IGF-1 Increases Collagen Deposition by Dermal Fibroblasts: Applications for Tissue Engineering.

Tissue engineering using the self-assembly approach represents a promising technology. However, age-related reductions in extracellular matrix deposition by stromal cells limit the mechanical robustness of reconstructed tissues what can be critical for midurethral sling reconstruction. Indeed, stress urinary incontinence predominantly affects women over 50 years of age and is commonly treated by implantation of midurethral slings, whose synthetic versions have raised concerns regarding safety and long-term tolerance. In this study, we investigated whether biochemical modulation could enhance collagen deposition and mechanical properties of self-assembled dermal tissues reconstructed from female donors of different ages. Dermal fibroblasts were cultured in the presence of ascorbic acid, and the effects of hormonal supplementation, metabolic and hypoxia-related stimuli, and insulin signaling activation were evaluated using collagen quantification, histological analyses, and mechanical testing. Fibroblasts derived from younger donors deposited significantly more collagen than those from older female donors. Among all tested conditions, insulin like growth factor 1 (IGF 1) markedly increased collagen deposition in a dose-dependent manner, including in fibroblasts from women over 50 years of age, whereas β-estradiol and progesterone had no significant effect on collagen content. Although β-estradiol slightly increased tissue thickness, only IGF-1 supplementation resulted in substantial improvements in perforation strength, stiffness, displacement at break, and toughness. These results demonstrate that IGF-1 is a potent enhancer of extracellular matrix production and mechanical performance in dermal tissues reconstructed by the self-assembly approach, and represents a promising strategy to improve the development of biological midurethral slings.