Abstract: The invention provides an in vitro method for inducing macrophage polarization to an M2 phenotype. The method comprises the in vitro exposure of macrophages to repeated series of hypoxia-reoxygenation. Activated M2 macrophages obtained by this method overexpress molecules important for tissue remodeling and amelioration of inflammation, thus they are useful as cell therapy for tissue regeneration. The invention also provides pharmaceutical compositions and kits comprising the M2 macrophages obtained by the method, as well as a device for inducing hypoxia and re-oxygenation conditions on isolated macrophages according to the method.