ABSTRACT
In this paper the properties of thermosensitive chitosan hydrogels, formulated with chitosan chloride with ß-glycerophosphate disodium salt hydrate and chitosan chloride with ß-glycerophosphate disodium salt hydrate enriched with calcium glycerophosphate, are presented. The study focused on the determination of the hydrogel structure after conditioning in water. The structure of the gels was investigated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The crystallinity of the gel structure was determined by X-ray diffraction analysis (XRD) and the thermal effects were determined based on DSC thermograms.
ABSTRACT
Thermosensitive injectable hydrogels based on chitosan neutralized with sodium beta-glycerophosphate (Na-ß-GP) have been studied as biomaterials for drug delivery and tissue regeneration. Magnesium (Mg) has been reported to stimulate adhesion and proliferation of bone forming cells. With the aim of improving the suitability of the aforementioned chitosan hydrogels as materials for bone regeneration, Mg was incorporated by partial substitution of Na-ß-GP with magnesium glycerophosphate (Mg-GP). Chitosan/Na-ß-GP and chitosan/Na-ß-GP/Mg-GP hydrogels were also loaded with the enzyme alkaline phosphatase (ALP) which induces hydrogel mineralization. Hydrogels were characterized physicochemically with respect to mineralizability and gelation kinetics, and biologically with respect to cytocompatibility and cell adhesion. Substitution of Na-ß-GP with Mg-GP did not negatively influence mineralizability. Cell biological testing showed that both chitosan/Na-ß-GP and chitosan/Na-ß-GP/Mg-GP hydrogels were cytocompatible towards MG63 osteoblast-like cells. Hence, chitosan/Na-ß-GP/Mg-GP hydrogels can be used as an alternative to chitosan/Na-ß-GP hydrogels for bone regeneration applications. However the incorporation of Mg in the hydrogels during hydrogel formation did not bring any appreciable physicochemical or biological benefit.