Antimicrobial Biomaterials Based On Poly(lactic-co-glycolic acid) Dispersed with Carbon Nanotubes

In this study, we assess the antimicrobial behavior of single-walled carbon nanotubes (CNT) within poly(lactic-co-glycolic acid) (PLGA) polymeric biomaterials. CNT of diameter 0.85 to 1.2 nm are synthesized via CO decomposition at 1073 K and 6 atm over a Co incorporated MCM-41 catalyst (with a 3% metal loading). CNT length is characterized via Raman spectroscopy and Transmission Electron Microscopy. CNT-PLGA thin films of thickness 150-200 nm are realized via a spin coating method. Contact angle measurements confirm the surface homogeneity of these thin film morphologies. Antimicrobial activity is assayed by exposing films to Escherichia coli (E. coli). We find E. coli viability and metabolic activity to be highly correlated with CNT length and concentration. Up to 86% of bacteria die following one hour of exposure on CNT containing samples, whereas 12% die on pure PLGA (control) films. Shorter CNT generally exhibit higher toxicity, most likely due to an increased density of open tube ends. This study demonstrates the potential usefulness of CNT-PLGA as an antimicrobial biomaterial.