Three-dimensional multilayered fibrous constructs for wound healing applications

Electrospun materials are promising scaffolds due to their light-weight, high surface-area and low-cost fabrication, however, such scaffolds are commonly obtained as ultrathin two-dimensional non-woven meshes, lacking on topographical specificity and surface side-dependent properties. Herein, it is reported the production of three-dimensional fibrous materials with an asymmetrical inner structure and engineered surfaces. The manufactured constructs evidence fibrous-based microsized conical protrusions [length: (10 ± 3) × 10² μm; width: (3.8 ± 0.8) × 10² μm] at their top side, with a median peak density of 73 peaks per cm², while their bottom side resembles to a non-woven mesh commonly observed in the fabrication of two-dimensional electrospun materials. Regarding their thickness (3.7 ± 0.1 mm) and asymmetric fibrous inner architecture, such materials avoid external liquid absorption while promoting internal liquid uptake. Nevertheless, such constructs also observed the high porosity (89.9%) and surface area (1.44 m² g^-1) characteristic of traditional electrospun mats. Spray layer-by-layer assembly is used to effectively coat the structurally complex materials, allowing to complementary tailor features such as water vapor transmission, swelling ratio and bioactive agent release. Tested as wound dressings, the novel constructs are capable of withstanding (11.0 ± 0.3) × 10⁴ kg m^-2 even after 14 days of hydration, while actively promote wound healing (90 ± 0.5% of wound closure within 48 hours) although avoiding cell adhesion on the dressings for a painless removal.