Encapsulation of AD-MSC- derived extracellular nanovesicles in an electrospun three-layer scaffold: characterization and controlled release analysis in vitro

The combining of therapeutic agents with electrospun nanofibers boosts their regeneration potential; therefore, Researchers have increasingly turned towards the development of electrospun nanofiber scaffolds to encapsulate or surface-adsorb biological payloads, such as cytokines, exosomes, peptides, nucleic acids, and enzymes. Due to their high surface-to-volume ratio, ease of manufacturing, and drug-loading capacity, electrospun nanofibers are hopeful in tissue engineering and scaffold fabrication. Electrospun multilayer scaffolds offer a promising construction for preserving the integrity and bioactivity of therapeutic factors while permitting the controlled and prolonged release of biomolecules into the environment. The present study aimed to evaluate the mechanism of controlled release of electrospun exosomes from a three-layer nanofiber scaffold and its effect on the expression of DDR2 and VEGF genes in fibroblast cells<i>in vitro</i>. Adipose-derived mesenchymal stem cells were obtained and isolated from liposuction surgery samples, and their intrinsic nature was confirmed using flow cytometry. After the exosomes were separated from the cell supernatant, their size, shape, and index markers were identified. The cytotoxicity, biocompatibility, and mechanical characteristics of scaffolds were evaluated. The qRT-PCR results showed the upregulation of DDR2 and VEGF genes in the three-layer scaffold containing the exosomes was 2.04 and 1.47-fold compared to the control group. The design and construction of multi-layered electrospun nanofibers loaded with bioactive substances and favorable mechanical and biological properties for controlled and sustained release will be promising and effective scaffolds for therapeutic purposes.