Role of Neuropeptides in the Regulation of Bone Healing under Normal Conditions and in Bone Replacement

Introduction

Bone injury is often associated with major losses of tissue. The lost bone has to be replaced. The purpose of bone replacement is to stimulate new bone formation by osteoinduction and osteoconduction, and to give mechanical support to the skeleton. There are several methods to build up new bone if there are bone defects. Autologous bone can be used, however, the size of the source is limited. Heterologous or xeno transplants can lead to host versus graft complications. Another possibility is to use demineralized or desantigenized materials [3] [4] [5]. The biological process of bone formation has several steps, among them the infiltration of the gap by undifferentiated cells, which is followed by vascular and neural ingrowth [8]. We have found that neural and vascular ingrowth goes parallel (unpublished), and the neural fibers contain significant amounts of neuropeptides: CGRP, NPY, and SP. These peptides are all vasoactive substances [1] [6] [7]. Therefore, it was interesting to study whether different bone replacing materials can influence differentially the callus bone formation and the microcirculation of the developing callus.

References

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