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1.
ACS Appl Mater Interfaces ; 13(31): 36697-36708, 2021 Aug 11.
Article in English | MEDLINE | ID: mdl-34313117

ABSTRACT

Development of drug-delivery systems that allow simultaneous in vivo imaging has gained much interest. We report a novel strategy to encapsulate metal nanoparticles (NPs) within alginate gel for in vivo imaging. The cell lysate of recombinant Escherichia coli strain, expressing Arabidopsis thaliana phytochelatin synthase and Pseudomonas putida metallothionein genes, was encapsulated within the alginate gel. Incubation of alginate gel with metal ion precursors followed by UV irradiation resulted in the synthesis of high concentrations of metal NPs, such as Au, Ag, CdSe, and EuSe NPs, within the gel. The alginate gel with metal NPs was used as a drug-delivery system by further co-encapsulating doxorubicin and rifampicin, the release of which was made to be pH-dependent. This system can be conveniently and safely used for in vitro and in vivo bioimaging, enabled by the metal NPs formed within the gel matrix without using toxic reducing reagents or surfactants.


Subject(s)
Alginates/chemistry , Drug Carriers/chemistry , Fluorescent Dyes/chemistry , Gels/chemistry , Metal Nanoparticles/chemistry , Aminoacyltransferases/genetics , Aminoacyltransferases/metabolism , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Arabidopsis/enzymology , Doxorubicin/chemistry , Doxorubicin/pharmacology , Drug Liberation , Escherichia coli/genetics , Hep G2 Cells , Humans , Male , Metallothionein/genetics , Metallothionein/metabolism , Metals/chemistry , Mice, Nude , Pseudomonas putida/enzymology , Rifampin/chemistry , Rifampin/pharmacology
2.
Nanoscale ; 9(26): 9210-9217, 2017 Jul 06.
Article in English | MEDLINE | ID: mdl-28650486

ABSTRACT

Multifunctional carbon-based nanodots (C-dots) are synthesized using atmospheric plasma treatments involving reactive gases (oxygen and nitrogen). Surface design was achieved through one-step plasma treatment of C-dots (AC-paints) from polyethylene glycol used as a precursor. These AC-paints show high fluorescence, low cytotoxicity and excellent cellular imaging capability. They exhibit bright fluorescence with a quantum yield twice of traditional C-dots. The cytotoxicity of AC-paints was tested on BEAS2B, THLE2, A549 and hep3B cell lines. The in vivo experiments further demonstrated the biocompatibility of AC-paints using zebrafish as a model, and imaging tests demonstrated that the AC-paints can be used as bio-labels (at a concentration of <5 mg mL-1). Particularly, the oxygen plasma-treated AC-paints (AC-paints-O) show antibacterial effects due to increased levels of reactive oxygen species (ROS) in AC-paints (at a concentration of >1 mg mL-1). AC-paints can effectively inhibit the growth of Escherichia coli (E. coli) and Acinetobacter baumannii (A. baumannii). Such remarkable performance of the AC-paints has important applications in the biomedical field and environmental systems.


Subject(s)
Carbon/chemistry , Fluorescence , Plasma Gases , Quantum Dots/chemistry , Acinetobacter baumannii/drug effects , Animals , Anti-Bacterial Agents/chemistry , Cell Line, Tumor , Escherichia coli/drug effects , Humans , Materials Testing , Polyethylene Glycols , Reactive Oxygen Species/metabolism , Zebrafish
3.
Mikrochim Acta ; 185(1): 53, 2017 12 14.
Article in English | MEDLINE | ID: mdl-29594533

ABSTRACT

The authors describe a method for real-time monitoring of the activity of ribonuclease H (RNase H). It is based on target-triggered rolling circle amplification (RCA). It utilizes a specially designed primer that contains a RNA sequence in the center and an amino group at the 3'-end. In the absence of RNase H, the primer when hybridized to a circular DNA template is not extended by DNA polymerase due to the amino group at the 3'-end. In contrast, the presence of RNase H specifically degrades the RNA sequence of the primer hybridized to the circular DNA template. This results in the conversion of the 3'-amino group to a 3'-hydroxy group and thereby enables the extension reaction promoted by DNA polymerase. This, consequently, leads to efficient RCA producing a long concatenated DNA strand. Its generation can be monitored in real-time by using the fluorescent dye SYBR green II which is specific for single-stranded DNA. Based on this RNase H-triggered RCA, RNase H activity can be selectively determined at levels as low as 0.019 U·mL-1 with a total assay time of <5 min. The diagnostic capability of this assay was demonstrated by monitoring the activity of RNase H in tumor cells. Graphical abstract Schematic of real-time monitoring of ribonuclease H (RNase H) activity based on target-triggered rolling circle amplification (RCA). RNase H that degrades RNA in primer, converts 3'-amino group to 3'-hydroxy group, which promotes RCA with fluorescence enhancement of the probe SYBR green II.


Subject(s)
Base Sequence , Biosensing Techniques/methods , DNA, Circular/chemistry , Nucleic Acid Amplification Techniques/methods , Ribonuclease H/analysis , DNA, Single-Stranded , Fluorescence , Organic Chemicals , Ribonuclease H/metabolism
4.
J Mater Chem B ; 5(12): 2231-2234, 2017 Mar 28.
Article in English | MEDLINE | ID: mdl-32263613

ABSTRACT

A simple and eco-friendly method has been developed for the one-pot synthesis of DNA-copper nanoflowers that exhibit high loading efficiencies, low cytotoxicities, and strong resistance against nucleases.

5.
Ecotoxicol Environ Saf ; 137: 103-112, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27915140

ABSTRACT

Two zinc-aminoclays [ZnACs] with functionalized primary amines [(-CH2)3NH2] were prepared by a simple sol-gel reaction using cationic metal precursors of ZnCl2 and Zn(NO3)2 with 3-aminopropyl triethoxysilane [APTES] under ambient conditions. Due to the facile interaction of heavy metals with primary amine sites and Zn-related intrinsic antimicrobial activity, toxicity assays of ZnACs nanoparticles (NPs) prior to their environmental and human-health applications are essential. However, such reports remain rare. Thus, in the present study, a cell viability assay of in-vitro HeLa cells comparing ZnCl2, Zn(NO3)2 salts, and ZnO (~50nm average diameter) NPs was performed. Interestingly, compared with the ZnCl2, and Zn(NO3)2 salts, and ZnO NPs (18.73/18.12/51.49µg/mL and 18.12/15.19/46.10µg/mL of IC50 values for 24 and 48h), the two ZnACs NPs exhibited the highest toxicity (IC50 values of 21.18/18.36µg/mL and 18.37/17.09µg/mL for 24 and 48h, respectively), whose concentrations were calculated on Zn elemental composition. This might be due to the enhanced bioavailability and uptake into cells of ZnAC NPs themselves and their positively charged hydrophilicity by reactive oxygen species (ROS) generation, particularly as ZnACs exist in cationic NP's form, not in released Zn2+ ionic form (i.e., dissolved nanometal). However, in an in-vivo embryotoxicity assay in zebrafish, ZnACs and ZnO NPs showed toxic effects at 50-100µg/mL (corresponding to 37.88-75.76 of Zn wt% µg/mL). The hatching rate (%) of zebrafish was lowest for the ZnO NPs, particularly where ZnAC-[(NO3)2] is slightly more toxic than ZnAC-[Cl2]. These results are all very pertinent to the issue of ZnACs' potential applications in the environmental and biomedical fields.


Subject(s)
Embryo, Nonmammalian/drug effects , Metal Nanoparticles/toxicity , Zebrafish/embryology , Zinc Compounds/toxicity , Zinc/toxicity , Animals , Cell Survival/drug effects , HeLa Cells , Humans , Metal Nanoparticles/chemistry , Propylamines/chemistry , Propylamines/toxicity , Reactive Oxygen Species/metabolism , Silanes/chemistry , Silanes/toxicity , Toxicity Tests , Zinc/chemistry , Zinc Compounds/chemistry
6.
Biosens Bioelectron ; 88: 48-54, 2017 Feb 15.
Article in English | MEDLINE | ID: mdl-27499380

ABSTRACT

We herein describe an innovative method for a universal fluorescence turn-on enzyme assay, which relies on the target enzyme-triggered DNA polymerase activity. In the first target recognition step, the target enzyme is designed to destabilize detection probe derived from an aptamer specific to DNA polymerase containing the overhang sequence and the complementary blocker DNA, which consequently leads to the recovery of DNA polymerase activity inhibited by the detection probe. This target-triggered polymerase activity is monitored in the second signal transduction step based on primer extension reaction coupled with TaqMan probe. Utilizing this design principle, we have successfully detected the activities of two model enzymes, exonuclease I and uracil DNA glycosylase with high sensitivity and selectivity. Since this strategy is composed of separated target recognition and signal transduction modules, it could be universally employed for the sensitive determination of numerous different target enzymes by simply redesigning the overhang sequence of detection probe, while keeping TaqMan probe-based signal transduction module as a universal signaling tool.


Subject(s)
Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , DNA-Directed DNA Polymerase/chemistry , Enzyme Assays/methods , Exodeoxyribonucleases/analysis , Taq Polymerase/chemistry , Uracil-DNA Glycosidase/analysis , Cell Line, Tumor , Exodeoxyribonucleases/metabolism , Humans , Spectrometry, Fluorescence/methods , Thermus/enzymology , Uracil-DNA Glycosidase/metabolism
7.
Nanotechnology ; 27(42): 425502, 2016 Oct 21.
Article in English | MEDLINE | ID: mdl-27622680

ABSTRACT

We devised a novel method for rapid and ultrasensitive detection of target microRNA (miRNA) by employing target-assisted isothermal exponential amplification (TAIEA) combined with poly (thymine)-templated fluorescent copper nanoparticles (CuNPs) as signaling probes. The target miRNA hybridizes to the unimolecular template DNA and works as a primer for the extension reaction to form double-stranded product, which consequently generates two nicking endonuclease recognition sites. By simultaneous nicking and displacement reactions, exponential amplification generates many poly (thymine) strands as final products, which are employed for the synthesis of fluorescent CuNPs. Based on the fluorescent signal from CuNPs, target miRNA is detected as low as 0.27 fM around 1 h of total analysis time. The diagnostic capability of this system has been successfully demonstrated by reliably detecting target miRNA from different cell lysates, showing its great potential towards real clinical applications.

8.
Small ; 12(2): 214-9, 2016 Jan 13.
Article in English | MEDLINE | ID: mdl-26584654

ABSTRACT

Recently, the appeal of 2D black phosphorus (BP) has been rising due to its unique optical and electronic properties with a tunable band gap (≈0.3-1.5 eV). While numerous research efforts have recently been devoted to nano- and optoelectronic applications of BP, no attention has been paid to promising medical applications. In this article, the preparation of BP-nanodots of a few nm to <20 nm with an average diameter of ≈10 nm and height of ≈8.7 nm is reported by a modified ultrasonication-assisted solution method. Stable formation of nontoxic phosphates and phosphonates from BP crystals with exposure in water or air is observed. As for the BP-nanodot crystals' stability (ionization and persistence of fluorescent intensity) in aqueous solution, after 10 d, ≈80% at 1.5 mg mL(-1) are degraded (i.e., ionized) in phosphate buffered saline. They showed no or little cytotoxic cell-viability effects in vitro involving blue- and green-fluorescence cell imaging. Thus, BP-nanodots can be considered a promising agent for drug delivery or cellular tracking systems.


Subject(s)
Biomedical Technology/methods , Nanoparticles/chemistry , Phosphorus/chemistry , Animals , Biocompatible Materials/pharmacology , Cell Line , Cell Survival/drug effects , Fluorescence , Humans , Microscopy, Atomic Force , Optical Phenomena , Spectrum Analysis, Raman , X-Ray Diffraction
9.
J Nanobiotechnology ; 13: 88, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26612177

ABSTRACT

We have investigated the cytotoxic assay of Fe-aminoclay (FeAC) nanoparticles (NPs) and simultaneous imaging in HeLa cells by photoluminescent carbon nanodots (CD) conjugation. Non-cytotoxic, photostable, and CD NPs are conjugated with cationic FeAC NPs where CD NPs play a role in bio-imaging and FeAC NPs act as a substrate for CD conjugation and help to uptake of NPs into cancer cells due to positively charged surface of FeAC NPs in physiological media. As increase of CD-FeAC NPs loading in HeLa cell in vitro, it showed slight cytotoxicity at 1000 µg/mL but no cytotoxicity for normal cells up to concentration of 1000 µg/mL confirmed by two 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutral red (NR) assays, with further observations by 4',6-diamidino-2-phenylindole (DAPI) stained confocal microscopy images, possessing that CD-FeAC NPs can be used as potential drug delivery platforms in cancer cells with simultaneous imaging. Graphical abstract CD conjugation with organo-building blocks of delaminated FeAC NPs.


Subject(s)
Carbon/chemistry , Imaging, Three-Dimensional/methods , Iron Compounds/chemistry , Iron/chemistry , Nanoparticles/chemistry , Silicates/chemistry , Animals , Cell Death , Cell Survival , Endocytosis , HeLa Cells , Humans , Hydrodynamics , Indoles/metabolism , Mice , Microscopy, Confocal , Nanoparticles/ultrastructure , Particle Size , Spectrometry, Fluorescence , Spectroscopy, Fourier Transform Infrared , Static Electricity , X-Ray Diffraction
10.
Sci Rep ; 4: 4665, 2014 Apr 11.
Article in English | MEDLINE | ID: mdl-24721805

ABSTRACT

Using a simple method of mass production of green carbon nanotags (G-tags) from harmful cyanobacteria, we developed an advanced and efficient imaging platform for the purpose of anticancer therapy. Approximately 100 grams of G-tags per 100 kilograms of harmful cyanobacteria were prepared using our eco-friendly approach. The G-tags possess high solubility, excellent photostability, and low cytotoxicity (<1.5 mg/mL for 24 h). Moreover, doxorubicin-conjugated G-tags (T-tags; >0.1 mg/mL) induced death in cancer cells (HepG2 and MCF-7) in-vitro at a higher rate than that of only G-tags while in-vivo mice experiment showed enhanced anticancer efficacy by T-tags at 0.01 mg/mL, indicating that the loaded doxorubicin retains its pharmaceutical activity. The cancer cell uptake and intracellular location of the G- and T-tags were observed. The results indicate that these multifunctional T-tags can deliver doxorubicin to the targeted cancer cells and sense the delivery of doxorubicin by activating the fluorescence of G-tags.


Subject(s)
Carbon/chemistry , Drug Carriers/chemistry , Nanostructures/chemistry , Animals , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/chemistry , CHO Cells , COS Cells , Cell Survival/drug effects , Chlorocebus aethiops , Cricetinae , Cricetulus , Cyanobacteria/metabolism , Doxorubicin/administration & dosage , Doxorubicin/chemistry , Hep G2 Cells , Humans , MCF-7 Cells , Male , Mice , Mice, Nude , Neoplasms/drug therapy , Transplantation, Heterologous
11.
Nanoscale ; 6(3): 1529-36, 2014.
Article in English | MEDLINE | ID: mdl-24322602

ABSTRACT

Enzyme-linked immunosorbent assays (ELISAs) have most widely been applied in immunoassays for several decades. However, several unavoidable limitations (e.g., instability caused by structural unfolding) of natural enzymes have hindered their widespread applications. Here, we describe a new nanohybrid consisting of Fe3O4 magnetic nanoparticles (MNPs) and platinum nanoparticles (Pt NPs), simultaneously immobilized on the surface of graphene oxide (GO). By synergistically integrating highly catalytically active Pt NPs and MNPs on GO whose frameworks possess high substrate affinity, the nanohybrid is able to achieve up to a 30-fold higher maximal reaction velocity (V(max)) compared to that of free GO for the colorimetric reaction of the peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB), and enable rapid detection of target cancer cells. Specifically, using this new assay system, clinically important breast cancer cells are detected in a 5 min time period at room temperature with high specificity and sensitivity. The remarkably high capability to catalyze oxidation reactions could allow the nanohybrid to replace conventional peroxidase-based immunoassay systems as part of new, rapid, robust and convenient assay systems which can be widely utilized for the identification of important target molecules.


Subject(s)
Breast Neoplasms/diagnosis , Colorimetry/methods , Graphite/chemistry , Metal Nanoparticles/chemistry , Oxides/chemistry , Platinum/chemistry , Benzidines/chemistry , Breast Neoplasms/metabolism , Catalysis , Female , Humans , Immunoassay , Kinetics , Magnetics , Microscopy, Electron, Scanning Transmission , Nanotechnology , Peroxidase/chemistry , Peroxidases/chemistry , Sensitivity and Specificity , X-Ray Diffraction
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