Biocompatible carbon nanotubes fiber coating for determining anandamide and 2-arachydonoylglicerol in rat brain by in vivo SPME-LC-MS/MS

• Grant number: 22/07510-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 15, 2022
• End date: November 14, 2023
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Maria Eugênia Queiroz Nassur
• Grantee: Igor Gustavo de Carvalho Oliveira
• Supervisor: Janusz Pawliszyn
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of Waterloo, Canada
• Associated to the scholarship: 20/06526-8 - Development of an organic monolithic phase with anion exchanger groups and hydrophilic coating to homocysteine and homocysteic acid determination in biological samples from patients with Alzheimer's Disease by in-tube SPME-UHPLC-MS/MS, BP.DR

Abstract

N-arachidonoyl-ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) are the main representatives of the endocannabinoid (EC) family, a group of neurotransmitters that act in signaling processes by activating the cannabinoid receptors type 1 and type 2 (CB1 and CB2). Given the role that AEA and 2-AG play in synaptic transmissions in the brain, they have been extensively studied as potential biomarkers of neurodegenerative diseases, such as Parkinson's Disease (PD). PD is a neurodegenerative disorder characterized by dopaminergic neuron loss, which causes motor dysfunctions. Clinical studies on PD animal models and biological samples obtained from PD patients have indicated that these individuals present increased AEA and 2-AG levels when compared to healthy individuals, which suggests that these ECs are potential PD biomarkers. AEA and 2-AG have been typically quantified in biological samples by ex vivo and in vitro methodologies. However, the employed methodologies cannot accurately indicate or predict the complex processes occurring in living organisms. In vivo sampling eliminates errors related to degradation or loss of short-lived and unstable analytes, a typical drawback of traditional sample preparation procedures. This project aims to develop an innovative method that combines in vivo solid-phase microextraction (SPME) and LC-MS/MS to determine AEA and 2-AG in the brain of awake and freely moving rats. To achieve this aim, a biocompatible carbon nanotubes (CNTs) SPME fiber coating will be developed, and different coating strategies and biocompatible materials will be evaluated. The high surface area and excellent adsorption capacity of CNTs should provide efficient analyte extraction, while the biocompatible layer should prevent macromolecules from the matrix from being adsorbed. This BEPE project is associated with the doctorate project that is being developed in Brazil and which aims to determine biomarkers in biological samples obtained from individuals with neurodegenerative diseases. (AU)