Synthetic Morphogens and Pro-morphogens for Aided Tissue Regeneration - Biologically Responsive Biomaterials for Tissue Engineering - page 42

Chapter 3
Synthetic Morphogens and Pro-morphogens
for Aided Tissue Regeneration

Matteo Santin

3.1 Introduction: Morphogen De fi nition

The main goal of developmental biology has been the understanding of tissue
morphology that is the mechanism by which tissue and organ structures form during
development. At cellular level, the fundamental question to be answered is how
cellular spacing and positioning within a tissue are controlled to form histological
and anatomical structures. It is now accepted that in a forming tissue there is a
specific group of cells, called “ organisers, ” that acquires a role of instructing neigh-
bour cells to exert specific functions [ 1 ]. At molecular level, these instructions are
biochemical signals, mainly proteins, which are received and interpreted by the
neighbour cells. This interpretation is not processed by the neighbour cells through
an “ on/off-mode ” mechanism, but it is modulated by a molecular machinery that is
able to quantitatively measure the strength and the distance of the signal, thus
assessing the distance of the neighbour cell from a given position. Such a type of
biochemical signal is called “ morphogen ” (Fig. 3.1 ) [ 2 ] .
The term morphogens was coined by the famous mathematician Alfred Turing
before the introduction of the concept of biochemical signalling [ 1 ] . Indeed, the
concept that some kind of cellular signalling could be present in developing organ-
isms was first introduced by two embryologists, Dalq and Pasteels, who suggested

M. Santin ( * )
Brighton Studies in Tissue-Mimicry and Aided Regeneration (BrightSTAR),
School of Pharmacy and Biomolecular Sciences, University of Brighton,
Huxley Building Lewes Road , Brighton BN2 4GJ , UK
e-mail: [e-mail]