Novel Recombinant Human Collagen for Wound Healing

Collagen deposition by fibroblasts is essential for cutaneous wound healingprocess. It promotes attachment, proliferation and differentiation of cells in-volved in inflammation, angiogenesis, and connective tissue reconstruction.Type I Collagen scaffolds dominate wound healing products. To date, the col-lagen source for such dressings is mainly of animal origin and to a lesser extentfrom cadavers, entailing several risks including pathogens and allergic reactionsdue to species differences. Moreover, the collagen extracted from animals andhumans is ‘‘recycled’’ as it had already been incorporated in the ECM, andconsequently has gone through irreversible cross-linking and harsh processingmethods that compromise its biological and mechanical functions. The purposeof this study was to set the technology for production of human collagen type Iin engineered tobacco plants for production of collagen based products. Usinggenetic engineering and traditional breeding techniques, we have successfullyintroduced five human genes into tobacco plants that operate in an orchestratedeffort to produce fully decorated recombinant human type I collagen. Two ofthe genes encode for the procollagen type I structural proteins - alpha1 and al-pha 2, and three encoding for post translational modifying enzymes - prolylhydroxylase alpha and beta, and lysyl hydroxylase isoform III. LC/MS-MS se-quencing of the recombinant purified collagen following tryptic digest showed100% identity to human collagen. It displays sensitivity to bacterial collagenaseand resistance to other proteases due to its stable triple-helical structure. Thepurified collagen is thermo-stable and assembles into collagen fibrils and colla-gen hydrogels. Inin vitrocell assays, the recombinant human collagen sup-ported cell attachment and proliferation similarly, or even superior to humantissue-derived collagen. The technology has been set for mass production ofhuman recombinant collagen in tobacco plants. This novel virgin human col-lagen will start a new era of collagen based medical devices for wound healing.Wound Rep Reg (2009)17A10–A53c2009 by the Wound Healing SocietyA15Abstracts