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The combination of chemotherapy and photothermal therapy displays improved anti-cancer effects and lower systematic toxicity of a free drug compared with monotherapy. In this study, we designed innovative, carrier-free nanodrugs (PTX/ICG NDs) composed of the chemotherapeutic agent paclitaxel (PTX) and the photosensitizer indocyanine green (ICG) via self-assembly. The nanodrugs not only incorporated two different modalities into one delivery system for combined chemo-photothermal therapy but also enhanced the solubility of PTX without the need for any carrier. The as-prepared PTX/ICG NDs exhibited the merits of a relatively uniform size of 140 ± 1.4 nm, surface charge of −36 ± 2.2 mV, and high drug loading content of PTX. The combination strategy exerted a synergistic effect on the cytotoxicity of cancer cells in vitro, which could be attributed to the high cellular uptake and sustained release of PTX. Furthermore, an in vivo study indicated that PTX/ICG NDs showed higher accumulation in the tumor site than free ICG and possessed strong synergistic chemo-photothermal therapy efficacy against tumors in H22 tumor-bearing mice. Taken together, our study demonstrates that PTX/ICG NDs hold promise to become an alternative chemo-photothermal therapy agent to treat cancers. [ABSTRACT FROM AUTHOR]

Occurrence and application of oligonucleotide probes have promoted great progress in the biochemical analysis field due to their unique biological and chemical properties. In this work, a long-stem shaped multifunctional molecular beacon (LS-MMB) that is responsive to a cancer-related gene, p53, is well-prepared. By designing the probe with long-paired bases at its two ends and short-paired bases between the middle region and the 3′ end, the LS-MMB is intelligently endowed with the ability to recognize the target analyte, serve as the polymerization primer/template, and signal the hybridization event synchronously, which is distinctly advantageous over the traditional molecular beacons (MBs). Moreover, it is excitingly found that the LS-MMB can be employed to exert intramolecular and intermolecular interactions for strand displacement amplification (SDA) without the involvement of any assistant probes; this therapy results in a really easy and rapid sensing system that provides an extremely low background noise and high target output signal. In this case, an excellent sensitivity and specificity to detect target gene down to picomolar level and resolution to even one nucleotide variation are achieved, respectively. In addition, the application potential for real genomic DNA analysis is realized. We envision that the probe of LS-MMB can act as a universal platform for biosensing and biomedical research. [ABSTRACT FROM AUTHOR]

In this work, we have proposed a chain anadiplosis-structured DNA nanowire by using two well-defined assembly strands (AS1 and AS2). The presence of a target analyte would drive the single-stranded AS1 dissociate from the pre-formatted nanowire, converting into a fully double-stranded form responsible for extensive accumulation of G-rich cleavage fragment1 (GCF1) because of an autonomously performed polymerization/nicking/displacement process. In turn, the produced GCF1 is able to hybridize with the un-peeled AS2, allowing the replication over AS2 to occur and generate large amounts of G-rich cleavage fragment2 (GCF2) with the ability to hybridize with the un-peeled AS1, thereafter initiating new enzymatic reactions for further collection of GCF1. Because the reactions occur repeatedly, the assembled nanowires gradually dissociated and completely collapsed in the end, achieving the goal of substantial signal amplification for the colorimetric readout of the target analytes. The sensing feasibility is firstly verified by one trigger primer (TP), and then exemplified with the detection of the target, the kras oncogene, with high sensitivity and specificity. As a proof-of-concept strategy, the intelligent signal readout pathway and desired assay ability provide unique insights into the materials research and biological studies. [ABSTRACT FROM AUTHOR]