Kansas State University researchers in the US have created a membrane-bounded vesicle formed entirely of peptides that could serve as a new drug delivery system to treat cancer and neurodegenerative diseases.
A study led by John Tomich, professor of biochemistry at Kansas State University, published in the journal PLOS ONE in September*, describes how the peptides, a set of self-assembling branched molecules made up of naturally occurring amino acids, create a vesicle or ‘bubble’ comprising a thin membrane that is hollow inside. Created in a water solution, the vesicle is filled with water.
The bubble can be made in a solution containing a drug or other molecule that becomes encapsulated as the peptide assembles, yielding a trapped compound, much like a gelatin capsule holds over-the-counter oral remedies. The peptide vesicles could then be delivered to appropriate cells in the body to treat diseases and minimise potential side-effects.
‘We see this as a new way to deliver any kind of molecule to cells,’ Tomich said. ‘We know that in certain diseases sub-populations of cells have gone awry, and we’d like to be able to specifically target them instead of attacking every cell, including healthy ones.’
The finding could improve gene therapy, which has the potential to cure diseases by replacing diseased cells with healthy ones.
The biggest challenge in gene therapy is how best to deliver the genes. Methods include cells with a virus being injected into the body or liposomes carrying the genes. However, these methods may present some problems. When a virus is used, the body’s immune system can attack the virus or cause a tumour. Lipid-based systems may cause inflammation and may not properly bind to cells.
The peptides created by Kansas State University researchers have advantages over their lipid counterparts. The peptides have improved stability and durability, are easier and quicker to create, and they could be delivered to a specific area in the body. The peptides can be designed to have the ability to target cells, tissues, tumours or organs, and to encapsulate chemical reagents, antibodies, toxins and inhibitors, Tomich said.
Partial funding for the study came from the Kansas State University Johnson Cancer Research Center, National Institutes of Health and Japan Society for the Promotion of Science.
Kansas State University collaborators include Sushanth Gudlur; Pinakin Sukthankar; Jian Gao; Luz Adriana Avila Flores; Yasuaki Hiromasa; Jianhan Chen from Kansas; and Takeo Iwamoto from the Jikei University School of Medicine in Japan. A patent for the discovery is pending.
*doi:10.1371/journal.pone.0045374.g003