Preparation and antitumor study of intelligent injectable hydrogel: Carboxymethyl chitosan–aldehyde gum Arabic composite graphene oxide hydrogel

In this study, we used polyaldehyde gum Arabic (OGA) and carboxymethyl chitosan (CMCS) as a gel matrix to form an injectable self-healing hydrogel by Schiff-base bonding. Further, graphene oxide (GO) was loaded with doxorubicin (DOX) to the hydrogel, which resulted in a CMCS-OGA/GO@DOX hydrogel. We achieved a DOX drug loading capacity of 43.80 ± 1.13 %. Rheological studies showed that GO hydrogels have improved mechanical properties. The in vitro release profile showed pH responsiveness with 88.21 % DOX release at pH 5.5. Biocompatibility studies showed that the hydrogel composition had good cytocompatibility with L929 cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed a cell survival rate of 93.88 % within 48 h. The DOX-loaded hydrogel exhibited higher cell mortality in breast cancer cells (4 T1), with an inhibition rate of 79.4 % at 48 h. Acridine orange/ethidium bromide staining experiments on 4 T1 cells showed that when loaded with the same DOX concentration, the hydrogel significantly reduced the toxic effects on normal cells, whereas it had significant cytotoxic effects on cancer cells. This result indicates that the prepared GO hydrogel drug delivery system can serve as a novel approach for localized breast cancer treatment.