The Effect of Negative electric field using charged PTFE membrane on Bone Healing of Rabbit Long Bone

Abstract

The biological principles of guided bone regeneration have been successfully applied for regeneration of bone both in experimental animal studies1-3) and in clinical studies4,5). Also, various procedures such as improving the barriers mechanical properties6) and peripheral sealing7) and using grafting materials8) have been tested to enhance, both qualitatively and quantitatively, bone repair in membrane-protected defects. This concept implies that a membrane barrier is placed to prevent non-desirable soft tissue cells from entering the wound area, thereby giving preference to bone-forming cells to repopulate the defect. Factors which stimulate bone repair are subjects for research in osseous regenerative therapy. Effects of cytokines, or growth factors, on bone repair9) are examples of such subjects. Another subject is electrical stimulation which naturally occurs in bone, as such bone may be particularly susceptible to electrical therapy10). Fukada and Yasuda11), on the piezoelectric effect of bone, gave impetus for research in medicine and implied that application of external forces in bone results in electric signals. Yasuda12) implanted electrodes into rabbit femurs and observed new bone in the vicinity of the cathods. Bassett et al.13) described in vivo osteogenesis in response to electric currents, and Friedenberg et al.14) reported on the clinical use of electricity to heal nonunions. Thus, these studies demonstrated that if endogenous stress-generated potentials effected bone remodeling, perhaps electric signals applied externally without the simultaneous application of stress could lead to a response resulting in bone formation12-14). The exact action mechanism of these electrical stimulation for osteogenesis are currently unclear, but investigators have reported various possible modes, such as decreased pO2 and increased pH in the vicinity of the cathode15); accumulation of positive charges16); differentiation of mesenchymal cells into osteoblast and osteocytes17); increased alkaline phosphatase activity18); elevation of cyclic