Bioperformance Studies of Biphasic Calcium Phosphate Scaffolds Extracted from Fish Bones Impregnated with Free Curcumin and Complexed with ß-Cyclodextrin in Bone Regeneration.

Fish bones are a natural calcium phosphate (CaP) sources used in biomaterials production for bone regeneration. CaP scaffolds can be enriched with other substances with biological activity to improve bone repair. This study aimed to evaluate the physicochemical properties and bone regeneration potential of biphasic calcium phosphate (BCP) scaffolds impregnated with free curcumin (BCP-CL) or complexed with ß-cyclodextrin (BCP-CD) compared to BCP scaffolds. Rietveld's refinement showed that BCP is composed of 57.2% of HAp and 42.8% of ß-TCP and the molar ratio of Ca/P corresponds to 1.59. The scaffolds presented porosity (macro and microporosity) of 57.21%. Apatite formation occurred on the BCP, BCP-CL, and BCP-CD surface, in vitro, in SBF. Micro-Raman technique showed a reduction in the dissolution rate of ß-TCP in the curcumin-impregnated scaffolds over time, and in vivo studies on critical-size defects, in rat calvaria, had no additional regenerative effect of BCP-CL and BCP-CD scaffolds, compared to BCP scaffolds. Despite this, the study showed that curcumin impregnation in BCP scaffolds prolongs the release of the ß-TCP phase, the BCP- phase with the higher osteoinductive potential, representing an advantage in tissue engineering.

Use of FT-IR, FT-Raman and thermal analysis to evaluate the gel formation of curdlan produced by Agrobacterium sp. IFO 13140 and determination of its rheological properties with food applicability.

Curdlan is a linear polysaccharide composed of glucose units joined by ß-(1,3) bonds that possesses unique gelation properties. This study aimed to characterize the structure and evaluate the gelling properties of curdlan produced by Agrobacterium sp. IFO 13140 and its gels, as well as apply it in food. FT-Raman analysis highlighted the structural changes that occurred during the formation of gels, with variations related to the hydrogen bonds and hydrophobic interactions, which occur with the formation of the low-set and high-set gels, respectively. Rheological analysis showed that the pre-gelled commercial curdlan and the curdlan produced by Agrobacterium sp. IFO 13140 differed in terms of gelation properties, which depends of the degree of polymerization of the polysaccharide, but when applied to pasta products, both improved the texture parameters. The curdlan gels were found to have great potential as gelling agents to improve texture, water retention capacity and stability of food products.