Bioengineered matrices--part 1: attaining structural success in biologic skin substitutes

Skin defect closure after injury or disease may present significant reconstructive challenges. Traditional epidermal coverage alone in the form of skin grafts often fall short in providing stable cover to restore structure and function of the skin. Excessive wound contraction and scar formation, particularly in defects of dermis and epidermis, may create functional and aesthetic problems. Progress in our understanding of molecular biology and tissue engineering have produced major advances in skin substitute technology, particularly relating to the dynamic cellular/extracellular matrix interaction that is critical to successful incorporation of a skin substitute. However, currently available skin substitutes still exhibit a range of problems including excessive wound contraction and scar formation, poor host tissue incorporation, revascularization and, in some cases, structural deficiencies in matrix design. The design principles and structural composition of the matrix must take into account collagenous forms, inherent resistance, porosity, and hydration. The ultimate matrix should be one that promotes intrinsic regeneration by encouraging cellular incorporation and cellular/extracellular cross communication. Attention to basic structural details rather than reliance on specialized cellular or peptide additions to the mix may well produce the advances we seek in improved incorporation of bioengineered skin substitutes.