Resonance Rayleigh scattering methods for the determination of chitosan with Congo red as probe

Synthesis of Chitosan Oligosaccharide-Loaded Glycyrrhetinic Acid Functionalized Mesoporous Silica Nanoparticles and In Vitro Verification of the Treatment of APAP-Induced Liver Injury

OBJECTIVE

the study was to find a suitable treatment for acute drug-induced liver injury. The use of nanocarriers can improve the therapeutic effect of natural drugs by targeting hepatocytes and higher loads.

METHODS

firstly, uniformly dispersed three-dimensional dendritic mesoporous silica nanospheres (MSNs) were synthesized. Glycyrrhetinic acid (GA) was covalently modified on MSN surfaces through amide bond and then loaded with COSM to form drug-loaded nanoparticles (COSM@MSN-NH₂-GA). The constructed drug-loaded nano-delivery system was determined by characterization analysis. Finally, the effect of nano-drug particles on cell viability was evaluated and the cell uptake in vitro was observed.

RESULTS

GA was successfully modified to obtain the spherical nano-carrier MSN-NH₂-GA (≤200 nm). The neutral surface charge improves its biocompatibility. MSN-NH₂-GA has high drug loading (28.36% ± 1.00) because of its suitable specific surface area and pore volume. In vitro cell experiments showed that COSM@MSN-NH₂-GA significantly enhanced the uptake of liver cells (LO2) and decreased the AST and ALT indexes.

CONCLUSION

this study demonstrated for the first time that formulation and delivery schemes using natural drug COSM and nanocarrier MSN have a protective effect on APAP-induced hepatocyte injury. This result provides a potential nano-delivery scheme for the targeted therapy of acute drug-induced liver injury.

The triple-wavelength overlapping resonance Rayleigh scattering method and the fluorescence quenching method for the determination of chitooligosaccharides using trisodium-8-hydroxypyrene-1,3,6-trisulfonate as a probe

In this assay, the triple-wavelength overlapping resonance Rayleigh scattering (TWO-RRS) method and the fluorescence quenching method for the quantitative detection of chitooligosaccharides (COS) were developed. In the weakly Britton-Robinson buffer solution, COS interacted with Trisodium-8-hydroxypyrene-1,3,6-trisulfonate (HPTS) to form an ion-association complex of HPTS-COS, which increased the RRS intensities at 321 nm, 430 nm and 511 nm and decreased the fluorescence intensities of the system at 512 nm. And the changes in the intensities of both methods were related to the changes in the concentration of COS. Moreover, for the TWO-RRS method, OP-10 made the RRS intensities increased stronger, finally, the three peaks' total was linear to the concentration of COS in the range of 1.00-8.00 μg/mL and the limit of detection (LOD) was 0.247 μg/mL, and for the fluorescence quenching method, the linear range was 0.50-3.50 μg/mL with the LOD of 0.108 μg/mL. Based on these, two new and fast spectral methods with high sensitivity and simplicity for the determination of trace COS had been established. The generation mechanism of the TWO-RRS and the fluorescence quenching was studied. At the same time, the two methods were applied to the determination of COS in health products with satisfactory results.