Dissolution and regeneration of silk fibroin: use of ionic liquids and their mixtures with dimethylsulfoxide

• Grant number: 21/11629-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2021
• Effective date (End): November 30, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Omar Abou El Seoud
• Grantee: Matheus Costa Lourenço
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes, AP.TEM

Abstract

This research project aims to study the dissolution of silk fibroin (FS) in binary mixtures of ionic liquids (LIs) and dimethylsulfoxide (DMSO), at fixed temperature and composition. The LIs to be investigated (eight in total) will be carboxylates based on imidazole, trimethyl(n-butyl)amine, and the superbase 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU). DMSO will be used as a co-solvent to decrease the viscosity of the biopolymer solution, thus increasing mass and heat transport. Using a robust protocol for the dissolution of FS - measured by the percentage in mass of dissolved FS (FS-%m) -, it is intended to correlate the efficiency of binary mixtures as solvents with the molecular structure of the LI. For this purpose, the maximum values of FS-%m will be correlated with the physicochemical properties of the FS solutions in these mixtures, determined using solvatochromic probes. The results of this correlation will be compared with those previously obtained by this research group on the dissolution of cellulose. Once dissolved, the FS will be regenerated in the form of films that will be characterized by scanning electron microscopy (SEM). Such films - when containing drugs - have the potential to be applied in a future project, on the treatment of wounds and burns.(AU)