Multifunctional peptide biointerfaces

In creating useful devices for biomedical and other applications that come into contact with biological fluids, it is of great interest to mimic the multifaceted control of complex biomolecular and cell interactions observed in nature. On the molecular level, all such interactions involve surfaces and interfaces. In biology, this is often a cell membrane interface. In devices, this is the surface or interface of an artificial material, be it a nanoparticle or the surface of a biomaterial or biosensor. Multifunctional biointerfaces aim to provide simultaneous modulation of several biological signals. This chapter highlights the use of both linear and multi-armed peptide designs specifically conceived for such multifunctional surface applications. As shown by the studies reviewed, this dedicated strategy has met with considerable success, not least because even relatively short oligopeptide sequences, including cell-instructive and antimicrobial motifs, are being shown to be capable of diverse and robust bioactivities. Moreover, these sequences (and related peptidomimics) may be rationally combined and conveniently synthesized by standardized solid phase peptide synthesis. In addition, research into multifunctional peptide biointerfaces has been greatly aided by advances in simple and facile surface immobilization chemistries (e.g. SAMs and DOPA/polydopamine), as well as the realization that proteins possess native “antifouling” properties that can be mimicked by simple and mostly zwitterionic residue compositions to suppress non-specific interactions and enhance biorecognition binding. Overall, functionalization of biointerfaces with multifunctional peptides stands out as a powerful strategy to engineer protein-mimetic bioactivity on artificial materials and device surfaces, and great scope remains for the development of applications based on even more diverse peptide architectures as well as an expanded range of protein-mimetic biorecognition and multifunctionality.