for successful tumor imaging in vivo. Anti‐macrophage‐1 antigen (Mac1), a macrophage differentiation antigen, antibody‐conjugated ZHIE NPs successfully realized targeted imaging of murine macrophage cell line Raw264.7 cells. In conclusion, ZHIE NPs are not toxic in vivo and antibody‐conjugated ZHIE NPs have great potential in applications, such as single cell labeling. 相似文献
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doi: 10.1111/j.1741‐2358.2011.00604.x Effect of the addition of silanated silica on the mechanical properties of microwave heat‐cured acrylic resin Objectives: The purpose of this study was to evaluate fthe flexural strength and Vickers hardness of a microwave energy heat‐cured acrylic resin by adding different concentrations of silane surface‐treated nanoparticle silica. Methods: Acrylic resin specimens with dimensions of 65 × 10 × 2.5 mm were formed and divided into five experimental groups (n = 10) according to the silica concentration added to the acrylic resin mass (weight %) prior to polymerisation : G1, without silica; G2, 0.1% silica; G3, 0.5% silica; G4, 1.0% silica; and G5, 5.0% silica. The specimens were submitted to a three‐point flexural strength test and to the Vickers hardness test (HVN). The data obtained were statistically analysed by anova and the Tukey test (α = 0.05). Results: Regarding flexural strength, G5 differed from the other experimental groups (G1, G2, G3 and G4) presenting the lowest mean, while G4 presented a significantly higher mean, with the exception of group G3. Regarding Vickers hardness, a decrease in values was observed, in which G1 presented the highest hardness compared with the other experimental groups. Conclusion: Incorporating surface‐treated silica resulted in direct benefits in the flexural strength of the acrylic resin activated by microwave energy; however, similar results were not achieved for hardness. 相似文献
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Liubov A. Osminkina Konstantin P. Tamarov Andrey P. Sviridov Rostislav A. Galkin Maxim B. Gongalsky Valery V. Solovyev Andrey A. Kudryavtsev Victor Yu. Timoshenko 《Journal of biophotonics》2012,5(7):529-535
Silicon nanoparticles (SiNPs) obtained by mechanical grinding of porous silicon have been used for visualization of living cells in vitro. It was found that SiNPs could penetrate into the cells without any cytotoxic effect up to the concentration of 100 μg/ml. The cell cytoplasm was observed to be filled by SiNPs, which exhibited bright photoluminescence at 1.6 eV. SiNPs could also act as photosensitizers of the singlet oxygen generation, which could be used in the photodynamic therapy of cancer. These properties of SiNPs are discussed in view of possible applications in theranostics (both in therapy and in diagnostics). (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The DNA delivery to mammalian cells is an essential tool for analyzing gene structure, regulation, and function. The approach holds great promise for the further development of gene therapy techniques and DNA vaccination strategies to treat and control diseases. Here, we report on the establishment of a cell-specific gene delivery and expression system by physical adsorption of a cell-recognition molecule on the nano-crystal surface of carbonate apatite. As a model, DNA/nano-particles were successfully coated with asialofetuin to facilitate uptake by hepatocyte-derived cell lines through the asialoglycoprotein receptor (ASGPr) and albumin to prevent non-specific interactions of the particles with cell-surface. The resulting composite particles with dual surface properties could accelerate DNA uptake and enhance expression to a notable extent. Nano-particles coated with transferrin in the same manner dramatically enhanced transgene expression in the corresponding receptor-bearing cells and thus our newly developed strategy represents a universal phenomenon for anchoring a bio-recognition macromolecule on the apatite crystal surface for targeted gene delivery, having immediate applications in basic research laboratories and great promise for gene therapy. 相似文献
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Nanoparticles: A Light Harvesting Antenna Using Natural Extract Graminoids Coupled with Plasmonic Metal Nanoparticles for Bio‐Photovoltaic Cells (Adv. Energy Mater. 18/2014) 
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下载免费PDF全文 Gede Widia Pratama Adhyaksa Eka Cahya Prima Dong Ki Lee Ilwoo Ock Su Yatman Brian Yuliarto Jeung Ku Kang 《Liver Transplantation》2014,4(18)
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Nanomaterials offer a number of properties that are of interest to the field of neural tissue engineering. Specifically, materials that exhibit nanoscale surface dimensions have been shown to promote neuron function while simultaneously minimizing the activity of cells such as astrocytes that inhibit central nervous system regeneration. Studies demonstrating enhanced neural tissue regeneration in electrical fields through the use of conductive materials have led to interest in piezoelectric materials (or those materials which generate a transient electrical potential when mechanically deformed) such as zinc oxide (ZnO). It has been speculated that ZnO nanoparticles possess increased piezoelectric properties over ZnO micron particles. Due to this promise in neural applications, the objective of the present in vitro study was, for the first time, to assess the activity of astroglial cells on ZnO nanoparticle polymer composites. ZnO nanoparticles embedded in polyurethane were analyzed via scanning electron microscopy to evaluate nanoscale surface features of the composites. The surface chemistry was characterized via X-ray photoelectron spectroscopy. Astroglial cell response was evaluated based on cell adhesion and proliferation. Astrocyte adhesion was significantly reduced on ZnO nanoparticle/polyurethane (PU) composites with a weight ratio of 50:50 (PU:ZnO) wt.%, 75:25 (PU:ZnO) wt.%, and 90:10 (PU:ZnO) wt.% in comparison to pure PU. The successful production of ZnO nanoparticle composite scaffolds suitable for decreasing astroglial cell density demonstrates their potential as a nerve guidance channel material with greater efficiency than what may be available today. 相似文献