Flash Nanoprecipitation Fabrication of PEI@Amorphous Calcium Carbonate Hybrid Nanoparticles for siRNA Delivery

RNA interference (RNAi) is a promising approach for disease treatments. But the development of safe and effective delivery carriers remains a major challenge. Organic–inorganic hybrid nanoparticles (NPs), with the integration of functions from distinct materials, show great potential in small interfering RNA (siRNA) delivery. Herein, pH responsive amorphous calcium carbonate NPs (ACC NPs) are prepared using flash nanoprecipitation and hybrid NPs are constructed by coating ACC NPs with polyethyleneimine (PEI) for efficient siRNA delivery. PEI/ACC NPs show robust pH responsiveness and stability as well as effective siRNA loading and protection. Furthermore, siRNA-loaded PEI/ACC NPs demonstrate enhanced cellular uptake and efficient endosomal escape, mediating improved siRNA delivery compared to pure PEI. These findings suggest that PEI/ACC NPs may have great potential in siRNA delivery for RNAi-based therapy.     

Asymmetric ring-opening reaction of azabenzonorbornadienes with phenols promoted by palladium/(R,R)-DIOP complex

An efficient asymmetric ring opening reaction of azabenzonorbornadienes with various phenols using Palladium/(R,R)-DIOP complex has been demonstrated, the reaction afforded the corresponding products in excellent yields (80–95%) with moderate enantioselectivities (50–64% ees). The syn-configuration of the product was confirmed by the single X-ray crystallography.     

Analysis of Local Anesthetics in Biological Samples via Kinetically Calibrated Liquid-Phase Solvent Bar Micro-Extraction Combined with HPLC

In this study, a liquid-phase solvent bar micro-extraction technique was used to investigate both the extraction and back-extraction processes of the target analyte. A novel concentration curve method and a classic time curve method, used under the same experimental conditions, verified the symmetry between the extraction process (target analyte moves from sample matrix to the organic solvent-based extraction phase) and the back-extraction process (target analyte moves from organic solvent to the sample matrix), providing the basis to use the target analyte in the back-extraction process to calibrate its extraction process. A quantitative calibration can be achieved using back extraction on the target analyte from the blank sample matrix in the organic solvent. Information from the process of back extraction of the target analyte, such as the time constant a, can be directly used to calculate the initial concentration of the target analyte in the sample matrix. This new kinetic calibration method employs a liquid-phase solvent bar micro-extraction technique combined with high-performance liquid chromatography with a diode array detector (HPLC-DAD) and was successfully used to analyze three local anesthetics in biological samples; it extends the application of the kinetic calibration to HPLC-DAD and establishes a novel, simple and accurate method to determine the concentration of the free drug in biological samples and its protein-binding ratio.

     

Analysis of Local Anesthetics in Biological Samples via Kinetically Calibrated Liquid-Phase Solvent Bar Micro-Extraction Combined with HPLC

In this study, a liquid-phase solvent bar micro-extraction technique was used to investigate both the extraction and back-extraction processes of the target analyte. A novel concentration curve method and a classic time curve method, used under the same experimental conditions, verified the symmetry between the extraction process (target analyte moves from sample matrix to the organic solvent-based extraction phase) and the back-extraction process (target analyte moves from organic solvent to the sample matrix), providing the basis to use the target analyte in the back-extraction process to calibrate its extraction process. A quantitative calibration can be achieved using back extraction on the target analyte from the blank sample matrix in the organic solvent. Information from the process of back extraction of the target analyte, such as the time constant a, can be directly used to calculate the initial concentration of the target analyte in the sample matrix. This new kinetic calibration method employs a liquid-phase solvent bar micro-extraction technique combined with high-performance liquid chromatography with a diode array detector (HPLC-DAD) and was successfully used to analyze three local anesthetics in biological samples; it extends the application of the kinetic calibration to HPLC-DAD and establishes a novel, simple and accurate method to determine the concentration of the free drug in biological samples and its protein-binding ratio.