Remote-controllable, tough, ultrastretchable, and magneto-sensitive nanocomposite hydrogels with homogeneous nanoparticle dispersion as biomedical actuators, and their tuned structure, properties, and performances

The development and property control of an intelligently magneto-sensitive (MS) and mechanically strong hydrogel practically usable for diverse biotechnological applications are challenging. In this work, we demonstrate the strategies to fabricate tough, ultrastretchable, and biocompatible MS nanocomposite hydrogels (MSNCHs) with homogeneous nanoparticle dispersion and to tune their network structure and properties for obtaining the optimal MSNCH. The MSNCHs were synthesized by the in-situ thermal polymerization of N,Ndimethylacrylamide (DMAAm), laponite nanoparticles (NPs), and Fe3O4 magnetic NPs (MNPs), and their structural, thermal, swelling, and mechanical properties were examined according to the weight fraction of Fe3O4 MNPs, w(F). In addition, their controllable magnetorheological (MR) properties were investigated for various w(F)s and applied magnetic field (MF) strengths, Hs. The correlation between their w(F)- and H-dependent structure and properties was analyzed, and the magneto-responsive performances in the air and water were also observed. Results showed that their MR properties and performance increased with increasing H, owing to the more robust filler network formed by the better-built alignment of Fe3O4 MNPs, and the dominant one of the reinforcing and interruption effects of Fe3O4 MNP content on the network structure determined the properties and performance of the MSNCH. The MSNCH possessing the homogenous nanoparticle dispersion and the structure, properties, and performances controlled while maintaining its high toughness, ultrastretchability, and biocompatibility holds great potential as a remote-controllable soft actuator for biomedical and pharmaceutical technologies.

Automated summary

In this study, we successfully synthesized tough, ultrastretchable, and biocompatible magneto-sensitive nanocomposite hydrogels with homogeneous nanoparticle dispersion. By evaluating their structure and properties under various weight fractions of magnetic nanoparticles and magnetic field strengths, we found that these hydrogels exhibit excellent magnetorheological properties and magneto-responsive performances. This hydrogel material holds significant potential for biomedical and pharmaceutical technologies.