Ultrasensitive and Signal‐on Electrochemiluminescence Aptasensor Using the Multi‐tris(bipyridine)ruthenium(II)‐<i>β</i>‐cyclodextrin Complexes

An inclusion complex of podophyllotoxin (PPT) with γ‐cyclodextrin (γ‐CD) was prepared. The behavior, characterization, and water solubility of the inclusion complex were carefully investigated via fluorescence spectroscopy, thermogravimetry, differential scanning calorimetry, X‐ray diffraction analysis, and 1H and 2D nuclear magnetic resonance spectroscopy. Furthermore, antitumor activity to human cancer lines and toxicity in mice were studied. Results showed that the inclusion complex formed in a 1:1 ratio with a considerable apparent stability constant Ks (4245.5 L·mol−1). Water solubility was considerably improved. In addition, the anticancer activity of the inclusion complex was better than that of cis‐platinum (DDP, positive control). Most importantly, the toxicity of podophyllotoxin inclusion complex reduced and became more safety to mice which will be great valuable to research its applications as a kind of antitumor drug to human in the further.

Inclusion Complex of Podophyllotoxin with γ‐Cyclodextrin: Preparation, Characterization, Anticancer Activity, Water‐Solubility and Toxicity

Guo

Zhang

et al. 2016

β‐Cyclodextrin and Its Derivatives Functionalized Magnetic Nanoparticles for Targeting Delivery of Curcumin and Cell Imaging

Zhou

Wang

et al. 2016

β‐Cyclodextrin (β‐CD) and its derivatives functionalized magnetic nanoparticles (MNPs) with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxypropyl/sulfobutyl ether‐β‐CD‐MNPs (CM/HP/SBE‐β‐CD‐MNPs) nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as‐prepared nanocarriers for the hydrophobic anti‐cancer drug curcumin was also investigated. The results revealed that the SBE‐β‐CD‐MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE‐β‐CD‐MNPs entered into the cell, and curcumin could be successfully delivered into the cell by SBE‐β‐CD‐MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE‐β‐CD‐MNPs were non‐toxic, while curcumin loaded SBE‐β‐CD‐MNPs showed high potential to kill the HepG2 cells. The as‐prepared magnetic composites were expected to expand their potential applications in biomedical field.

Ultrasensitive Electrochemical Aptasensor Based on Surface‐Initiated Enzymatic Polymerization

Wang

Wan

et al. 2016

Coupled with the ability of fast and quantitative response, electrochemical aptasensors (EA) have great potential in the application of early diagnosis of cancer biomarker. In order to determine the rare biomarkers in the complicate clinical samples, scientists are making unremitting efforts towards improving the sensitivity and selectivity of EA. Herein, a "sandwich"-structure electrochemical aptasensor (SEA) is developed for analysis of cancer biomarker carcino-embryonic antigen (CEA). Two DNA aptamers are employed, one of which is thiolated at 3'-terminal and immobilized onto the gold electrode as a capture probe, while the other one is served as signal probe. The two aptamers could "sandwich" the target and signal probe is then subjected to the terminal deoxynucleotidyl transferase (TdT)-catalyzed incorporation of biotin labeled dNTPs into its 3'-terminal. Thus the as-generated long DNA oligo tails allow specific binding of numerous avidin modified horseradish peroxidase (Av-HRP), resulting in enhanced peroxidase catalyzed electrochemical signals. This signal amplification strategy is termed as surface initiated enzymatic polymerization (SIEP). This SIEP amplified SEA has a detection limit of 10 pg•mL 1 , indicating the outstanding amplification efficiency.