The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xiaogang Liu - One of the best experts on this subject based on the ideXlab platform.
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Upconversion Nanoparticle-Mediated Optogenetics.
Advances in experimental medicine and biology, 2021Co-Authors: Angelo H. All, Xiaogang LiuAbstract:Upconversion Nanoparticle-mediated optogenetics enables remote delivery of upconverted visible light from a near-infrared light source to targeted neurons or areas, with the precision of a pulse of laser light in vivo for effective deep-tissue neuromodulation. Compared to conventional optogenetic tools, Upconversion Nanoparticle-based optogenetic techniques are less invasive and cause reduced inflammation with minimal levels of tissue damage. In addition to the optical stimulation, this design offers simultaneously temperature recording in proximity to the stimulated area. This chapter strives to provide life science researchers with an introduction to Upconversion optogenetics, starting from the fundamental concept of photon Upconversion and Nanoparticle fabrication to the current state-of-the-art of surface engineering and device integration for minimally invasive neuromodulation.
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Upconversion Nanoparticle powered microneedle patches for transdermal delivery of sirna
Advanced Healthcare Materials, 2020Co-Authors: Min Wang, Yiyuan Han, Liangliang Liang, Hao Chang, David C Yeo, Christian Wiraja, Mei Ling Wee, Linbo Liu, Xiaogang LiuAbstract:Microneedles (MNs) permit the delivery of nucleic acids like small interfering RNA (siRNA) through the stratum corneum and subsequently into the skin tissue. However, skin penetration is only the first step in successful implementation of siRNA therapy. These delivered siRNAs need to be resistant to enzymatic degradation, enter target cells, and escape the endosome-lysosome degradation axis. To address this challenge, this article introduces a Nanoparticle-embedding MN system that contains a dissolvable hyaluronic acid (HA) matrix and mesoporous silica-coated Upconversion Nanoparticles (UCNPs@mSiO2 ). The mesoporous silica (mSiO2 ) shell is used to load and protect siRNA while the Upconversion Nanoparticle (UCNP) core allows the tracking of MN skin penetration and NP diffusion through Upconversion luminescence imaging or optical coherence tomography (OCT) imaging. Once inserted into the skin, the HA matrix dissolves and UCNPs@mSiO2 diffuse in the skin tissue before entering the cells for delivering the loaded genes. As a proof of concept, this system is used to deliver molecular beacons (MBs) and siRNA targeting transforming growth factor-beta type I receptor (TGF-βRI) that is potentially used for abnormal scar treatment.
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expanding the toolbox of Upconversion Nanoparticles for in vivo optogenetics and neuromodulation
Advanced Materials, 2019Co-Authors: Angelo H. All, Xiao Zeng, Daniel Boon Loong Teh, Ankshita Prasad, Toru Ishizuka, Nitish V Thakor, Yawo Hiromu, Xiaogang LiuAbstract:Optogenetics is an optical technique that exploits visible light for selective neuromodulation with spatio-temporal precision. Despite enormous effort, the effective stimulation of targeted neurons, which are located in deeper structures of the nervous system, by visible light, remains a technical challenge. Compared to visible light, near-infrared illumination offers a higher depth of tissue penetration owing to a lower degree of light attenuation. Herein, an overview of advances in developing new modalities for neural circuitry modulation utilizing Upconversion-Nanoparticle-mediated optogenetics is presented. These developments have led to minimally invasive optical stimulation and inhibition of neurons with substantially improved selectivity, sensitivity, and spatial resolution. The focus is to provide a comprehensive review of the mechanistic basis for evaluating Upconversion parameters, which will be useful in designing, executing, and reporting optogenetic experiments.
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near infrared deep brain stimulation via Upconversion Nanoparticle mediated optogenetics
Optical Biopsy XVII: Toward Real-Time Spectroscopic Imaging and Diagnosis, 2019Co-Authors: Shuo Chen, Xiaogang Liu, Thomas J MchughAbstract:Optogenetic stimulation of neurons, driven by the development of light-gated rhodopsins, has revolutionized the experimental interrogation of neural circuits and holds promise for next-generation treatment of neurological disorders. However, it is limited by the inability of visible light to penetrate deep inside brain tissue. Optical stimulation of deep brain neurons, for example, has hitherto required the insertion of invasive optical fibers because the activating blue-green wavelengths are strongly scattered and absorbed by endogenous chromophores. Red-shifted variants of rhodopsins have been developed, but their action spectra still fall out of the near-infrared (NIR) optical window (650-1350 nm) where light has its maximal depth of penetration in brain tissue. Here, we developed a novel approach for NIR optogenetics, where lanthanide-doped Upconversion nanocrystals (UCNPs) were used to absorb tissue-penetrating 980 nm NIR and emit visible light for rhodopsin activation. Due to lanthanides’ ladder-like electronic energy structure, the emission of UCNPs can be precisely tuned to a particular wavelength by control of energy transfer via selective lanthanide-ion doping. For instance, incorporation of Tm3+ into Yb3+ doped host lattices leads to blue emission (~470 nm) that matches the maximum absorption of channelrhodopsin-2 (ChR2) for neuronal activation, while the Yb3+/Er3+ couple emits green light (~540 nm) compatible with activation of halorhodopsin (NpHR) or archaerhodopsin (Arch) for neuronal inhibition. We demonstrated that molecularly tailored UCNPs could serve as optogenetic actuators of transcranial NIR to functionally stimulate deep brain neurons in mice. Transcranial NIR UCNP-mediated optogenetics evoked dopamine release from genetically tagged neurons in the ventral tegmental area, induced brain oscillations via activation of inhibitory neurons in the medial septum, silenced seizure via inhibition of excitatory cells in the hippocampus, and triggered memory recall via excitation of a hippocampal engram. UCNP technology would open the door to less-invasive optical neuronal activity manipulation with the potential for remote therapy.
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thiazole derivative modified Upconversion Nanoparticles for hg 2 detection in living cells
Nanoscale, 2016Co-Authors: Yi Zhou, Xiao Zhang, Xiaowang Liu, Yuhai Zhang, Robert S Marks, Hua Zhang, Xiaogang Liu, Qichun ZhangAbstract:Mercury ion (Hg2+) is an extremely toxic ion, which will accumulate in human bodies and cause severe nervous system damage. Therefore, the sensitive and efficient monitoring of Hg2+ in human bodies is of great importance. Upconversion Nanoparticle (UCNPs) based nano probes exhibit no autofluorescence, deep penetration depth and chemical stability in biological samples, as well as a large anti-stokes shift. In this study, we have developed thiazole-derivative-functionalized UCNPs, and employed an Upconversion emission intensity ratio of 540 nm to 803 nm (I540/I803) as a ratiometric signal to detect Hg2+ in living cells showing excellent photo stability and high selectivity. Our nano probe was characterized using transmission electron microscopy (TEM) and powder X-ray diffraction (PXRD). The low cytotoxicity of our probe was confirmed by an MTT assay and the UCL test in HeLa cells was carried out by confocal microscopy. Our results demonstrated that organic-dye-functionalized UCNPs should be a good strategy for detecting toxic metal ions when studying cellular biosystems.
Fan Zhang - One of the best experts on this subject based on the ideXlab platform.
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near infrared triggered azobenzene liposome Upconversion Nanoparticle hybrid vesicles for remotely controlled drug delivery to overcome cancer multidrug resistance
Advanced Materials, 2016Co-Authors: Chi Yao, Peiyuan Wang, Junli Hou, Leyong Wang, Fan ZhangAbstract:Overcoming multidrug resistance is achieved by developing a novel drugdelivery-system paradigm based on azobenzene liposome and phosphatidylcholine-modified Upconversion Nanoparticle (UCNP) hybrid vesicles for controlled drug release using a nearinfrared (NIR) laser. Upon 980 nm light irradiation, the reversible photoisomerization of the azobenzene derivatives by simultaneous UV and visible light emitted from the UCNPs makes it possible to realize NIR-triggered release of the chemotherapeutic drug doxorubicin.
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bioapplications and biotechnologies of Upconversion Nanoparticle based nanosensors
Analyst, 2016Co-Authors: Chengli Wang, Xiaomin Li, Fan ZhangAbstract:Upconversion Nanoparticles (UCNPs), which can emit ultraviolet/visible (UV/Vis) light under near-infrared (NIR) excitation, are regarded as a new generation of nanoprobes because of their unique optical properties, including a virtually zero auto-fluorescence background for the improved signal-to-noise ratio, narrow emission bandwidths and high resistance to photo-bleaching. These properties make UCNPs promising candidates as luminescent bioprobes in biomedicine and biotechnology. In this review, we focus on the recent progress in the development of UCNP-based nanoprobes for biosensing. Firstly, as the FRET process is a widely used method for biosensing to improve the sensitivity, we summarize recent research studies about UCNP-based nanocomposites utilizing the FRET process for biosensing. Different energy acceptors (organic dyes, noble metal Nanoparticles, carbon nanomaterials and semiconductor nanomaterials) with their own advantages and limitations are well summarized in this review. Secondly, since UCNPs have been utilized for the detection of different kinds of analytes, we introduce recent research studies about UCNPs for ions, gas molecules, biomolecules and thermal sensing. Finally, we highlight the typical detection techniques and UCNP based devices for bioapplications.
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single band Upconversion nanoprobes for multiplexed simultaneous in situ molecular mapping of cancer biomarkers
Nature Communications, 2015Co-Authors: Lei Zhou, Chengli Wang, Chi Yao, Rui Wang, Xiaoyan Zhang, Aijun Zeng, Dongyuan Zhao, Fan ZhangAbstract:The identification of potential diagnostic markers and target molecules among the plethora of tumour oncoproteins for cancer diagnosis requires facile technology that is capable of quantitatively analysing multiple biomarkers in tumour cells and tissues. Diagnostic and prognostic classifications of human tumours are currently based on the western blotting and single-colour immunohistochemical methods that are not suitable for multiplexed detection. Herein, we report a general and novel method to prepare single-band Upconversion Nanoparticles with different colours. The expression levels of three biomarkers in breast cancer cells were determined using single-band Upconversion Nanoparticles, western blotting and immunohistochemical technologies with excellent correlation. Significantly, the application of antibody-conjugated single-band Upconversion Nanoparticle molecular profiling technology can achieve the multiplexed simultaneous in situ biodetection of biomarkers in breast cancer cells and tissue specimens and produce more accurate results for the simultaneous quantification of proteins present at low levels compared with classical immunohistochemical technology.
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Upconversion Nanoparticle based nanocomposites
2015Co-Authors: Fan ZhangAbstract:In recent years, the development of multi-functional nanomaterials with fantastic physical, chemical, and biological properties has become an attractive research topic, demonstrating high potential in biomedicine, catalysis, energy conversion, water treatment adsorbents, and so on. As one of the most important luminescence nanomaterials, Upconversion Nanoparticles (UCNPs) were also used to fabricate multi-functional nanocomposites (UCNPs-X). In this chapter, we summarize recent advanced Upconversion Nanoparticles-based nanocomposites, including UCNPs-mSiO2 (mSiO2 = mesoporous SiO2), UCNPs-MNPs (MNPs = magnetic Nanoparticles), UCNPs-metal, and UCNPs-semiconductor nanocomposites.
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anisotropic growth induced synthesis of dual compartment janus mesoporous silica Nanoparticles for bimodal triggered drugs delivery
Journal of the American Chemical Society, 2014Co-Authors: Lei Zhou, Fan Zhang, Yong Wei, Ahmed Mohamed Eltoni, Dongyuan ZhaoAbstract:Multifunctional dual-compartment Janus mesoporous silica nanocomposites of UCNP@SiO2@mSiO2&PMO (UCNP = Upconversion Nanoparticle, PMO = periodic mesoporous organosilica) containing core@shell@shell structured UCNP@SiO2@mSiO2 nanospheres and PMO single-crystal nanocubes have been successfully synthesized via a novel anisotropic island nucleation and growth approach with the ordered mesostructure. The asymmetric Janus nanocomposites show a very uniform size of ~300 nm and high surface area of ~1290 m(2)/g. Most importantly, the Janus nanocomposites possess the unique dual independent mesopores with different pore sizes (2.1 nm and 3.5-5.5 nm) and hydrophobicity/hydrophilicity for loading of multiple guests. The distinct chemical properties of the silica sources and the different mesostructures of the dual-compartments are the necessary prerequisites for the formation of the Janus nanostructure. With the assistance of the near-infrared (NIR) to ultraviolet/visible (UV-vis) optical properties of UCNPs and heat-sensitive phase change materials, the dual-compartment Janus mesoporous silica nanocomposites can be further applied into nanobiomedicine for heat and NIR light bimodal-triggered dual-drugs controllable release. It realizes significantly higher efficiency for cancer cell killing (more than 50%) compared to that of the single-triggered drugs delivery system (~25%).
Angelo H. All - One of the best experts on this subject based on the ideXlab platform.
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Upconversion Nanoparticle-Mediated Optogenetics.
Advances in experimental medicine and biology, 2021Co-Authors: Angelo H. All, Xiaogang LiuAbstract:Upconversion Nanoparticle-mediated optogenetics enables remote delivery of upconverted visible light from a near-infrared light source to targeted neurons or areas, with the precision of a pulse of laser light in vivo for effective deep-tissue neuromodulation. Compared to conventional optogenetic tools, Upconversion Nanoparticle-based optogenetic techniques are less invasive and cause reduced inflammation with minimal levels of tissue damage. In addition to the optical stimulation, this design offers simultaneously temperature recording in proximity to the stimulated area. This chapter strives to provide life science researchers with an introduction to Upconversion optogenetics, starting from the fundamental concept of photon Upconversion and Nanoparticle fabrication to the current state-of-the-art of surface engineering and device integration for minimally invasive neuromodulation.
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expanding the toolbox of Upconversion Nanoparticles for in vivo optogenetics and neuromodulation
Advanced Materials, 2019Co-Authors: Angelo H. All, Xiao Zeng, Daniel Boon Loong Teh, Ankshita Prasad, Toru Ishizuka, Nitish V Thakor, Yawo Hiromu, Xiaogang LiuAbstract:Optogenetics is an optical technique that exploits visible light for selective neuromodulation with spatio-temporal precision. Despite enormous effort, the effective stimulation of targeted neurons, which are located in deeper structures of the nervous system, by visible light, remains a technical challenge. Compared to visible light, near-infrared illumination offers a higher depth of tissue penetration owing to a lower degree of light attenuation. Herein, an overview of advances in developing new modalities for neural circuitry modulation utilizing Upconversion-Nanoparticle-mediated optogenetics is presented. These developments have led to minimally invasive optical stimulation and inhibition of neurons with substantially improved selectivity, sensitivity, and spatial resolution. The focus is to provide a comprehensive review of the mechanistic basis for evaluating Upconversion parameters, which will be useful in designing, executing, and reporting optogenetic experiments.
Shaoqin Gong - One of the best experts on this subject based on the ideXlab platform.
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nir induced spatiotemporally controlled gene silencing by Upconversion Nanoparticle based sirna nanocarrier
Journal of Controlled Release, 2017Co-Authors: Guojun Chen, Ruosen Xie, Yuyuan Wang, Kefeng Dou, Shaoqin GongAbstract:Spatiotemporal control over the release or activation of biomacromolecules such as siRNA remains a significant challenge. Light-controlled release has gained popularity in recent years; however, a major limitation is that most photoactivable compounds/systems respond only to UV irradiation, but not near-infrared (NIR) light that offers a deeper tissue penetration depth and better biocompatibility. This paper reports a simple NIR-to-UV Upconversion Nanoparticle (UCNP)-based siRNA nanocarrier for NIR-controlled gene silencing. siRNA is complexed onto a NaYF4:Yb/Tm/Er UCNP through an azobenzene (Azo)-cyclodextrin (CD) host-guest interaction. The UV emission generated by the NIR-activated UCNP effectively triggers the trans-to-cis photoisomerization of azobenzene, thus leading to the release of siRNA due to unmatched host-guest pairs. The UCNP-siRNA complexes are also functionalized with PEG (i.e., UCNP-(CD/Azo)-siRNA/PEG NPs), targeting ligands (i.e., EGFR-specific GE11 peptide), acid-activatable cell-penetrating peptides (i.e., TH peptide), and imaging probes (i.e., Cy5 fluorophore). The UCNP-(CD/Azo)-siRNA/PEG NPs with both GE11 and TH peptides display a high level of cellular uptake and an excellent endosomal/lysosomal escape capability. More importantly, NIR-controlled spatiotemporal knockdown of GFP expression is successfully achieved in both a 2D monolayer cell model and a 3D multicellular tumor spheroid model. Thus, this simple and versatile nanoplatform has great potential for the selective activation or release of various biomacromolecules.
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neuroendocrine tumor targeted Upconversion Nanoparticle based micelles for simultaneous nir controlled combination chemotherapy and photodynamic therapy and fluorescence imaging
Advanced Functional Materials, 2017Co-Authors: Guojun Chen, Renata Jaskulasztul, Corinne R Esquibel, Qifeng Zheng, Ajitha Dammalapati, April D Harrison, Kevin W Eliceiri, Weiping Tang, Herbert Chen, Shaoqin GongAbstract:Although neuroendocrine tumors (NETs) are slow growing, they are frequently metastatic at the time of discovery and no longer amenable to curative surgery, emphasizing the need for the development of other treatments. In this study, multifunctional Upconversion Nanoparticle (UCNP)-based theranostic micelles are developed for NET-targeted and near-infrared (NIR)-controlled combination chemotherapy and photodynamic therapy (PDT), and bioimaging. The theranostic micelle is formed by individual UCNP functionalized with light-sensitive amphiphilic block copolymers poly(4,5-dimethoxy-2-nitrobenzyl methacrylate)-polyethylene glycol (PNBMA-PEG) and Rose Bengal (RB) photosensitizers. A hydrophobic anticancer drug, AB3, is loaded into the micelles. The NIR-activated UCNPs emit multiple luminescence bands, including UV, 540 nm, and 650 nm. The UV peaks overlap with the absorption peak of photocleavable hydrophobic PNBMA segments, triggering a rapid drug release due to the NIR-induced hydrophobic-to-hydrophilic transition of the micelle core and thus enabling NIR-controlled chemotherapy. RB molecules are activated via luminescence resonance energy transfer to generate 1O2 for NIR-induced PDT. Meanwhile, the 650 nm emission allows for efficient fluorescence imaging. KE108, a true pansomatostatin nonapeptide, as an NET-targeting ligand, drastically increases the tumoral uptake of the micelles. Intravenously injected AB3-loaded UCNP-based micelles conjugated with RB and KE108—enabling NET-targeted combination chemotherapy and PDT—induce the best antitumor efficacy.
Yong Zhang - One of the best experts on this subject based on the ideXlab platform.
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core shell Upconversion Nanoparticle semiconductor heterostructures for photodynamic therapy
Scientific Reports, 2015Co-Authors: Qingqing Dou, Adith Rengaramchandran, Subramanian Tamil Selvan, Ramasamy Paulmurugan, Yong ZhangAbstract:Core-shell Nanoparticles (CSNPs) with diverse chemical compositions have been attracting greater attention in recent years. However, it has been a challenge to develop CSNPs with different crystal structures due to the lattice mismatch of the nanocrystals. Here we report a rational design of core-shell heterostructure consisting of NaYF4:Yb,Tm Upconversion Nanoparticle (UCN) as the core and ZnO semiconductor as the shell for potential application in photodynamic therapy (PDT). The core-shell architecture (confirmed by TEM and STEM) enables for improving the loading efficiency of photosensitizer (ZnO) as the semiconductor is directly coated on the UCN core. Importantly, UCN acts as a transducer to sensitize ZnO and trigger the generation of cytotoxic reactive oxygen species (ROS) to induce cancer cell death. We also present a firefly luciferase (FLuc) reporter gene based molecular biosensor (ARE-FLuc) to measure the antioxidant signaling response activated in cells during the release of ROS in response to the exposure of CSNPs under 980 nm NIR light. The breast cancer cells (MDA-MB-231 and 4T1) exposed to CSNPs showed significant release of ROS as measured by aminophenyl fluorescein (APF) and ARE-FLuc luciferase assays, and ~45% cancer cell death as measured by MTT assay, when illuminated with 980 nm NIR light.
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Upconversion Nanoparticle based lret system for sensitive detection of mrsa dna sequence
Biosensors and Bioelectronics, 2013Co-Authors: Jinliang Liu, Jinting Cheng, Yong ZhangAbstract:In this short communication we report an efficient and versatile method for the detection of methicillin-resistant staphylococcus aureus (MRSA) DNA sequence with high sensitivity and specificity. This method is based on Upconversion Nanoparticles (UCNs) and luminescence resonance energy transfer (LRET) between NaYF4:Yb, Er UCNs, the energy donor, and carboxytetramethylrhodamine (TAMRA), the energy acceptor. The NaYF4:Yb, Er UCNs were prepared with citrate capping thus dispersible in aqueous solutions. MRSA capture oligonucleotides were covalently immobilized onto the surface of the UCNs. TAMRA labeled MRSA DNA report oligonucleotides were brought close to the UCNs upon sandwich hybridization between the capture and report oligonucleotides and a long MRSA target DNA, resulting in an efficient LRET. Specific detection of MRSA DNA sequences with a detection limit as low as 0.18nM was achieved using this method. To the best of our knowledge, this is the first report to detect MRSA DNA sequence by using UCNs as energy donor through an efficient LRET process.
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Upconversion Nanoparticle based fret system for study of sirna in live cells
Langmuir, 2010Co-Authors: Shan Jiang, Yong ZhangAbstract:Investigation of the intracellular fate of small interference RNA (siRNA), after their delivery into cells by Nanoparticles, is of great interest to the development of more efficient methods for transfection of siRNA. The fluorescence resonance energy transfer (FRET) based method using Upconversion fluorescent Nanoparticles (UCN) as energy donor is established to study intracellular release and biostability of siRNA in live cells. The UCN/siRNA-BOBO3 complex is prepared where BOBO-3-stained siRNAs are attached to the surface of amino-group-modified silica/NaYF4:Yb,Er UCN. The energy is transferred from the UCN donor to the BOBO-3 acceptor under excitation of a near-infrared (NIR) laser. The FRET efficiency is established as a reliable parameter to follow the release and biostability of siRNA in phosphate buffered saline (PBS) and live cells. Intracellular FRET analysis shows that siRNA is gradually released into cells for a duration of 24 h, which is confirmed by confocal microscopy colocalization measure...
