Critical Study of the Recognition between C‑Reactive Protein and Surface-Immobilized Phosphorylcholine by Quartz Crystal Microbalance with Dissipation

C-reactive protein (CRP), a biomarker for cardiovascular disease, has been reported to have a strong affinity to zwitterionic phosphorylcholine (PC) groups in the presence of calcium ions. In addition, PC-immobilized surfaces have been used as a nonfouling coating to prevent nonspecific protein binding. By appropriately using the features of PC-immobilized surfaces, including specific recognition to CRP and nonfouling surface, it is reasonable to create an antibody-free biosensor for the specific capture of CRP. In this study, PC-functionalized 3,4-ethylenedioxythiophene (EDOT) monomers were used to prepare PC-immobilized surfaces. The density of PC groups on the surface can be fine-tuned by changing the composition of the monomer solutions for the electropolymerization. The density of PC group was confirmed by X-ray photoelectron spectroscopy (XPS). The specific interaction of CRP with PC groups was monitored by using a quartz crystal microbalance with dissipation (QCM-D). The amount of protein binding could be estimated by the reduction in frequency readout. Through the QCM-D measurement, we revealed the nonfouling property and the specific CRP capture from our PC-immobilized surfaces. Notably, the dissipation energy also dropped during the binding process between CRP and PC, indicating the release of water molecules from the PC groups during CRP adsorption. We anticipate that surface-bound water molecules are mainly released from areas near the immobilized PC groups. Based on Hofmeister series, we further examined the influence of ions by introducing four different anions including both kosmotrope (order maker) and chaotrope (disorder maker) into the buffer for the CRP binding test. The results showed that the concentration and the type of anions play an important role in CRP binding. The present fundamental study reveals deep insights into the recognition between CRP and surface-immobilized PC groups, which can facilitate the development of CRP sensing platforms

Surface Engineering of Phenylboronic Acid-Functionalized Poly(3,4-ethylenedioxythiophene) for Fast Responsive and Sensitive Glucose Monitoring

In this study, we have successfully demonstrated a nanostructured phenylboronic acid-grafted poly­(3,4-ethylenedioxythiophene), poly­(EDOT-PBA), platform for fast and sensitive glucose monitoring. The poly­(EDOT-PBA) films of well-organized tubular nanostructures can be fabricated by direct electropolymerization without templates. Compared to the smooth poly­(EDOT-PBA), the nanotubular poly­(EDOT-PBA) shows enhanced glucose sensitivity and a different adsorption process of bovine serum albumin (BSA). Besides, the BSA blocking and low concentration of fructose and galactose do not affect the sensitivity of this platform. Both quartz crystal microbalance (QCM) and electrochemical impedance spectroscopy (EIS) methods are used and compared for glucose monitoring by applying nanotubular poly­(EDOT-PBA) as conductive substrates. Compared to QCM analysis, EIS has a higher sensitivity to glucose and the detection limit is about 50 μM. Besides, the binding with glucose on poly­(EDOT-PBA) is highly reversibly. On the basis of these observations, the nanotubular poly­(EDOT-PBA) has a great potential for enzyme-free electrodes targeting continuous glucose monitoring applications

Activation of NF-κB by nicotine in SLCO3A1 overexpressing cells.

<p>(A) HEK293T cells were transfected with the NF-κB reporter plasmids, together with an empty vector or SLCO3A1 constructs. Addition of 0.8 µM nicotine for 24 hours resulted in increased NF-κB activity in cells overexpressing SLCO3A1 (*<i>P</i><0.05). (B) Western blot analysis from cell lysates demonstrates equal transfection efficiencies.</p

Demographic data of populations in Illumina (stage 1) and Sequenom (stage 2).

<p>*Illumina HumanOmni1-Quad_v1-0_B containing 1,016,423 SNPs.</p><p>**Sequenom MassARRAY system examining 38 SNPs.</p

Overexpression of SLCO3A1 induces NF-κB activation, enhances the phosphorylation of two classes of MAPKs (ERK and JNK), and augments NF-κB activity.

<p>(A) Overexpression of SLCO3A1 induced approximately 6-fold higher NF-κB activation (**<i>P</i><0.01). (B) Overexpression of SLCO3A1 in HEK293T cells resulted in increased p65 expression (*<i>P</i><0.05). (C) ERK and JNK expression increased with overexpression of SLCO3A1, while expression of p38 and AKT showed no difference (*<i>P</i><0.05). All experiments were performed at least 3 times.</p

Genotype and phenotype analysis of SLCO3A1 (rs207959).

<p>Inf: infinity.</p><p>NaN: Not a number.</p