Diabetes mellitus is a metabolic disorder that affects 450 millions of people in the world. In biomedical area efforts have been focused on the development of new therapeutic strategies and models to treat this disease. In this perspective, marine origin polymers represent a relatively untapped source that can be used in the creation of hydrogels to attend these needs. Algae, for instance, synthesize a wide variety of polymers and smaller compounds with several bioactivity properties. Fucoidan (Fu) is an important example, an underexploited sulfated polysaccharide extracted from the cell wall of brown seaweeds. It has relevant properties namely reducing blood glucose, antioxidant and anti-inflammatory actions. This study intends to assess the biomedical potential of Fu-based hydrogels for diabetes treatment. For that purpose, blended hydrogels were produced combining Fu with agarose (Aga), a polysaccharide derived from the cell wall of red seaweeds, through a thermal crosslinking reaction.
The hydrogels AgaFu were obtained from 3 or 5 wt% Fu aqueous solutions and adding 3 or 5 wt% Aga powder, using different proportions (50:50; 70:30 and 40:60). Chemical characterization of blends was addressed by FTIR, 1HNMR and XPS. Moreover, the developed hydrogels were characterized assessing swelling in Dulbecco ́s phosphate buffer solution (DPBS) and Rosewell Park Memorial Institute medium (RPMI medium) for 24 hours and stability in same solutions for 28 days. The rheological behaviour was also characterized by submitting the hydrogels to rotational and oscilatory expirements using parallel plate as geometry. The ability of the developed materials to encapsulate human pancreatic cells in a viable step was assessed using 1.1B4 cell line (2x106 cells/ml) during up to 7 days. The characterization revealed that the obtained AgaFu hydrogels are stable in RPMI medium and PBS for 28 days. The chemical characterization confirmed the presence of the two polymers in the structure of hydrogels, with rheological tests revealing a non-newtonian, viscoelastic behaviour. Furthermore, the biological assessment of culture of pancreatic beta cells into the hydrogels demonstrated that cells tend to form pseudo-islets during the culture period studied. Furthermore, the results suggest that this system could be used for the treatment of type I diabetes mellitus as they sustain beta cells viability and proliferation.