Vancomycin–impregnated electrospun polycaprolactone (PCL) membrane for the treatment of infected bone defects: An animal study

There is no consensus for the management of critical infected bone defects. The purpose of this study was to produce a vancomycin–impregnated electrospun polycaprolactone (PCL) membrane for the treatment of infected critical bone defects, and test it in a rabbit model. Electrospinning produced a resorbable PCL fiber membrane containing vancomycin approximately 1 mm in thickness, with a pore diameter of <10 μm. Femur defects were made in the limbs of 18 rabbits and infected with Staphylococcus aureus. The rabbits were divided into three groups according to treatment: (1) Experimental group: rabbit freeze-dried allogeneic bone graft and the vancomycin–PCL membrane. (2) Control group 1: bone graft. (3) Control group 2: vancomycin–PCL membrane only. Culture showed no difference in osteoclast activity between the three groups. Transwell testing showed that almost no fibroblasts passed through the membrane during the first 24 h, but some fibroblasts were able to pass it after 72 h. At 12 weeks after surgery, there was significantly less inflammatory cell infiltration in the experimental compared to the control groups. New bone formation and fracture bone callus were greater in the experimental group than control groups. We thus conclude the resorbable electrospun vancomycin–impregnated PCL membrane was effective at controlling bone infection, and in the regeneration of bone in a critical bone defect animal model.