(235g) Endoprotease-Mediated Intracellular Protein Delivery

Proteins possess many distinct signaling, structural, regulation, and enzymatic properties which allow them to have tremendous implications in therapeutic fields. However, due to the fragility of most proteins, intracellular delivery of native, active protein is very challenging. Polymeric materials may aid protein entry into cells however upon cellular entry, a mechanism for cargo release is needed. In this study, a biomimetic delivery vehicle is proposed which can be degraded by a ubiquitous intracellular protease after cellular entry. Proteins were encapsulated in nanocapsules (NCs) constructed with monomers and a synthesized bisacryolated peptide crosslinker which is recognized and cleaved by the protease. Release of encapsulated protein was confirmed in a cell-free system upon proteolytic degradation of NCs. In vitro cell culture studies demonstrated successful intracellular delivery of protein NCs and elucidated the importance of the recognizable crosslinker and presence of intracellular protease for observed release of protein. Upon further development, this proteolytically triggered intracellular delivery system may be able to effectively deliver many biological components including proteins, siRNA, and DNA.