Design of a shear-thinning recoverable peptide hydrogel from native sequences and application for influenza H1N1 vaccine adjuvant

Abstract

Peptide hydrogels are considered injectable materials for drug delivery and tissue engineering applications. Most published hydrogel-forming sequences contain either alternating-charged and non-charged residues or amphiphilic blocks. Here, we report a self-assembling peptide, h9e (FLIVIGSIIGPGGDGPGGD), designed by rationally combining two native sequences from an elastic segment of spider silk and a trans-membrane segment of human muscle L-type calcium channel. The turning segment GSII of h9e promoted hydrogel formation in both Ca²⁺ solution and acidic pH conditions at water content greater than 99.5%. Although h9e Ca²⁺ hydrogel and h9e acidic hydrogel have the same sequence, they have distinct physical properties. The shear-thinning, rapid-strength-recovering h9e Ca²⁺ hydrogel was used as an H1N1 influenza vaccine adjuvant. The h9e adjuvant was biologically safe and improved immune response by ∼70% compared with an oil-based commercial adjuvant.