Development of potential bone scaffolds via 3D printing using hydrogels of microwave-modified starch and surface treatment with cold plasma

• Grant number: 25/00927-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2025
• End date: July 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Bianca Chieregato Maniglia
• Grantee: Fernanda Pavani Silva
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 20/08727-0 - Starch modification by green methods for elaboration via 3D printing of bone scaffolds activated by the presence of hydroxyapatite nanoparticles replaced by Sr2+, AP.JP

Abstract

In the field of 3D printing of biomaterials, such as bone scaffolds, the development of inks with high levels of printability and biocompatibility is challenging due to the need to balance the processability and functionality of these materials. Starch has shown promise as a candidate for the fabrication of biomaterials, and its use in 3D printing has already been reported. However, native starch presents limitations, such as inadequate rheology for processing and unfavorable physicochemical properties, including swelling and hydrophilicity, which impair its functionality.To overcome these limitations, modifications to native starch can be implemented before hydrogel production. Physical modification of starch is considered simple, economical, and "green," as it does not require solvents and is free of residues. Among physical modifications, the microwave route is categorized as a thermal modification, with a mechanism based on dielectric loss. The electric and magnetic components of microwaves act on the material, creating molecular friction and collisions, converting electromagnetic energy into thermal energy, and consequently heating the material. Compared to other thermal modifications, microwave treatment offers speed and high-efficiency advantages. The effects of this modification on the physicochemical properties of starch, such as grain morphology, crystallization, and gelatinization, have been studied, showing potential applications in the development of inks. In this study, the modification will be performed by altering parameters such as treatment time and microwave power to achieve optimal starch functionalization for hydrogel production for 3D printing. Additionally, the functionality of the printed bone scaffolds can be enhanced through further treatment. One approach involves applying cold plasma treatment to modify the scaffold surface regarding surface free energy, roughness, adhesion, and hydrophobicity.Therefore, the main objective of this project is to conduct 3D printing of bone scaffolds using microwave-modified starch hydrogels and apply cold plasma treatment to the surface of the scaffolds to improve the processability of the formulations and the functionalization of potential biomaterials. The rheological properties of the formulations will be evaluated, and the bone scaffolds will be characterized regarding their mechanical, morphological (surface and porosity), functional (biodegradability, swelling), and biological (cytotoxicity and mineralization) properties. Finally, this study will enable the assessment of the potential of a pre-treatment of natural source raw materials combined with a post-treatment of the printed material, integrating innovative and sustainable technologies for developing new biomaterials aimed at bone tissue regeneration.