A New Antimicrobial Agent: Poly (3-hydroxybutyric acid) Oligomer

In this work, it is first reported that the poly (3-hydroxybutyric acid) (PHB) oligomer with a few degrees of polymerization possesses effective antibacterial and antifungal properties. Two preparation methods for the PHB oligomer are described, namely, one-step ring-opening polymerization of β-butyrolactone and extraction from the fermented PHB polymer. An appropriate amount of the synthesized PHB oligomer shows no physiological toxicity to the skin and major organs of mice. Topological application of the synthesized PHB oligomer imparts antimicrobial ability to non-antibacterial fabrics with washing resistance. The synthesized PHB oligomer offers effective sterilization and promotes wound healing in infected nude mice. Most importantly, the PHB oligomer is also reactive to drug-resistant bacteria. These results suggest that the PHB oligomer is not only a great candidate for antimicrobial modification but also a promising one for biomedical applications. Finally, the antimicrobial mechanisms of the PHB oligomer are revealed, and these include disruption of biofilm and the bacterial wall/membrane, leakage of the intracellular content, inhibition of protein activity, and change in the transmembrane potential.