never completely reproduces the pre-wound architecture of the skin tissue. In some wounds healing fails to progress through the sequential phases and a chronic wound develops. These wounds are often characterised by increased levels of inflammatory cells that are associated with elevated levels of proteases; these appear to degrade the ECM components, growth factors and receptors that are essential for healing. Recognising and removing these barriers to healing has led to the concept of wound bed preparation, which emphasises the need to debride non-viable and denatured ECM [54] . The importance of re-establishing a functional ECM in chronic wounds has led to the development of dressings that reduce excessive protease levels, and new technologies are exploring how to temporarily replace the degraded ECM in chronic wounds to facilitate healing. Clearly, the optimal care and treatment of chronic wounds requires an understanding of the key role ECM plays in normal healing, recognition of how this is altered in chronic wounds and the inclusion of appropriate clinical treatments to re-establish a functional ECM. This article is supported by an educational grant from Mlnlycke Health Care. The views expressed in this article are those of the authors and do not necessarily reflect those of Mlnlycke Health Care. Other links : Amelogenin proteins (XelmaT) are being evaluated for the promotion of healing in hard-to-heal wounds based on their ability to provide a temporary ECM protein for cell attachment. Further information can be found at: www.tendra.com Glossary of terms Chemokines Chemokines are small molecules released