ABSTRACT
Many polymer decorated/modified 2D nanomaterials have been developed as enhanced drug delivery systems and photothermal theranostic nanoagents. However, few reports describe the use of these novel nanomaterials as nanoplatforms for biomolecule sensing. Herein, we used calcium-cation-doped polydopamine-modified (PDA-modified) 2D black phosphorus (BP) nanosheets (BP@PDA) as a sensing nanoplatform for the detection of nucleic acids and proteins in complex biological samples. Fluorescent-dye-labeled single-strand DNA aptamer/probes are adsorbed by the Ca2+-doped BP@PDA mediated by calcium-cation coordination. The PDA coating enhances the stability of the inner BP, provides binding sites to DNA nucleobases, and quenches fluorescence. Without any chemical conjugation, this sensing nanoplatform selectively and specifically detects protein (human thrombin, linear range: 10-25 nM, detection limit: 0.02 nM), single-strand DNA (linear range: 1-10 nM, detection limit: 0.52 nM) in 1% serum diluted samples, and senses intracellular mRNAs (C-myc, and actin) in living cells. The nanoplatform exhibits the advantages of both the 2D nanomaterial (BP) and the coating polymer (PDA), naturally enters living cells unaided by transfection agents, resists enzymatic lysis and shows high biocompatibility. This nanoplatform design contributes towards future biomolecule analytical method development based on polymer decorated/modified 2D nanomaterials.
Subject(s)
Calcium/chemistry , Indoles/chemistry , Nanostructures/chemistry , Phosphorus/chemistry , Polymers/chemistry , Spectrometry, Fluorescence/methods , Thrombin/analysis , Cations/chemistry , Cell Survival/drug effects , DNA Probes/chemistry , DNA Probes/metabolism , DNA, Single-Stranded/analysis , DNA, Single-Stranded/chemistry , Fluorescent Dyes/chemistry , Hep G2 Cells , Humans , Limit of Detection , Microscopy, Confocal/methods , Nanostructures/toxicity , Proto-Oncogene Proteins c-myc/genetics , RNA, Messenger/analysisABSTRACT
Recent evidence suggests that Oxymatrine (OMT) has excellent effects in anticancer. The mechanism, however, remains unclear. In the present study, we investigated the potential mechanism of OMT against cancer. The differential expression of miRNA was screened by miRNA array. The expression of miRNA-520 and VEGF in lung cancer was assayed by real-time PCR, Western blot and immunohistochemistry, respectively. The direct interaction between miRNA-520 and VEGF was assayed by luciferase activity assay and their roles in lung cancer proliferation, invasion and migration were analyzed in vivo and in vitro. We found that miR-520 was markedly down-regulated and VEGF was markedly up-regulated in lung cancer tissues compared with adjacent normal tissues, which had significant negative correlation. Dual-luciferase assays confirmed that miR-520 directly targeting VEGF by binding to its upstream promoter region. Through in vitro and in vivo experiments, we found that different doses of OMT could up-regulate miR-520, selectively inhibit VEGF and thus inhibit the proliferation and migration of lung cancer. Our findings indicate that OMT inhibited cancer progression and metastasis by upregulation of miR-520 and downregulation of VEGF, which provide new support for OMT may be as a novel anticancer drug for the treatment of lung cancer in the future.