No abstract

Finding a timely, sensitive, and noninvasive detection method has become an urgent need for asymptomatic early diagnosis of Alzheimer’s disease (AD). MicroRNA-193b (miR-193b) and Aβ42 oligomers (AβO42) in neurogenic exosomes were confirmed to reflect pathological changes in the AD early stage. The combination of two biomarkers is promising for the earlier detection of AD. In this study, a detection system based on the principle of the entropy-driven strand displacement reaction (ESDR) was developed, including a dumbbell detection probe (H), an indicator probe (R), and graphene oxide (GO). In the detection system, the two hairpins of H were opened by the interaction of miR-193b (T1) and AβO42 (T2) with the aptamer. Then R hybridized with H and began to displace T, initiating the next round of ESDR to achieve sensitive detection of T. GO specifically adsorbed free R and quenched the fluorescence, further reducing the intensity of the background signal. Both of these points provided the system with a more sensitive analytical performance. The detection limit of miR-193b was 77 pM and the detection limit of AβO42 was 53 pM. This sensor detected the change of “one increase (AβO42) and one decrease (miR-193b)” in the exosome sample. Additionally, results showed that this detection system could distinguish the model of early AD from the non-AD control, which was sufficient for earlier and more sensitive detection of AD. This strategy has strong specificity, high sensitivity, and easy operation, which provides broad prospects for the early diagnosis of AD.

No abstract

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of early atherosclerosis (AS). Targeting foam cell formation can be a promising approach...

Water-soluble starlike polymers containing concentrated carboxyl groups were conveniently synthesized via the combination of ''click'' chemistry and atom transfer radical polymerization. The starlike polymer was composed of a shorter polyacrylate main chain and longer poly(acrylic acid) side chains. Alkyne and azide groups were introduced to the structure units of the main chain by esterification and the chain end of the side chain by substitution reaction of NaN 3 to bromine, respectively. By click chemistry between alkyne and azide group, welldefined starlike polymers were obtained. FT-IR, gel permeation chromatography, and 1 H NMR were used to characterize the resulting polymers. Aggregation behavior demonstrated by transmission electron microscopy was observed when the starlike polymers were dispersed in water at pH 7.0-7.5. Using the starlike polymers as templates, water-soluble silver nanoclusters mainly consisting of Ag 2 supported by the generated nanoparticles and carboxyl groups were successfully synthesized. Also, their optical properties and morphology were characterized by UV-vis absorption spectra and TEM.