An Acidic Heteropolysaccharide Isolated from Pueraria lobata and Its Bioactivities.

A novel water-soluble acidic heteropolysaccharide, called PPL-1, was purified from Pueraria lobata. PPL-1 had an average molecular weight of 35 Kad, and it was composed of glucose, arabinose, galactose and galacturonic acid (6.3:0.8:0.8:2.1). In accordance with methylation and nuclear magnetic resonance analyses, PPL-1 primarily consisted of (1→2)-linked α-Araf, (1→4)-linked α-Glcp, (1→)-linked ß-Glcp, (1→6)-linked α-Glcp, (1→3,6)-linked α-Galp, (1→)-linked ß-GalpA and (1→4)-linked α-GalpA. In terms of bioactivities, PPL-1 exhibited remarkable scavenging ability towards DPPH (1,1-Diphenyl-2-picrylhydrazyl) radicals and moderate activity by enhancing the proliferation rate of RAW 264.7 cells by approximately 30% along with the secretion of NO. This work demonstrates that PPL-1 can be a potential source of immunoenhancers and antioxidants.

A graphene-based electrochemical flow analysis device for simultaneous determination of dopamine, 5-hydroxytryptamine, and melatonin.

Developing an accurate, sensitive, and efficient portable device for simultaneous detection of disease-related biomolecules is an attractive challenge for point-of-care testing (POCT). In this work, we introduced a novel graphene-based electrochemical flow analysis device (GEFAD), which combined a 3D-printed flow cell with a three-electrode system based on a gold nanoparticle-modified graphene (AuNPs@Gr) working electrode to simultaneously detect depression-related biomolecules: dopamine (DA), 5-hydroxytrypserotonin (5-HT), and melatonin (MEL). Electrochemical studies showed that the GEFAD had high selectivity and sensitivity in the determination of DA, 5-HT, and MEL with their significant separation peaks. The linear ranges of DA, 5-HT, and MEL were respectively found to be 0.1-70 µM, 0.1-100 µM, and 0.1-150 µM, with the corresponding detection limits of 0.054 µM, 0.071 µM, and 0.087 µM (S/N = 3). In addition, the GEFAD presented a good anti-interference ability and satisfactory reproducibility, and can be used in real calf serum sample analysis. The introduced in-flow electrochemical detection device showed excellent repeatability, less sample consumption, and simple operation, which increases the possibility to implement POCT. This study also proposed a promising application prospect for the development of portable biomolecules detection devices.

Hybrid 3D printed integrated microdevice for the determination of copper ions in human body fluids.

On-site screening of copper ions in body fluid plays a critical role in monitoring human health, especially in heavy pollution areas. In this study, we have developed a hybrid 3D printed integrated microdevice for the determination of copper ions in human body fluids. A fixed and low volume of sample was detected by using the integrated microdevice without any preprocessing. The hybrid channel enables sample uniform mixing and quantitative dilution with buffer solution by inducing the "horseshoe vortex" phenomenon. The electrolytic microcell based on the flow detection system shows a more effective copper ion reaction ratio and, as a result, a better sensitivity. The simulation of the finite element method (FEM) determined the relevant optimum parameters of the hybrid channel and the microcell. The design, fabrication, and detection procedure of the integrated microdevice are here illustrated. The microdevice presented superior detection properties towards copper ions. The calibration curves covered two linear ranges varying from 20 to 100 ppb and 100 to 400 ppb, respectively. The limit of detection was estimated to be 15 ppb (S/N = 3). The relative standard deviation of the peak current measurements was 2.26%. The designed microdevice was further applied to detect copper ions in practical samples (calf serum sample and synthetic human urine sample) using a standard addition method, and the average recovery was found to be 95-104%. The performance of copper ion detection with the integrated microdevice was consistent with that of the inductively coupled plasma mass spectrometry (ICP-MS) in the same practical samples, demonstrating significant practicality in the test of body fluidics. The portable integrated microdevice is an excellent choice for on-site detection and has a promising prospect in the point-of-care testing (POCT) applications.

A three-electrode integrated electrochemical platform based on nanoporous gold for the simultaneous determination of hydroquinone and catechol with high selectivity.

In this study, a novel three-electrode integrated electrochemical platform (TEIEP) has been designed and fabricated for the simultaneous detection of hydroquinone (HQ) and catechol (CC), in which nanoporous gold (NPG) served as the working electrode, and Pt particles and nanoporous Ag/AgCl served as the courter electrode and the reference electrode, respectively. Due to the remarkable catalytic activity of NPG, the TEIEP exhibits high selectivity and sensitivity towards HQ and CC determination with a distinct separation between the peaks for their coexistence. The oxidation peak current densities of HQ and CC were linear over the range of 0.2-100 µM with the detection limits of 0.083 µM (S/N = 3) for HQ and 0.119 µM (S/N = 3) for CC. Moreover, TEIEP has a satisfactory reproducibility and anti-interference ability, and can be used in real water sample analysis. This work undoubtedly provides a remarkable choice for catalytic materials and an integrated structure, and further a promising application prospect for developing novel sensors for on-site environmental monitoring.

Effects of polysaccharide from Pueraria lobata on osteoarthritis in rats.

The effects of Pueraria lobata polysaccharide (PPL-1) on osteoarthritis (OA) disease were comprehensively evaluated by using chondrocytes and synoviocytes extracted from the joints of SD rats based on in vitro cell experiments and by establishing pathological models of OA rats. The results showed that concentrations of 1.25-10 and 0.2-1.6 µg/mL, PPL-1 did not inhibit or promote chondrocytes and synoviocytes in vitro. However, at concentrations of 1.25-10 and 0.2-1.6 µg/mL, it can promote cartilage and synovial membrane cells after LPS stimulation of cell activity and inhibite LPS-induced apoptosis. The results of animal experiments showed that PPL-1 can reduce the symptoms of joint swelling in OA rats, decrease the production of serum inflammatory cytokines TNF-α, IL-1ß, and IL-6, and slow down the occurrence of inflammation. Therefore, from the perspective of symptoms, inflammatory factors and pathology, PPL-1 has therapeutic effects on OA rats and alleviates the development of inflammation. It indicated that PPL-1 has the potential to be developed into an OA therapeutic drug with anti-inflammatory properties that protects and activates chondrocytes.

High-performance non-enzymatic biofuel cells based on an organic copper complex cathode and a nanoporous gold nanoparticle anode.

We developed efficient compartment-less non-enzymatic biofuel cells (NEFCs) with an electrografted copper complex of 3,5-diamino-1,2,4-triazole and nanoporous gold nanoparticles as catalysts, which could not only work in a neutral solution, but also drive the self-powered sensing of pyrophosphate via the stronger coordination of Cu2+ with O than N at the cathode.