Short and simple peptide-based pH-sensitive hydrogel for antitumor drug delivery

Since self-assembled peptide hydrogels can solve the problems such as low solubility, poor selectivity and serious adverse effects of traditional chemotherapy drugs, they have been widely used as carrier materials for drug delivery. In this study, we developed a novel and injectable drug delivery platform for the antitumor drug doxorubicin (DOX) using a pH-responsive ionic-complementary octapeptide FOE. This octapeptide could self-assemble into stable hydrogel under neutral conditions, while disassemble under the tumor microenvironment. Especially, at pH 5.8, its micromorphology displayed a transition from nanofibers to nanospheres with the change of secondary structure, which enhanced cellular uptake of DOX. In addition, FOE hydrogel serves as a smart drug reservoir by localized injection to achieve sustained drug release and improve antitumor efficacy. This octapeptide opens up new avenues for promoting the clinical translation of anticancer drugs on account of excellent injectable properties and economic benefits of simple and short sequence.