Publications by authors named "Chiung-Wen Kuo"

41 Publications

Immune cell shuttle for precise delivery of nanotherapeutics for heart disease and cancer.

Sci Adv 2021 Apr 23;7(17). Epub 2021 Apr 23.

Ph.D. Program in Translational Medicine, National Taiwan University and Academia Sinica, Taipei, Taiwan.

The delivery of therapeutics through the circulatory system is one of the least arduous and less invasive interventions; however, this approach is hampered by low vascular density or permeability. In this study, by exploiting the ability of monocytes to actively penetrate into diseased sites, we designed aptamer-based lipid nanovectors that actively bind onto the surface of monocytes and are released upon reaching the diseased sites. Our method was thoroughly assessed through treating two of the top causes of death in the world, cardiac ischemia-reperfusion injury and pancreatic ductal adenocarcinoma with or without liver metastasis, and showed a significant increase in survival and healing with no toxicity to the liver and kidneys in either case, indicating the success and ubiquity of our platform. We believe that this system provides a new therapeutic method, which can potentially be adapted to treat a myriad of diseases that involve monocyte recruitment in their pathophysiology.
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http://dx.doi.org/10.1126/sciadv.abf2400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8064633PMC
April 2021

Evaluation of Nanoparticle Penetration in the Tumor Spheroid Using Two-Photon Microscopy.

Biomedicines 2020 Dec 24;9(1). Epub 2020 Dec 24.

Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.

Mesoporous silica nanoparticles (MSNs) have emerged as a prominent nanomedicine platform, especially for tumor-related nanocarrier systems. However, there is increasing concern about the ability of nanoparticles (NPs) to penetrate solid tumors, resulting in compromised antitumor efficacy. Because the physicochemical properties of NPs play a significant role in their penetration and accumulation in solid tumors, it is essential to systematically study their relationship in a model system. Here, we report a multihierarchical assessment of the accumulation and penetration of fluorescence-labeled MSNs with nine different physicochemical properties in tumor spheroids using two-photon microscopy. Our results indicated that individual physicochemical parameters separately could not define the MSNs' ability to accumulate in a deeper tumor region; their features are entangled. We observed that the MSNs' stability determined their success in reaching the hypoxia region. Moreover, the change in the MSNs' penetration behavior postprotein crowning was associated with both the original properties of NPs and proteins on their surfaces.
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http://dx.doi.org/10.3390/biomedicines9010010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7824314PMC
December 2020

Recent advances in the use of fluorescent nanoparticles for bioimaging.

Nanomedicine (Lond) 2019 07 12;14(13):1759-1769. Epub 2019 Jul 12.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.

Rapid and recent progress in fluorescence microscopic techniques has allowed for routine discovery and viewing of biological structures and processes in unprecedented spatiotemporal resolution. In these imaging techniques, fluorescent nanoparticles (NPs) play important roles in the improvement of reporting systems. A short overview of recently developed fluorescent NPs used for advanced imaging will be discussed in this mini-review. The discussion begins with the contribution of fluorescence imaging in exploring the fate of NPs in biological systems. NP applications for imaging, including cell labeling, multimodal imaging and theranostic agents, are then discussed. Finally, despite all of the advancements in bioimaging, some unsolved challenges will be briefly discussed concerning future research directions.
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http://dx.doi.org/10.2217/nnm-2019-0105DOI Listing
July 2019

Organic Electrochemical Transistors/SERS-Active Hybrid Biosensors Featuring Gold Nanoparticles Immobilized on Thiol-Functionalized PEDOT Films.

Front Chem 2019 26;7:281. Epub 2019 Apr 26.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.

In this study we immobilized gold nanoparticles (AuNPs) onto thiol-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films as bioelectronic interfaces (BEIs) to be integrated into organic electrochemical transistors (OECTs) for effective detection of dopamine (DA) and also as surface-enhanced Raman scattering (SERS)-active substrates for the selective detection of -cresol (PC) in the presence of multiple interferers. This novel PEDOT-based BEI device platform combined (i) an underlying layer of polystyrenesulfonate-doped PEDOT (PEDOT:PSS), which greatly enhanced the transconductance and sensitivity of OECTs for electrochemical sensing of DA in the presence of other ascorbic acid and uric acid metabolites, as well as amperometric response toward DA with a detection limit (S/N = 3) of 37 nM in the linear range from 50 nM to 100 μM; with (ii) a top interfacial layer of AuNP-immobilized three-dimensional (3D) thiol-functionalized PEDOT, which not only improved the performance of OECTs for detecting DA, due to the signal amplification effect of the AuNPs with high catalytic activity, but also enabled downstream analysis (SERS detection) of PC on the same chip. We demonstrate that PEDOT-based 3D OECT devices decorated with a high-density of AuNPs can display new versatility for the design of next-generation biosensors for point-of-care diagnostics.
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http://dx.doi.org/10.3389/fchem.2019.00281DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6498878PMC
April 2019

Lightsheet localization microscopy enables fast, large-scale, and three-dimensional super-resolution imaging.

Commun Biol 2019 9;2:177. Epub 2019 May 9.

1Research Center for Applied Sciences, Academia Sinica, Taipei, 11529 Taiwan.

Recent advances in super-resolution microscopy allow the localization of single molecules within individual cells but not within multiple whole cells due to weak signals from single molecules and slow acquisition process for point accumulation to reconstruct super-resolution images. Here, we report a fast, large-scale, and three-dimensional super-resolution fluorescence microscope based on single-wavelength Bessel lightsheet to selectively illuminate spontaneous blinking fluorophores tagged to the proteins of interest in space. Critical parameters such as labeling density, excitation power, and exposure time were systematically optimized resulting in a maximum imaging speed of 2.7 × 10 µm s. Fourier ring correlation analysis revealed a reconstructed image with a lateral resolution of ~75 nm through the accumulation of 250 image volumes on immobilized samples within 15 min. Hence, the designed system could open new insights into the discovery of complex biological structures and live 3D localization imaging.
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http://dx.doi.org/10.1038/s42003-019-0403-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6509110PMC
April 2020

Correlational Study of Nonalcoholic Fatty Liver Disease Diagnosed by Ultrasonography with Lipid Profile and Body Mass Index in Adult Nepalese Population.

J Med Ultrasound 2019 Jan-Mar;27(1):19-25. Epub 2018 Dec 5.

Department of Medical Imaging and Radiological Technology, Yuanpei University of Medical Technology, Hsinchu, Taiwan.

Objective: The purpose of this study was to categorize patients into different grades of nonalcoholic fatty liver disease (NAFLD) by ultrasonography and to compare the findings with their serum lipid profile.

Materials And Methods: Descriptive, cross-sectional study design was used. One hundred and nine patients without a history of alcohol consumption of age more than 16 years attending general health checkup were selected at Tribhuvan University Teaching Hospital, Maharajganj, Kathmandu, as per the exclusion and inclusion criteria. Ultrasound scanning of the patients was done and their liver size, as well as grading of fatty liver, was done. Data were collected in predesigned pro forma and were analyzed using Statistical Package for the Social Sciences (SPSS) 16.0, IBM (SPSS Inc., Chicago, IL).

Results: In this study, the mean age of fatty liver in males was found to be 44.3 years and in females was found to be 51.9 years. 22.9% of patients with NAFLD had increased liver size. Significant association with increasing grades of fatty liver was found with increasing levels of cholesterol ( = 0.028), low-density lipoprotein (LDL) ( = 0.017), liver size ( = 0.001), and body mass index (BMI) ( = 0.045) in patients diagnosed with NAFLD. No significant association with increasing grades of fatty liver was found with increasing levels of triglyceride ( = 0.32) and high-density lipoprotein ( = 0.25).

Conclusion: Ultrasound is a safe and first-line modality for the evaluation of fatty liver and its grading. Increasing grades of fatty liver had significant association with increasing levels of cholesterol LDL, increasing liver size, and BMI of patients.
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http://dx.doi.org/10.4103/JMU.JMU_53_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445041PMC
December 2018

Signaling pathway of globo-series glycosphingolipids and β1,3-galactosyltransferase V (β3GalT5) in breast cancer.

Proc Natl Acad Sci U S A 2019 02 11;116(9):3518-3523. Epub 2019 Feb 11.

Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan;

The globo-series glycosphingolipids (GSLs) SSEA3, SSEA4, and Globo-H specifically expressed on cancer cells are found to correlate with tumor progression and metastasis, but the functional roles of these GSLs and the key enzyme β1,3-galactosyltransferase V (β3GalT5) that converts Gb4 to SSEA3 remain largely unclear. Here we show that the expression of β3GalT5 significantly correlates with tumor progression and poor survival in patients, and the globo-series GSLs in breast cancer cells form a complex in membrane lipid raft with caveolin-1 (CAV1) and focal adhesion kinase (FAK) which then interact with AKT and receptor-interacting protein kinase (RIP), respectively. Knockdown of β3GalT5 disrupts the complex and induces apoptosis through dissociation of RIP from the complex to interact with the Fas death domain (FADD) and trigger the Fas-dependent pathway. This finding provides a link between SSEA3/SSEA4/Globo-H and the FAK/CAV1/AKT/RIP complex in tumor progression and apoptosis and suggests a direction for the treatment of breast cancer, as demonstrated by the combined use of antibodies against Globo-H and SSEA4.
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http://dx.doi.org/10.1073/pnas.1816946116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6397564PMC
February 2019

Random and aligned electrospun PLGA nanofibers embedded in microfluidic chips for cancer cell isolation and integration with air foam technology for cell release.

J Nanobiotechnology 2019 Feb 19;17(1):31. Epub 2019 Feb 19.

Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.

Background: Circulating tumor cells (CTCs) comprise the high metastatic potential population of cancer cells in the blood circulation of humans; they have become the established biomarkers for cancer diagnosis, individualized cancer therapy, and cancer development. Technologies for the isolation and recovery of CTCs can be powerful cancer diagnostic tools for liquid biopsies, allowing the identification of malignancies and guiding cancer treatments for precision medicine.

Methods: We have used an electrospinning process to prepare poly(lactic-co-glycolic acid) (PLGA) nanofibrous arrays in random or aligned orientations on glass slips. We then fabricated poly(methyl methacrylate) (PMMA)-based microfluidic chips embedding the PLGA nanofiber arrays and modified their surfaces through sequential coating with using biotin-(PEG)-amine through EDC/NHS activation, streptavidin (SA), and biotinylated epithelial-cell adhesion-molecule antibody (biotin-anti-EpCAM) to achieve highly efficient CTC capture. When combined with an air foam technology that induced a high shear stress and, thereby, nondestructive release of the captured cells from the PLGA surfaces, the proposed device system operated with a high cell recovery rate.

Results: The morphologies and average diameters of the electrospun PLGA nanofibers were characterized using scanning electron microscopy (SEM) and confocal Raman imaging. The surface chemistry of the PLGA nanofibers conjugated with the biotin-(PEG)-amine was confirmed through time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging. The chip system was studied for the effects of the surface modification density of biotin-(PEG)-amine, the flow rates, and the diameters of the PLGA nanofibers on the capture efficiency of EpCAM-positive HCT116 cells from the spiked liquid samples. To assess their CTC capture efficiencies in whole blood samples, the aligned and random PLGA nanofiber arrays were tested for their abilities to capture HCT116 cells, providing cancer cell capture efficiencies of 66 and 80%, respectively. With the continuous injection of air foam into the microfluidic devices, the cell release efficiency on the aligned PLGA fibers was 74% (recovery rate: 49%), while it was 90% (recovery rate: 73%) on the random PLGA fibers, from tests of 200 spiked cells in 2 mL of whole blood from healthy individuals. Our study suggests that integrated PMMA microfluidic chips embedding random PLGA nanofiber arrays may be suitable devices for the efficient capture and recovery of CTCs from whole blood samples.
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http://dx.doi.org/10.1186/s12951-019-0466-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6379968PMC
February 2019

Real-time in vivo imaging of subpopulations of circulating tumor cells using antibody conjugated quantum dots.

J Nanobiotechnology 2019 Feb 6;17(1):26. Epub 2019 Feb 6.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.

Introduction: The detection of circulating tumor cells (CTCs) is very important for cancer diagnosis. CTCs can travel from primary tumors through the circulation to form secondary tumor colonies via bloodstream extravasation. The number of CTCs has been used as an indicator of cancer progress. However, the population of CTCs is very heterogeneous. It is very challenging to identify CTC subpopulations such as cancer stem cells (CSCs) with high metastatic potential, which are very important for cancer diagnostic management.

Results: We report a study of real-time CTC and CSC imaging in the bloodstreams of living animals using multi-photon microscopy and antibody conjugated quantum dots. We have developed a cancer model for noninvasive imaging wherein pancreatic cancer cells expressing fluorescent proteins were subcutaneously injected into the earlobes of mice and then formed solid tumors. When the cancer cells broke away from the solid tumor, CTCs with fluorescent proteins in the bloodstream at different stages of development could be monitored noninvasively in real time. The number of CTCs observed in the blood vessels could be correlated to the tumor size in the first month and reached a maximum value of approximately 100 CTCs/min after 5 weeks of tumor inoculation. To observe CTC subpopulations, conjugated quantum dots were used. It was found that cluster of differentiation (CD)24+ CTCs can move along the blood vessel walls and migrate to peripheral tissues. CD24+ cell accumulation on the solid tumors' sides was observed, which may provide valuable insight for designing new drugs to target cancer subpopulations with high metastatic potential. We also demonstrated that our system is capable of imaging a minor population of cancer stem cells, CD133+ CTCs, which are found in 0.7% of pancreatic cancer cells and 1%-3% of solid tumors in patients.

Conclusions: With the help of quantum dots, CTCs with higher metastatic potential, such as CD24+ and CD133+ CTCs, have been identified in living animals. Using our approach, it may be possible to investigate detailed metastatic mechanism such as tumor cell extravasation to the blood vessels. In addition, the number of observed CTCs in the blood stream could be correlated with tumor stage in the early stage of cancer.
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http://dx.doi.org/10.1186/s12951-019-0453-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6364392PMC
February 2019

Loss of Gut Microbiota Alters Immune System Composition and Cripples Postinfarction Cardiac Repair.

Circulation 2019 01;139(5):647-659

Program in Molecular Medicine, National Yang Ming University and Academia Sinica, Taipei, Taiwan (T.W.H.T., P.C.C.H.).

Background: The impact of gut microbiota on the regulation of host physiology has recently garnered considerable attention, particularly in key areas such as the immune system and metabolism. These areas are also crucial for the pathophysiology of and repair after myocardial infarction (MI). However, the role of the gut microbiota in the context of MI remains to be fully elucidated.

Methods: To investigate the effects of gut microbiota on cardiac repair after MI, C57BL/6J mice were treated with antibiotics 7 days before MI to deplete mouse gut microbiota. Flow cytometry was applied to examine the changes in immune cell composition in the heart. 16S rDNA sequencing was conducted as a readout for changes in gut microbial composition. Short-chain fatty acid (SCFA) species altered after antibiotic treatment were identified by high-performance liquid chromatography. Fecal reconstitution, transplantation of monocytes, or dietary SCFA or Lactobacillus probiotic supplementation was conducted to evaluate the cardioprotective effects of microbiota on the mice after MI.

Results: Antibiotic-treated mice displayed drastic, dose-dependent mortality after MI. We observed an association between the gut microbiota depletion and significant reductions in the proportion of myeloid cells and SCFAs, more specifically acetate, butyrate, and propionate. Infiltration of CX3CR1+ monocytes to the peri-infarct zone after MI was also reduced, suggesting impairment of repair after MI. Accordingly, the physiological status and survival of mice were significantly improved after fecal reconstitution, transplantation of monocytes, or dietary SCFA supplementation. MI was associated with a reorganization of the gut microbial community such as a reduction in Lactobacillus. Supplementing antibiotic-treated mice with a Lactobacillus probiotic before MI restored myeloid cell proportions, yielded cardioprotective effects, and shifted the balance of SCFAs toward propionate.

Conclusions: Gut microbiota-derived SCFAs play an important role in maintaining host immune composition and repair capacity after MI. This suggests that manipulation of these elements may provide opportunities to modulate pathological outcome after MI and indeed human health and disease as a whole.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.118.035235DOI Listing
January 2019

The Bioimaging Applications of Mesoporous Silica Nanoparticles.

Enzymes 2018;43:123-153. Epub 2018 Sep 10.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan. Electronic address:

The unique features of Mesoporous Silica Nanoparticles (MSNs) provide a suitable platform to carry fluorescence dyes for various bioimaging applications. Several strategies have been developed to conjugate a variety of dyes either in the pores or on the surfaces of MSNs to form the fluorescence MSNs (FMSNs). In this chapter, we will discuss recent research progress and future development of FMSNs for living system imaging. We will first describe different strategies for the fabrications of FMSNs. Then, we will discuss the recent developments of cellular and intracellular imaging including self-probe for the interactions of FMSNs with the cells, receptor and organelle labeling, sensing and tracking of biological system, and monitoring the drug delivery and release processes. Moreover, we will include the applications of FMSNs as contrast agents for in vivo imaging. Finally, we will conclude and highlight the challenges and opportunities for MSNs in medical applications.
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http://dx.doi.org/10.1016/bs.enz.2018.07.006DOI Listing
July 2019

Palbociclib enhances radiosensitivity of hepatocellular carcinoma and cholangiocarcinoma via inhibiting ataxia telangiectasia-mutated kinase-mediated DNA damage response.

Eur J Cancer 2018 Oct 10;102:10-22. Epub 2018 Aug 10.

Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan; National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan. Electronic address:

Aim: Palbociclib is an oral cyclin-dependent kinase 4/6 inhibitor, which is efficacious in treating breast cancer. Currently, there are numerous active clinical trials testing palbociclib alone or in combination with other medications for treating various types of malignancies. Here, we evaluated the anti-cancer effect of palbociclib in combination with radiation therapy (RT) for treating human hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) and addressed the molecular mechanism behind the combination therapy.

Methods: Immunofluorescence staining of γH2AX or 53BP1 was used to determine the effect of palbociclib on double-strand break (DSB) repair. Clonogenic assays, sphere formation and cell death ELISA were performed to study the sensitising effect of palbociclib on radiation-induced cytotoxicity. Signal alteration in DSB repair pathways was examined by Western blot analysis. Finally, we evaluated the in vivo anti-cancer activity and the associated molecular events of the combination therapy in a preclinical HCC xenograft model.

Results: Palbociclib affected the kinetics of DNA repair and enhanced the radiation sensitivity of HCC and CCA cells. Importantly, we found that palbociclib inhibits ataxia telangiectasia-mutated (ATM) kinase, the key upstream kinase responding to RT-induced DSBs. Furthermore, we showed that the inhibitory effect of palbociclib on RT-induced ATM kinase activation is mediated by protein phosphatase 5 (PP5). Both in vitro and in vivo investigations revealed that the inhibition of the PP5-ATM axis by palbociclib after DNA damage is responsible for the synergism between palbociclib and RT.

Conclusion: Our findings provide a novel combination strategy against liver cancer cells. Clinical trials using palbociclib as an adjuvant in RT are warranted.
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http://dx.doi.org/10.1016/j.ejca.2018.07.010DOI Listing
October 2018

Antagonizing SET Augments the Effects of Radiation Therapy in Hepatocellular Carcinoma through Reactivation of PP2A-Mediated Akt Downregulation.

J Pharmacol Exp Ther 2018 09 18;366(3):410-421. Epub 2018 Jun 18.

Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (C.-Y.H.); Division of Medical Oncology, Department of Oncology, Taipei Veterans General Hospital, Taipei, Taiwan (M.-H.H.); Institute of Biopharmaceutical Sciences (C.-T.S.) and School of Medicine (M.-H.H.), National Yang-Ming University, Taipei, Taiwan; Department of Medical Research (F.-S.H., M.-H.T., S.-S.C., Y.-J.H, L.-J.C., K.-F.C.) and National Center of Excellence for Clinical Trial and Research (K.-F.C.), National Taiwan University Hospital, Taipei, Taiwan; Department of Medical Imaging and Radiological Technology, Yuanpei University, Hsinchu, Taiwan (C.-Y.H., C.-W.K.); and SupremeCure Pharma Inc., Taipei, Taiwan (T.-I.C.)

Increasing evidence suggests that SET functions as an oncoprotein and promotes cancer survival and therapeutic resistance. However, whether SET affects radiation therapy (RT)-mediated anticancer effects has not yet been explored. We investigated the impact of SET on RT sensitivity in hepatocellular carcinoma (HCC). Using colony and hepatosphere formation assays, we found that RT-induced proliferative inhibition was critically associated with SET expression. We next tested a novel SET antagonist, N-(3-ethynylphenyl)-6,7-dimethoxy-N-(4-phenoxyphenyl) quinazoline-2,4-diamine (EMQA), in combination with RT. We showed that additive use of EMQA significantly enhanced the effects of RT against HCC in vitro and in vivo. Notably, compared with mice receiving either RT or EMQA alone, the growth of PLC5 xenografted tumor in mice receiving RT plus EMQA was significantly reduced without compromising treatment tolerability. Furthermore, we proved that antagonizing SET to restore protein phosphatase 2A-mediated phospho-Akt (p-AKT) downregulation was responsible for the synergism between EMQA and RT. Our data demonstrate a new oncogenic property of SET and provide preclinical evidence that combining a SET antagonist and RT may be effective for treatment of HCC. Further investigation is warranted to validate the clinical relevance of this approach.
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http://dx.doi.org/10.1124/jpet.118.249102DOI Listing
September 2018

Poly(3,4-ethylenedioxythiophene)-Based Nanofiber Mats as an Organic Bioelectronic Platform for Programming Multiple Capture/Release Cycles of Circulating Tumor Cells.

ACS Appl Mater Interfaces 2017 Sep 1;9(36):30329-30342. Epub 2017 Sep 1.

Research Center for Applied Sciences, Academia Sinica , Taipei 11529, Taiwan.

In this investigation, we employed a novel one-step electrospinning process to fabricate poly(ethylene oxide) (PEO)/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) core/shell nanofiber structures with improved water resistance and good electrochemical properties and characterized them using scanning electron microscopy, transmission electron microscopy, and time-of-flight secondary ion mass spectrometry imaging. We then integrated a biotinylated poly-(l-lysine-graft-ethylene glycol) (PLL-g-PEG-biotin) coating with three-dimensional (3D) PEDOT-based nanofiber devices for dynamic control over the capture/release performance of rare circulating tumor cells (CTCs) on-chip. The detailed capture/release behavior of the circulating tumor cells was studied using an organic bioelectronic platform comprising PEO/PEDOT:PSS nanofiber mats with 3 wt % (3-glycidyloxypropyl)trimethoxysilane as an additive. We have demonstrated that these nanofiber mats deposited on five-patterned indium tin oxide finger electrodes are excellent candidates for use as functional bioelectronic interfaces for the isolation, detection, sequential collection, and enrichment of rare CTCs through electrical activation of each single electrode. This combination behaved as an ideal model system displaying a high cell-capture yield for antibody-positive cells while resisting the adhesion of antibody-negative cells. Taking advantage of the electrochemical doping/dedoping characteristics of PEDOT:PSS materials, the captured rare cells could be electrically triggered release through the desorption phenomena of PLL-g-PEG-biotin on device surface. More than 90% of the targeted cancer cells were captured on the 3D PEDOT-based nanofiber microfluidic device; over 87% of captured cancer cells were subsequently released for collection; approximately 80% of spiked cancer cells could be collected in a 96-well plate. Therefore, this 3D PEDOT-based nanofiber approach appears to be an economical route for the large-scale preparation of systems for enhancing the downstream characterization of rare CTCs.
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http://dx.doi.org/10.1021/acsami.7b07042DOI Listing
September 2017

Flexible nanopillars to regulate cell adhesion and movement.

Nanotechnology 2016 Nov 24;27(47):475101. Epub 2016 Oct 24.

Department of Optics and Photonics, National Central University, Taoyuan 32001, Taiwan.

Flexible polymer nanopillar substrates were used to systematically demonstrate cell alignment and migration guided by the directional formation of focal adhesions. The polymer nanopillar substrates were constructed to various height specifications to provide an extensive variation of flexibility; a rectangular arrangement created spatial confinement between adjacent nanopillars, providing less spacing in the horizontal and vertical directions. Three polymer nanopillar substrates with the diameter of 400 nm and the heights of 400, 800, and 1200 nm were fabricated. Super-resolution localization imaging and protein pair-distance analysis of vinculin proteins revealed that Chinese hamster ovary (CHO) cells formed mature focal adhesions on 1200 nm high nanopillar substrates by bending adjacent nanopillars to link dot-like adhesions. The spacing confinement of the adjacent nanopillars enhanced the orthogonal directionality of the formation tendency of the mature focal adhesions. The directional formation of the mature focal adhesions also facilitated the organization of actin filaments in the horizontal and vertical directions. Moreover, 78% of the CHO cells were aligned in these two directions, in conformity with the flexibility and nanotopographical cues of the nanopillars. Biased cell migration was observed on the 1200 nm high nanopillar substrates.
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http://dx.doi.org/10.1088/0957-4484/27/47/475101DOI Listing
November 2016

Dovitinib Acts As a Novel Radiosensitizer in Hepatocellular Carcinoma by Targeting SHP-1/STAT3 Signaling.

Int J Radiat Oncol Biol Phys 2016 06 20;95(2):761-71. Epub 2016 Jan 20.

Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan; National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan. Electronic address:

Purpose: Hepatocellular carcinoma (HCC) is among the most lethal human malignancies, and curative therapy is not an option for most patients. There is growing interest in the potential benefit of combining targeted therapies with radiation therapy (RT). This study aimed to characterize the efficacy and mechanism of an investigational drug, dovitinib, used in combination with RT.

Methods And Materials: HCC cell lines (PLC5, Hep3B, SK-Hep1, HA59T, and Huh-7) were treated with dovitinib, RT, or both, and apoptosis and signal transduction were analyzed.

Results: Dovitinib treatment resulted in Src homology region 2 (SH2) domain-containing phosphatase 1 (SHP-1)-mediated downregulation of p-STAT3 and promoted potent apoptosis of HCC cells. Ectopic expression of STAT3, or inhibition of SHP-1, diminished the effects of dovitinib on HCC cells. By ectopic expression and purified recombinant proteins of various mutant forms of SHP-1, the N-SH2 domain of SHP-1 was found to be required for dovitinib treatment. Overexpression of STAT3 or catalytic-dead mutant SHP-1 restored RT-induced reduction of HCC cell survival. Conversely, ectopic expression of SHP-1 or activation of SHP-1 by dovitinib enhanced the effects of RT against HCC in vitro and in vivo.

Conclusions: SHP-1/STAT3 signaling is critically associated with the radiosensitivity of HCC cells. Combination therapy with RT and the SHP-1 agonist, such as dovitinib, resulted in enhanced in vitro and in vivo anti-HCC effects.
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http://dx.doi.org/10.1016/j.ijrobp.2016.01.016DOI Listing
June 2016

Construction of single fluorophore ratiometric pH sensors using dual-emission Mn(2+)-doped quantum dots.

Biosens Bioelectron 2016 Oct 29;84:133-40. Epub 2016 Jan 29.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan. Electronic address:

We present a novel ratiometric pH sensor design using water-soluble, dual-emission, Mn(2+)-doped quantum dots (Qdots) decorated with D-penicillamine (DPA-MnQdots). In contrast to more commonly used ratiometric pH sensors that rely on the coupling of two fluorophores, our design uses only a single emitter, which simplifies ratiometric sensing and broadens the applications of the sensor. Our single-emitter DPA-MnQdots exhibit two emission bands, at 510nm (green) and 610nm (red), which are, respectively, attributable to exciton recombination and emission of the Mn(2+) dopants. The emission intensity ratio (I510/I610) of the DPA-MnQdots depends linearly on surrounding pH values within physiological conditions (from pH 4.5 to 8.5). Moreover, the biocompatible DPA-MnQdots were used for long-term monitoring of local pH values in HeLa cells.
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http://dx.doi.org/10.1016/j.bios.2016.01.079DOI Listing
October 2016

Integrated 3D conducting polymer-based bioelectronics for capture and release of circulating tumor cells.

J Mater Chem B 2015 Jul 27;3(25):5103-5110. Epub 2015 May 27.

Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Road, Taishan, New Taipei City 243, Taiwan.

Here we develop a novel fabrication approach for producing three-dimensional (3D) conducting polymer-based bioelectronic interfaces (BEIs) that can be integrated on electronic devices for rare circulating tumor cell (CTC) isolation, detection, and collection via an electrically triggered cell released from chips. Based on the chemical oxidative polymerization of carboxylic acid-modified 3,4-ethylenedioxythiophene and modified poly(dimethylsiloxane) (PDMS) transfer printing technology, the high-aspect-ratio structures of poly(3,4-ethylenedioxythiophene) (PEDOT)-based "nanorod" arrays can be fabricated on indium tin oxide (ITO) electrodes when using the Si "microrod" arrays as masters. Furthermore, we integrated the biotinylated poly-(l)-lysine-graft-poly-ethylene-glycol (PLL-g-PEG-biotin) coating with 3D PEDOT-based BEIs for dynamic control of the capture/release performance of CTCs on chips; this combination exhibited an optimal cell-capture yield cells of ∼45 000 cells cm from EpCAM-positive MCF7 while maintaining resistance from the adhesion of EpCAM-negative HeLa cells at a density of ∼4000 cells cm. By taking advantage of the electrochemical doping/dedoping properties of PEDOT materials, the captured CTCs can be triggered to be electrically released through the desorption phenomena of the PLL-g-PEG-biotin. More than 90% of the captured cells can be released while maintaining very high cell viability. Therefore, it is conceivable that the use of a 3D PEDOT-based BEI platform will meet the requirements for the development of downstream characterization of CTCs, as well as the next generation of bioelectronics for biomedical applications.
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http://dx.doi.org/10.1039/c5tb00096cDOI Listing
July 2015

Detection of residual rifampicin in urine via fluorescence quenching of gold nanoclusters on paper.

J Nanobiotechnology 2015 Jun 26;13:46. Epub 2015 Jun 26.

Research Center for Applied Sciences, Academia Sinica, Taipei, 115, Taiwan, ROC.

Background: Rifampicin or rifampin (R) is a common drug used to treat inactive meningitis, cholestatic pruritus and tuberculosis (TB), and it is generally prescribed for long-term administration under regulated dosages. Constant monitoring of rifampicin is important for controlling the side effects and preventing overdose caused by chronic medication. In this study, we present an easy to use, effective and less costly method for detecting residual rifampicin in urine samples using protein (bovine serum albumin, BSA)-stabilized gold nanoclusters (BSA-Au NCs) adsorbed on a paper substrate in which the concentration of rifampicin in urine can be detected via fluorescence quenching. The intensity of the colorimetric assay performed on the paper-based platforms can be easily captured using a digital camera and subsequently analyzed.

Results: The decreased fluorescence intensity of BSA-Au NCs in the presence of rifampicin allows for the sensitive detection of rifampicin in a range from 0.5 to 823 µg/mL. The detection limit for rifampicin was measured as 70 ng/mL. The BSA-Au NCs were immobilized on a wax-printed paper-based platform and used to conduct real-time monitoring of rifampicin in urine.

Conclusion: We have developed a robust, cost-effective, and portable point-of-care medical diagnostic platform for the detection of rifampicin in urine based on the ability of rifampicin to quench the fluorescence of immobilized BSA-Au NCs on wax-printed papers. The paper-based assay can be further used for the detection of other specific analytes via surface modification of the BSA in BSA-Au NCs and offers a useful tool for monitoring other diseases.
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http://dx.doi.org/10.1186/s12951-015-0105-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4482266PMC
June 2015

Investigation of size-dependent cell adhesion on nanostructured interfaces.

J Nanobiotechnology 2014 Dec 5;12:54. Epub 2014 Dec 5.

Research Center for Applied Sciences, Academia Sinica, 128, Section 2, Academia Road, Nankang, Taipei, 11529, Taiwan.

Background: Cells explore the surfaces of materials through membrane-bound receptors, such as the integrins, and use them to interact with extracellular matrix molecules adsorbed on the substrate surfaces, resulting in the formation of focal adhesions. With recent advances in nanotechnology, biosensors and bioelectronics are being fabricated with ever decreasing feature sizes. The performances of these devices depend on how cells interact with nanostructures on the device surfaces. However, the behavior of cells on nanostructures is not yet fully understood. Here we present a systematic study of cell-nanostructure interaction using polymeric nanopillars with various diameters.

Results: We first checked the viability of cells grown on nanopillars with diameters ranging from 200 nm to 700 nm. It was observed that when cells were cultured on the nanopillars, the apoptosis rate slightly increased as the size of the nanopillar decreased. We then calculated the average size of the focal adhesions and the cell-spreading area for focal adhesions using confocal microscopy. The size of focal adhesions formed on the nanopillars was found to decrease as the size of the nanopillars decreased, resembling the formations of nascent focal complexes. However, when the size of nanopillars decreased to 200 nm, the size of the focal adhesions increased. Further study revealed that cells interacted very strongly with the nanopillars with a diameter of 200 nm and exerted sufficient forces to bend the nanopillars together, resulting in the formation of larger focal adhesions.

Conclusions: We have developed a simple approach to systematically study cell-substrate interactions on physically well-defined substrates using size-tunable polymeric nanopillars. From this study, we conclude that cells can survive on nanostructures with a slight increase in apoptosis rate and that cells interact very strongly with smaller nanostructures. In contrast to previous observations on flat substrates that cells interacted weakly with softer substrates, we observed strong cell-substrate interactions on the softer nanopillars with smaller diameters. Our results indicate that in addition to substrate rigidity, nanostructure dimensions are additional important physical parameters that can be used to regulate behaviour of cells.
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http://dx.doi.org/10.1186/s12951-014-0054-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4265325PMC
December 2014

3D bioelectronic interface: capturing circulating tumor cells onto conducting polymer-based micro/nanorod arrays with chemical and topographical control.

Small 2014 Aug 3;10(15):3012-7. Epub 2014 Apr 3.

Department of Materials Engineering, Ming Chi University of Technology, 84 Gunjuan Road, Taishan, New Taipei City, 24301, Taiwan; Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.

The three-dimensional (3D) poly(3,4-ethylenedioxythiophene) (PEDOT)-based bioelectronic interfaces (BEIs) with diverse dimensional micro/nanorod array structures, varied surface chemical pro-perties, high electrical conductivity, reversible chemical redox switching, and high optical transparency are used for capturing circulating tumor cells (CTCs). Such 3D PEDOT-based BEIs can function as an efficient clinical diagonstic and therapeutic platform.
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http://dx.doi.org/10.1002/smll.201400429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4125486PMC
August 2014

Hybrid contact and interfacial adhesion on well-defined periodic hierarchical pillars.

Nanoscale 2013 Feb 19;5(3):1018-25. Epub 2012 Dec 19.

Research Center for Applied Sciences, Academia Sinica, 128, Section 2, Academia Road, Nankang, Taipei 115, Taiwan.

Herein, we describe a simple fabrication procedure for creating artificial hierarchical micro/nanopillars on silicon substrates that allows an effective, precise control of the interfacial adhesion and surface hydrophobicity. These well-defined hierarchical micro/nanostructures have four possible wetting states: Cassie-Cassie (C-C), Cassie-Wenzel (C-W), Wenzel-Cassie (W-C) and Wenzel-Wenzel (W-W). By controlling the critical height of the micro/nanopillars, it is possible to fabricate hierarchical micro/nanostructures in these four states. Thus, the hierarchical superhydrophobic surfaces proposed and fabricated in this study are promising for mimicking either lotus leaves with low adhesion or rose petals with high adhesion.
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http://dx.doi.org/10.1039/c2nr31946bDOI Listing
February 2013

Development of chitosan oligosaccharide-modified gold nanorods for in vivo targeted delivery and noninvasive imaging by NIR irradiation.

Bioconjug Chem 2012 Nov 16;23(11):2173-82. Epub 2012 Oct 16.

Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.

In the present study, we demonstrate the synthesis and applications of multifunctional gold nanorod-based probes for specific targeting and noninvasive imaging based on localized heating generated by gold nanorods after NIR irradiation. The structural design of the probe consists of MUA (11-mercaptoundecanoic acid)-capped gold nanorods covalently linked with low-molecular-weight chitosan oligosaccharide (M(w) ~5000) via carbodiimide (EDC) coupling agent. This surface modification is performed for complete replacement of toxic CTAB (hexadecyltrimethyl-ammonium chloride) and acid-responsive delivery of gold nanorods in acidic environment as known to be present at tumor surrounding areas. The resulting chitosan oligosaccharide-modified gold nanorods (CO-GNRs) were further conjugated with tumor targeting monoclonal antibody against EGFR (epidermal growth factor receptor) to provide localized targeting functionality owing to the overexpression of EGFR in human oral adenosquamous carcinoma cell line CAL 27. Initial in vitro and in vivo toxicity assessments indicated that CO-GNRs did not induce any significant toxicity and are thus suitable for biological applications. Furthermore, selective targeting and accumulation of CO-GNRs were observed in vitro via two-photon luminescence imaging studies in CAL 27, which was also observed through in vivo targeting studies performed via NIR (near-infrared) laser irradiation in CAL 27 xenografts of BALB/c nude mice. Hence, the CO-GNRs that we have developed are biocompatible and nontoxic and can be a potential candidate for in vivo targeted delivery, noninvasive imaging based on localized hyperthermia, and photothermal-related therapies.
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http://dx.doi.org/10.1021/bc3001276DOI Listing
November 2012

Electrically tunable organic bioelectronics for spatial and temporal manipulation of neuron-like pheochromocytoma (PC-12) cells.

Biochim Biophys Acta 2013 Sep 12;1830(9):4321-8. Epub 2012 Sep 12.

Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.

Background: Organic bioelectronic devices consisting of alternating poly(3,4-ethylenedioxythiophene) (PEDOT) and reduced graphite oxide (rGO) striped microelectrode arrays were fabricated by lithography technology. It has been demonstrated that the organic bioelectronic devices can be used to spatially and temporally manipulate the location and proliferation of the neuron-like pheochromocytoma cells (PC-12 cells).

Methods: By coating an electrically labile contact repulsion layer of poly(l-lysine-graft-ethylene glycol) (PLL-g-PEG) on the PEDOT electrode, the location and polarity of the PC-12 cells were confined to the rGO electrodes.

Results: The outgrowth of spatially confined bipolar neurites was found to align along the direction of the 20μm wide electrode. The location of the PC-12 cells can also be manipulated temporally by applying electrical stimulation during the neurite differentiation of PC-12 cells, allowing the PC-12 cells to cross over the boundary between the PEDOT and the rGO regions and construct neurite networks in an unconfined manner where the contact repulsive coating of PLL-g-PEG was removed.

Conclusions: This adsorption and desorption of the PLL-g-PEG without and with electrical stimulation can be attributed to the tunable surface properties of the PEDOT microelectrodes, whose surface charge can switch from being negative to positive under electrical stimulation.

General Significance: The electrically tunable organic bioelectronics reported here could potentially be applied to tissue engineering related to the development and regeneration of mammalian nervous systems. The spatial and temporal control in this device would also be used to study the synapse junctions of neuron-neuron contacts in both time and space domains. This article is part of a Special Issue entitled Organic Bioelectronics - Novel Applications in Biomedicine.
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http://dx.doi.org/10.1016/j.bbagen.2012.08.028DOI Listing
September 2013

Synthesis of tunable and multifunctional Ni-doped near-infrared QDs for cancer cell targeting and cellular sorting.

Bioconjug Chem 2012 Mar 17;23(3):421-30. Epub 2012 Feb 17.

Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan.

Here, we report the facile preparation of tunable magnetic Ni-doped near-infrared (NIR) quantum dots (MNIR-QDs) as an efficient probe for targeting, imaging, and cellular sorting applications. We synthesized the MNIR-QDs via a hot colloidal synthesis approach to yield monodisperse and tunable QDs. These hydrophobic QDs were structurally and compositionally characterized and further functionalized with amino-PEG and carboxyl-PEG to improve their biocompatibility. Since QDs are known to be toxic due to the presence of cadmium, we have evaluated the in vitro and in vivo toxicity of our surface-functionalized MNIR-QDs. Our results revealed that surface-functionalized MNIR-QDs did not exhibit significant toxicity at the concentrations used in the experiments and are therefore suitable for biological applications. For further in vitro applications, we covalently linked folic acid to the surface of amino-PEG-coated MNIR-QDs through NHS chemistry to target the folate receptors largely present in the HeLa cells to demonstrate the specific targeting and magnetic behavior of these MNIR-QDs. Improved specificity has been observed with treatment of HeLa cells with the folic acid-linked amino PEG-coated MNIR QDs (FA-PEG-MNIR-QDs) compared to the one without folic acid. Since the synthesized probe has magnetic property, we have also successfully demonstrated sorting between the cells which have taken up the probe with the use of a magnet. Our findings strongly suggest that these functionalized MNIR-QDs can be a potential probe for targeting, cellular sorting, and bioimaging applications.
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http://dx.doi.org/10.1021/bc200435eDOI Listing
March 2012

Manipulating location, polarity, and outgrowth length of neuron-like pheochromocytoma (PC-12) cells on patterned organic electrode arrays.

Lab Chip 2011 Nov 16;11(21):3674-80. Epub 2011 Sep 16.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan 11529.

In this manuscript, we describe a biocompatible organic electrode system, comprising poly(3,4-ethylenedioxythiophene) (PEDOT) microelectrode arrays on indium tin oxide (ITO) glass, that can be used to regulate the neuron type, location, polarity, and outgrown length of neuron-like cells (PC-12). We fabricated a PEDOT microelectrode array with four different sizes (flat; 20, 50, and 100 μm) through electrochemical polymerization. Extracellular matrix proteins absorbed well on these organic electrodes; cells absorbed selectively on the organic electrodes when we used polyethylene oxide/polypropylene oxide/polyethylene oxide triblock copolymers (PEO/PPO/PEO, Pluronic™ F108) as the anti-adhesive coating. In this system, the neurite polarities and neuron types could be manipulated by varying the width of the PEDOT microelectrode arrays. On the unpatterned PEDOT electrode, PC-12 cells were randomly polarized, with approximately 80% having multi-polar cell types. In contrast, when we cultured PC-12 cells on the 20 μm wide PEDOT line array, the neurites aligned along the direction of the organic electrodes, with the percentage of uni- and bipolar PC-12 cells increasing to greater than 90%. The outgrowth of neurites on the microelectrodes was promoted by ~60% with an applied electrical stimulation. Therefore, these electroactive PEDOT microelectrode arrays have potential for use in tissue engineering related to the development and regeneration of mammalian nervous systems.
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http://dx.doi.org/10.1039/c1lc20675cDOI Listing
November 2011

Exploring the formation of focal adhesions on patterned surfaces using super-resolution imaging.

Small 2011 Oct 22;7(20):2906-13. Epub 2011 Aug 22.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.

The formation of focal adhesions on various sizes of fibronectin patterns, ranging from 200 μm to 250 nm, was systematically investigated by total internal reflection fluorescence microscopy and super-resolution imaging. It was found that cells adhered to and spread on these micro/nanopatterns, forming focal adhesions. On a micrometer scale the shape of the focal adhesions was elongated. However, on the nanometer scale, the shape of focal adhesions became dotlike. To further explore the distribution of focal adhesion proteins formed on surfaces, a localization-based super-resolution imaging technique was employed in order to determine the position and density of vinculin proteins. A characteristic distance of 50 nm was found between vinculin molecules in the focal adhesions, which did not depend on the size of the fibronectin nanopatterns. This distance was found to be crucial for the formation of focal adhesions. In addition, the density of vinculin at the focal adhesions formed on the nanopatterns increased as the pattern size decreased. The density of the protein was found to be 425 ± 247, 584 ± 302, and 703 ± 305 proteins μm(-2) on the 600, 400, and 250 nm fibronectin patterns respectively. Whereas 226 ± 77 proteins μm(-2) was measured for the matured focal adhesions on homogeneous fibronectin coated substrates. The increase in vinculin density implies that an increase in mechanical load was applied to the focal adhesions formed on the smaller nanopatterns.
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http://dx.doi.org/10.1002/smll.201100753DOI Listing
October 2011

Investigation of the growth of focal adhesions using protein nanoarrays fabricated by nanocontact printing using size tunable polymeric nanopillars.

Nanotechnology 2011 Jul 17;22(26):265302. Epub 2011 May 17.

Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.

Here we describe a simple approach to create various sizes of protein nanoarrays for the investigation of cell adhesion. Using a combination of nanosphere lithography, oxygen plasma treatment, deep etching and nanomolding processes, well-ordered polymeric nanopillar arrays have been fabricated with diameters in the range of 50-600 nm. These nanopillar arrays were used as stamps for nanocontact printing to create fibronectin nanoarrays, which were used to study the size dependent formation of focal adhesion. It was found that cells can adhere and spread on fibronectin nanoarrays with a fibronectin pattern as small as 50 nm. It was also found that the average size of focal adhesion decreased as the size of the fibronectin pattern was reduced.
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http://dx.doi.org/10.1088/0957-4484/22/26/265302DOI Listing
July 2011

Targeted nuclear delivery using peptide-coated quantum dots.

Bioconjug Chem 2011 Jun 10;22(6):1073-80. Epub 2011 May 10.

Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 115, Taiwan.

Core/shell quantum dots (CdSe/Zns) conjugated with various nuclear localization signaling (NLS) peptides, which could facilitate the transportation of quantum dots across the plasma membrane into the nucleus, have been utilized to investigate the uptake mechanism of targeted delivery. Because of their brightness and photostability, it was possible to trace the trajectories of individual quantum dots in living cells using both confocal and total internal reflection microscopes. We found that, when the quantum dots were added to a cell culture, the peptide-coated quantum dots entered the cell nucleus while the uncoated quantum dots remained in the cytoplasm. At 8 nM, most of the peptide coated quantum dots were found in the cytoplasm due to aggregation. However, at a lower concentration (0.08 nM), approximately 25% of the NLS peptide-coated quantum dots entered the cell nucleus. We also found that some quantum dots without NLS coating could also enter the nucleus, suggesting that the size of the quantum dots may play an important role in such a process.
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http://dx.doi.org/10.1021/bc100527mDOI Listing
June 2011

Development of lipid targeting Raman probes for in vivo imaging of Caenorhabditis elegans.

Chemistry 2011 Apr 15;17(18):5165-70. Epub 2011 Mar 15.

Research Center For Applied Sciences, Academia Sinica, Taipei-115, Taiwan.

A simple, sensitive, and highly specific lipid targeting Raman probe (Nile red coated silver nanoparticles) has been developed to image living nematode Caenorhabditis elegans (C. elegans). Our idea of imaging lipids in C. elegans is to combine the specificity of the fluorescent dye, Nile red, and the highly enhanced Raman scattering on the silver nanoparticles. Our strategy involves the fabrication of a lipid targeting probe, which is incorporated into the intracellular intestinal granules of C. elegans by incubating these worms in the solution containing Raman probes, resulting in an uptake and subsequent incorporation of these Raman probes into the intestinal granule, thus allowing fast visualization of lipid droplets through a conventional confocal imaging technique.
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http://dx.doi.org/10.1002/chem.201002896DOI Listing
April 2011
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