Dar-Bin Shieh
National Cheng Kung University, Basic medical sciences, Faculty Member
- Ecology, Prehistoric Archaeology, Evolutionary Biology, Molecular Biology, Biochemistry, Cell Biology, and 7 moreRNA interference, Archaeology, Biology, Nanotechnology, Materials Science and Engineering, Pathology, and Dentistry(RNA interference, Archaeology, Biology, Nanotechnology, Materials Science and Engineering, Pathology, and Dentistry)edit
Gelsolin (GSN) is one of actin filament-severing proteins that play a key role in the actin cytoskeleton rearrangement and the modification of tumor cell proliferation and metastasis. TGF-beta has ...
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Research Interests: Chemistry, Dentistry, Electrochemistry, Medicine, Patch-clamp and imaging techniques, and 15 moreHumans, Keratinocytes, Dental, Peptides, Potassium, Mouth Neoplasms, Mouth mucosa, Keratinocyte, Ion Transport, Honeybee, Caffeic Acid Phenethyl Ester, Patch Clamp, Depolarization, Hydroxy acids, and Barrier function
Quantitative polymerase chain reaction (qPCR) is the most important quantitative sensing technique for pathogens, especially for emerging pandemics such as coronavirus outbreak this year. The qPCR chip and device were investigated to meet... more
Quantitative polymerase chain reaction (qPCR) is the most important quantitative sensing technique for pathogens, especially for emerging pandemics such as coronavirus outbreak this year. The qPCR chip and device were investigated to meet the unmet needs of ultrafast inspection time, high accuracy, and small system volume. Therein, the fluorescence intensity was the most important signal in qPCR quantification of DNA amplifications, which is essential not only in the confirmative diagnosis of positive or negative infection, but also in the assessment of viral load for therapeutic and quarantine decision making. As the target DNAs got amplified, the interaction of fluorescence dye and double strand DNA will generate fluorescence signal proportional to amplified DNA in the intensity when excited by certain wavelength. A miniature spectro-detector was employed to receive the fluorescence scattering for digital output of the intensity in the qPCR chip in this study, and the optical simulation and actual experimental design and results according to the optical simulation results were performed to study the effect of the stray light shutter (SLS) in the improvement of the signal in fluorescence detection. The analysis results showed that the signal-to-noise ratio (SNR) of the fluorescence can be enhanced significantly for 5 times of the control using the SLS with a shape of extended component aperture, where the protruding structure was positioned away from the center. The experimental results showed that fluorescence intensity can be enhanced by 15.50% and 9.86% when adding the above shape of SLS in resin- and in glass-based chip, respectively. The results also demonstrated that the optical setup had good stability and repeatability in fluorescence detection, and variation was less than 1.00 %. Our results can provide important reference to the development of qPCR chip to obtain the high SNR fluorescence signal in DNA quantification process.
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Quantitative polymerase chain reaction (qPCR) has been widely employed for the positive or negative detection of bacteria or viruses, particularly SARS-CoV-2. Fluorescence signal and cycle threshold information is critical for the... more
Quantitative polymerase chain reaction (qPCR) has been widely employed for the positive or negative detection of bacteria or viruses, particularly SARS-CoV-2. Fluorescence signal and cycle threshold information is critical for the positive and negative detection of target test samples in qPCR systems. To determine viral concentration, the fluorescence intensity of each cycle must be recorded using a qPCR system. In general, the time points of fluorescence excitation and excitation light intensity affect fluorescence intensity. Thus, this study proposed an effective excitation method for enhancing fluorescence intensity. Several parameters, including excitation light intensity, the excitation time point, and the reaction time of the reagent at each temperature stage, were modified in assessing fluorescence performance and determining suitable parameters for fluorescence excitation in a qPCR system. Fluorescence intensity resulted in the most optimal fluorescence performance; specifically, excitation was triggered by using a 30 mA current, and the excitation light was activated when the temperature decreased to 60 °C. Total reaction time was 1 s, and the concentrated fluorescence value and suitable cycle threshold value were obtained. Overall, high efficiency, low fluorescence decay, and high light stability were observed. The present findings demonstrate that controlling the time point of excitation light can enhance the fluorescence efficiency and performance of qPCR systems, with relevant benefits in medical diagnostics and rapid viral detection, among other applications.
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This study proposes an optical method to improve the yield efficiency of QPCR. The concept is that the conversion efficiency of fluorescent dyes is not high, and the light intensity signal is weak and difficult to distinguish. Therefore,... more
This study proposes an optical method to improve the yield efficiency of QPCR. The concept is that the conversion efficiency of fluorescent dyes is not high, and the light intensity signal is weak and difficult to distinguish. Therefore, the intensity signal of the excitation light source is reduced to obtain the fluorescent signal. Using the DNA binding dye as a model, the excitation light signals captured by the different angles between the incident light and the speculary reflected light are used to determine the correct fluorescent detection position, and to explore the efficiency of the test tube diameter for capturing fluorescent signals. The simulation results show that the standard diameter test tube has a minimum noise interference at the 45 degree position, which means that the fluorescent signal can be intercepted most effectively. This method does not change any chemical configuration and process conditions, saves a lot of time and process steps, and has high stability and zero pollution.
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The fluorescence signal of Sybr Green can represent the amount of target DNA copy numbers in the samples, thereby determine a positive or negative diagnostic results after polymerase chain reaction (PCR). For precision quantification of... more
The fluorescence signal of Sybr Green can represent the amount of target DNA copy numbers in the samples, thereby determine a positive or negative diagnostic results after polymerase chain reaction (PCR). For precision quantification of the target gene in the sample, the fluorescent signal should be recorded in each cycle. Traditionally, highly sensitive devices such as silicon photomultipliers and high-power light source such as laser diode were used to excite and detect the fluorescence from double strand DNA selective dyes. However, the costs of these components were too high to be widely applied for rapidly on-site screening of outbreak causing pathgens in local clinics and fields of tests. In this study, low-cost optical element such as LED and photodiode were used to implementan off-plane excitation method to enhance the fluorescence signal. Several parameters such as illumination angle between LED and photodiode in horizontal direction and tilted illumination in vertical direction were optimized in the experiment to ensure the performance. The results showed that the fluorescence intensity can be enhanced approximately 25 %. These results indicated that the developed illumination architecture had advantages of low background noise, high sensitivity and high fluorescence variation. This research has successfully demonstrated an off-plane excitation method for enhancing the resolution of qPCR system and applying in medical diagnostics, rapid screening and related applications.
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Calcium-fluoride-like deposits play a key role in caries prevention by topical fluoride. Previous microhardness analyses have introduced errors due to a substrate effect, and thereby could not substantiate the early loss of these... more
Calcium-fluoride-like deposits play a key role in caries prevention by topical fluoride. Previous microhardness analyses have introduced errors due to a substrate effect, and thereby could not substantiate the early loss of these deposits. To address this question, we applied Atomic Force Microscopy (AFM) and a nano-indentation technique in this study to characterize the nano-mechanical properties and topographic structure of enamel surfaces following topical fluoride treatment. The deposits were found to have a low nano-hardness and a high nano-wear depth, which explains the early loss of calcium-fluoride-like deposits. However, a 22% increase in the fluoride concentration could still be detected on the treated enamel surface following the removal of the surface deposits, justifying the long-term effectiveness of topical fluoride treatment.
Research Interests: Materials Science, Dentistry, Fluoride, Nanoindentation, Nanotechnology, and 15 moreAtomic Force Microscopy, Medicine, Nano, Humans, Dental, Hardness, Calcium Fluoride, Surface Properties, Cariostatic Agents, Long Term Effect, Dental Enamel, Materials Testing, Electron Probe Microanalysis, Biomechanical Phenomena, and Mechanical Property
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Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Nanoparticles (NPs) are ideal vectors to deliver analytic probes or therapeutic agents into cells and subcellular compartments. Among many nanomaterials, gold NPs is... more
Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Nanoparticles (NPs) are ideal vectors to deliver analytic probes or therapeutic agents into cells and subcellular compartments. Among many nanomaterials, gold NPs is widely used as a model platform for biomedical research because of their favorable physical and chemical properties. Thus, gold NPs has been employed for various applications, especially in medicine. Through surface modification of gold NPs with functional bio-macromolecules (i.e., peptides, nucleic acids and antibodies) may improve the ability of imaging, clinical diagnostics and therapeutics. Cellular uptake of gold NPs is highly dependent on their size, shape, and surface properties. For targeted therapy, the common strategy for specific cells or cellular compartments delivery is to modify NPs with peptides or lignads. The outcome is highly dependent on the peptide sequence and cell types. Therefore, we treated CaSKi, HeLa and SiHa cervical cancer cells with different peptide-modified gold NPs for 24 hours and determined the cellular localization of the NPs from laser confocal microscopy equipped with DIC channel. We found that gold NPs modified with the nuclear localization signal (NLS) peptide from SV40 virus (GNP-PEG/SV40) accumulated around the cytoplasmic side of nuclear membrane (perinuclear accumulation) in CaSKi and HeLa carcinoma cells and translocate into nucleus in SiHa squamous cells. For adenovirus (ADV) peptide modified NPs (GNP-PEG/ADV), nuclear localization was observed in all cervical cancer cells. We then performed cell survival test (MTT assay) for various time intervals (24 to 96 hours) to identify the relationship between NPs’ distribution and cellular response. The particles exhibited perinuclear and nuclear accumulation decreased cell survival greater than cell and particles control (GNP-PEG) did. For perinuclear accumulation in HeLa cells, through annexin V/PI stain, there was no increase in apoptosis after long-term treatment with GNP-PEG/SV40 particles, but a significant increase in LC3-II expression in the GNP-PEG/SV40-treated group, suggesting activation of autophagy. On the contrary, an apoptotic cell population was found in nuclear accumulated SiHa cells. These findings suggest that different cellular distribution of NPs may link with specific death pathways. In conclusion, this study may have implications in the development of new therapeutic modality for specific cancer cells or prevention of long-term toxicities from treatment with different peptide modified NPs. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 375. doi:10.1158/1538-7445.AM2011-375
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Cancer therapy is still a grand challenge due to their aggressive invasion and metastasis to adjacent tissues and distant organs. Only few reported integrated approaches capable of for simultaneous diagnosis and therapy. In this study,... more
Cancer therapy is still a grand challenge due to their aggressive invasion and metastasis to adjacent tissues and distant organs. Only few reported integrated approaches capable of for simultaneous diagnosis and therapy. In this study, gold nanorods (AuNR) were synthesized to construct a novel theranostics platform. The characteristic tunable surface plasmon bands in the near-infrared region (800 nm) enabled efficient tissue penetration of the NIR activation light source. PEG and Her2 antibodies were conjugated on the AuNR for targeting oral cancer cells while present adequate biological stealth. The specific in vivo targeting and biodistribution of the AuNR800-PEG5K-Her2 were evaluated in mice implanted with tumor cells over-expression of Her2 by atomic absorption spectroscopy. Molecular photoacoustic imaging was performed using a hydrophone transducer containing a tunable pulsed laser system. A maximum signal of 4.2 dB was recorded within the tumor site 12 hours after injection. Moreover, AuNRs conjugated with Her2 antibodies significantly reduced non-specific liver and spleen uptake compared to AuNRs lacking the antibodies. For the evaluation of therapeutic efficacy, solid-state C.W. lasers at 808nm peak wavelength were established to scan the tumor lesions for laser induced hyperthermia. A significant increase in the tumor local temperature was observed in tumor-bearing mice injected with AuNRs conjugated with HER2 antibodies compared to PBS and AuNR control groups. Furthermore, AuNR800-PEG5K-Her2 treated mice exhibited an improved overall survival compared to the control groups. In conclusion, we successfully demonstrate an integrated system capable of real-time photoacoustic imaging of the tumor lesions and perform laser induced hyperthermia therapy using AuNR800-PEG5K-Her2 as the probe and NIR laser as the light source. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C174.
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RGD-PEG-GNRs facilitate specific targeting of integrin αvβ6 that is selectively overexpressed in head and neck cancer, including HSC3. The GNRs were internalized to endosome and lysosomal vesicles through attaching to the cytoplasmic... more
RGD-PEG-GNRs facilitate specific targeting of integrin αvβ6 that is selectively overexpressed in head and neck cancer, including HSC3. The GNRs were internalized to endosome and lysosomal vesicles through attaching to the cytoplasmic membrane. We further showed that facilitating RGD-PEG-GNR uptake in cancer cells significantly enhanced their radiosensitivity and thus increased DNA damage. In vivo distribution revealed significant accumulation of the RGD-PEG-GNRs in tumor tissues as compared to other major organs. Such tumor lesion accumulation peaked at 12 h followed by a decline over time. In the RESs, the liver is the major organ for RGD-PEG-GNR accumulation followed by the lung and then the spleen. Our results encouraged further development of RGD-PEG-GNR-augmented megavoltage radiation therapy and potential integration with chemotherapy targeting molecular mechanisms of DNA damage repair.
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Research Interests: Microbiology, Clostridium difficile, Medicine, Vancomycin, Antimicrobial, and 2 moreAntibiotics and Spore(Antibiotics and Spore)
(Antibiotics and Spore)
... Ming-Hua Hsu, Thainashmuthu Josephrajan, Chen-Sheng Yeh, Dar-Bin Shieh, Wu-Chou Su and Jih Ru Hwu. Bioconjugate Chemistry 2007 18 (6 ... Christopher E. Bunker, Kyle C. Novak, Elena A. Guliants, Barbara A. Harruff, M. Jaouad Meziani,... more
... Ming-Hua Hsu, Thainashmuthu Josephrajan, Chen-Sheng Yeh, Dar-Bin Shieh, Wu-Chou Su and Jih Ru Hwu. Bioconjugate Chemistry 2007 18 (6 ... Christopher E. Bunker, Kyle C. Novak, Elena A. Guliants, Barbara A. Harruff, M. Jaouad Meziani, Yi Lin, and Ya-Ping Sun. Langmuir ...
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Research Interests: Biotechnology, Computer Aided Design, Biology, Medicine, Molecular Imaging, and 15 moreAntibodies, Humans, Gold, Mice, Animals, Male, Nanostructures, Drug Delivery Systems, In Vivo, Mouth Neoplasms, Cancer Cell, Equipment Design, Equipment Failure Analysis, Electrical And Electronic Engineering, and Elasticity Imaging Techniques
Abstract-Recent studies reported gold nano rod (AuNRs) exhibit surface plasmonic resonance frequency (SPR) proportional to their aspect ratio. The interaction of AuNRs with electromagnetic radiation corresponding to their SPR could... more
Abstract-Recent studies reported gold nano rod (AuNRs) exhibit surface plasmonic resonance frequency (SPR) proportional to their aspect ratio. The interaction of AuNRs with electromagnetic radiation corresponding to their SPR could generate local regional heat. With precise ...
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Glass ionomers have been used for perforation repair and retrograde filling where biointegration with periodontal tissue is required. Collagen has been demonstrated to promote cellular adhesion and enhance mineral tissue compressive... more
Glass ionomers have been used for perforation repair and retrograde filling where biointegration with periodontal tissue is required. Collagen has been demonstrated to promote cellular adhesion and enhance mineral tissue compressive strength. It was hypothesized that an appropriate concentration of collagen integrated into glass ionomer may improve both bio-compatibility and the mechanical properties of the material. By SEM and AFM, we discovered 70-nm granules appearing on the surfaces of glass-ionomer/collagen hybrids. Acid-etching revealed irregularly shaped particles interlinked by membrane-like sheets on the surface of the material with the typical 70-nm granules. WST-1 assay showed that acid-etching significantly enhanced the viability of attached gingival fibroblasts. However, the glass-ionomer/collagen hybrids’ combined surface-etching outperformed other groups. The glass-ionomer/collagen hybrids presented enhanced compressive strength when integrated with 0.01% collagen, while higher concentrations of collagen compromised their mechanical property. In summary, collagen improved both the mechanical and biocompatible properties of glass ionomers. Further in vivo study is warranted.
Research Interests: Materials Science, Dentistry, Cell Adhesion, Medicine, Humans, and 15 moreCompressive Strength, Dental, Composite Material, Gingiva, Perforation, Surface Properties, Materials Testing, Ionomer, Biocompatible Materials, Cell Survival, Glass Ionomer Cement, fibroblasts, Mechanical Property, Glass ionomer cements , and Collagen type I
Purpose Altered gene expression is involved not only in the initiation of cancers, but also in tumor progression and treatment response. Cancer gene therapy is an emerging concept for advanced malignant disease management. However, most... more
Purpose Altered gene expression is involved not only in the initiation of cancers, but also in tumor progression and treatment response. Cancer gene therapy is an emerging concept for advanced malignant disease management. However, most of current approaches in gene silencing act in the mRNA levels such as siRNA, ribozyme and anti-sense strategies. These approaches only gave partial and temporal gene expression suppression. Besides, delivery system of such approaches is also challenging. This study aimed to develop a Near-Infrared, Artificial, Targeted, Light-Activated Nanoscissor (NIR-ATLANS) to perform gene sequence specific double strand scission to permanently silence target cancer genes. Materials and methods The NIR-ATLANS comprised gold nanorod core with a monolayer of cypate-modified triplex-forming oligonucleotides (TFOs) that targets EGFP as a model system. The NIR-ATLANS activation specific wavelength is around 808 nm. After laser exposure at 808 nm peak wavelength, we used real-time polymerase chain reaction to check the gene cleavage efficiency. Results We discovered that the NIR-ATLANS could selectively target gene through electrophoretic mobility shift assay. When activated the nanoscissor by near-infrared laser, we observed decreased EGFP expression at both mRNA and protein level in the NIR-ATLANS combined lasing group, while not as significant in all other groups. Conclusions Our results showed a permanent gene silencing at the genomic level by combined ATLANS and laser activation. The gold nanorod could act as a quencher to prevent non-specific NIR-ATLANS cutting through free radical attack, thus protects non-target DNA from collateral damage. In our study, NIR-ATLANS successfully down regulate EGFP expression. Both reported gene and functional gene were able to be down regulated in cancer cell through our approach. We anticipate such technology hold a great potential in the future cancer gene therapy.
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Purpose Traditional chemotherapies are still far from satisfactory due to the development of drug resistance and side effects derived from non-specific targeting of healthy normal cells. Recent reports suggest that combined physical and... more
Purpose Traditional chemotherapies are still far from satisfactory due to the development of drug resistance and side effects derived from non-specific targeting of healthy normal cells. Recent reports suggest that combined physical and chemical approaches in cancer therapy may have synergistic advantage such as hyperthermia and chemotherapy especially when both approaches are delivered under synchronized manner. In addition, previous studies reported that CD44 plays multiple functions in oral squamous cell carcinoma (OSCC) progression. CD44 can be triggered to internalize by extracellular matrix or antibody and to form the transcriptional complex. Their nuclear translocation could turn on cancer reprogramming genes. In this study, we use this internalization pathway to design a novel hyperthermo-chemotherapy that shuttled the oligonucleotide magnetite nanoparticles from cell membrane to the nucleus. Materials and methods The designed nanoparticle includes a high-saturation magnetization (94 emu/g) magnetite nanocrystals core conjugated with polynucleotide loaded with 5-fluorouracil (5-FU) shells and anti-CD44 mAb. We used two OSCC cell lines (OEC-M1 and HSC-3) and two normal cells (NHOK and HUVEC) in targeting internalization study. We utilized radiofrequency (RF) to induce magnetic hyperthermia (MHT) and evaluated the efficacy in HSC-3 bearing NOD/SCID mice. Results In the in vitro study, we discovered internalization of the membrane CD44 in OSCC cells significantly high than normal cells. The cytotoxicity text showed OSCC cells present significantly lower than normal cells after nanoparticle treatment. We further confirmed nanoparticle treatment combined RF can decrease cell viability in a time-dependent manner. The in vivo results showed only a single dose I.V. injection combined RF treatment caused tumor cell damage and decrease in tumor volume. Conclusion This novel therapy consists of two stages: First, the CD44 induced internalization of the nanoparticle could augment both extra-and intracellular MHT by RF in oral cancer. Second, the 5-FU released during MHT provides effective chemotherapy to retard tumor re-progression. We anticipate such achievements could inspire further nano drug delivery strategy to advance oral cancer therapeutics.
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Abstract Ovarian cancer (OVCA) is one of the most lethal gynecological cancers due to its high mortality rate. Although ~ 70% of OVCA patients initially respond to the first line of treatment, chemoresistance is a major obstacle to a... more
Abstract Ovarian cancer (OVCA) is one of the most lethal gynecological cancers due to its high mortality rate. Although ~ 70% of OVCA patients initially respond to the first line of treatment, chemoresistance is a major obstacle to a long-term therapeutic success. Dysregulation of proapoptotic and antiapoptotic factors, mutations of tumor suppressor genes, upregulation of oncogenic proteins, as well as the tumor microenvironment (TME) have been shown to contribute to OVCA sensitivity to cisplatin (cis-diamminedichloroplatinum; CDDP) and its derivatives. Also, these cellular and molecular mechanisms vary from patient-to-patient; hence, making a common and effective treatment an impossible task to achieve. As a result of this heterogeneity in OVCA patients, there is an urgent need to focus on patient-personalized treatment taking into consideration the molecular and cellular profiles of the patient's tumor, biomarkers and other necessary clinical data. This chapter focuses on the multidisciplinary approaches in the study of OVCA chemoresistance and patient-tailored treatments.
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Research Interests: Immunology, Rheumatoid Arthritis, Medicine, Genetic Enhancement, Animals, and 14 moreMale, Arthritis, Clinical Sciences, Rats, Public health systems and services research, Transforming Growth Factor Beta, Blood Vessels, Vascular Endothelial Growth Factor, Interleukin, Severity of Illness Index, Synovial membrane, Genetic Therapy, collagen-induced arthritis, and Thrombospondin
How to improve the selectivity and efficacy of anticancer agents and to reduce side effects has always been a big challenge in clinical cancer therapy. Chemotherapeutic agents are usually toxic to both cancer and normal tissues, thus... more
How to improve the selectivity and efficacy of anticancer agents and to reduce side effects has always been a big challenge in clinical cancer therapy. Chemotherapeutic agents are usually toxic to both cancer and normal tissues, thus rendering compromised overall clinical outcome. Here we developed zero-valent iron nanoparticles (ZVI NPs) that exhibited selectivity toward higher toxicity to most cancerous cells thus opening a new era of anti-cancer therapy or adjuvant therapy through a novel molecular signaling pathway. We used head-and-neck cancer (HNC) cells and ovarian cancer (OVCA) cells to test the anti-cancer properties of ZVI NPs. The ZVI NPs served as a strong reactive oxygen species (ROS) inducer and caused irreversible mitochondria membrane potential lost in sensitive cancer cells that lead to cancer cell autophagy and growth suppression, while not significantly affect normal cell population. Further, the cytotoxicity of the ZVI NPs is highly depended on its redox state as oxidation of the NPs upon aging reduced their cytotoxic potency. In vivo study revealed a dose dependent tumor size reduction in tumor-bearing mice model without significant weight loss and pathological signs. These results suggest that ZVI NPs may serve as a new class of anticancer agent for a wide spectra of neoplastic diseases.
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Gold and iron were processed to form core shell (gold coated on iron, Fe@Au) or alloy nanoparticles and transferred to aqueous phase by ethanol rinse and magnetic separation. Both types of nanoparticles presented selective and significant... more
Gold and iron were processed to form core shell (gold coated on iron, Fe@Au) or alloy nanoparticles and transferred to aqueous phase by ethanol rinse and magnetic separation. Both types of nanoparticles presented selective and significant (P < 0.0001) inhibition of head and neck cancer cell proliferation in vitro at doses as low as 5 μg/mL, while having little adverse effect on normal healthy control cells. The Fe@Au particle treatment induced delay in cell-cycle progression, especially in the S-phase. There was no significant difference in the nanoparticle uptake between cancer and control cells. The cytotoxicity resulted primarily from the iron core, before oxidation, rather than the Fe ions released from the core. The nanoparticles triggered lost of mitochondria membrane potential in cancerous cells but not in normal cells. The nanoparticles do not induce significant apoptotic response but autophagy was detected from both ultrastructural observation and immunoblot of markers. The nanoparticles presented therapeutic efficacy in cancer bearing animal and a significant synergistic effect was found when co-treat with anti-cancer drug methotrexate. The Fe@Au nanoparticle showed better anti-cancer effect than the FeAu alloy nanoparticle in the same dosage. In contrast to most magnetic nanoparticles for medical application that usually serve as drug carriers or diagnostic probes or hyperthermia energy transducer, the FeAu nanoparticles selectively suppressed cancer cell growth and left healthy control cells unaffected in vitro and in vivo. This novel nanomaterial holds great promise as a therapeutic tool in nanomedicine.1 page(s