Sonication-Aided Formation of Hollow Hybrid Nanoparticles as High-Efficiency Absorbents for Dissolved Toluene in Water

Regulating polymer adsorption on colloid by surface morphology

The study of polymer adsorption on colloidal particles has attracted intensive attention. In this work, we investigated polymer adsorption on substrate colloidal particles with two complementary morphologies, one of which has bulges (raspberry-like) on the surface and the other of which has holes instead (strawberry-like). Compared to the bulges, the holes on the colloidal particles were found to prevent polymer adsorption and this effect was dependent on the relative dimensions of the polymer coil and hole. This surface morphology effect was attributed mainly to the reduced polymer accessibility to the adsorption sites in holes when the hydrodynamic size of the polymer coil is larger than the hole, due to the size limiting effect. When the hydrodynamic size of the polymer coil is smaller than that of the holes, no difference in polymer adsorption was observed between raspberry-like and strawberry-like colloids. This study provides a strategy for regulating polymer adsorption on colloidal particles by adjusting the fine structures on the surface, which may be advantageous when limited chemical compositions are allowed. For example, protein adsorption on colloidal drugs may be found to be significantly reduced when colloids with surface holes are used.

Porous Particle-Reinforced Bioactive Gelatin Scaffold for Large Segmental Bone Defect Repairing

Large segmental bone defect repairing remains a big challenge in clinics, and synthetic bone grafts suitable for this purpose are still highly demanded. In this article, hydrophilic composite scaffolds (bioactive hollow particle (BHP)-gel scaffold) composed of bioactive hollow nanoparticles and cross-linked gelatin have been developed. The bioactive nanoparticles have a porous structure as well as high specific surface area; thus, they interact strongly with gelatin to overcome the swelling problem that a hydrophilic polymer scaffold will usually face. With this combination, these BHP-gel scaffolds showed porous structure and mechanical properties similar to those of the cancellous bone. They also showed excellent bioactivity and cell growth promotion performance in vitro. The best of them, namely, 10BHP-gel scaffold, was evaluated in vivo on a rat femur model, where it was found that the 5 mm segmental bone defect almost healed with new bone tissue formed in 12 weeks and the scaffold itself degraded at the same time. Thus, 10BHP-gel scaffold may become a potential bone graft for large segmental bone defect healing in the future.