Long-circulating drug carriers are highly desirable in drug delivery system.However,nonspecific protein adsorption leaves a great challenge in drug delivery of intravenous administration and significantly affects both the pharmacokinetic profiles of the carrier and drugs,resulting in negatively affect of therapeutic efficiency.Therefore,it is important to make surface modification of drug carriers by protein-resistant materials to prolong the blood circulation time and increase the targeted accumulation of therapeutic agents.In this review,we highlight the possible mechanism of protein resistance and recent progress of the alternative protein-resistant materials and their drug carriers,such as poly(ethylene glycol),oligo(ethylene glycol),zwitterionic materials,and red blood cells adhesion.
Recently much attention has been paid to the application of metal hybrid nanoparticles in industrial catalytic fields because of their super-efficient catalytic activity and attractive properties. We explored a novel strategy to prepare GSH-capped Pt–Au–Ag-hybrid nanoclusters through the synergistic effect between ascorbic acid(VC) and glutathione(GSH) with chloroplatinic acid, chloroauric acid, and silver nitrate as precursors. The potential utilization of as-prepared GSH-capped Pt–Au–Aghybrid nanoclusters for catalytic applications has been evaluated through the reduction of 4-nitrophenol(4-NP) with NaBH4; we obtained the kinetic data by monitoring with UV-Vis spectroscopy. Our results illustrate that GSH-capped Pt–Au– Ag-hybrid nanoclusters could facilitate the process of reduction of 4-NP in a way that is unprecedented. This approach may offer a novel, non-cytotoxicity, efficient catalyst for industry.
Biocompatible carbon-spheres-based nanocomposites exhibit great potential in biomedical and clinical applications. In this contribution we report the first green photochemical synthesis of carbon spheres through in-situ enwrapping around silver nanoparticles(CS–Ag NPs). Since mesoporous carbon spheres can provide the location for combining Ag NPs and other agents, one-step synthesis of glutathione-stabilized CS–Ag NPs could be readily realized by photoreduction. TEM characterization of CS–Ag NPs nanocomposites illustrates that Ag NPs were superbly wrapped inside the carbon spheres and also adhered to the surfaces of the carbon spheres. These porous CS–Ag NPs show excellent fluorescence and effective antibacterial efficiency, exhibiting ideal lengthened activities against Escherichia coli and Staphylococcus aureus compared with bare Ag NPs. The relevant rationale behind it could be attributed to the fact that CS–Ag NPs nanocomposites can provide some excellent niches for the durable and slow release of silver ions. This raises the possibility of promising applications of CS–Ag NPs nanocomposites as excellent antibacterial agents for the efficient monitoring of some disease-related bacteria.
Wei GeXiaoli LiuJing YeQiwei LiHui JiangXuemei Wang
Alzheimer's disease(AD) is a progressive and age-related irreversible neurodegenerative disease. When AD occurs, the relevant amount of zinc ions in brain considerably changes. In this contribution, we have explored the possibility of in vivo rapid fluorescence imaging of AD through accurate targeting biomarker of zinc gluconate. By using the 3- and 6-month-old Alzheimer's model mice(AD-1) as the experimental models, our observations demonstrate that zinc gluconate molecules could pass through the blood–brain barrier and then produce hippocampus region-specific accumulation of fluorescent zinc nanoclusters in vivo, thus allowing kinetically controlled selective imaging of AD by fluorescence bioimaging.
Lanmei LaiChunqiu ZhaoMeina SuJing YeHui JiangXuemei Wang
The extraction of nucleic acid is recognized as one of the most essential steps in molecular biology for initiating other downstream applications such as sequencing, amplification, hybridization, and cloning. Many commercial kits and methods are currently available that allow the extraction of only one type of nucleic acids-DNA or RNA. However, in parallel clinical detection of several diseases, a method for simultaneous extraction of both DNA and RNA from the same source is needed in such cases. In this study, a method for simultaneous extraction of DNA and RNA from bacteria based on magnetic nanoparticles(MNPs) was described. Lysis buffers were prepared to help the nucleic acid released and adsorbed to MNPs. Then, two washing buffers were used to remove the contamination of proteins and carbohydrates. The nucleic acids were finally eluted by Deoxyribonuclease(DNase) and Ribonucleases(RNase) free water. Different factors which might affect the purification of the nucleic acid were investigated, and the quantity and quality parameters of the nucleic acid were also recorded. The DNA and RNA extracted from bacteria were then respectively subjected to polymerase chain reaction(PCR) and reverse transcription PCR(RT-PCR) to further confirm its quality. The results indicated that our method can be successfully used to simultaneously extract DNA and RNA from bacteria.
目的:探讨CFSE荧光负染法用于检测RAW264.7小鼠单核巨噬细胞白血病细胞吞噬超顺磁性氧化铁纳米粒子(super paramaganetic iron oxide nanoparticles,SPIO)的可行性及其荧光特征。方法:体外对RAW264.7细胞进行SPIO的标记,然后分别采用普鲁士蓝染色方法和CFSE荧光负染法检测RAW264.7细胞对SPIO的摄取情况;用台盼蓝染色法检测CFSE荧光负染细胞的活力;应用激光扫描共聚焦显微镜进行荧光负染法检测RAW264.7细胞对SPIO的摄取。结果:普鲁士蓝将RAW264.7细胞内吞噬的SPIO标记为醒目的蓝色,核固红将细胞核标记为红色,在荧光图像上表现为荧光负染区,呈筛孔状。CFSE荧光负染法与普鲁士蓝染色法的检测结果具有很好的对应性。RAW264.7细胞经过SPIO和CFSE双重标记后,对细胞活力的影响较小,死细胞比例较低。结论:CFSE荧光负染法可用于RAW264.7活细胞吞噬SPIO的检测,同普鲁士蓝染色法具有很好的对应性,两者的检测结果可相互印证。
