I welcome you to this special edition of WOUNDS focusing on the extracellular matrix (ECM). The topic of ECMs and their role in tissue and wound repair has become increasingly important as clinicians become more familiar with the use of modalities designed for difficult-to-heal wounds. The purpose of this particular edition is to introduce 3 more commonly used ECMs by allowing the scientists involved in their development and production to provide a scientific basis for their role in tissue repair and include any available clinical correlations.
       Extracellular matrices are designed for use in full-thickness wounds with matrix defects that are not responding well to what are considered standard treatment modalities. They are also indicated for tissue augmentation in the surgical setting, as may be the case with ligament and tendon damage. Application in other surgical settings has also been studied. Applying best care practices in conjunction with appropriate selection of wound dressings, application of adjunctive devices, and addressing intrinsic and extrinsic factors related to individual healing deficiencies, may be adequate for damaged tissue in the majority of wounds to repair without further complications. Use of an ECM may benefit the difficult-to-heal or recalcitrant chronic wound.
       Bear in mind that ECMs are not living tissues, as opposed to cellular products designed as temporary dermal or skin substitutes. Extracellular matrices are also not classified as drugs, as may be the case with a growth factor approved by the US Food and Drug Administration (FDA). Extracellular matrices are clearly defined in their name “extracellular matrix.” They are designed to provide the scaffolding for cell migration, differentiation, and eventual replacement by host tissue thereby assisting with the modulation of activity in the wound bed. Extracellular matrices are intended to be one of the many components of comprehensive wound care, which may include but is certainly not limited to addressing extrinsic factors affecting tissue repair, nutritional status, bacterial burden, inflammation, and other intrinsic factors, which may delay or impede wound healing.
       As section editor, I hope the manuscripts selected for this special edition will provide background information on some currently available ECM products. I encourage you to further research the literature for materials that support their individual applications prior to their use in a wound or in a surgical setting. Further research is encouraged with this category of treatment as few well designed and randomized trials are available in the literature that clearly define the role of ECMs in the clinical setting. More extensive information is available regarding surgical applications. Clarification of ideal settings for application with supporting information on selection of adjunctive modalities and treatments based on clinically supported data will be welcomed for future publication. I sincerely hope that the material contained in this section will assist you in progressing another step forward in your quest for new knowledge in treating damaged tissue and problematic wounds.