Thermo-and pH-responsive chitosan/gellan gum hydrogels incorporated with the β-cyclodextrin/curcumin inclusion complex for efficient curcumin delivery

Abstract Thermo- and pH-sensitive hydrogels based on chitosan (CS) and gellan gum (GG) were used for efficient curcumin (CUR) delivery for the first time. β-Cyclodextrin/curcumin (βCD/CUR) inclusion complex was mixed with aqueous GG solution and associated with CS solution aliquots. CS/GG hydrogels incorporated with the βCD-CUR inclusion complex containing CS between 40 and 80 wt% were prepared by cooling CS/GG/βCD/CUR mixtures. The materials were characterized by infrared spectroscopy, thermal analysis, X-ray diffraction, scanning electron microscopy, confocal scanning microscopy, and mechanical measurements. The CS/GG-βCD-CUR ratio in the mixture significantly influenced the hydrogel properties. The pH-responsive hydrogels presented porosity between 76 and 84%, mechanical strength between 247 and 747 Pa, and disintegration rate lower than 25% in simulated intestinal fluid (SIF). The CUR release was investigated in simulated intestinal (SIF) and simulated gastric (SGF) fluids with and without lysozyme (27.8 μg/mL) and Tween 80 (1% v/v). Lysozyme and Tween 80 enhanced the CUR release in SIF, reaching 69.40% (10.10 mg/g) after 240 h. The Ritger-Peppas and Higuchi mathematical models adjusted well to the experimental CUR release kinetic curves. The materials were cytocompatible toward healthy VERO cells. This study reports durable polysaccharide-based assemblies for CUR delivery created following a method in-situ.