Development via 3D printing of bone scaffolds based on starch hydrogels added with annatto extract; investigation of strategies with natural deep eutectic solvents (NADES) and encapsulation

Abstract

Recent advances in tissue engineering have been recorded in the development of resorbablebone scaffolds, seeking to replicate the structure and function of natural bone. To beconsidered an effective substitute for bone, the material must meet essential requirements,including mechanical properties like those of bone tissue, adequate biodegradability and theability to stimulate biochemical reactions crucial for osteointegration and osteoconduction.In this context, composites based on organic matrices containing biominerals, capable ofimitating the characteristics of bones, show promise in meeting such requirements. Starch,notably, has stood out as a viable candidate in the manufacture of biomaterials intended fortargeted bone regeneration, and its use has already been documented in recent research. Theuse of bioactive compounds also presents itself as a possibility of bringing to the biomaterialan antioxidant, anti-inflammatory capacity and even helping to improve its mechanical andrheological properties. Within this context, the extract obtained from the seeds of annatto(Bixa orellana L), a plant originating in Central and South America, has a high antioxidantand anti-inflammatory capacity, making it an interesting proposal for this application. Theextraction of these compounds can be done using common organic solvents (SOCs) or theso-called deep eutectic solvents (NADES), the latter being less aggressive to theenvironment, considered a green extraction method. Furthermore, in order to protect thebiological properties of bioactive compounds, the encapsulation technique using liposomescovered with tripolyphosphate and chitosan (TPP-chitosan) has been used. Among thevarious methods for producing biomaterials, 3D printing can be highlighted, an additivemanufacturing technique that allows the production of biomaterials with physicalcharacteristics and personalized composition. Finally, this project aims to develop, through3D printing, starch-based biomaterials added with bioactive compounds from annatto,extracted by the SOC and NADES methods and encapsulated by covered liposomes (TPPchitosan). Therefore, this project seeks to obtain personalized materials that have suitablemechanical, rheological, and biological properties for use as bone substitutes, thuscontributing to the development of the area of tissue engineering aiming at guided boneregeneration