Researchers are trying to find better, cheaper ways to produce biodegradable and bio-based polymers. Although one of the main drivers for this research is to compete with fossil-fuel-based polymers in large-volume, consumer plastics applications, medical applications, such as microcapsules for drug delivery, may also benefit. While it seems odd, the researchers found that waste oil from cooking fried food can be used as a raw material in the polymer production process.
The poly(hydroxyalkanoate) (PHA) family of polyesters (e.g., poly 3-hydroxybutyrate or PHB) is immunologically inert and degrades slowly in animal tissue, which gives it potential as a material for slow-release drug forms. The polymers are synthesized by bacteria in fermentation processes and typically use glucose as a starting material. Researchers from the interdisciplinary Institute of Healthcare Science at the University of Wolverhampton in the UK recently found that waste cooking oil can be used as starting material to reduce processing costs, the University explained in a press release. “The cost of glucose as a starting material has seriously hampered the commercialization of bioplastics,” said Iza Radecka, PhD, the research team leader, in the release.
The bacteria used in the experiment grew better in oil and produced three times more PHB over 48 hours than the same bacteria grown in glucose, according to the press release. Nanofibers spun from the resulting polymer were also less crystalline than those from the glucose-based process. Lower crystallinity makes the polymers more suited to medical applications, said the researchers.