Poly(hydroxybutyrate-co-hydroxyvalerate) bilayer skin tissue engineering constructs with improved epidermal rearrangement

Bilayer skin substitutes constitute an attractive strategy towards improved skin wound healing. Therefore, solvent casting and freeze-drying methodologies are used to produce polyhydroxybutyrate-co-hydroxyvalerate (PHBV) thin nanoporous membranes and 3D porous scaffolds that are combined in bilayer structures to recreate the epidermal and dermal layers, respectively. The combination of these methodologies allow attaining a bilayer structure with a high water retention capability and adequate mechanical properties, susceptible to enzymes degradative action. Cultures established with human keratinocytes (hKC) and dermal fibroblasts (hDFb) confirm the suitability of the PHBV structures to support cell adhesion and proliferation. Nonetheless, when co-cultured under defined conditions, hKC are able to grow and rearrange in a multilayer structure with proliferative cells in the basal layer, and cells expressing a terminal differentiation marker in the upper layer. Therefore, PHBV bilayer structures demonstrate properties that favor skin cells performance, thus representing a promising strategy to improve wound healing.