46.5 kHz Time average acoustic intensity of 167 mW/cm2 1 : 3 duty cycle 18 h
Gentamicin
Average gentamicin release was higher in the insonated samples for all three bone cements, although none of these differences were statistically significant.
43 kHz CW, 15 min at three time points in 4 h period
Ciprofloxacin
Biofilm accumulation on ciprofloxacin-loaded hydrogels with ultrasound-induced drug delivery was significantly reduced compared to the accumulation of biofilms grown in control experiments.
46.5 kHz Average acoustic intensity of 167 mW/cm2 1 : 3 duty cycle 18 h
Gentamicin
Pulsed ultrasound significantly enhanced gentamicin release from gentamicin-loaded beads, whereas gentamicin release from the gentamicin-loaded bone cements was not significantly enhanced.
E. coli S. aureusCoagulase-negative staphylococci P. aeruginosa
46.5 kHz mean acoustic intensity of 167 mW/cm2 1 : 3 duty cycle 40 h
Gentamicin Gentamicin/clindamycin
Application of pulsed ultrasound in combination with antibiotic release by antibiotic-loaded bone cements yielded a reduction of both planktonic and biofilm bacterial viability compared with antibiotic release without application of ultrasound.
46.5 kHz Average intensity of 300 mW/cm2 2 : 1 duty cycle 12 h
Vancomycin
The enhanced reduction in hip aspirates from ultrasound group 0–12 h was 1.62 CFU/ml (), and that in hip aspirates from ultrasound group 12–24 was 2.77 CFU/ml ().
In vitro and in vivo study of antibiotic-loaded bone cement
S. aureus
25 kHz 100 or 300 mW/cm2 for in vitro study 300 mW/cm2 for in vivo study CW, 0.5 h
Vancomycin
LFU increased the drug elution by 2.57–27.44% when compared with the controls in vitro. LFU increased local by 47.6 mg/mL and urinary elimination of vancomycin by 109.56 mg but failed to prolong local . Decreased bacterial vitality and relieved inflammation in the infected hip treated were also observed in ultrasound group.
46.5 kHz Spatial-average-time-average intensity of 1.2 W/cm2 1 : 2 duty cycle 40 min
Vancomycin
Intermittent watt-level ultrasonication improved the ultrasound-enhanced vancomycin release from cement in view of the prolonged and the inhibited subtherapeutic release compared with continuous ultrasonication.
In vitro study showed the eluted vancomycin from the vancomycin + ultrasound + microbubbles group was significantly more effective against the planktonic S. aureus than in any of the other study groups (). In vivo study showed the viable count of S. aureus that survived when vancomycin + ultrasound + microbubbles cylinders were implanted was significantly lower than in each of the other study groups ().
There were significant increases in elution amount for LFU treatment groups compared with the non-LFU groups (). The correlations between LFU duration and total elution amount were significant ().
CW: continuous wave ultrasound. NA: not applicable.