Multifunctional tri-layer wound dressing containing ZNO nanoparticles and IGF-1 as an efficient biomaterial for healing of full thickness skin injuries.

Mimicking the hierarchical structure of the skin is one of the most important strategies in skin tissue engineering. Monolayer wound dressings are usually not able to provide several functions at the same time and cannot meet all clinical needs. In order to maximize therapeutic efficiency, herein, we fabricated a Tri-layer wound dressing, where the middle layer was fabricated via 3D-printing and composed of alginate, tragacanth and zinc oxide nanoparticles (ZnO NPs). Both upper and bottom layers were constructed using electrospinning technique; the upper layer was made of hydrophobic polycaprolactone to mimic epidermis, while the bottom layer consisted of Soluplus® and insulin-like growth factor-1 (IGF-1) to promote cell behavior. Swelling, water vapor permeability and tensile properties of the dressings were evaluated and the Tri-layer dressing exhibited impressive antibacterial activity and cell stimulation following by the release of ZnO NPs and IGF-1. Additionally, the Tri-layer dressing led to faster healing of full-thickness wound in rat model compared to monolayer and Bilayer dressings. Overall, the evidence confirmed that the Tri-layer wound dressing is extremely effective for full-thickness wound healing.