The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michael J Sailor - One of the best experts on this subject based on the ideXlab platform.
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Gated Luminescence Imaging of Silicon Nanoparticles.
ACS nano, 2015Co-Authors: Jinmyoung Joo, Erkki Ruoslahti, Xiangyou Liu, Venkata Ramana Kotamraju, Yoonkey Nam, Michael J SailorAbstract:The luminescence lifetime of nanocrystalline Silicon is typically on the order of microseconds, significantly longer than the nanosecond lifetimes exhibited by fluorescent molecules naturally present in cells and tissues. Time-gated imaging, where the image is acquired at a time after termination of an excitation pulse, allows discrimination of a Silicon nanoparticle probe from these endogenous signals. Because of the microsecond time scale for Silicon emission, time-gated imaging is relatively simple to implement for this biocompatible and nontoxic probe. Here a time-gated system with ∼10 ns resolution is described, using an intensified CCD camera and pulsed LED or laser excitation sources. The method is demonstrated by tracking the fate of mesoporous Silicon Nanoparticles containing the tumor-targeting peptide iRGD, administered by retro-orbital injection into live mice. Imaging of such systemically administered Nanoparticles in vivo is particularly challenging because of the low concentration of probe in the targeted tissues and relatively high background signals from tissue autofluorescence. Contrast improvements of >100-fold (relative to steady-state imaging) is demonstrated in the targeted tissues.
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In vivo time-gated fluorescence imaging with biodegradable luminescent porous Silicon Nanoparticles
Nature communications, 2013Co-Authors: David J. Hall, Jinmyoung Joo, Zhengtao Qin, Emily Anglin, David J. Mooney, Stephen B. Howell, Michael J SailorAbstract:Fluorescence imaging is one of the most versatile and widely used visualization methods in biomedical research. However, tissue autofluorescence is a major obstacle confounding interpretation of in vivo fluorescence images. The unusually long emission lifetime (5-13 μs) of photoluminescent porous Silicon Nanoparticles can allow the time-gated imaging of tissues in vivo, completely eliminating shorter-lived ( 50-fold in vitro and by >20-fold in vivo when imaging porous Silicon Nanoparticles. Time-gated imaging of porous Silicon Nanoparticles accumulated in a human ovarian cancer xenograft following intravenous injection is demonstrated in a live mouse. The potential for multiplexing of images in the time domain by using separate porous Silicon Nanoparticles engineered with different excited state lifetimes is discussed.
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in vivo time gated fluorescence imaging with biodegradable luminescent porous Silicon Nanoparticles
Nature Communications, 2013Co-Authors: David J. Hall, David J. Mooney, Stephen B. Howell, Luo Gu, Emily J Anglin, Michael J SailorAbstract:Tissue autofluorescence can lead to considerable noise in fluorescence imaging of biological tissues. Here Gu et al. demonstrate that the use of photoluminescent Silicon Nanoparticles with long emission lifetimes enable a late time-gated imaging technique where autofluorescence effects are avoided.
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biodegradable luminescent porous Silicon Nanoparticles for in vivo applications
Nature Materials, 2009Co-Authors: Jiho Park, Erkki Ruoslahti, Geoffrey Von Maltzahn, Sangeeta N Bhatia, Michael J SailorAbstract:Nanomaterials that can cir culate in the body hold great potential to diagnose and treat disease 1‐4 . For such applications, it is important that the nanomaterials be harmlessly eliminated from the body in a reasonable period of time after they carry out their diagnostic or therapeutic function. Despite efforts to improve their targeting efficiency, significant quantities of systemically administered nanomaterials are cleared by the mononuclear phagocytic system before finding their targets, increasing the likelihood of unintended acute or chronic toxicity. However, there has been little effort to engineer the self-destruction of errant Nanoparticles into non-toxic, systemically eliminated products. Here, we present luminescent porous Silicon Nanoparticles (LPSiNPs) that can carry a drug payload and of which the intrinsic near-infrared photoluminescence enables monitoring of both accumulation and degradation in vivo. Furthermore, in contrast to most optically active nanomaterials (carbon nanotubes, gold Nanoparticles and quantum dots), LPSiNPs self-destruct in a mouse model into renally cleared components in a relatively short period of time with no evidence of toxicity. As a preliminary in vivo application, we demonstrate tumour imaging using dextran-coated LPSiNPs (D-LPSiNPs). These results demonstrate a new type of multifunctional nanostructure with a low-toxicity degradation pathway forinvivo applications. The in vivo use of nanomaterials as therapeutic and diagnostic agents is of intense interest owing to their unique properties such as large specific capacity for drug loading 2 , strong superparamagnetism 3 ,efficientphotoluminescence 1,5 ordistinctive Raman signatures 4 , among others. Materials with sizes in the range of 20200nm can avoid renal filtration, leading to prolonged resi
Stephen R Leone - One of the best experts on this subject based on the ideXlab platform.
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characterization of carrier cooling bottleneck in Silicon Nanoparticles by extreme ultraviolet xuv transient absorption spectroscopy
Journal of Physical Chemistry C, 2021Co-Authors: Ilana J Porter, Angela Lee, Scott K Cushing, Hungtzu Chang, Justin C Ondry, Paul A Alivisatos, Stephen R LeoneAbstract:Silicon Nanoparticles have the promise to surpass the theoretical efficiency limit of single-junction Silicon photovoltaics by the creation of a “phonon bottleneck,” a theorized slowing of the cool...
Yi Cui - One of the best experts on this subject based on the ideXlab platform.
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stable li ion battery anodes by in situ polymerization of conducting hydrogel to conformally coat Silicon Nanoparticles
Nature Communications, 2013Co-Authors: Lijia Pan, Nian Liu, Matthew T Mcdowell, Zhenan Bao, Yi CuiAbstract:Nanostructured Silicon is a promising anode material for lithium ion batteries but needs to tolerate large volume increase upon lithiation. Wu et al. solve this problem by binding Silicon Nanoparticles to a conducting polymer hydrogel via in-situ polymerization, which also improves cycling stability.
Luo Gu - One of the best experts on this subject based on the ideXlab platform.
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in vivo time gated fluorescence imaging with biodegradable luminescent porous Silicon Nanoparticles
Nature Communications, 2013Co-Authors: David J. Hall, David J. Mooney, Stephen B. Howell, Luo Gu, Emily J Anglin, Michael J SailorAbstract:Tissue autofluorescence can lead to considerable noise in fluorescence imaging of biological tissues. Here Gu et al. demonstrate that the use of photoluminescent Silicon Nanoparticles with long emission lifetimes enable a late time-gated imaging technique where autofluorescence effects are avoided.
Chongwu Zhou - One of the best experts on this subject based on the ideXlab platform.
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scalable preparation of porous Silicon Nanoparticles and their application for lithium ion battery anodes
Nano Research, 2013Co-Authors: Mingyuan Ge, Jiepeng Rong, Xin Fang, Anyi Zhang, Yunhao Lu, Chongwu ZhouAbstract:Nanostructured Silicon has generated significant excitement for use as the anode material for lithium-ion batteries; however, more effort is needed to produce nanostructured Silicon in a scalable fashion and with good performance. Here, we present a direct preparation of porous Silicon Nanoparticles as a new kind of nanostructured Silicon using a novel two-step approach combining controlled boron doping and facile electroless etching. The porous Silicon Nanoparticles have been successfully used as high performance lithium-ion battery anodes, with capacities around 1,400 mA·h/g achieved at a current rate of 1 A/g, and 1,000 mA·h/g achieved at 2 A/g, and stable operation when combined with reduced graphene oxide and tested over up to 200 cycles. We attribute the overall good performance to the combination of porous Silicon that can accommodate large volume change during cycling and provide large surface area accessible to electrolyte, and reduced graphene oxide that can serve as an elastic and electrically conductive matrix for the porous Silicon Nanoparticles.
