Evaluation of pH‐Sensitive Poly(β‐amino ester)‐graft‐poly(ethylene glycol) and its Usefulness as a pH‐Sensor and Protein Carrier

Abstract In this study, some possible biomedical applications of a pH‐sensitive and amphiphilic copolymer as a pH sensor and protein delivery system are reported. PAE‐g‐PEG was used as a pH‐sensitive polymer that can exhibit a sharp pH‐dependent transition. Various fluorescent dyes including pyrene and RITC can be used to label the pH‐sensitive polymer PAE‐g‐PEG, which was evaluated for protein encapsulation. pH‐sensing was possible by observing excimer formation of the labeled pyrene via pH‐dependent expansion of the polymeric chain. Also, it was confirmed that FITC‐BSA could be entrapped in RITC‐labeled pH‐sensitive micelles of PAE‐g‐PEG by FRET. As a result, PAE‐g‐PEG can be a pH sensor and carrier for protein delivery. magnified image