Stimuli-Responsive Peptide Gatekeepers for Smart Nanocarriers

Peptides have attracted great interests due to their potential for versatile application in preparation of drug carriers because of their specific targeting capability to desired tissues and bioresponsiveness toward various biological molecules such as enzymes for selective cleavage or bio-responsive folding into specific conformation. Therefore, the introduction of peptides as a gatekeeper on the surface would provide MSNs with triggered release property of guest molecules in response to a variety of biological stimuli including specific enzymes at specific target sites. In this review, we discuss the recent progress of peptide gatekeepers on MSNs by classification of the stimuli for triggering the release of payloads from the mesopore. We also describe the on-off gatekeepers by employing the motif of conformational transformation of peptides in response to external stimuli. The myriad biological functions of peptides by interaction with biomolecules, cells and organs endow the peptide gatekeepers on MSNs with great potential to construct smart nanocarriers.