NANOFILMS OF ADSORBED THYMOL FORMED ON TITANIUM SURFACES FOR BIOMEDICAL APPLICATIONS. ANTIMICROBIAL ACTIVITY AND BIOCOMPATIBILITY

GRILLO, C. A; MIÑAN, A; FERNANDEZ LORENZO DE MELE, M; GONZALEZ, A; SCHILARDI, P.L

Mar del Plata, Buenos Aires

Encuentro; Reunión Anual de SOCIEDADES DE BIOCIENCIA; 2019

Titanium (Ti) and its alloys are widely used in the construction of permanent orthopedic and cardiovascular implants. However, one of the most frequent causes of failures are bacterial infections by Staphylococcus aureus. This is aggravated by the abusive use of antibiotics that generate microbial resistance to conventional therapies. As a consequence, new antimicrobial nanotechnologies emerge as promising alternatives to prevent prosthetic infections.The objective of this work was to evaluate the antimicrobial effect of an innovative nanotechnology: thymol (phenolic phytocompound) nano-films adsorbed on Ti(NPTOH-Ti)against Staphylococcus aureus. The biocompatibility was also determined using preosteoblast cells (MC3T3-E1). To that end, 1 cm diameter Tigrade 2 discs were used and thymol was adsorbed onto their surface by simple 2-hour immersion in 0.1M thymol, 0.5M H2SO4solutions. NPTOH-Tiwas detected by infrared spectroscopy (FTIR-ATR). The antibiofilm activity of NPTOH-Ti and Ti (control) was determined by immersing the metal discs in a suspension of S. aureus (108 bacteria/ml) for 3 hours. Subsequently, the number of bacteria adhered on the discs was evaluated after sonication by colony forming unit (CFU) counting. In addition, live/ dead staining was used to determine if the amount of adhered bacteria that were alive or dead. Finally, biocompatibility tests of the nano-films formed in MC3T3-E1 cells were performed by staining with acridine orange.The results showed that NPTOH-Ti had effective anti-biofilm properties since the plate counts revealed that there was no S. aureus CFU and bacteria were red (dead) after live/dead staining, while control Ti revealed 4 ± 0.5 x105adhered bacteria that were mostly (95%) green (alive).The results showed that NPTOH-Ti had effective anti-biofilm properties. On the one hand, viable bacteria were not observed (enumerated) by the plating count method and live/dead staining assay exhibited only dead (red) bacteria on the surface. On the other hand, control Ti revealed 4 ± 0.5 x105 adhered bacteria that were mostly (95%) alive (green).Moreover, NPTOH-Ti was biocompatible since cell viability was slightly higher than that of the control (107 ± 12%).It was concluded that NPTOH is biocompatible and has antibiofilm properties which make them promising to prevent prosthetic infections.