Magnetic Removal of Candida albicans Using Salivary Peptide-Functionalized SPIONs

Bernhard Friedrich,1 Rainer Tietze,1 Michaela Dümig,2 Alexandru Sover,3 Marius-Andrei Boca,3 Eveline Schreiber,1 Julia Band,1 Christina Janko,1 Sven Krappmann,2 Christoph Alexiou,1,* Stefan Lyer1,4,* 1Department of Otorhinolaryngology, Head and Neck Surgery, Section of Experimental Oncology and Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung Professorship, Universitätsklinikum Erlangen, Erlangen, Germany; 2Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany; 3Faculty of Engineering, Ansbach University of Applied Sciences, Ansbach, Germany; 4Department of Otorhinolaryngology, Head and Neck Surgery, Section of Experimental Oncology and Nanomedicine (SEON), Professorship for AI-Controlled Nanomaterials, Universitätsklinikum Erlangen, Erlangen, Germany*These authors contributed equally to this workCorrespondence: Stefan Lyer, Section of Experimental Oncology & Nanomedicine (SEON), Glückstraße 10a, Erlangen, 91054, Germany, Tel +49-9131-85-33142, Fax +49-9131-85-34828, Email stefan.lyer@uk-erlangen.dePurpose: Magnetic separation of microbes can be an effective tool for pathogen identification and diagnostic applications to reduce the time needed for sample preparation. After peptide functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) with an appropriate interface, they can be used for the separation of sepsis-associated yeasts like Candida albicans. Due to their magnetic properties, the magnetic extraction of the particles in the presence of an external magnetic field ensures the accumulation of the targeted yeast.Materials and Methods: In this study, we used SPIONs coated with 3-aminopropyltriethoxysilane (APTES) and functionalized with a peptide originating from GP340 (SPION-APTES-Pep). For the first time, we investigate whether this system is suitable for the separation and enrichment of Candida albicans, we investigated its physicochemical properties and by thermogravimetric analysis we determined the amount of peptide on the SPIONs. Further, the toxicological profile was evaluated by recording cell cycle and DNA degradation. The separation efficiency was investigated using Candida albicans in different experimental settings, and regrowth experiments were carried out to show the use of SPION-APTES-Pep as a sample preparation method for the identification of fungal infections.Conclusion: SPION-APTES-Pep can magnetically remove more than 80% of the microorganism and with a high selective host-pathogen distinction Candida albicans from water-based media and about 55% in blood after 8 minutes processing without compromising effects on the cell cycle of human blood cells. Moreover, the separated fungal cells could be regrown without any restrictions.Keywords: Candida albicans, SPIONs, fungal sepsis, GP340, microbiological identification