Injectable hydrogel based on dialdehyde galactomannan and N-succinyl chitosan: a suitable platform for cell culture

Regenerative medicine proposes to regenerate or even replace human damaged tissues to return to normal functions. Hence, biomaterials have been used to provide appropriate environment for cell development. Among the groups of biodegradable biomaterials, hydrogels, which are characterized by three-dimensional and cross-linked networks of water-soluble polymers, have been highlighted as suitable matrices for such applications. An injectable hydrogel based on oxidized galactomannan (OxGM) from Delonix regia and N-succinyl chitosan (NSC) was developed and characterized according to its physicochemical and biocompatible properties. The hydrogel was formed by Schiff base (-CH = N-) cross-linking between aldehyde groups from OxGM and NH₂ groups from NSC, in few minutes (9.7 min) without any external stimulus. A hydrogel with macroporous structure, interconnected pores, and porosity of 69% was obtained. The biomaterial exhibited excellent injectability. No change in volume or integrity was observed in the hydrogel after its swelling in phosphate buffered saline (PBS) medium. This is an important property because when the hydrogel is injected into the site of interest and it fills the environment, it will not have additional space to occupy. Biocompatibility studies were conducted in vitro, which revealed the non-cytotoxic nature of the material and demonstrated the potential of the hydrogel based on dialdehyde galactomannan and N-succinyl chitosan for cell culture and soft tissue engineering.