In situ forming gelatin/gellan gum hybrid hydrogels containing graphene quantum dots for imaging and effective drug delivery of 5-fluorouracil in local therapy of breast cancer.

This study describes the development of novel in situ gelling hydrogels for the localized delivery of 5-fluorouracil (5-FU) in breast cancer treatment. The hydrogels were fabricated based on a Schiff-base reaction between oxidized gellan gum (OGG) and gelatin (G) in the presence of β-glycerophosphate containing graphene quantum dots (GQDs) as potential imaging agents. X-Ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the crystalline nature and nano-sized structure of the incorporated GQDs. The obtained GQDs indicated a size distribution of about 48.73 nm with a zeta potential of -36.6 mV via dynamic light scattering (DLS) study. Characterization revealed chemical alteration of OGG, as well as the successful hydrogel formation with porous structures, confirmed by FT-IR and SEM analysis. Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) demonstrated enhanced thermal stability and established the phase transition behavior of the composite network. The hydrogels exhibited high swelling and degradability. Rheological studies confirmed the elastic nature of the hydrogels across the tested frequency range. Mechanical characterization via compressive testing revealed that the addition of GQDs significantly improved the structural integrity. In vitro release studies demonstrated sustained 5-FU release, with 99% and 86% release observed at pH = 5.8 and 7.4, respectively. Hemolysis assays further validated the hemocompatibility of the system, showing negligible erythrocyte damage. Cytotoxicity studies using MTT assays indicated good biocompatibility of the blank hydrogels on MCF-7 cells, while the 5-FU-loaded hydrogel demonstrated pronounced cytotoxicity against MCF-7 cells. The obtained results emphasize the potential of the developed hydrogels for local breast cancer treatment.