“…The results obtained demonstrated that it was possible to in vitro re-create a tissue-engineered trachea with mechanical properties that allow normal functioning, providing successful treatment for patients [ 166 ]. Following this, many studies using a single type of tissue-specific stem cells [ 158 , 170 , 181 , 182 , 183 , 184 , 185 ] or induced pluripotent cells [ 185 , 186 , 187 , 188 ] were carried out, and others are currently ongoing, in order to identify the best 3D supports able to boost cell differentiation and successfully produce in vitro functional tissues and organs for future possible transplantation. In parallel, both synthetic and biological scaffolds were repopulated with terminally differentiated cells, including fibroblasts [ 155 ], mature hepatocytes [ 189 , 190 , 191 ], and pancreatic endocrine [ 192 , 193 , 194 ], cardiac [ 195 ], and ovarian cells [ 196 ].…”