Utilization of supercritical carbon dioxide for development of antibacterial surgical sutures

Outbreak of surgical infections and bacterial resistance against synthetic antibiotic has prompted research towards development of antibacterial medical devices. For that purpose, absorbable surgical sutures were impregnated with natural compound thymol using an environmentally friendly medium. The supercritical solvent impregnation process was performed at 35 °C and 10 MPa during 1, 2, 3 and 6 h, resulting in thymol loadings of 3.9–5.6%. All tested samples expressed antibacterial activity against E. coli and S. aureus. Release tests in PBS at 37 °C showed that impregnated material released loaded thymol in a gradual manner. While sutures impregnated during 6 h released complete amount of loaded thymol during 6 days, shorter impregnation process resulted in sutures that retained significant thymol amounts (~ 20–40%) after 10 days of release test. The effect of proposed process on final material properties and its application were explained in detail using characterization techniques SEM, FTIR, DSC and DMA.