Exosomes are generated from host embryonal carcinoma or embryonic progenitor cell lines and used for induced tissue regeneration. These inventive compositions and methods provide for induced tissue regeneration in aged or diseased mammalian tissues in vivo without the use of transgenically-expressed genes. Cells are reprogrammed to a prenatal, indeed a pre-fetal state, as indicated by for example in the case of many stromal cell types, by a decrease in the markers ADIRF and COX7A1.
