Poly(vinyl alcohol)/sodium alginate/magnetite composites: magnetic force microscopy for tracking magnetic domains

Autor(es)

Alavarse, Alex Carvalho ; Silva, Jean Bezerra ; Ulrich, Henning ; Siqueira Petri, Denise Freitas

• Tipo de documento: Artigo Científico
• Fonte: SOFT MATTER; v. 19, n. 14, p. 11-pg., 2023-03-15.

Resumo

Hydrogels of poly(vinyl alcohol) (PVA)/sodium alginate (SA), and magnetic nanoparticles (MNPs) were prepared by solvent casting in the absence and in the presence of magnets, in order to obtain MNPs distributed randomly (PVA/SA-rMNP) and magnetically oriented MNPs (PVA/SA-gMNP) in the polymer matrix. Atomic force microscopy (AFM) and magnetic force microscopy (MFM) techniques were used to evaluate the topography and to map the distribution of magnetic domains in the polymer matrix, respectively. The tip-surface distance (lift distance) of 50 nm during the MFM analyses facilitated the mapping of magnetic domains because the van der Waals forces were minimized. The magnetic signal stemming from clusters of MNPs were more easily identified than that from isolated MNPs. PVA and SA, PVA/SA, PVA/SA-rMNP, and PVA/SA-gMNP coatings with surface roughness (R-a) values of 3.8 nm, 28.7 nm, and 49.8 nm, respectively, were tested for the proliferation of mouse hippocampal HT-22 cells. While PVA/SA, PVA/SA-rMNP, and PVA/SA-gMNP coatings preserved cell viability >70% in comparison to the control (plastic plate) over 48 h, cell proliferation tended to decrease on surfaces with higher R-a values (PVA/SA-gMNP). These findings showed that the orientation of magnetic domains led to an increase of surface roughness, which decreased the viability of HT-22 cells. Thus, these results might be interesting for situations, where the control of cell proliferation is necessary. (AU)

• Processo FAPESP: 18/13492-2 - Arcabouços sintéticos e naturais aplicados à medicina regenerativa
• Beneficiário: Luiz Henrique Catalani
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/07366-4 - Receptores de purinas e cininas como alvos de estudo e intervenção terapêutica em doenças neurológicas
• Beneficiário: Alexander Henning Ulrich
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/01907-3 - Determinação das propriedades mecânicas de arcabouços magnéticos a base de polissacarídeos
• Beneficiário: Alex Carvalho Alavarse
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/08178-0 - EMU concedido no processo 2018/13492-2: microscópio de força atômica
• Beneficiário: Luiz Henrique Catalani
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários