Injectable chitosan copolymer/gold nanoparticles/gelatin hybrid hydrogels for delivery of doxorubicin for breast cancer treatment.

In the current study, we report the preparation of an injectable hydrogel by poly (N-isopropylacrylamide)-g-chitosan copolymer (CS-g-PNIPAAm)/gold nanoparticles (CS-g-PNIPAAm@AuNPs) hybrid hydrogel formation with gelatin using genipin as chemical crosslinker aimed for the local delivery of doxorubicin (DOX) in the breast cancer treatment. To prepare (CS-g-PNIPAAm), carboxyl terminated PNIPAAm was prepared via free radical polymerization in the presence of 3-mercaptopropionic acid and it was further grafted to CS via amine conjugation reaction. The chemical structure and porous architecture of the prepared hydrogel were characterized by FT-IR and SEM tests, respectively. The synthesized hydrogel was evaluated for in vitro degradation test. To assess the rheological behavior of hydrogels such as storage and loss modulus, the rheological test was performed. The DOX was released from the CS-g-PNIPAAm@AuNPs hydrogel in a pH-responsive manner which revealed an enriched release of DOX in acidic media. The cytotoxicity evaluation indicated that the prepared hydrogel alone remained cytocompatible on MCF-7 cells, while the DOX-loaded CS-g-PNIPAAm@AuNPs hydrogel could prompt cytotoxicity in examined cells. Based on these results, the DOX-loaded CS-g-PNIPAAm@AuNPs hydrogel could be considered an injectable thermo and pH-responsive system for the local delivery of DOX to breast cancer tumor cells. [ABSTRACT FROM AUTHOR]