The stem cell niche
Stem cells are defined as much by where they sit as by what they are.
A stem cell niche is the local microenvironment that maintains a cell in a stem-like state: neighbouring cells, matrix, soluble signals, oxygen tension, and mechanical context together. Remove a cell from its niche and its behaviour changes — which is why cells cultured on plastic often stop resembling their in vivo counterparts, and why passage number matters so much in reproducible work.
The niche concept reframes what a scaffold is for. A construct is not only a structure to fill a space; it is an attempt to reconstitute enough of a niche that transplanted or recruited cells behave correctly. Published work on pulp regeneration makes this explicit: a 3D pulp-specific microenvironment is described as facilitating regeneration of the pulp-dentin complex — the environment, not merely the cells, does the work.
It also underpins Cell homing: if a niche can be recreated, resident cells may migrate in on their own.
Related articles
- CellsMesenchymal stem cellsThe most widely studied cells in regenerative medicine — and a reassessment of what they actually do.
- CellsCell homingRecruiting the patient's own cells into a scaffold instead of transplanting cells at all.
- FoundationsThe extracellular matrixThe structural and signaling scaffold cells build around themselves — and the template engineered scaffolds try to imitate.
- BiomaterialsScaffold design principlesPorosity, strength, and degradation rate — the competing requirements every scaffold has to reconcile.
- DentalThe dentin-pulp complexWhy dentin and pulp are treated as one functional unit, and what makes rebuilding it so difficult.
- CellsStem cell differentiationHow an uncommitted cell chooses a fate — under chemical, mechanical, and spatial instruction.