Living magnetorheological composites: from the synthesis to the in vitro characterization

Abstract

A new type of magnetorheological (MR) material is reported that brings together conventional MR composites (MRCs) and biomaterials. Living MRCs based on carbonyl iron microparticles (CIPs) as magnetoactive filler, sodium alginate as elastomer and cells as biological components were prepared and characterized. The effect of CIPs concentration in isotropic alginate composites was examined by using thermogravimetric analysis, infrared spectroscopy, swelling and degradation tests in culture medium (Dulbecco’s Modified Eagle’s Medium, DMEM). To self-assemble the CIPs within the polymer matrix, the cross-linking process took place under an external magnetic field (24 mT). The cytotoxicity experiments were performed with human mesenchymal stem cells and human fibroblasts loaded inside of the hydrogel. It was demonstrated that the living MRCs supported cell survival and proliferation. The rheological response of the MRCs was evaluated in dynamic oscillatory tests in the absence and presence of magnetic fields. The viscoelastic response of the living MRCs improved when a magnetic field was applied. This work demonstrates the possibility to use CIPs in the fabrication of living composites with MR response. Results could be of interest in smart biomedical applications.