ABSTRACT
The active ingredient of traditional Chinese medicine, silybin (SBN), can inhibit the proliferation of cancer cells and enhance the anticancer effect of doxorubicin (DOX). However, due to non-targeting and short half-life of SBN and DOX, as well as different administration routes and pharmacokinetic processes, this combination drug cannot act on the tumor in the set order, seriously eliminating the synergistic effect between them and limiting the effect in vivo. Therefore, we intended to construct a nano-delivery system based on molybdenum disulfide (MoS2), modified by polyethylene glycol (PEG) and sialic acid (SA), and co-loaded with SBN and DOX. The system induced the release of combined drugs under the dual-stimulation of pH and near infra-red (NIR), increased the free concentration of intracellular drugs, so as to achieve the synergistic effect between them. The animal welfare and experimental procedures were in accordance with the regulations of the Animal Ethics Committee of Fujian University of Traditional Chinese Medicine. MoS2-PEG-SA-SBN/DOX circulated in vivo, and effectively accumulated at tumor sites through enhanced permeability and retention effect (EPR) and SA-mediated active targeting. Under near infrared light irradiation, MoS2-PEG-SA-SBN/DOX realized the combination of synergistic chemotherapy and photothermal therapy for tumor, thus achieving excellent anti-tumor effect in vivo. This study can provide a new idea and strategy for the clinical treatment of lung cancer. Taken together, MoS2-PEG-SA-SBN/DOX can offer a new idea and strategy for the clinical treatment of lung cancer.
ABSTRACT
Molybdenum disulfide ( MoS2) quantum dots ( QDs) were synthesized using one-step hydrothermal method with an acceptable fluorescence property. Based on the quenching effect between doxycycline hyclate ( DOX) and MoS2QDs, a fluorescence method for detection of DOX was established. The interaction between MoS2QDs and DOX was discussed with a final proposal of the static quenching mechanism. A good linear correlation for detection of DOX using fluorescenct MoS2QDs was obtained in the concentration range of 0. 86-55. 40 μg/mL, with a detection limit of 0. 023 μg/mL (S/N=3). The fabricated sensor was applied to the detection of DOX in real samples with RSDs of less than 5% . The relative error of determination results of MoS2QDs method compared with HPLC was from -4. 5% to 0. 8% and -4. 6% to 2. 8% for DOX tablet and DOX spiked milk, respectively. The fluorescence detection of DOX in real sample using MoS2QDs was simple, rapid and reliable.
ABSTRACT
A highly sensitive and selective DNA biosensor is described based on the fluorescence quenching ability of MoS2 nanosheet and exonucleaseⅢ( ExoⅢ) assisted dual-signal amplification. In this sensor, the fluorescence probes ( HP1 and HP2 ) cannot be degraded by Exo Ⅲdue to the 3 '-termini protrusion and thus are adsorbed on the surface of MoS2 nanosheets, which will result in the quenching of MoS2 nanosheets toward the probes and induce a low fluorescent signal. The presence of the target DNA leads to the desorption of probes on the surface of MoS2 nanosheets due to the hybridization toward probes, generating many fluorescent fragments by Exo Ⅲdigestion and inducing dual-signal amplification. This method can improve the sensitivity and detection limit compared with single amplification method, and shows excellent selectivity in the discrimination of single base mismatched targets. On the basis of the significantly high sensitivity, the developed biosensor can be potentially extended to detect various DNA targets with excellent sequence selectivity.