Functional Properties of a Purified Reconstituted Bilayer Matrix Design Support Natural Wound Healing Activities

Biomaterial engineering has produced numerous matrices for use in tissue repair, utilizing various materials and processing methods, which can impact the ability of the products to encourage wound healing. Recently, we observed favorable clinical outcomes, using a novel purified reconstituted bilayer matrix (PRBM; Geistlich Derma-Gide) to treat chronic diabetic foot ulcers.

Evaluations of the structural and functional characteristics of PRBM in vitro were performed to assess how this biomaterial may affect the favorable clinical results observed by influencing the wound environment and key physiologic mechanisms necessary for the healing process. Investigations included scanning electron microscopy, cell culture analyses, gene expression assays, matrix metalloproteinase activity assessment, and pH measurement.

Cross-sectional scanning electron microscopy demonstrated a distinct bilayer structure with porous and compact layers. The PRBM structure allowed cell types involved in wound healing to bind and proliferate. Expression analysis of growth factor-responsive genes demonstrated binding and preservation of bioactive growth factors TGF-β1, bFGF, and VEGF by PRBM. Boyden chamber migration assays revealed increased cellular migration compared with controls. In the presence of PRBM, the activity of MMP-1, MMP-2, and MMP-9 was significantly lower compared with control samples. pH of the PRBM in solution was slightly acidic.

Based on in vitro evaluations, it appears that the PRBM processing without deleterious chemical crosslinking results in a suitable ECM possessing characteristics to aid natural wound healing, including cell attachment, migration, proliferation, differentiation, and angiogenesis. These in vitro data support the promising healing rate observed clinically when chronic DFUs are treated with PRBM.