Redox-responsive supramolecular hydrogel based on 10-hydroxy camptothecin-peptide covalent conjugates with high loading capacity for drug delivery

•A redox-responsive supramolecular hydrogel system was developed for delivering 10-hydroxy camptothecin (HCPT).•The hydrogel was formed by a biocompatible of cleaving disulfide bond.•The drug loading efficiency of the hydrogel was > 6.6 mg/mL.•The hydrogel possessed recovery and shear-shinning properties and could be used as injectable drug delivery system.•The hydrogel had a significantly sustained-release characteristic and possessed a favorable anticancer efficacy.

A redox-responsive supramolecular hydrogel system was developed for delivering 10-hydroxy camptothecin (HCPT). The hydrogel was formed by cleaving disulfide bond. The combination of hydrophobic HCPT with hydrogel was a simple and effective way to improve the solubility of HCPT and the drug loading capacity of delivery system. The transmission electron microscopy (TEM) image revealed the self-assembled hydrogel was long and thin nanofibers with a width of < 10 nm. Rheological test verified the hydrogel had fine physical properties. In vitro release experiment showed that the accumulative releasing percentages within 72 h of HCPT-peptide hydrogels at 3.0%, 4.0%, 5.0% were 16.8%, 21.3%, and 26.8% respectively, which indicated the HCPT-peptide hydrogels had a significantly sustained-release characteristic. Besides, in vitro anticancer assay showed that HCPT-peptide hydrogels possessed a favorable anticancer efficacy. These results indicated that HCPT-peptide hydrogel had great potential for cancer treatment as a novel injectable drug delivery system.

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