Improved Methods to Produce Tissue-Engineered Skin Substitutes Suitable for the Permanent Closure of Full-Thickness Skin Injuries

Abstract

There is a clinical need for skin substitutes to replace full-thickness skin loss. Our group has developed a bilayered skin substitute produced from the patient's own fibroblasts and keratinocytes referred to as Self-Assembled Skin Substitute (SASS). After cell isolation and expansion, the current time required to produce SASS is 45 days. We aimed to optimize the manufacturing process to standardize the production of SASS and to reduce production time. The new approach consisted in seeding keratinocytes on a fibroblast-derived tissue sheet before its detachment from the culture plate. Four days following keratinocyte seeding, the resulting tissue was stacked on two fibroblast-derived tissue sheets and cultured at the air–liquid interface for 10 days. The resulting total production time was 31 days. An alternative method adapted to more contractile fibroblasts was also developed. It consisted in adding a peripheral frame before seeding fibroblasts in the culture plate. SASSs produced by both new methods shared similar histology, contractile behavior in vitro and in vivo evolution after grafting onto mice when compared with SASSs produced by the 45-day standard method. In conclusion, the new approach for the production of high-quality human skin substitutes should allow an earlier autologous grafting for the treatment of severely burned patients.

Effective use of mesenchymal stem cells in human skin substitutes generated by tissue engineering

“…In recent years, tissue engineering has developed as an alternative regenerative medicine approach for the clinical treatment of severe skin diseases, as it allows the efficient treatment of large and deep skin conditions (Garzon et al, 2015;Kober et al, 2016). Numerous models of human skin, generated by tissue engineering, have been developed to date (Beaudoin Cloutier et al, 2017;Bhowmick et al, 2017;Forouzandeh et al, 2010;Hartmann-Fritsch et al, 2016;Klar et al, 2018;Larouche et al, 2016;Lloyd et al, 2015;Pensalfini et al, 2017;Reuter et al, 2017;Strong et al, 2017;Vig et al, 2017). However, few clinical trials have been conducted to test the biological security (phase I and II assays) of human skin models (Boa et al, 2013;Boyce et al, 2006;Boyce et al, 1999;Boyce et al, 2017;Germain et al, 2018;Moravvej et al, 2016;Yamada et al, 2012).…”

Bioengineered Skin Substitutes: The Role of Extracellular Matrix and Vascularization in the Healing of Deep Wounds

“…Scaffold-free microtissues can be obtained by organizing cells in sheets [79] (with a thickness ranging from 50 to 100 µm) or spheres [80,81] (diameters up to 200 µm). Scaffold-based microtissues are obtained by entrapping cells in micrometric scaffolds, such as porous microspheres [81], non-porous microspheres [82][83][84][85], non-spherical microparticles [78] or wires of hydrogels [84]. Sheets of human fibroblast are obtained by culturing fibroblasts in flat dishes and promoting the synthesis of the extracellular matrix.…”

“…Sheets of human fibroblast are obtained by culturing fibroblasts in flat dishes and promoting the synthesis of the extracellular matrix. When the sheets achieve confluency, they are detached from the culture dishes and, by stacking different sheets of cells, a thicker tissue can be obtained [85]. When placed in close proximity, cell-cell contacts and extracellular matrix-extracellular matrix contacts lead to the formation of continuum structures made by fibroblasts embedded in their own extracellular matrix.…”

“…Finally, tissue wire technology can be used to produce living fibers treated as textile and woven fibers [84]. These modular approaches lead to several advantages, such as fine control over the final architecture, control over the final shape, and control over the spatial organization of engineered biologic structures [79][80][81][82][83][84][85][86][87]92,93].…”

Újdonságok az égéssebészetben

“…Ezt követően a beteg hámsejtjeit ezen a bioszintetikus irhavázon tenyésztik, amíg kialakul az irharéteggel és többrétegű hámmal bíró bőrhelyettesítő. Az utolsó tíz napon a tenyésztett bőrt a tenyészmédium-levegő határ-ra kiemelve kiváltják a hámfelszín elszarusodását, így mintegy 10 hét után teljesértékű bőr átültetését tudják biztosítani [19].…”