No abstract

We have discovered a novel method to prepare a protein‐based hydrogel, that is, a ‘three‐dimensional nanostructured protein hydrogel’ (3D NPH), which is composed of loosely inter‐connected protein–polymer hybrid nanoparticles. The 3D NPH can be easily prepared by spotting a protein/polymer mixture on a substrate. Surprisingly, gold nanoparticles carrying protein molecules easily diffuse into the 3D NPH through pores and spaces. We have shown that the protein chip made by our 3D NPH method has tremendously improved sensitivity in detecting protein–protein interactions compared with that by direct protein immobilization methods.

Nanoparticles have gained immense attention as drug carriers in biodegradable drug delivery systems. Particle size is one of the most important characteristics of nanoparticles. It determines the in vivo distribution and targeting ability of nanoparticle drug delivery systems. In this study, we developed a surfactant-free method for the preparation of poly(lactic acid)/hydroxyapatite (PLA/HAp) particles for drug delivery applications. PLA/HAp particles decompose safely in the body. In this study, we investigated the effect of PLA content and ionic concentrations on the particle size of PLA/HAp particles. The particle size of PLA/HAp particles with different PLA contents and ionic concentrations was determined by SEM. The results showed that the PLA content played a crucial role in increasing the particle size of the PLA/HAp particles.

We have discovered a novel protein immobilization method, i.e., a "Three-Dimensional Nanostructured Protein Hydrogel" (3-D NPH), which is composed of protein-reactive polymer hybrid nanoparticles to detect protein-protein interactions. The 3-D NPH can be easily prepared by spotting a protein/reactive polymer mixture on a substrate. The resulting 3-D NPH is characterized by large amounts of immobilized proteins and a novel porous structure.The 3-D NPH technology was applied to immobilize streptavidin (SA) onto Au-coated surface for surface plasmon resonance imaging (SPRi). By using 3-D NPH method, it was possible to improve the sensitivity of protein-protein interactions drastically comparing to the conventional protein immobilization method.