Efficient fabrication of reversible pH-induced carboxymethyl chitosan nanoparticles for antitumor drug delivery under...

Searching for the carrier systems for drug controlled release under weakly acidic condition related to tumor environment has attracted a tremendous level of attention. In this study, amphiphilic carboxymethyl chitosan (CMC) was employed to fabricate nanoparticles (NPs) with an efficient and simple method by adjusting the pH values of CMC aqueous solutions. The prepared NPs could not only capture the doxorubicin hydrochloride (DOX) efficiently and alleviate the initial burst release, but also exhibit pH sensitivity under weakly acidic microenvironment for tumor therapy. Importantly, rectorite (REC) with lamellar structure could be intercalated with CMC chains to construct more compact structure and DOX could be captured in the interlayer of REC, which could contribute to heightening the encapsulation efficiency and loading capacity of DOX, as well as reducing the initial burst release and prolonging the therapeutic time. The NPs displayed the behavior of controlled DOX release at pH 4.5, which suggested that the intelligent colloids might be utilized in tumor therapy.