Structural Biochemistry/Protein Design & Drug Delivery

Novel Peptide leads to breakthrough in Drug Delivery

Drug delivery to specific tissues in the human body is a major hurdle that must be overcome for safer, more effective use of therapeutic compounds. Many negative side effects can be avoided if the majority of the bodily tissues are bypassed by the compound on its way through the blood to the target site. One of the best ways to accomplish this is by encapsulating the molecule in a membrane that is more likely to release its contents within specific tissue types. Powerful medicines such as those used in chemotherapy to kill cancer cells need to be prevented from killing healthy cells. Also, gene therapy must be targeted so that the newly introduced genes enter only sick cells. Traditionally, liposomes and viruses were tasked with transportation, but a recent discovery has allowed for the sequencing and synthesis of amphiphilic branched peptides that can form water filled bilayers. These peptide spheres are similar to liposomes in that they self assemble. Otherwise they very different because peptides confer several key advantages over lipids such as increased stability under a variety of physiological conditions, fine tuned specificity, and more favorable interactions with antigens and therefore the immune system. This technique promises to revolutionize drug delivery for cancer patients and those suffering from a multitude of other diseases, including alzheimers which must be treated with care given that the blood brain barrier is a challenge for transport and the brain tissue surrounding the plaques is irreplaceable so collateral damage must be minimized at all costs. In practice, the compound to be delivered is placed in solution to which the self assembling peptide is added, the vesicles form around the compound, and it is ready to be purified and administered. By altering the surface of the peptide, researchers hope to fine tune delivery to specific tissue types throughout the body in order to treat a variety of disorders.

References

• Gudlur S, Sukthankar P, Gao J, Avila LA, Hiromasa Y, et al. (2012) Peptide Nanovesicles Formed by the Self-Assembly of Branched Amphiphilic Peptides. PLoS ONE 7(9): e45374. doi:10.1371/journal.pone.0045374