Hydrogel scaffolds based on k-Carrageenan/xyloglucan blends to host spheroids from human adipose stem cells

Hydrogels are water-swollen networks of hydrophilic polymer. They can be fabricated in various shapes and swell in water or aqueous solutions maintaining their original shape or undergo progressive erosion; can exibit large volume phase transitions with the change of one environmental parameter (stimuli-responsivness), shock absorption and low sliding friction properties (1). The morphology and mechanical properties of hydrogels are strongly affected by the network composition, the nature and degree of crosslinking and the degree of swelling. Indeed, when hydrogels are designed as scaffolds for human tissues remodeling, they must have sufficient mechanical integrity to provide support to the cells from the time of implantation to the completion of the process. The large amount of water present in the hydrogels and its microscopic pores interconnectivity allows transportation of nutrients, oxygen and metabolites, that ensures cells viability, and permits cells migration and scaffold colonization. The polymeric network can immobilize biomolecules that may affect cells growth or differentiation, control drug release profiles and enzymatic degradation (2,3). The combination of two hydrogelforming polymers with different chemistries and crosslinking densities can be used to tailor the morphology, mechanical strength and toughness of the scaffold to meet specific requirements (1). This work investigates the physico-chemical, morphological and mechanical properties of hydrogels formed by the blend of two polysaccharides, k-Carrageenan (k-C) and Degalactosylated Xyloglucan (Deg-XG) undergoing salt-induced and temperature-induced solgel transition, respectively. It also studies the compatibility of the two biopolymers with spheroids from adipose-derived stem cells (S-ASCs) in the prospect of developing instructive scaffolds for use in regenerative medicine.