Bone-guided regeneration: from inert biomaterials to bioactive polymer (nano) composites

Natural bone is a unique nanostructured material made of collagen fibre matrix and hydroxyapatite (HA) nanocrystals, providing mechanical support and protection from the vertebrate skeleton. However, in severe cases like bone-deficiencies, bone needs to be externally'' repaired. Initially, different biological solutions were developed in bone-guided regeneration. However, due to the limitations with the existing biological grafts, a lot of researches have been devoted toward biomaterials including metals, ceramics, and polymers. On the basis of the interface reactions between the implant and the surrounding tissues, these biomaterials may be classified as nearly inert'' or bioactive. Interestingly, the bioactive materials exhibit a specific biological response, leading to the formation of a natural bonding junction between the bone and the implant during bone regeneration. Recently, a special attention has been paid to a new generation of bioactive materials, i.e. (nano) structured biomaterials composed of a bioresorbable polymer matrix reinforced with bioactive inorganic compounds. While (bio) ceramic component provides the bioactivity, these materials can be readily engineered in such a way that their resorption rate in the body match the formation rate of the new tissue. This review hence reports the different biological and non-biological solutions developed in bone-guided regeneration, with a special emphasis on polymer-based materials, and our recent results obtained in osseointegration The bone physiology, and its natural regeneration are also described. Copyright (C) 2011 John Wiley & Sons, Ltd.