News

New role for plastic: Bacteria fighter

Oct. 23, 2003

University of South Florida chemists have developed a new class of synthetic antibiotics and nanosized plastic vehicles to deliver them. The new drugs -- members of the beta-lactams family of antibiotics -- selectively attack methicillin-resistant staph (MRSA) bacteria, which is the culprit for most hospital-borne infections becoming resistant to antibiotics.

Amy Higgins

Shown here is a comparison of the nanoparticle-bound drug versus penicillin, vancomycin, a nanoparticle without attached drug, and a nanoparticle with a free form of the drug against a strain of MRSA.

A scanning electron microscope image of the nanoparticle.

The drugs ride into bacteria cells on the backs of tiny plastic spheres one-millionth the size of a pinhead. Using a process called microemulsion polymerization, the drugs are chemically bonded to the surface of the spheres. These water-soluble nanoballs, many times smaller than the bacteria cells, look like potential food and bacteria gobble them up. Once inside the bacteria cell, the balls release high concentrations of the drug where it wreaks havoc on the cell's internal machinery.

"The delivery of pharmaceutical agents that are water-insoluble to targets within the human body has always been a challenge," says USF chemistry professor Edward Turos."Many potentially valuable drugs that look promising are, unfortunately, not very soluble in water and their clinical uses are greatly restricted because they are unable to get into the bloodstream."

Researchers hope to soon design and custom-prepare nanosized delivery vehicles of different shapes and sizes and tailor their functions to different biomedical and nanotechnology applications.