Anticorpos sintéticos preparados a partir de epítopo do vírus SARS-CoV-2 através da eletrofiação reativa

Abstract

The identification of high-risk pathogens, such as SARS-CoV-2, is of great assist in rapid diagnosis for preventing and fighting against pandemics. Developed “synthetic antibodies” through polymers imprinted with biological molecules can provide an attractive alternative compared to natural antibodies based on proteins (e.g., immunoglobulins) under adverse and hash conditions, being resistant to variations in pH, temperature, and organic solvents. The objective of this work was to produce “synthetic antibodies” based on the SARS-CoV-2 epitope as biofunctionalized nanofibers to test the hypothesis that the high surface area of nanofibers imprinted with SARS-CoV-2 epitope would improve the capability of detection of the synthetic antibody. To this end, a SARS-CoV-2 epitope peptide (J5) was designed, simulated through bioinformatics tools (in silico), and synthesized as a model molecule for imprinting. Epitope-imprinted polymers (EIP) based on J5 and Non-Imprinted Polymers (NIPs) were prepared with polymeric networks derived from acrylamide and acrylic acid comonomers in the form of bulk samples and electrospun fibers. Bovine serum albumin was also used as a model molecule for the preparation of molecular imprinted polymers (MIP) to serve as a control system. EIP electrospun nanofibers were obtained using a reactive electrospinning setup that allows the simultaneous photopolymerization and fiber formation. SEM images, infrared spectroscopy results, and swelling tests were performed, showing that EIP, MIP, NIP bulk samples, and electrospun nanofibers were successfully obtained. Rebinding tests, in which the obtained EIPs, MIPs and NIPs were put in contact with the target molecules, showed that the obtained synthetic antibodies could interact more efficiently with the target molecules than the corresponding NIP sample. Moreover, the rebinding capacity (Q) of EIP and MIP as electrospun nanofibers showed higher capabilities of interacting with the target molecules, i.e., J5 and albumin, respectively, than the same imprinted polymers as bulk samples (Q was 11923 ± 1762 µg/g when SARS-CoV-2 epitope was imprinted in nanofibers, while Q was 6065 ± 755 µg/g for bulk samples with the same epitope imprints). The obtained results suggest that synthetic antibodies based on imprinting epitopes on electrospun fibers have high enough degrees of affinity and specificity to be considered promising candidates to be applied in the design of more stable and accessible biosensors and other diagnostic tools for diseases, such as COVID19.