A Biomimetic, Silaffin R5-Based Antigen Delivery Platform

Abstract

Nature offers a wide range of evolutionary optimized materials that combine unique properties with intrinsic biocompatibility and that can be exploited as biomimetic materials. The R5 and RRIL peptides employed here are derived from silaffin proteins that play a crucial role in the biomineralization of marine diatom silica shells and are also able to form silica materials in vitro. Here, we demonstrate the application of biomimetic silica particles as a vaccine delivery and adjuvant platform by linking the precipitating peptides R5 and the RRIL motif to a variety of peptide antigens. The resulting antigen-loaded silica particles combine the advantages of biomaterial-based vaccines with the proven intracellular uptake of silica particles. These particles induce NETosis in human neutrophils as well as IL-6 and TNF-α secretion in murine bone marrow-derived dendritic cells.

The secondary structure of diatom silaffin peptide R5 determined by two-dimensional infrared spectroscopy

“…16 Silaffin peptides are thought to act as templates for this reaction, where the polyamines of post-translational modifications can improve the reaction conditions of the condensation by leading the reactants together. 2 R5-biosilica particles have been applied to immobilize enzymes, 17,18 encapsulate and release cargo molecules, 19 as a vaccine delivery platform 20 and an R5 derivative was also used to synthesize antimicrobial peptide nanoparticles. 21 Regardless of the many applications and vast potential of R5-biosilica, the structure of the peptide during silicification is not yet fully understood.…”

“…R5–biosilica particles have been applied to immobilize enzymes, 17,18 encapsulate and release cargo molecules, 19 as a vaccine delivery platform 20 and an R5 derivative was also used to synthesize antimicrobial peptide nanoparticles. 21…”