Preparation of model starch complex hydrogels

Abstract

Amylose can form molecular inclusion complexes by forming a helix around ligands and thus protecting them and increasing their bioavailability. Hydrogels are biomaterials that have been used in drug and nutrient delivery. In this study, we have used a simple method to fabricate 3-D porous hydrogels using starch inclusion complexes as the structural material. Native maize starch and myristic acid as a model ligand were complexed and subsequently cross-linked with trisodium trimetaphosphate (TTP) to synthesize the hydrogels and pores were created after freeze-drying. X-ray diffraction and DSC thermal analysis verified the presence of amylose inclusion complexes in the hydrogels matrix. The starch complex hydrogels had 70% porosity with pores ranging from approximately 50 μm–250 μm that swelled up to approximately 600 μm upon hydration. As a result, the equilibrium water content and the degree of swelling of the hydrogels were 66.8% and 191.7%, respectively, while Young's modulus of elasticity of the hydrogels was 56.6 kPa. The starch complex hydrogels had a slow degradation rate in the presence of α-amylase and lost ∼38% of their weight after 36 days of incubation at 37 °C.