Fig. 5.

Doxycycline release tests. A) Calibration curve for doxycycline at 224 nm (corrected for absorbance of the sodium acetate buffer) with fitting of R² = 0.8673. B) Mean concentrations of doxycycline after releasing for 72 h at absorbance 224 nm (*p < 0.05, sample numbers = 15). C) Cumulative doxycycline release in the release solution at different release time points measured by absorbance at 224 nm with SD. D) Doxycycline Release the in release solution per hour measured by absorbance at 224 nm with SD (n = 3). The samples showed a significant release only after 24h indicating that doxycycline is chemically bound to the implant surface.