Figure 1.

Confocal fluorescence microscope showing a dispersion of ciprofloxacin loaded into the fibrin hydrogel. a–b) No particle could be observed in the fibrin hydrogel alone. c–d) Meanwhile, the fibrin hydrogel loaded with 1500 μg/ml ciprofloxacin showed undissolved crystalline structure, which had intrinsic fluorescence. e) 20× and f) 40× magnification micrographs revealed the needle-like bundles and aggregates of the ciprofloxacin crystals. a & c: the fluorescence micrographs. b & d–f: the overlaid of phase contrast micrographs.