  Bone regeneration is a clinical challenge that requires multiple approaches.
Sometimes, it also includes the development of new osteogenic and antibacterial
biomaterials to treat the occurrence of possible infection processes derived
from surgery. This study evaluates the antibacterial properties of
meso-macroporous scaffolds coated with gelatin and based on a bioactive glass
and after being doped with 4% ZnO (4ZN-GE) and loaded with saturated and
minimally inhibitory concentrations of one of the antibiotics levofloxacin
(LEVO), vancomycin (VANCO), rifampicin (RIFAM) or gentamicin (GENTA). After the
physicochemical characterization of the materials, inorganic ion and antibiotic
release studies were performed from the scaffolds. In addition, molecular
modeling allowed the determination of electrostatic potential density maps and
hydrogen bonds of the antibiotics and the glass matrix. In vitro antibacterial
studies (in plankton, inhibition halos and biofilm destruction) with S. aureus
and E. coli as model bacteria showed a synergistic effect of zinc ions and
antibiotics. The effect was especially noticeable in planktonic cultures of S.
aureus with 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and in cultures
of E. coli with LEVO or GENTA. Furthermore, S. aureus biofilms were completely
destroyed by 4ZN-GE scaffolds loaded with VANCO, LEVO or RIFAM and total
destruction of E. coli biofilm was achieved with 4ZN-GE scaffolds loaded with
GENTA or LEVO. This approach could be an important step in the fight against
microbial resistance and provide much needed options for the treatment of bone
infection.
