Multifunctional DNA Nanoflower Applied for High Specific Photodynamic Cancer Therapy In Vivo.

Photodynamic therapy (PDT) is a newly emerged strategy for disease treatment. One challenge of the application of PDT drugs is the side-effect caused by the non-specificity of the photosensitive molecules. Most of the photosensitizers may invade not only the pathogenic cells but also the normal cells.

Recent Advances in Constructing Higher-Order DNA Structures.

Molecular self-assembly is widely used in the fields of biosensors, molecular devices, efficient catalytic materials, and medical biomaterials. As the carrier of genetic information, DNA is a kind of biomacromolecule composed of deoxyribonucleotide units. DNA nanotechnology extends DNA of its original properties as a molecule that stores and transmits genetic information from its biological environment by taking advantage of its unique base pairing and inherent biocompatibility to produce structurally-defined supramolecular structures.

DNA nanostructure-based nucleic acid probes: construction and biological applications.

In recent years, DNA has been widely noted as a kind of material that can be used to construct building blocks for biosensing, imaging, drug development, and disease therapy because of its advantages of good biocompatibility and programmable properties. However, traditional DNA-based sensing processes are mostly achieved by random diffusion of free DNA probes, which were restricted by limited dynamics and relatively low efficiency. Moreover, in the application of biosystems, single-stranded DNA probes face challenges such as being difficult to internalize into cells and being easily decomposed in the cellular microenvironment.

Isothermal cross-boosting extension-nicking reaction mediated exponential signal amplification for ultrasensitive detection of polynucleotide kinase.

A novel nucleic acid-based isothermal signal amplification strategy, named cross-boosting extension-nicking reaction (CBENR) is developed and successfully used for rapid and ultrasensitive detection of polynucleotide kinase (PNK) activity. Only two simple oligonucleotides (recognition substrate (RS) and TaqMan probe) are applied to construct the PNK-sensing platform. In the presence of PNK, the 3'-phosphate end of RS will be converted to the 3'-hydroxyl one, and then extended to a long poly-adenine (poly-A) sequence under the catalysis of terminal deoxynucleotidyl transferase (TdT).

Chiral Interaction Is a Decisive Factor To Replace d-DNA with l-DNA Aptamers.

Nucleic acid aptamers have been widely used in various fields such as biosensing, DNA chip, and medical diagnosis. However, the high susceptibility of nucleic acids to ubiquitous nucleases reduces the biostability of aptamers and limits their applications in biological contexts. Therefore, improving the biostability of aptamers becomes an urgent need.

pH-Controlled Intracellular in Situ Reversible Assembly of a Photothermal Agent for Smart Chemo-Photothermal Synergetic Therapy and ATP Imaging.

To advance anti-tumor efficiency and lessen the adverse effect caused by nanodrug residues in the body, a smart nanoagent system is developed and successfully used in intracellular ATP imaging and in vivo chemo-photothermal synergetic therapy. The nanoagent system is facilely prepared using a DNA complex to modify gold nanoparticles (AuNPs). The DNA complex is formed by three oligonucleotides (ATP aptamer, rC-DNA, and rG-DNA).

Nanolantern-Based DNA Probe and Signal Amplifier for Tumor-Related Biomarker Detection in Living Cells.

The introduction of nanotechnology can overcome some inherent drawbacks of traditional DNA probes, thus promoting their applications in living cells. Herein, a three-dimensional DNA nanostructure, a DNA nanolantern, was prepared via simple nucleotide hybridization of four short-stranded oligonucleotides and successfully applied to the construction of a novel DNA probe and signal amplifier. Compared to most reported DNA nanostructures, a DNA nanolantern shows the distinct advantages of low cost, easy design and preparation, more and arbitrary adjusted probe numbers, and high fluorescence resonance energy transfer (FRET) signal readout.

Trifunctional integrated DNA-based universal sensing platform for detection of diverse biomolecules in one-pot isothermal exponential amplification mode.

A biosensor with all the advantages of ultra-high sensitivity, easy operation, straightforward signal output and universal applicability is introduced. The biosensor was demonstrated to work well in the detection of polynucleotide kinase and DAM methyltransferase, thus providing a powerful tool for clinical diagnosis, drug screening and disease therapeutic assay.

A modified exponential amplification reaction (EXPAR) with an improved signal-to-noise ratio for ultrasensitive detection of polynucleotide kinase.

We applied a modified exponential amplification reaction (EXPAR) strategy to design a label-free and "one-pot" biosensor for ultrasensitive detection of polynucleotide kinase (PNK). This method was also successfully applied in the screening of PNK inhibitors and analysis of the endogenous PNK activity at the single-cell level.

Label-Free Telomerase Detection in Single Cell Using a Five-Base Telomerase Product-Triggered Exponential Rolling Circle Amplification Strategy.

Telomerase is a universal biomarker of malignant tumors. Sensitive and reliable analysis for telomerase activity is of vital importance for both early diagnosis and therapy of malignant tumors. Herein, a novel fluorescent strategy was proposed for sensitive and label-free detection of telomerase activity.

Terminal Deoxynucleotidyl Transferase-Catalyzed Preparation of pH-Responsive DNA Nanocarriers for Tumor-Targeted Drug Delivery and Therapy.

Developing a highly efficient carrier for tumor-targeted delivery and site-specific release of anticancer drugs is a good way to overcome the side effects of traditional cancer chemotherapy. Benefiting from the nontoxic and biocompatible characteristics, DNA-based drug carriers have attracted increasing attention. Herein, we reported a novel and readily manipulated strategy to construct spherical DNA nanocarriers.

G-Quadruplex/Porphyrin Composite Photosensitizer: A Facile Way to Promote Absorption Redshift and Photodynamic Therapy Efficacy.

Photosensitizer is one of the most important elements of photodynamic therapy (PDT). Herein, we reported a novel strategy to prepare a new series of composite photosensitizers. The composite photosensitizer was prepared by simply mixing DNA G-quadruplexes with a hydrophilic porphyrin (TMPipEOPP)·4I.

An integrated-molecular-beacon based multiple exponential strand displacement amplification strategy for ultrasensitive detection of DNA methyltransferase activity.

DNA methylation is a significant epigenetic mechanism involving processes of transferring a methyl group onto cytosine or adenine. Such DNA modification catalyzed by methyltransferase (MTase) plays important roles in the modulation of gene expression and other cellular activities. Herein, we develop a simple and sensitive biosensing platform for the detection of DNA MTase activity by using only two oligonucleotides.

Cationic porphyrins with large side arm substituents as resonance light scattering ratiometric probes for specific recognition of nucleic acid G-quadruplexes.

Specific G-quadruplex-probing is crucial for both biological sciences and biosensing applications. Most reported probes are focused on fluorescent or colorimetric recognition of G-quadruplexes. Herein, for the first time, we reported a new specific G-quadruplex-probing technique-resonance light scattering (RLS)-based ratiometric recognition.

Terminal Deoxynucleotidyl Transferase and T7 Exonuclease-Aided Amplification Strategy for Ultrasensitive Detection of Uracil-DNA Glycosylase.

As one of the key initiators of the base excision repair process, uracil-DNA glycosylase (UDG) plays an important role in maintaining genomic integrity. It has been found that aberrant expression of UDG is associated with a variety of diseases. Thus, accurate and sensitive detection of UDG activity is of critical significance for biomedical research and early clinical diagnosis.