Fig 1.
Preparation and mechanism of CMs(GM)-β-TCP/gelatin composite scaffolds (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate; CS: Chitosan; S. aureus: Staphylococcus aureus).
Fig 2.
Characterization of microspheres.
a Macroscopic observation of CMs(GM). b The antibacterial activity of the CMs(GM). (1)—(5) represent paper disks contained 15, 20, 25, 30, and 35 μg mL-1 GM, respectively. (6)—(8) represent disks contained 1-fold, 2-fold and 4-fold dilutions of CMs(GM) leachate. c SEM images of CMs(GM) with (i) scale bar = 30 μm and (ii) scale bar = 10 μm. (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate; SEM: Scanning electron microscopy).
Fig 3.
Characterization of CMs(GM)-β-TCP/gelatin composite scaffolds.
a Macroscopic observation of CMs(GM)-β-TCP/gelatin composite scaffolds. b FTIR spectra for the β-TCP/gelatin composite scaffolds. c SEM images of (i) CMs-β-TCP/gelatin composite scaffolds (left to right: Scale bars = 1 mm, 200 μm, and 50 μm, respectively) and (ii) CMs(GM)-β-TCP/gelatin composite scaffolds (left to right: Scale bars = 1 mm, 200 μm, and 50 μm, respectively). (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate; SEM: Scanning electron microscopy; FTIR: Fourier transform infrared spectroscopy).
Fig 4.
Cumulative release curves of (a) CMs(GM) and (b) CMs(GM)-β-TCP/gelatin composite scaffolds. (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate).
Fig 5.
Construction of (a) radial segmental bone defect models (control group; n = 6 rabbits) and (b) rabbit radial segmental bone defect models accompanied by infection (infected group; n = 6 rabbits); (c) recanalization of bone marrow and implantation of CMs(GM)-β-TCP/gelatin composite scaffolds in the 4th week after model generation (experimental group; n = 3 rabbits). (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate).
Fig 6.
Radiograph results of (a) control group, (b) infected group at 4th week after modeling, and (c) experimental group on the 1st day after implantation (n = 3 rabbits per group).
Fig 7.
Histological observations of (a) muscle and (c) bone tissue in the control group and (b) muscle and (d) bone tissue in the infected group in the 4th week after model generation. The black arrows represent inflammatory cells (scale bar = 50 μm; n = 3 rabbits per group). (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate).
Fig 8.
Effects of composite scaffolds on repair of bone defect accompanied by infection in vivo.
a Macroscopic observations of radii in the (i) control, (ii) infected, and (iii) experimental groups in the 13th week after model generation (n = 3 rabbits per group). b van Gieson staining of bone tissues in the (i) control, (ii) infected, and (iii) experimental groups in the 13th week after model generation. The black arrows represent newly formed bone (top to bottom: Scale bars = 50 μm and 250 μm, respectively; n = 3 rabbits per group). (CMs: Chitosan microspheres; GM: Gentamycin; β-TCP: β-tricalcium phosphate).