Regenerative Medicine

Considerable progress has been made in recent years using induced human pluripotent stem cells (PSCs) for regenerative medicine and tissue engineering (Fisher and Mauck, 2013; Tabar and Studer, 2014).

The figure below outlines requirements for the generation of organs using tissue engineering (Moreno-Borchart, 2004).

Figure 1: Requirements for the generation of organs using tissue engineering (Moreno-Borchart, 2004).

Figure 1: Requirements for the generation of organs using tissue engineering (Moreno-Borchart, 2004).

Induced human PSCs have been reprogrammed into a variety of cell types:

  • human cardiomyocytes (Addis and Epstein, 2013; Martins et al., 2014)
  • lung epithelial cells (Weiss, 2014)
  • kidney cells with the formation of three dimensional (3D) nephric tubules and glomeruli from renal progenitor cells (Taguchi et al., 2014; Hariharan et al., 2015)
  • 3D gastric tissue in vitro – gastric organoids (McCracken et al., 2014)
  • human intestinal organoids (Watson et al., 2014).

Intestinal organoids derived from induced human PSCs or embryonic stem cells, when grafted into immunodeficient mice form functional mature human intestinal epithelium (Watson et al., 2014). Human intestinal organoids in combination with an artificial polymer scaffold offer an alternative approach to generating tissue engineered human intestine, although considerable progress needs to be made in this area before a fully functional tissue engineered human intestine is made (Finkbeiner et al., 2015).

Recent progress in the generation of kidneys from stem cells has been reported in the construction of a urine excretion pathway using porcine stem cell-generated embryonic kidneys. The procedure involved connecting the recipient ureter with a bladder grown from a transplanted embryonic cloaca; a technique known as 'stepwise peristaltic ureter'. In addition to urine excretion, the newly generated kidney continued to grow (Yokote et al., 2015).