PEGylation of SPIONs by polycondensation reactions: a new strategy to improve colloidal stability in biological media

Author(s)

Viali, Wesley Renato ^[1] ; Nunes, Eloiza da Silva ^[1] ; dos Santos, Caio Carvalho ^[1] ; da Silva, Sebastiao William ^[2] ; Aragon, Fermin Herrera ^[2] ; Huamani Coaquira, Jose Antonio ^[2] ; Morais, Paulo Cesar ^{[2, 3]} ; Jafelicci, Jr., Miguel ^[1]

Affiliation

^[1] Univ Estadual Paulista, Lab Mat Magnet & Coloides, Dept Quim Fis, Inst Quim, BR-14801970 Araraquara, SP - Brazil

^[2] Univ Brasilia, Inst Fis, Nucleo Fis Aplicada, BR-70910900 Brasilia, DF - Brazil

^[3] Huazhong Univ Sci & Technol, Dept Control Sci & Engn, Wuhan 430074 - Peoples R China

• Document type: Journal article
• Source: JOURNAL OF NANOPARTICLE RESEARCH; v. 15, n. 8 AUG 2013.
• Web of Science Citations: 8

Abstract

In this study, we report on a new route of PEGylation of superparamagnetic iron oxide nanoparticles (SPIONs) by polycondensation reaction with carboxylate groups. Structural and magnetic characterizations were performed by X-ray diffractometry (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM). The XRD confirmed the spinel structure with a crystallite average diameter in the range of 3.5-4.1 nm in good agreement with the average diameter obtained by TEM (4.60-4.97 nm). The TGA data indicate the presence of PEG attached onto the SPIONs' surface. The SPIONs were superparamagnetic at room temperature with saturation magnetization (MS) from 36.7 to 54.1 emu/g. The colloidal stability of citrate-and PEG-coated SPIONs was evaluated by means of dynamic light scattering measurements as a function of pH, ionic strength, and nature of dispersion media (phosphate buffer and cell culture media). Our findings demonstrated that the PEG polymer chain length plays a key role in the coagulation behavior of the Mag-PEG suspensions. The excellent colloidal stability under the extreme conditions we evaluated, such as high ionic strength, pH near the isoelectric point, and cell culture media, revealed that suspensions comprising PEG-coated SPION, with PEG of molecular weight 600 and above, present steric stabilization attributed to the polymer chains attached onto the surface of SPIONs. (AU)

• FAPESP's process: 10/20546-0 - Core@shell magnetic nanoparticles: multifunctional materials with tunable properties for technological applications
• Grantee: Miguel Jafelicci Junior
• Support Opportunities: Regular Research Grants