NIH thinks that a biological motor from bacteriophage phi29 indeed has a potential for the future of nanomedicine, for a number of reasons.
The press office of Purdue University explains:
A multidisciplinary Purdue research team will lead one of eight national nanomedicine development centers.
The National Institutes of Health awarded the team $7 million over five years to study the use of a nanomotor, a microscopic biological machine, for potential use in the diagnosis and treatment of diseases such as cancer, AIDS, hepatitis B and influenza.
The team will take the first steps in research that could lead to using nanomotors to package and deliver therapeutic DNA or RNA to disease-causing cells. This is a feat that could revolutionize medicine, but it faces many challenges, said Peixuan Guo, director of the center and a professor of molecular virology…
Guo’s nanomotor is derived from the biological motor of bacteriophage phi29, a virus that infects bacteria. The virus uses the motor to package DNA and move it into the capsid, a shell made of proteins, as part of the viral reproduction process. The viral motor is geared by six packaging ribonucleic acid (pRNA) molecules arranged in a ring. Adenosine triphosphate (ATP), the same biological energy used for muscle movement, fuels the RNA motor. The DNA is cranked through the center of the RNA ring and into the capsid like a screw through a bolt.
Guo discovered this pRNA in 1987, and his research was published in the journal Science. In 1986 he was able to achieve a functional phi29-imitating nanomotor in a cell-free system, and his research was published in the Proceedings of the National Academy of Sciences. The team now will work to use the nanomotor to package DNA in the same way, but move it into and out of a therapeutic delivery vehicle.
Guo and his team constructed the DNA-packaging systems of the nanomotors to contain modified synthetic pRNA and re-engineered protein molecules. The nanomotors retain the modified and re-engineered viral components, which are harmless to human cells because the phi29 bacteriophage only infects bacteria. The modified nanomotors have the additional advantage of lowering the chance of an adverse immunologic response in a patient.
“The phi29 motor is considered to be the most powerful biological motor constructed to date and is well-characterized and understood due to Guo’s extensive research,” said Rashid Bashir, professor of electrical and computer engineering in the Weldon School of Biomedical Engineering. “Nature has created this highly efficient biological machine through billions of years of evolution. We are attempting to harness this delivery process. We want to learn from nature to make our approaches better.”
The motor also has the advantage of being the correct size.
“The nanoscale size range is ideal for delivery inside the body,” Guo said. “Anything smaller would be filtered out through the kidneys too quickly to be effective, and larger molecules would not be able to enter cells.”