Regenerace

Regenerace, or regeneration, is the process by which living organisms replace or repair damaged or lost tissue, organs, or limbs. It ranges from simple tissue renewal to complete organismal regeneration in some species and is driven by a combination of cell proliferation, differentiation, and pattern formation.

In nature, regenerative capacity varies widely. Certain invertebrates and early-branching vertebrates can reconstruct complex structures: planarian flatworms can reform a whole body from fragments; urodeles such as salamanders can regrow limbs, jaws, or spinal tissue; and some echinoderms can restore arms. In mammals, regeneration is more restricted but evident: the liver can regenerate after partial removal; skin and bone repair; the intestine renews its lining. Regeneration in the central nervous system is limited, and heart tissue in adult mammals shows very constrained regrowth.

Mechanisms often involve stem or progenitor cells that persist in tissue or are mobilized after injury. Dedifferentiation of mature cells, formation of a blastema in species that regrow limbs, and subsequent proliferation and patterning rebuild functional tissue. Signaling pathways such as Wnt, FGF, and Notch, together with interactions with the immune system and extracellular matrix, coordinate these processes.

Regenerative medicine applies these principles to human health, aiming to repair or replace damaged tissues through stem cell therapies, tissue engineering, and organ regeneration. Challenges include controlling tissue growth, ensuring proper integration with host tissue, immune compatibility, and ethical considerations.

In plants, regeneration relies on meristematic tissue and can occur after wounding, grafting, or pruning, enabling vegetative propagation and resilient recovery.