Pendent functionalization of biodegradable
polymers provides unique
importance in biological applications. In this work, we have synthesized
a polymeric nanocarrier for the controlled release of the anticancer
drug doxorubicin (DOXI). Inspired by the pH responsiveness of acylhydrazine
bonds along with the interesting self-assembly behavior of amphiphilic
copolymers, this report delineates the development of a PEG-SS-PCL-DOXI copolymer consisting of DOXI, PEG, and a caprolactone backbone.
First, the inclusion of a PEG moiety in the copolymer helps to achieve
biocompatibility and aqueous solubility as well as a prolonged circulation
time of the nanocarrier. Second, an acid-sensitive acylhydrazine-based
linkage is chosen to attach DOXI to trigger sustained drug release,
whereas the inclusion of an enzymatically cleavable disulfide linkage
in the backbone adds to the advantage of backbone biodegradability
at the intracellular level.