Controllable Synthesis of Polyphenol Spheres via Amine-Catalyzed Polymerization-Induced Self-Assembly.

A facile and general strategy for preparing uniform and multifunctional polyphenol-based colloidal particles through amine-catalyzed polymerization-induced self-assembly is described. The size and interfacial adhesion of polyphenol spheres can be easily controlled over a wide range via adjusting the concentration of the cosolvent and monomer. Moreover, the polyphenol spheres showed excellent thermal and chemical stability and highly active properties and could efficiently deplete the reactive oxygen species (ROS), which are helpful for in vivo ROS regulation for inflammatory therapeutic. The accessible and versatile method provides a feasible way for the rational engineering of multifunctional polyphenol spheres, which have great potential in many fields.

The room-temperature, ambient-pressure conversion of CO2 into value-added pharmaceutical products quinazoline-2,4(1H,3H)-diones.

As global warming due to CO2 emissions has become a widely recognized concern, CO2 capture, sequestration, neutralization, and conversion have become possible solutions to address this concern. Among these approaches, the conversion of CO2 into fuels or value-added products has attracted considerable attention. In this work, we report the high-efficiency conversion of CO2 to important industrial raw materials for pharmaceutical compounds, quinazoline-2,4(1H,3H)-diones, via reactions with 2-aminobenzonitriles at room temperature and under ambient pressure, with high conversion yields (91.5-99.3%). 1,8-Diazabicyclo-[5.4.0]-undec-7-ene (DBU), 1,1,3,3-tetramethylguanidine (TMG), and cholinium (Ch) ammonium-based ionic liquids (ILs) are employed as catalysts during the process. Cations with a pKa value near 11.9 and anions with a pKa value range of 10 to 15 are necessary for the reaction. The experimental results indicate that the ionic liquid pair [HDBU+][3-Cl-PhO-] has high efficiency under very mild conditions, obtaining high product yields of 91.5% at 25 °C and 1 atm and 99.3% at 30 °C and 1 atm. More importantly, the catalysts retain high efficiency and activity after 5 consecutive cycles. To gain insightful understanding of the reaction, density functional theory (DFT) calculations were conducted to study the reaction mechanism. The computational results indicate that the catalytic process contains three stages: cyano activation, intramolecular rearrangement, and intramolecular cyclization. Of these, the rate-determining step is cyano activation, which shows an energy barrier of 24.5 kcal mol-1. Tuning the types of ions in ILs can effectively reduce this energy barrier and allow high efficiencies.

[Construction of controllable polyethylene glycol bioactive coating with hemocompatibility from the surface of modified glass substrate].

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.

Bioactive zwitterionic polymer brushes grafted from silicon wafers via SI-ATRP for enhancement of antifouling properties and endothelial cell selectivity.

Zwitterionic copolymers keep good resistance to platelet adhesion and nonspecific protein adsorption. In this study, A block copolymer brushes consisting of carboxybetaine methacrylate (CBMA) and glycidyl methacrylate (GMA) were grafted from silicon wafers via surface-initiated atom transfer radical polymerization, and then the Arg-Glu-Asp-Val (REDV) peptide was attached to the polymer brush via an reactive epoxy group of the P(GMA) unit to improve endothelial cells (ECs) selectivity. These modified surfaces were evaluated with scanning electron microscopy, atomic force microscopy, attenuated total reflectance-Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and static water contact angle measurement. The results showed that REDV-modified zwitterionic brushes were successfully constructed on silicon wafers. The biocompatibility of the membrane was determined by plasma recalcification time assay and platelet adhesion test. The results showed that the modified substrate exhibited good blood compatibility. Moreover, the proliferation of ECs and smooth muscle cells onto the REDV-modified copolymer brushes were examined to demonstrate the synergistic effect of CBMA with antifouling property and REDV peptide with ECs selectivity. All assays showed that the silicon wafers displayed excellent EC selectivity after modification. In summary, REDV-modified zwitterionic brushes had great potential for cardiovascular stent implantation.