Nonionic Block Copolymers Assemble on the Surface of Protein Bionanoparticle

Efficient delivery of therapeutic proteins to a target site remains a challenge due to rapid clearance from the body. Here, we selected tobacco mosaic virus (TMV) as a model protein system to investigate the interactions between the protein and a nonionic block copolymer as a possible protecting agent for the protein. By varying the temperature, we were able to obtain core–shell structures based on hydrophobic interactions among PO blocks and noncovalent interactions between TMV and EO blocks. The protein–polymer interactions were characterized by dynamic light scattering and isothermal titration calorimetry. This study establishes principles for the possible design of clinically useful protein delivery systems.