Silica Nanoparticle Exposure Caused Brain Lesion and Underlying Toxicological Mechanism:Route-Dependent Bio-Corona Formation and GSK3βPhosphorylation Status

When nanoparticles(NPs)enter a physiological environment,they tend to adsorb proteins to form a so-called corona.A comprehensive understanding of the effect of protein corona on NPs’toxicity is required.Our previous study indicated that silica nanoparticles(SiO_(2)NPs)exposure with different routes resulted in distinct brain damage;however,an exact molecular mechanism of protein corona on the regulation of SiO_(2)NPsinduced damages needs further investigation.SiO_(2)NPs exposure via intravenous injection may encounter a protein-rich bio-matrix,which drives the adsorption of serum protein on their surface to form a stable SiO_(2)NPs@serum complex.On the contrary,SiO_(2)NPs exposure via intranasal instillation remained their original feature,due to a protein infertile environment of cerebrospinal fluid.Apparently,surface adsorption of proteinaceous substances altered inherent toxic behavior of SiO_(2)NPs.In addition,glycogen synthase kinase 3 beta(GSK3β)phosphorylate was found at different residues,which play an essential role in orchestrating apoptosis and autophagy threshold.Route-dependent corona formation determined GSK3βphosphorylation status and ultimately the toxic behavior of SiO_(2)NPs.This work presented the evidence of biocorona on the regulation of SiO_(2)NPs-induced toxicity,which can be used to guide risk assessment of environmental NPs.

Rapid detection of pathogenic bacteria based on a universal dual-recognition FRET sensing system constructed with aptamer-quantum dots and lectin-gold nanoparticles

The threat to public health from bacterial infections has led to an urgent need to develop simpler,faster and more reliable bacterial detection methods.In this work,we developed a universal dual-recognition based sandwich fluorescence resonance energy transfer(FRET)sensor by using specific aptamer-modified quantum dots(Aptamer-QDs)as energy donor and lectin concanavalin A(Con A)modified gold nanoparticles(Con A-AuNPs)as energy acceptor to achieve rapid and sensitive detection of Escherichia coli(E.coli)within 0.5 h.In the presence of the target E.coli,the energy donor of Aptamer-QDs and acceptor of Con A-AuNPs were close to each other,causing changes of FRET signals.Based on the constructed FRET sensor,a linear detection range of from 10^(2)cfu/mL to 2×10^(8)cfu/mL with the detection limit of 45 cfu/mL for E.coli was achieved.Furthermore,the FRET sensor was applied to detect E.coli in the milk and orange juice with the detection limit of 300 cfu/mL and 200 cfu/mL,respectively and recovery rate from 83.1%to 112.5%.The strategy holds great promise in pathogenic bacteria detection due to its rapid and sensitivity.

Aptamer-quantum dots and teicoplanin-gold nanoparticles constructed FRET sensor for sensitive detection of Staphylococcus aureus

The detection of bacterial pathogen such as Staphylococcus aureus(S.aureus) is essential for the regulation of food hygiene and disease diagnosis.Herein,we developed a simple one-step fluorescence resonance energy transfer(FRET)-based sensor for specific and sensitive detection of S.aureus in food and serum samples,in which aptamer-modified quantum dots(aptamer-QDs) was employed as the energy donor and antibiotic of teicoplanin functionalized-gold nanoparticles(Teico-AuNPs) was chosen as the energy acceptor.Within 1 h,the FRET-based sensor showed a linear range of from 10 cfu/mL to 5 × 10^(8) cfu/mL,with the low limit of detection(LOD,2 cfu/mL) for S.aureus in buffer.When further applied to assay S.aureus in real samples,the FRET-based sensor showed good recoveries ranging from 84.5% to 110.0%,with relative standard derivations(RSDs) of 0.01%-0.44% and a LOD of 100 cfu/mL in milk,orange juice and human serum.