As part of our research programme on self-assembling peptide amphiphiles (PAs) we will investigate the temperature- and pH- dependent self-assembly behaviour of a novel series of PAs based on C16-KTTKS (MatrixylTM) containing the collagen-stimulating KTTKS sequence. BioSAXS will be used to probe the self-assembled structure in aqueous solution, via analysis of form factor in dilute solution. This builds on our earlier research on this system, but the new compounds contain novel lipid chains and PEG spacers desgined to both influence the molecular packing and the bioactivity.