Advantage of the Presence of Living Dermal Fibroblasts within in Vitro Reconstructed Skin for Grafting in Humans

Abstract

Methods for serial cultivation of human keratinocytes can provide large quantities of epidermal cells, which have the potential of restoring the vital barrier function of the epidermis in extensive skin defects such as burns. To investigate the value of combining an epidermis with a dermal component, fibroblasts originated from the superficial dermis were used to seed a collagen lattice as described by E. Bell (dermal equivalent). Beginning in 1981, we grafted 18 patients (burns and giant nevi) using 35 grafts 10 x 10 cm in size. In the course of this work, the original technique was modified and improved as experience was gained. We began by using small skin biopsy samples as a source of keratinocytes cultured on a dermal equivalent before grafting in a one-step procedure, but this gave poor cosmetic results, because of a nonhomogeneous epidermalization. We then chose to cover the graft bed using a two-step procedure. The first step consisted of grafting a dermal equivalent to provide a dermal fibroblast-seeded substrate for subsequent in vivo epidermalization by cultured epidermal sheets. Whatever the epidermalization technique used, a living dermal equivalent applied to the graft bed was found to reduce pain, to provide good hemostasis, and to improve the mechanical and cosmetic properties of the graft. A normal undulating dermal-epidermal junction reappeared by 3 to 4 months after grafting and elastic fibers were detectable 6 to 9 months after grafting. As a result of the biosynthesis of these products, the suppleness (e.g., elasticity) of the grafts was closer to that of normal skin than the cicatricial skin usually obtained with epidermal sheets grafted without the presence of living dermal cells. This rapid improvement of the mechanical properties of the graft could be attributed to the presence of fibroblasts cultured from the dermis and seeded into the collagen matrix.

A review of tissue-engineered skin bioconstructs available for skin reconstruction

“…However, these biomaterials act rather like temporary biologically active wound dressings (Supp & Boyce 2005), providing growth factors, cytokines and ECM for host cells while initiating and regulating wound healing. There are reports of host immunogenic tolerance to allogeneic fibroblasts (Coulomb et al 1998) and their survival in the host up to three weeks (Morimoto et al 2005). Long-term preservation of allogeneic fibroblasts and their proliferation up to two months in the host without signs of immune rejection have also been reported (Sher et al 1983;Bell et al 1984;Eaglstein et al 1999;Hebda & Dohar 1999;Sandulache et al 2003;Griffiths et al 2004).…”

Emerging therapy for improving wound repair of severe radiation burns using local bone marrow-derived stem cell administrations

“…The main features of radiation skin burns, if compared with thermal burns, are firstly, a very marked dose dependence of the clinical pattern (dry epidermitis (12)(13)(14)(15), moist desquamation (15)(16)(17)(18)(19)(20), and necrosis ( > 25-30 Gy), secondly, the association with a paroxysmal and chronic pain resistant to opiates, and thirdly, the occurrence of uncontrolled successive inflammatory waves during several weeks, months, or years. In all cases, the healing is long, frail, and uncertain.…”

Vascularization of Novel Porcine Acellular Dermal Matrix

“…FB has a far-reaching significance in tissueengineered skin. Researches showed that, in in vitro culture, addition of certain amount of FB in collagen gel could enhance the mechanical strength and resistance ability to enzymatic hydrolysis of dermal scaffold 16) . Implanting newborn foreskin FB in nylon net could promote the vascular invasion and growth, and reduce the inflammatory response to nylon and silicone 17) .…”