Abstract
Regardless of the cell type used as a building block for differentiation/transdifferentiation into pancreatic cells, there are only a few strategies that can be used to modify, both in vitro and in vivo, their fate and behavior. Conventional approaches are based on the addition of chemical soluble agents to the culture medium (signal-driven strategies), in an attempt to mimic the complex symphony of differentiation/specification factors that drive the process in vivo. Extracellular matrices and cell growth substrates may help increase the overall efficiency of these methods. Alternatively, external signaling can be bypassed by means of adding constitutively activated copies of key transcription factors or – more recently – cell-permeable proteins. The rationale of in vivo differentiation is that only the recipient’s body can provide developing cells with the adequate microenvironment to support terminal maturation.