Thermal-reversible and self-healing hydrogel containing magnetic microspheres derived from natural polysaccharides for drug delivery

Abstract Hydrogels with and self-healing properties and responsiveness to external stimuli have been extensively investigated as cell scaffolds and wound dressings, due to their diversity and prolonged lifetime. In this report, we developed magnetic microspheres based on chitosan derivatives through a facile Schiff-base crosslinking procedure. X-Ray diffraction (XRD), scanning electron microscopy (SEM) and thermal gravity (TG) were utilized to characterize the magnetic microspheres. A thermal-reversible and self-healing hydrogel was prepared via electrostatic interactions between positively charged chitosan and negatively charged cellulose. By introducing the magnetic microspheres into polymer hydrogels, hybrid scaffolds were synthesized with facile preparation technology, controllable shape and mobility under magnetic force. Swelling property, degradation rate and morphology of these scaffolds have been investigated. Results revealed that the magnetic microsphere exhibit spherical morphology, good dispersity with narrow size distribution and capability of maintaining structure in physical environment. Rheological study demonstrated the thermal reversibility and self-healing ability of chitosan-cellulose hydrogels. Moreover, the obtained composite hydrogels and lyophilized porous scaffolds exhibited excellent homogeneity, controllable formation, magnetic responsiveness as well as good stability in physiological environment. Moreover, this thermal-reversible and self-healing scaffold showed a controlled in vitro drug release under an external magnetic field. The magnetic gel scaffold suggest an alternative approach to provide intelligent and versatile scaffolds for biomedical applications.