Preparation and application of curcumin molecularly imprinted composite membrane based on ATRP technique / 中草药

Objective: To prepare the molecularly imprinted composite membrane of curcumin by the atom transfer radical polymerization (ATRP) technique and develop a method for the separation and enrichment of curcumin in actual samples. Methods Curcumin MIM were prepared by thermal polymerization method using curcumin as template molecule, methylacrylic acid as functional monmers, cuprous chloride as catalyst, pentamethyldiethylenetriamine as ligand, and polyvinylidene fluoride as base membrane. The microstructure of MIM was investigated by SEM. The maximum adsorption and adsorption equilibrium time of MIM were investigated by static and dynamic adsorption experiment, and the selective penetration capacity was studied. The MIM as membrane material of osmotic device combined with HPLC was used for separation, enrichment and determination of curcumin in samples. Results The results showed that the prepared curcumin MIM had a regular distribution of pores and a uniform size. The maximum adsorption capacity was 3.81 mg/g, and the adsorption equilibrium could be achieved in 15 min. In the selective permeation process of ferulic acid, quercetin and curcumin, MIM had a high selective permeability to curcumin. The average recovery rates of curcumin in ginger, turmeric and curry were (94.100 ± 3.952)%, (98.300 ± 3.637)%, and (97.900 ± 3.133)%, respectively. The RSD was less than 4.2%. The limit of detection was 1.76 μg/kg. Conclusion The prepared MIM is a new material for strong selectivity, separation and enrichment of Chinese medicine curcumin with fast adsorption speed. At the same time, it also provides reference for chemical composition research of other Chinese materia medica.

Construction of controllable polyethylene glycol bioactive coating with hemocompatibility from the surface of modified glass substrate / 生物医学工程学杂志

A diblock copolymer, poly(ethylene glycol) methacrylate-block-glycidyl methacrylate (PEGMA-GMA), was prepared on glass substrate by surface-initiated atom transfer radical polymerization (SI-ATRP), and endothelial specific peptide Arg-Glu-Asp-Val (REDV) was immobilized at the end of the PEGMA-GMA polymer brush by ring opening reaction through the rich epoxy groups in the GMA. The structure and hydrophilicity of the polymer brushes were characterized by static water contact angle, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results showed that the REDV modified copolymer brushes were successfully constructed on the glass substrates. The REDV peptide immobilized onto surface was quantitatively characterized by ultraviolet-visible spectroscopy (UV-VIS). The blood compatibility of the coating was characterized by recalcification time and platelet adhesion assay. The results showed that the polymer coating had good blood compatibility. The multifunctional active polymer coating with PEGMA and peptide produced an excellent prospect in surface construction with endothelial cells selectivity.

Preparation of Carboxybetaine-based Hydrophilic Interaction Chromatographic Column and Its Performance Exploration / 分析化学

2-(Dimethylamino)ethyl methacrylate and sodium monochloroacetate were employed to synthesize [2-(Methacryloyloxy)ethyl] dimethyl ammonium acetate (CBMA) functional monomer.CBMA was grafted on the surface of silica by surface initiated atom transfer radical polymerization (SI-ATRP) to obtain silica-CBMA hydrophilic interaction stationary phase.Three silica-CBMA stationary phases with different grafted density of CBMA monomer were synthesized in SI-ATRP progress by changing the concentration of CBMA under the same conditions.The ability to separate organic acid compounds of the synthesized silica-CBMA stationary phases was evaluated under different conditions, including effects of pH value, salt concentration and content of water of mobile phase on retention of solutes.The results showed that the stationary phases could effectively separate organic acid compounds in HILIC mode, which followed a mixed mode of chromatography of ion exchange and hydrophilic interaction.The retention of solutes decreased with the increases of salt concentration of mobile phase, which consistent with the characteristics of ion exchange;the pH value of mobile phase had significant influence on ionization of the stationary phase and solutes, i.e., the retention of solutes increased as the increasing of pH value of mobile phase.However, the retention of solutes decreased with the increasing of the content of water in mobile phase, which was the typical characteristic of HILIC.The method of hydrophilic interaction chromatography combined with silica-CBMA stationary phases could conveniently determinate the content of vitamin C and rutin in rutin tablets, providing a new method for the separation and determination of strong polar samples.