Fully Synthetic 3D Fibrous Scaffolds for Stromal Tissues—Replacement of Animal?Derived Scaffold Materials Demonstrated by Multilayered Skin
The combination of electrospun fibers and extensive amounts of porogens maximize the porosity of sub?micrometer fibrous scaffolds. The ensemble of loose fiber networks and appropriately sized pores enable the infiltration with stromal cells and the transformation to biological tissues. Thereby, the limitations of animal?derived scaffolds like decellularized tissues and hydrogels for tissue engineering applications or advanced therapy medicinal products are overcome.The extracellular matrix (ECM) of soft tissues in vivo has remarkable biological and structural properties. Thereby, the ECM provides mechanical stability while it still can be rearranged via cellular remodeling during tissue maturation or healing processes. However, modern synthetic alternatives fail to provide these key features among basic properties. Synthetic matrices are usually completely degraded or are inert regarding cellular remodeling. Based on a refined electrospinning process, a method is developed to generate synthetic scaffolds with highly porous fibrous structures and enhanced fiber?to?fiber distances. Since this approach allows for cell migration, matrix remodeling, and ECM synthesis, the scaffold provides an ideal platform for the generation of soft tissue equivalents. Using this matrix, an electrospun?based multilayered skin equivalent composed of a stratified epidermis, a dermal compartment, and a subcutis is able to be generated without the use of animal matrix components. The extension of classical dense electrospun scaffolds with high porosities and motile fibers generates a fully synthetic and defined alternative to collagen?gel?based tissue models and is a promising system for the construction of tissue equivalents as in vitro models or in vivo implants.