fibroplasia

Fibroplasia is the growth or formation of fibrous tissue, driven by fibroblasts that synthesize extracellular matrix components such as collagen. It is a normal part of tissue repair but can also occur in response to chronic irritation or disease. The term can refer to the general process of fibroblast-driven connective tissue formation as well as to the proliferation of fibroblasts themselves.

In the context of wound healing, fibroplasia occurs during the proliferative phase, following inflammation. Fibroblasts migrate into the wound, proliferate, and lay down a provisional extracellular matrix that supports ingrowth of capillaries and other cells. This activity contributes to granulation tissue and the restoration of tissue integrity, with collagen deposition gradually replacing the provisional matrix as the wound matures.

Fibroblast activity is regulated by a network of growth factors and cytokines, including transforming growth factor-beta (TGF-β), platelet-derived growth factor (PDGF), and fibroblast growth factors (FGFs). Some fibroblasts differentiate into myofibroblasts, which express contractile proteins that help contract the wound edges. Extracellular matrix remodeling involves matrix metalloproteinases and enzymes such as lysyl oxidase that cross-link collagen fibers, shaping the strength and quality of the repaired tissue.

Pathologically, excessive fibroplasia can lead to fibrosis and scar formation, sometimes resulting in hypertrophic scars or keloids. In chronic inflammatory conditions or persistent irritation, persistent fibroblastic activity may contribute to dense fibrous tissue and restricted organ function. Fibroplasia is also a feature of certain desmoplastic reactions seen in tumors and other fibrous tissue responses.

Understanding fibroplasia is important in wound management, fibrotic diseases, and therapies aimed at modulating scar formation and tissue remodeling.