(IMAGE) Tokyo Medical and Dental University Caption (a) Preparation scheme. (b) Nanoparticles with varying PEG density on the surface. (c) Behavior in the blood circulation. (d) Delivery of luciferase mRNA. Credit Department of Advanced Nanomedical Engineering, TMDU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.