A Novel Ketal-Based Chitosan as Nano-Vehicles for Potential pH-Sensitive Nanomedicine Delivery

In this communication, a novel pH-sensitive ketal based chitosan polymer, mPEG-Chitosan-Ketal (PCK), was designed. The structure of the PCK was characterized by FTIR and H-1-NMR. PCK could deliver drugs to the acidic environments of tumor. PCK carried the pH-sensitive ketal group as hydrophobic moieties and PEG group as hydrophilic moieties. The PCK micelles encapsulated curcumin was prepared and improved the solubility of curcumin (Cur). The diameter of most PCK micelles was about 100 nm. The PCK micelles could release encapsulated curcumin with 89% at pH 5.0 compared with 57% at pH 7.4. The results of cytotoxicity assay indicated that encapsulated curcumin in PCK micelles (Cur-PCKM) were stable and have less toxicity compared to curcumin suspension. The anti-tumor efficacy in vivo suggested that Cur-PCKM suppressed tumor growth most efficiently compared to saline. These findings have shed some light on the PCK polymer as vehicles for potential pH-sensitive drug delivery.