Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, ...Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, and remote monitoring. Due to the development of research on nature-inspired bionic structures and the demand for highly efficient, low-cost microfabrication techniques, an understanding of and the ability to replicate the mechanism of structural coloration have become increasingly significant. These sophisticated structures have many unique functions and are used in many applications. Many sensors have been proposed based on their novel structures and unique optical properties. Several of these bio-inspired sensors have been used for infrared radiation/thermal, pH, and vapor techniques, among others, and have been discussed in detail, with an intense focus on several biomedical applications. However, many applications have yet to be discovered. In this review, we will describe these nanostructured materials based on their sources in nature and various structures, such as layered, hierarchical, and helical structures. In addition, we discuss the functions endowed by these structures, such as superhydrophobicity, adhesion, and high strength, enabling them to be employed in a number of applications in biomedical fields, including cell cultivation, biosensors, and tissue engineering.展开更多
Nanomedicine is an emerging field that integrates nanotechnology, biomolecular engineering, life sciences and medicine; it is expected to produce major breakthroughs in medical diagnostics and therapeutics. Due to the...Nanomedicine is an emerging field that integrates nanotechnology, biomolecular engineering, life sciences and medicine; it is expected to produce major breakthroughs in medical diagnostics and therapeutics. Due to the size-compatibility of nano-scale structures and devices with proteins and nucleic acids, the design, synthesis and application of nanoprobes, nanocarders and nanomachines provide unprecedented opportunities for achieving a better control of biological processes, and drastic im- provements in disease detection, therapy, and prevention. Recent advances in nanomedicine include the development of func- tional nanoparticle based molecular imaging probes, nano-structured materials as drug/gene carders for in vivo delivery, and engineered molecular machines for treating single-gene disorders. This review focuses on the development of molecular imag- ing probes and engineered nucleases for nanomedicine, including quantum dot bioconjugates, quantum dot-fluorescent protein FRET probes, molecular beacons, magnetic and gold nanoparticle based imaging contrast agents, and the design and validation of zinc finger nucleases （ZFNs） and TAL effector nucleases （TALENs） for gene targeting. The challenges in translating nano- medicine approaches to clinical applications are discussed.展开更多
Understanding the mechanisms underlying the assembly of nucleobases is a great challenge. The ability to deeply understand how nucleobases interact with themselves as well as with other molecules will allow us to gain...Understanding the mechanisms underlying the assembly of nucleobases is a great challenge. The ability to deeply understand how nucleobases interact with themselves as well as with other molecules will allow us to gain valuable insights into how we might be able to harness these interesting biological molecules to construct complex nanostructures and materials. Uracil and thymine derivatives have been reported for use in biological applications and in self-assembling triple hydrogen bonded systems. Either uracil or thymine possesses three binding sites （Site 1, Site 2, and Site 3） that can induce strong directional N-H...O=C hydrogen bonding interaction. In this paper, theoretical calculations are carded out on the structural features and binding energies of hydrogen-bonded dimers and trimers formed by uracil and thymine bases. We find that the hydrogen bonds formed through Site 1 are the strongest, those formed through Site 3 are next, while those formed through Site 2 are the weakest. The atoms in molecules analysis show that the electron densities at the bond critical points and the corresponding Laplacians have greater values for those hydrogen bonds formed through Site 1 than through Site 2. All these results indicate that a uracil （or thymine） would interact with another uracil or thymine most likely through Site 1 and least likely through Site 2. We also find that a simple summation rule roughly exists for the binding energies in these dimers and trimers.展开更多
Silver nanoparticles （AgNPs） are widely used antimicrobial compounds; however, they may pose a threat to non-targeted bacteria in the environment. In this study high-throughput sequencing was used to investigate the...Silver nanoparticles （AgNPs） are widely used antimicrobial compounds; however, they may pose a threat to non-targeted bacteria in the environment. In this study high-throughput sequencing was used to investigate the effects of different concentrations of AgNPs （10, 50, and 100 mg kg-1） on soil microbial community structure during short-term （7 d） exposure. The amounts of Acidobacteria, Actinobacteria, Cyanobacteria, and Nitrospirae significantly decreased with increasing AgNP concentration; meanwhile, several other phyla （e.g., Proteobacteria and Planctomycetes） increased and dominated. Nitrosomonas europaea, a well-characterized ammonia- oxidizing bacterium, was used to study the sensitivity of bacteria to AgNPs and ionic silver （Ag＋）. Flow cytometry was used to monitor the toxicity of low （1 mg L-l）, middle （10 mg L-l）, and high concentrations （20 mg L-1） of AgNPs, as well as Ag＋ （1 mg L-1） released into the medium from 20 mg L-1 concentration of AgNPs, towards N. europaea. After 12 h of exposure, the survival rate of N. europaea treated with 1 mg L-1 Ag＋ was significantly lower than those treated with low （1 mg L-1） and middle concentrations （10 mg L-1） of AgNPs, but the survival rate in the treatment with high concentration （20 mg L-1） of AgNPs was much lower. Additionally, necrosis rates were higher in the treatment with 20 mg L-1 AgNPs. Electron microscopy showed that Ag＋ caused serious damage to the cell wall of N. europaea, disintegrated the nucleoids, and condensed next to the cell membrane; however, dissolved Ag＋ is only one of the antibacterial mechanisms of AgNPs.展开更多
The controlled synthesis of gold nanocrystals has been the subject of intensive studies for decades because the properties and functions of gold nanomaterials are highly dependent on their particle size, shape, and di...The controlled synthesis of gold nanocrystals has been the subject of intensive studies for decades because the properties and functions of gold nanomaterials are highly dependent on their particle size, shape, and dimensionality. Especially, anisotropic gold nanocrystals, such as nanowires, nanobelts, nanoplates and nanosheets, have attracted much attention due to their striking properties and promising applications in electronics, catalysis, photonics, sensing and biomedicine. In this review, we will summarize the recent developments of one- dimensional （1D） and two-dimensional （2D） gold nanostructures. Various kinds of synthetic methods for preparation of these 1D and 2D gold nanocrystals will be described. Moreover, we will also briefly introduce the properties and potential applications of these 1D and 2D gold nanocrystals.展开更多
基金Acknowledgements We gratefully acknowledge financial support from the Innovative and Entrepreneurial Talent Recruitment Program of Jiangsu Province, the National Natural Science Foundation of China （21405014, 21635001, 21627806 and 21501026）, Key Research and Development Plan of Jiangsu Province BE2016002, the Project of Special Funds of Jiangsu Province for the Transformation of Scientific and Technological Achievements （BA2015067）, the 111 Project （B 17011, Ministry of Education of China）, and the Natural Science Foundation of Jiangsu Province （B K20140626 and B K20140619）. China Postdoctoral Science Foundation funded Project （2017M621597）. The Fundamental Research Funds for the Central Universities （2242018R20011）.
文摘Natural anisotropic nanostructures occurring in several organisms have gained more and more attention because of their obvious advantages in sensitivity, stability, security, miniaturization, portability, online use, and remote monitoring. Due to the development of research on nature-inspired bionic structures and the demand for highly efficient, low-cost microfabrication techniques, an understanding of and the ability to replicate the mechanism of structural coloration have become increasingly significant. These sophisticated structures have many unique functions and are used in many applications. Many sensors have been proposed based on their novel structures and unique optical properties. Several of these bio-inspired sensors have been used for infrared radiation/thermal, pH, and vapor techniques, among others, and have been discussed in detail, with an intense focus on several biomedical applications. However, many applications have yet to be discovered. In this review, we will describe these nanostructured materials based on their sources in nature and various structures, such as layered, hierarchical, and helical structures. In addition, we discuss the functions endowed by these structures, such as superhydrophobicity, adhesion, and high strength, enabling them to be employed in a number of applications in biomedical fields, including cell cultivation, biosensors, and tissue engineering.
基金supported by the National Heart Lung and Blood Institute of the National Institutes of Health(NIH) as a Program of Excellence in Nanotechnology Award(Grant No.HHSN268201000043C to Bao Gang)an NIH Nanomedicine Development Center Award(Grant No.PN2 EY018244 to Bao Gang)
文摘Nanomedicine is an emerging field that integrates nanotechnology, biomolecular engineering, life sciences and medicine; it is expected to produce major breakthroughs in medical diagnostics and therapeutics. Due to the size-compatibility of nano-scale structures and devices with proteins and nucleic acids, the design, synthesis and application of nanoprobes, nanocarders and nanomachines provide unprecedented opportunities for achieving a better control of biological processes, and drastic im- provements in disease detection, therapy, and prevention. Recent advances in nanomedicine include the development of func- tional nanoparticle based molecular imaging probes, nano-structured materials as drug/gene carders for in vivo delivery, and engineered molecular machines for treating single-gene disorders. This review focuses on the development of molecular imag- ing probes and engineered nucleases for nanomedicine, including quantum dot bioconjugates, quantum dot-fluorescent protein FRET probes, molecular beacons, magnetic and gold nanoparticle based imaging contrast agents, and the design and validation of zinc finger nucleases （ZFNs） and TAL effector nucleases （TALENs） for gene targeting. The challenges in translating nano- medicine approaches to clinical applications are discussed.
基金supported by the National Natural Science Foundation of China (20973088)the Educational Department of Liaoning Province (2007T091, 2008T106)
文摘Understanding the mechanisms underlying the assembly of nucleobases is a great challenge. The ability to deeply understand how nucleobases interact with themselves as well as with other molecules will allow us to gain valuable insights into how we might be able to harness these interesting biological molecules to construct complex nanostructures and materials. Uracil and thymine derivatives have been reported for use in biological applications and in self-assembling triple hydrogen bonded systems. Either uracil or thymine possesses three binding sites （Site 1, Site 2, and Site 3） that can induce strong directional N-H...O=C hydrogen bonding interaction. In this paper, theoretical calculations are carded out on the structural features and binding energies of hydrogen-bonded dimers and trimers formed by uracil and thymine bases. We find that the hydrogen bonds formed through Site 1 are the strongest, those formed through Site 3 are next, while those formed through Site 2 are the weakest. The atoms in molecules analysis show that the electron densities at the bond critical points and the corresponding Laplacians have greater values for those hydrogen bonds formed through Site 1 than through Site 2. All these results indicate that a uracil （or thymine） would interact with another uracil or thymine most likely through Site 1 and least likely through Site 2. We also find that a simple summation rule roughly exists for the binding energies in these dimers and trimers.
基金supported by the National Natural Science Foundation of China (No. 41430752)
文摘Silver nanoparticles （AgNPs） are widely used antimicrobial compounds; however, they may pose a threat to non-targeted bacteria in the environment. In this study high-throughput sequencing was used to investigate the effects of different concentrations of AgNPs （10, 50, and 100 mg kg-1） on soil microbial community structure during short-term （7 d） exposure. The amounts of Acidobacteria, Actinobacteria, Cyanobacteria, and Nitrospirae significantly decreased with increasing AgNP concentration; meanwhile, several other phyla （e.g., Proteobacteria and Planctomycetes） increased and dominated. Nitrosomonas europaea, a well-characterized ammonia- oxidizing bacterium, was used to study the sensitivity of bacteria to AgNPs and ionic silver （Ag＋）. Flow cytometry was used to monitor the toxicity of low （1 mg L-l）, middle （10 mg L-l）, and high concentrations （20 mg L-1） of AgNPs, as well as Ag＋ （1 mg L-1） released into the medium from 20 mg L-1 concentration of AgNPs, towards N. europaea. After 12 h of exposure, the survival rate of N. europaea treated with 1 mg L-1 Ag＋ was significantly lower than those treated with low （1 mg L-1） and middle concentrations （10 mg L-1） of AgNPs, but the survival rate in the treatment with high concentration （20 mg L-1） of AgNPs was much lower. Additionally, necrosis rates were higher in the treatment with 20 mg L-1 AgNPs. Electron microscopy showed that Ag＋ caused serious damage to the cell wall of N. europaea, disintegrated the nucleoids, and condensed next to the cell membrane; however, dissolved Ag＋ is only one of the antibacterial mechanisms of AgNPs.
文摘The controlled synthesis of gold nanocrystals has been the subject of intensive studies for decades because the properties and functions of gold nanomaterials are highly dependent on their particle size, shape, and dimensionality. Especially, anisotropic gold nanocrystals, such as nanowires, nanobelts, nanoplates and nanosheets, have attracted much attention due to their striking properties and promising applications in electronics, catalysis, photonics, sensing and biomedicine. In this review, we will summarize the recent developments of one- dimensional （1D） and two-dimensional （2D） gold nanostructures. Various kinds of synthetic methods for preparation of these 1D and 2D gold nanocrystals will be described. Moreover, we will also briefly introduce the properties and potential applications of these 1D and 2D gold nanocrystals.
