The interaction of human macrophage subsets with silicone as a biomaterial

Issue title: Selected Presentations held at the 34th Conference of the German Society for Clinical Microcirculation and Hemorheology, Regensburg, Germany, 27–28 November, 2015

Guest editors: L. Prantl, E.M. Jung and F. Jung

Article type: Research Article

Authors: Vijaya Bhaskar, Thanga Bhuvanesh^{a; b; d} | Ma, Nan^{a; c; d} | Lendlein, Andreas^{a; b; c; d} | Roch, Toralf^{a; d; *}

Affiliations: [a] Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany | [b] Institute of Chemistry, University of Potsdam, Potsdam, Germany | [c] Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany | [d] Helmholtz Virtual Institute – Multifunctional Biomaterials for Medicine, Teltow and Berlin, Germany

Correspondence: [*] Corresponding author: Dr. Toralf Roch, Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513 Teltow, Germany. Tel.: +49 3328 352 459; Fax: +49 3328 352 452; E-mail: toralf.roch@hzg.de

Abstract: Silicones are widely used as biomaterials for medical devices such as extracorporeal equipments. However, there is often conflicting evidence about their supposed cell- and histocompatibility. Macrophages could mediate silicone-induced adverse responses such as foreign body reaction and fibrous encapsulation. The polarization behaviour of macrophages could determine the clinical outcome after implantation of biomaterials. Induction of classically activated macrophages (CAM) may induce and support uncontrolled inflammatory responses and undesired material degradation. In contrast, polarization into alternatively activated macrophages (AAM) is assumed to support healing processes and implant integration. This study compared the interaction of non-polarized macrophages (M0), CAM, and AAM with commercially available tissue culture polystyrene (TCP) and a medical grade silicone-based biomaterial, regarding the secretion of inflammatory mediators such as cytokines and chemokines. Firstly, by using the Limulus amoebocyte lysate (LAL) test the silicone films were shown to be free of soluble endotoxins, which is the prerequisite to investigate their interaction with primary immune cells. Primary human monocyte-derived macrophages (M0) were polarized into CAM and AAM by addition of suitable differentiation factors. These macrophage subsets were incubated on the materials for 24 hours and their viability and cytokine secretion was assessed. In comparison to TCP, cell adhesion was lower on silicone after 24 hours for all three macrophage subsets. However, compared to TCP, silicone induced higher levels of certain inflammatory and chemotactic cytokines in M0, CAM, and AAM macrophage subsets. Conclusively, it was shown that silicone has the ability to induce a pro-inflammatory state to different magnitudes dependent on the macrophage subsets. This priming of the macrophage phenotype by silicone could explain the incidence of severe foreign body complications observed in vivo.

Keywords: Biomaterials, silicone, macrophage subsets, cytokines/chemokines

DOI: 10.3233/CH-151991

Journal: Clinical Hemorheology and Microcirculation, vol. 61, no. 2, pp. 119-133, 2015