Proliferationsphase

Proliferationsphase is a term used in German-language biology to denote the period in a biological process when cell division and tissue growth predominate. It is used across disciplines such as embryology, tissue regeneration, and oncology to describe phases where proliferation, rather than differentiation, is the primary activity.

In wound healing, the proliferative phase follows the inflammatory phase and can last from several days to a few weeks depending on tissue. Fibroblasts proliferate and synthesize extracellular matrix and collagen, endothelial cells form new blood vessels, and keratinocytes migrate to re-epithelialize the surface. This phase is supported by growth factors including VEGF, PDGF, FGF, and TGF-β, and by signals that promote cell cycle progression (G1 to S).

In development and tissue homeostasis, the proliferationsphase contributes to organ growth and regeneration, balanced with differentiation and maturation. Abnormalities in this phase can lead to chronic non-healing wounds or excessive scarring. In cancer biology, uncontrolled proliferation is a key feature and is used to assess tumor aggressiveness with proliferation markers such as Ki-67.

The term is sometimes used in broader contexts to describe any period of active cell division within a growth process. See also: wound healing, cell cycle, proliferation.