One of the limitations in tissue engineering is the restricted ability to expand the number of cells, because somatic cells can duplicate a limited number of times before they lose the ability to divide, leading to a senescent state. Here we report that the interaction of senescent fibroblasts with fibrin polymer can modify the senescent phenotype and partially restore the ability of growth-arrested cells to continue replicating. Primary human dermal fibroblasts were grown to >90% SA/β-Gal (senescence associated β-galactosidase) . The senescent cells were immobilized in fibrin-polymers by mixing fibrinogen and thrombin solutions. Immobilized senescent cell cultures grew, however, their growth arrested after 24 h of immobilization. The percentage of cells with a positive reaction at SA/β-Gal did not decrease significantly after immobilization, but the intensity of the stain decreased. The glycolytic activity in immobilized senescent fibroblast was re-established at pre-senescent levels. In conclusion, fibrin induces changes in the phenotype of senescent human fibroblasts. This simple procedure could complement available tissue-engineering techniques to increase the amount of biomass seeded on a fibrin scaffold, which could be beyond senescence.
- Human fibroblasts