Preparation, fractionation, and characterization of solubilized elastin and comparison of cellular response on fibroblasts and macrophages

Abstract

Elastin and elastin-derived compounds are promising biomaterials due to their biological activity, unique natural crosslinks, and ability to mimic native tissue properties. Solubilized elastin peptides retain the bioactivity of elastin and are more suitable for wound care applications than the insoluble form. Chemically solubilized elastins have shown advantageous effects in skin regeneration in humans. Here, five solubilized elastins were prepared via chemical (stepwise and continuously hydrolyzed with oxalic acid - OxA-st-ELN and OxA-ELN, or with potassium hydroxide - KOH-ELN), enzymatic (Enz-ELN), or combined (Combi-ELN) methods. OxA-st-ELN had the largest molecular weights (MWs) fragments, while Enz-ELN and Combi-ELN yielded the smallest. The effects of elastin preparations were evaluated on primary human cells - dermal fibroblasts and macrophages. In fibroblast assays, Enz-ELN induced elastin, collagen, and fibrillin-2 protein deposition, while other preparations exhibited levels comparable to the control. alpha-smooth muscle actin (SMA) expression remained low across all conditions. Continuous oxalic acid hydrolysis simplified the traditional stepwise approach while maintaining bioactivity. Macrophage studies showed chemical hydrolysates preserved the M0-like subtype, while Enz-ELN promoted a pro-inflammatory M1-like phenotype, and Combi-ELN had mixed effects. OxA-ELN and KOH-ELN appeared to be the most promising options for developing biomaterial dermal scaffolds that support tissue regeneration in vivo.