Effect of silane-modified silica/MAO-supported Et[Ind]2ZrCl2 metallocene catalyst on copolymerization of ethylene

Effect of SiCl₄-modified silica/MAO-supported Et[Ind]₂ZrCl₂ metallocene catalyst on copolymerization of ethylene with -olefins was investigated. Effect of SiCl₄ on activities was diminished with higher -olefins. Molecular weights of copolymers decreased with SiCl₄ modification. SiCl₄ modification also resulted in a lower molecular weight distribution. ¹³C NMR showed that ethylene incorporation in all systems gave copolymers with similar triad distribution. In addition, a narrow branching distribution can be achieved with SiCl₄ modification.     

Use of Three‐Dimensional Arterial Models To Predict the In Vivo Behavior of Nanoparticles for Drug Delivery

Nanomaterials have been widely used for applications in biomedical fields and could become indispensable in the near future. However, since it is difficult to optimize in vivo biological behavior in a 3D environment by using a single cell in vitro, there have been many failures in animal models. In vitro prediction systems using 3D human‐tissue models reflecting the 3D location of cell types may be useful to better understand the biological characteristics of nanomaterials for optimization of their function. Herein we demonstrate the potential ability of 3D engineered human‐arterial models for in vitro prediction of the in vivo behavior of nanoparticles for drug delivery. These models enabled optimization of the composition and size of the nanoparticles for targeting and treatment efficacy for atherosclerosis. In vivo experiments with atherosclerotic mice suggested excellent biological characteristics and potential treatment effects of the nanoparticles optimized in vitro.