Diabetes mellitus is a life-threating disease that affect 450 millions of people in the world. It is the sixth most common cause of death. Therefore, it is crucial to develop 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 drug delivery systems to attend these needs. Seaweeds, 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. This polymer is mainly composed of L-fucose and its sulfated esters and may include glucuronic acid and other sugars. It has relevant properties namely reducing blood glucose, antioxidant and anti-inflammatory actions. In this work, the biomedical potential of fucoidan-based materials as a drug delivery system was assessed by processing modified fucoidan (MFu) into particles by photocrosslinking using superhydrophobic surfaces and visible light. Fucoidan was modified by methacrylation reaction using 12% v/v of methacrylic anhydride. Further, MFu particles with and without insulin (5% w/v) were produced by pipetting a solution of 5% MFu with triethanolamine and eosin-y onto a superamphiphobic surface and then photocrosslinking using visible light. Degree of methacrylation and sulfation of modified fucoidan was addressed by FTIR and 1HNMR. Moreover, the developed particles were characterized assessing their morphological features and insulin release in phosphate buffer solution (PBS) and simulated intestinal fluid (SIF) for 24 hours. The characterization revealed that the obtained MFu has a methacrylation degree of 14%, and the produced particles have an average diameter of 1.53 mm. The insulin release in PBS and SIF demonstrate that the particles can release insulin in a sustained manner under the studied period. The ability of the developed materials to support adhesion and proliferation of cells was assessed by suspension culture of human pancreatic cells 1.1B4 (3.5x105 cells/ml) in contact with MFu microparticles up to 7 days. The biological tests regarding the culture of pancreatic beta cells demonstrate that cells tend to form pseudo-islets during the culture period studied. Furthermore, the results suggest this system could be used for treatment of type I diabetes mellitus as they sustain beta cells viability and proliferation. The findings also suggested, MFu particles as a good candidate as drug delivery vehicles for the diabetes mellitus treatment.Acknowledgment: L. L. Reys, S. S. Silva, N.M. Oliveira and D.S. Costa specially acknowledge financial support from Portuguese FCT. This work is also financially supported by the R&D&I Structured Project with reference NORTE-01- 0145-FEDER-000021, supported by the ERDF under Programa Operacional Regional do Norte (NORTE2020).

Acknowledgment: L. L. Reys, S. S. Silva, N.M. Oliveira and D.S. Costa specially acknowledge financial support from Portuguese FCT. This work is also financially supported by the R&D&I Structured Project with reference NORTE-01- 0145-FEDER-000021, supported by the ERDF under Programa Operacional Regional do Norte (NORTE2020).