A Recombinant Elastic Peptide Rescues Elasticity From a Self-Assembled Dermal Sheet Model Treated With Ascorbic Acid

The extracellular matrix (ECM) plays a pivotal role in determining the structure and function of the skin. Collagen and elastin, in particular, are responsible for providing tensile strength and elasticity, respectively. However, imbalances in the components of the extracellular matrix (ECM) during tissue engineering often result in the deterioration of the mechanical properties and physiological relevance of dermal substitutes, in part due to the detrimental effect of ascorbic acid (AA) on elastic fibre biosynthesis. The objective of this study is to investigate the potential of a synthetic elastic protein (SEP) to improve ECM remodelling and to restore the equilibrium between collagen and elastin in reconstructed dermal tissues. Primary fibroblasts monolayers were treated with increasing concentrations of SEP in the presence or not of AA without affecting cytotoxicity. Western blot and immunofluorescence analyses showed that in the presence of AA - which typically reduced elastin synthesis- SEP improved elastic fibre formation without affecting type I collagen assembly. Additionally, 3D dermal substitutes treated with SEP and AA were analysed at the ultrastructural scale showing a specific colocalization of SEP with fibrillin-rich fibrils. Finally, dynamic mechanical analyses were conducted to measure mechanical properties of decellularized ECM. In the presence of SEP, we observed an increase of 46% and 40% of elastic and Young's moduli respectively. By restoring ECM integrity, SEP is emerging as a promising biomimetic tool for the development of 3D skin substitutes. Its application has the potential to improve the physiological relevance and therapeutic value of engineered skin tissues.