Synthesis of Polylactic Acid Oligomers for Broad-Spectrum Antimicrobials

Infectious microbial diseases are a major public health hazard, calling for more innovative antimicrobials. Herein, polylactic acid (PLA) oligomers have been explored and reported as a bio-safe and eco-friendly functional antimicrobial agent against pathogens, such as viruses (H1N1, H3N2, and SARS-CoV-2), bacteria (E. coli, S. aureus, K. pneumoniae, MRSA), and fungi (C. albicans). The PLA oligomers were prepared by direct catalyst-free condensation polymerization of l-lactic acid monomers and characterized by FT-IR and H-1-NMR. The antiviral results demonstrate that PLA oligomers possess robust (inhibiting rate > 99%) and rapid (<20 min) antiviral activity against two pandemic ssRNA viruses, including influenza A virus (IAV) and coronavirus (CoV). Furthermore, the PLA oligomers exhibit high antibacterial activities against both Gram negative (G(-)) and Gram positive (G(+)) bacteria. The PLA oligomers also perform efficiently in killing a large amount of C. albicans as high as 10(5) cfu/mL down to zero at the concentration of 10 mg/mL. Thus, the broad-spectrum antimicrobial activity endowed the PLA oligomers with a promising biocidal option, except antibiotics in a wide range of applications, such as medical textiles, food preservation, water disinfection, and personal hygiene, in light of their unique biodegradability and biocompatibility.

Automated summary

Polylactic acid (PLA) oligomers are bio-safe and eco-friendly antimicrobial agents that exhibit robust and rapid antiviral activity against viruses, including influenza A virus and coronavirus. They also demonstrate high antibacterial efficacy against both Gram negative and Gram positive bacteria, as well as efficient antifungal activity against Candida albicans. PLA oligomers have broad-spectrum antimicrobial properties and hold great potential for applications in medical textiles, food preservation, water disinfection, and personal hygiene, due to their unique biodegradability and biocompatibility.