Applicability of bioengineered human skin: from preclinical skin humanized mouse models to clinical regenerative therapies.

Ongoing progress in the field of regenerative medicine, in combination with the development of tissue-engineered skin products, has opened new possibilities for the treatment of certain diseases in which current treatments are aimed at alleviating symptoms but are not able to get a permanent cure. Our laboratory has developed a fibrin-based bioengineered human skin that has been successfully used for permanent regenerative therapies in different situations in the clinic. Moreover, we have been able to stably regenerate human skin by orthotopic grafting of this skin equivalent onto the back of immunodeficient mice. The so-called skin-humanized mouse model system has permitted us to model several monogenic skin diseases, when keratinocytes and fibroblasts harboring the genetic defect were used. In most cases different gene therapy approaches for ex vivo correction of cells have proved effective in reverting the phenotype using this model. More importantly, the feasibility of the system has allowed us to generate a skin humanized mouse model for psoriasis, a common chronic inflammatory disease where the immune component has a pivotal role in the pathogenesis. Establishing reliable humanized animal models for skin diseases is necessary to gain a deeper knowledge of the pathogenesis and to develop novel therapeutic strategies. In this sense, the skin humanized mouse model developed in our laboratory meets the needs of this field of research.