Branched peptides for enzymatic assembly and mitochondria drug delivery

  • This invention describes a novel targeting delivery of cytotoxic drugs to mitochondria maysignificantly increase the toxicity to control cell fate;
  • The branched hydrogelator is specifically designed with three fragments including the FLAG-tagDYKDDDK, a self-assembling hydrophobic peptide moiety, and a spacer liking these two parts;
  • This novel approach for mitochondria targeting drug delivery demonstrates rapid cellular uptakeand specific accumulation in mitochondria in vitro.


This invention introduces a new platform technology accomplishing mitochondria-targeting cargos delivery to selectively inhibit or rescue different types of cells. Due to the importance of mitochondria for living cells, the branched peptides have the potential to control the fate of cells, via delivering diverse bifunctional molecules to mitochondria. The targeting delivery of cytotoxic drugs to mitochondria may significantly increase the toxicity, while the mitochondrial accumulation of some bioactive molecules (e.g. pifithrin-) may rescue normal tissue from radiotherapy. To meet the need of mitochondria-targeting cargos delivery, a branches peptide is designed to control the fate of cells, either inhibit or rescue, via delivering diverse bio functional molecules to mitochondria. The generation of supramolecular hydrogel via branched peptides upon the addition of a serine protease: enterokinase (ENTK). The said peptide consists of 3 fragments: i) the FLAG-tag DYKDDDK, as the substrate of ENTK for proteolysis, ii) a hydrophobic peptide moiety which self-assembles into nanofibers after the cleavage of FLAG-tag, and iii) a Glycine, as the spacer for I and ii. The enzymatic cleavage of the hydrophilic FLAG branch by ENTK turns the branched peptide hydrogelator to nanofibers, resulting into supramolecular hydrogel. The merit of this invention is, to carry multiple negative charges and can escape from endosome after rapid cellular uptake and specifically accumulate in mitochondria. Bioactive molecules, such as proteins and anti-cancer drugs, can be encapsulated by the branched peptides and eventually delivered to mitochondria.


  • The invention reports a new possible mechanism for targeting mitochondria other than traditionallipophilic and cationic molecules;
  • This work illustrates a new approach to encapsulate bioactive molecules, such as proteins andanti-cancer drugs, into the designed branched peptides and eventually get delivered tomitochondria;
  • The invention introduces a mitochondrion –specific drug delivery of cargo molecules by theFLAG-tagged precursors which is promising for various application in biomedicine.