Nanotechnology is poised to make potentially revolutionary innovations in areas of biomedical science, such as gene therapy and drug therapy. A recently developed nanodelivery strategy involves the use of hydrophilic polymers as carriers of proteins and siRNA. By controlling the reaction conditions during polymer production, various degrees of anionic charge, cationic charge, and cross‐linking can be added, thereby changing their capabilities as protein and nucleic acid carriers and promoting effective cell membrane permeation. The efficiency of a specific controlled‐release polymeric system is determined in part by its unique physical and chemical properties and biodegradation rate. In this review, we will summarize recent progress in the ability to modify drug release of hydrophilic polymers nanoparticles.