Thermoresponsive gamma-cyclodextrin-based porous composite functionalized with N-isopropylacrylamide and soybean hull polysaccharide for controlled curcumin delivery

A thermoresponsive composite carrier, γ-cyclodextrin metal–organic frameworks (γ-CD-MOFs) functionalized with N-isopropylacrylamide (PNIPAm) and soy hull polysaccharides (SHP), was developed to enhance curcumin (Cur) encapsulation and controlled release. X-Ray diffraction (XRD) confirmed that surface functionalization preserved the crystalline structure of γ-CD-MOF, while FTIR indicated hydrogen bonding as the primary interaction between γ-CD-MOF and Cur. Successful PNIPAm and SHP integration was verified by their characteristic functional group signals and the detection of nitrogen and sulfur elements via X-ray photoelectron spectroscopy (XPS). Thermal analyses revealed improved stability of the Cur-loaded composite. The encapsulation efficiency of Cur reached 56.60 ± 0.14 %. In vitro release studies demonstrated suppressed release below the lower critical solution temperature (LCST), with a cumulative release of only 16.51 ± 0.51 % at 25 °C. At elevated temperatures (37 °C and 45 °C), PNIPAm collapse triggered rapid release of 79.68 ± 0.78 % and 81.58 ± 0.31 %, respectively. Kinetic modeling showed Fickian diffusion at 25 °C and non-Fickian diffusion at higher temperatures, reflecting the combined effects of diffusion and matrix erosion. Overall, γ-CD-MOF-PNIPAm@SHP provides a stable, thermoresponsive platform for efficient encapsulation and temperature-triggered release of hydrophobic bioactives, highlighting the potential of MOF-polymer composites for targeted and stimuli-responsive delivery in functional food and pharmaceutical applications.