Dermal extracellular matrix extracts for wound healing: a pleiotropic trigger

Extracellular matrix (ECM) role is defined by direct cell-ECM interactions and biomechanics and also by its capacity to store biochemical cues that are vital in tissue’s repair. With this in mind, an in-house method was devised to obtain extracts comprised of structural ECM components (strECM) and enriched in soluble ECM-derived factors (sECM). Herein we hypothesised that each ECM fraction may trigger different biological functions in multiple cell types, objectively confering them therapeutic and biomimetic potential.

To prove the concept, we used human dermal fibroblasts (hdFBs) to obtain the ECM extracts, prepared by fractioning cultured cells’ own ECM. Extracts were analysed by mass spectrometry to obtain a proteomic profile and then regarding their in vitro functionality. Human dermal endothelial cells (hDMECs), keratinocytes (hKCs) and dFBs, were used to confirm the features identified by the proteomic profiling. The effect of the extracts over cell adhesion (focal adhesion formation) was analysed. A Matrigel assay was used to evaluate a potential angiogenic effect of the extracts. Moreover, hKCs migration and ability to differentiate and form a stratified epidermis was assessed. Finally, matrix (Collagen, elastin, GAGs) deposition by hdFBs and metalloproteinases (MMP 1, 2, 9)secretion and activity were measured.

Proteomic analysis revealed that strECM and sECM complement each other, preserving the native ECM protein profile. The GO accessions linked to each fraction allowed pinpointing the specific cues provided by either of them. strECM was mainly comprised of components that were able to promote cell adhesion and spatial organization. On the other hand sECM proteomic profile revealed factors that play a role in wound healing such as angiogenesis, ECM remodeling and re-epithelialization. A dose-dependent response was observed regarding the formation of tubular structures in the angiogenic assay. The presence of sECM leads to a significant increase in the migration and proliferative ability (Ki67) of hKCs while maintaining their phenotype. Finally, sECM led to enhanced collagen, elastin and GAGs deposition by hDFbs while increasing the expression of MMPs.

Our results validate the hypothesis that each ECM fraction effectively triggers different biological functions in multiple cell types. Overall the presence of sECM boosted the major cellular mechanisms that lead to successful wound healing, while strECM  provides cues for cellular adhesion and organization.

This study supports the use of ECM extracts as a wound healing enhancer, which might aid in the development of future therapies or improve the biomimicry of ECM-based 3D tissue models.