Antibacterial activity of ciprofloxacin-impregnated 3D-printed polylactic acid discs: an in vitro study

Three-dimensional (3D) printing technology allows incorporation of various substances including antibiotics into different structures. This study aimed to evaluate the antibacterial activity of ciprofloxacin-impregnated 3D discs against Escherichia coli.

Polylactic acid pellets were coated with ciprofloxacin at 1% and 2% concentrations, then filaments were produced from these pellets, and antibiotic-containing discs were obtained using fused deposition modeling 3D printers. The working temperatures during filament extrusion and 3D printing processes were 200 °C and 215 °C, respectively. Therefore, in order to test the thermal stability of ciprofloxacin during these processes, the antibiotic was exposed to 200 °C and 215 °C in an oven, and then tested against E. coli. Following this, efficiencies of antibiotic-coated pellets, filaments and discs against E. coli were determined by diffusion tests.

Ciprofloxacin heated at 200 °C and 215 °C was stable and retained its antibacterial activity. Pellets, filaments and discs coated with 1% or 2% concentration of ciprofloxacin produced inhibition zones in the culture plates. Increasing ciprofloxacin concentration did not significantly affect the diameter of inhibition zones (p > 0.05). Ciprofloxacin-containing polylactic acid pellets produced significantly larger inhibition zones than those of filaments and discs (p < 0.0001). The difference in zone diameters around ciprofloxacin-containing filaments and discs was not statistically significant (p > 0.05).

Ciprofloxacin-coated polylactic acid-based 3D discs displayed antibacterial activity against E. coli. This suggests that, various polylactic acid-based ciprofloxacin-containing 3D products can be obtained and evaluated for antibacterial activity in future studies.