Scientists from Kansas State University, University of Nebraska, and PNNL used two native functional sequences from spider flagelliform silk protein and a trans-membrane motif of human muscle L-type calcium channel to design a self-assembling peptide, h9e.
The h9e peptide formed two novel hydrogels in Ca2+ solution and acidic pH conditions—h9e Ca2+ hydrogel and h9e acidic hydrogel. The shear-thinning, rapid-strength-recovering h9e Ca2+ hydrogel proved to have potential for drug delivery and tissue-engineering applications and was tested on mice as an injectable adjuvant for H1N1 swine influenza virus killed vaccine. The study showed it was biologically safe, improved immune response on killed H1N1 virus antigen by approximately 70%, and induced a similar H1N1-specific IgG1 antibody response compared with an oil-based commercial adjuvant.
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 [similar]70% compared with an oil-based commercial adjuvant.