Comprehensive and systematic analysis of the immunocompatibility of polyelectrolyte capsules

The immunocompability of polyelectrolyte capsules synthesized by layer-by-layer deposition has been investigated. Capsules of different architecture and composed of either non-degradable or biodegradable polymers, with either positively or negatively charged outer surface, and with micrometer size, have been used, and the capsule uptake by different cell lines has been studied and quantified. Immunocompatibility studies were performed with peripheral blood mononuclear cells (PBMCs). Data demonstrate that incubation with capsules, at concentrations relevant for practical applications, did not result in a reduced viability of cells, as it did not show an increased apoptosis. Presence of capsules also did not result in an increased expression of TNF-α, as detected with antibody staining, as well as at mRNA level. It also did not result in increased expression of IL-6, as detected at mRNA level. These results indicate that the polyelectrolyte capsules used in this study are immunocompatible.This work was supported by the German Research Foundation (DFG grant PA 794/21-1 to W.J.P.) and the Sino-German cooperative project No. GZ 905 from the Sino German Center. We gratefully acknowledge financial support from the Carlos III Health Institute of Spain (ISCIII, FIS PI14/01538), Fondos FEDER (EU), Junta Castilla-Leon BIO/SA07/15, Fundacion Solorzano FS/23-2015. The Proteomics Units belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001. P.D. is supported by a JCYL-EDU/346/2013 PhD scholarship. D.P. acknowledges the FTA: Nanomedicines for Personalized Theranostics of the Israeli National Nanotechnology Initiative and the Leona M. and Harry B. Helmsley Nanotechnology Research Fund. A.E. acknowledges Junta de Andalucía (Spain) for a Talentia Postdoc Fellowship, cofinanced by the European Union Seventh Framework Programme, grant agreement no 267226.Peer Reviewe