Fabrication of PMMA particles with surface-immobilized polyglutamate containing sialoglycans and encapsulated Fe3O4 nanoparticles

There is a strong demand for technology that can simply and rapidly concentrate, separate, and recover small amounts of viruses, bacteria, and toxic proteins from specimens using an external magnetic field. In this study, we fabricated poly(methyl methacrylate) (PMMA) particles encapsulating multiple Fe 3 O 4 nanoparticles (Fe 3 O 4 /PMMA particles) and immobilized sialoglycopolypeptides that have binding affinity to human influenza virus and SARS-CoV-2 on their surface. The Fe 3 O 4 nanoparticles prepared by the coprecipitation method were surface-modified with oleic acid to increase their affinity with the methyl methacrylate monomer. The oleic acid-modified Fe 3 O 4 particles were dispersed in methyl methacrylate monomer and then added to an aqueous solvent. After ultrasonication of the solution, 2,2′-azobis(2-methylpropionamidine) dihydrochloride (V-50), an initiator with an amidine group, was added and polymerized for 3 h to obtain Fe 3 O 4 /PMMA particles. The Fe 3 O 4 /PMMA particles could be collected from water by a magnet within 90 s. The Fe 3 O 4 /PMMA particle surface was sialoglycosylated by mixing a suspension of Fe 3 O 4 /PMMA particles with a solution of an artificial sialoglycopolypeptide, poly[Neu5Acα2,6LacNAc-β-NHCO(CH 2 ) 5 NH-/γ-polyglutamic acid] (α2,6SLN-γPGA), for 2 h. The immobilization of α2,6SLN-γPGA was confirmed by a shift in the particles’ zeta potential, from a positive charge from the V-50 amidine groups to a negative charge from the α2,6SLN-γPGA carboxyl groups, and by the quantitative analysis of the α2,6SLN-γPGA using high-performance liquid chromatography. An assay with lectins that are specific and nonspecific to sialic acid confirmed that the glycan functionality remained intact even after immobilization on the particles. • PMMA particles containing multiple Fe 3 O 4 particles were fabricated in an aqueous phase. • Artificial sialoglycopolypeptides were immobilized on the Fe 3 O 4 /PMMA particle surface. • The sialoglycans were immobilized on the particles simply by mixing them in water. • The particles could be collected within 90 s using an external magnetic field. • The particles immobilizing sialoglycans specifically adsorbed lectins.