Bone
infections are a challenge for modern medicine. The most common pathogen is Staphylococcus aureus, which usually develops a biofilm inside the infected bone. Local release of
antibiotics within the infected tissue may diminish this problem because high concentrations of the
antibiotic would be delivered to the required place. This study was carried out to evaluate
silica-based mesoporous material
SBA-15 as a delivery system for three
antibiotics with activity against S. aureus, namely
vancomycin,
rifampicin and
linezolid, alone or in combination.
SBA-15 disks were loaded with
antibiotics by adsorption using a 1000 mg/L
solution. Measurements of
biological activity were carried out by bioassay tests, and
antibiotic release was monitored by high-performance liquid chromatography (HPLC). In all cases, the ceramic disks released most of the
antibiotics at the initial stage of the experiments, with concentrations above the susceptibility breakpoints. The most active
antibiotic was
rifampicin, with an active concentration of 96.14 mg/L at 24 h, followed by
linezolid (7.2 mg/L) and
vancomycin (5.5 mg/L). In the HPLC measurements, the
antibiotic that showed the best release was
linezolid, followed by
vancomycin;
rifampicin alone could not be measured by HPLC with precision. Taking into account all these results, the
antibiotic that remains most active after loading and release is
vancomycin (77.46%), followed by
linezolid (24%). The results presented here demonstrate the efficacy of
SBA-15 bioceramics for local release of
antibiotics, which could be of interest in the context of bone
infection.