Abstract
PDMS/NdFeB composites are promising materials for soft magnetic actuators, but NdFeB particles corrode in body fluids and release toxic metal ions, limiting their biomedical use. We developed ~ 100 µm spin-coated PDMS-chitosan (PDMS-CHIT) and PDMS-polycaprolactone (PDMS-PCL) coatings that solve this problem. Over 24 weeks of immersion, these coatings reduced neodymium and iron release by more than 95%, keeping ion concentrations well below cytotoxicity thresholds. Importantly, the PDMS-PCL coating fully preserved magnetorheological actuation (ΔG’ ≈ 61 kPa under 0.5 T, comparable to uncoated composite), while PDMS-CHIT provided superior ion barrier at the cost of reduced actuation force. Biological validation confirmed cytocompatibility with fibroblasts, hemocompatibility with erythrocytes, and strong suppression of bacterial biofilm formation. These results establish a validated materials platform for biocompatible soft magnetic actuators.
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The data that support the findings of this study are available from the corresponding author upon reasonable request.
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Funding
This research was financed by the Ministry of Science and Higher Education (Poland) under the Regional Excellence Initiative 2024–2027, grant title “Actively controlled elastic magnetic band for lymphatic drainage”, grant no MRID/WM/5/2024 (project manager: Assoc. Prof. Joanna Mystkowska), and by the Ministry of Science and Higher Education (Poland) through the project “A system for rheological measurements and observation of biological samples in a magnetic field,” contract no. 7135/IA/SP/2020 (project manager: Prof. Robert Bucki).
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Conceptualization: J.M., D.Ł., A.Cz., R.B., A.M.; methodology and investigation: J.M., D.Ł., A.Cz., E.P., P.D.; writing—original draft preparation: J.M., D.Ł., A.Cz.; writing—review and editing: J.M., D.Ł., A.Cz., E.P., P.D., R.B., D.P., J.A., A.M.; visualization, D.Ł., P.D., E.P.; supervision, project administration and funding acquisition: J.M. All authors have read and agreed to the published version of the manuscript.
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Mystkowska, J., Łysik, D., Czerniakiewicz, A. et al. Chitosan and polycaprolactone blended PDMS coatings improve biocompatibility of magnetic elastomers. Sci Rep (2026). https://doi.org/10.1038/s41598-026-40085-6
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DOI: https://doi.org/10.1038/s41598-026-40085-6
