ZnO nanoparticles are well known for their ability to generate Reactive Oxygen Species (ROS) which have a potential role in biological systems. ROS can enhance wound healing by improved cell adhesion and cell migration through growth factor mediated pathways. Here we report the fabrication of electrospun polycaprolactone scaffolds incorporated with ZnO nanoparticles and their ability to perform as skin substitute materials which promote the healing process. The plain or ZnO nanoparticle incorporated PCL membranes were implanted subcutaneously in guinea pigs. Immunological, macroscopical and histological evaluations have shown that the use of membranes containing ZnO nanoparticles enhances the cell adhesion and migration. The ZnO nanoparticle embedded membranes do not show any significant sign of inflammation. The implant also enhanced the wound healing without any scar formation.

Angiogenesis through tissue engineering scaffolds is an important factor that determines the success of a tissue engineering endeavor. Zinc oxide (ZnO) nanoparticles are well known for their ability to generate reactive oxygen species (ROS) which have a potential role in biological systems. ROS can induce angiogenesis through growth factor mediated mechanisms. Here, we report the fabrication of electrospun polycaprolactone scaffolds incorporated with ZnO nanoparticles and their ability to induce angiogenesis. This study demonstrated that the induction of angiogenesis was by the expression of key proangiogenic factors, fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF), upregulated due to the presence of ZnO nanoparticles. This is the first report suggesting the use of a metal/metal oxide nanoparticle in tissue engineering scaffolds to enhance angiogenesis.

Electrospun polycaprolactone (PCL) tissue engineering scaffolds have been developed and used for a wide range of tissue engineering applications, where successful incorporation and conservation of the therapeutic activity of the embedded nanoparticles into scaffolds is critically needed for effective tissue engineering. Incorporation of pro-angiogenic nanomaterials to promote vascularization is a novel approach. Our group has well-demonstrated the potent pro-angiogenic properties of europium hydroxide nanorods (EHNs) using in vitro and in vivo systems. In the present study, electrospun PCL tissue engineering scaffolds containing EHNs were fabricated and characterized for various morphological and physico-chemical properties. Furthermore, biological studies showed enhanced cell growth and a greater density of endothelial cells grown on the scaffolds incorporated with EHNs (PCL-EHNs). The PCL-EHNs also exhibited good hemo-compatibility towards blood cells. Fluorescence microscopy and SEM observations showed good endothelial cell adhesion over these scaffolds. The PCL-EHNs demonstrated augmented growth of blood vessels in an in vivo chick embryo angiogenesis model. Furthermore, protein expression studies illustrated promoted angiogenesis of HUVECs on scaffolds in a VEGFR2/Akt mediated signaling cascade. Together, the above observations strongly suggest potent applications of EHN-incorporated PCL scaffolds in promoting angiogenesis/vascularization and their effective use in tissue engineering and vascular disease therapy.

This review gives a brief description on the skin and its essential functions, damages or injury which are common to the skin and the role of skin substitute to replace the functions of the skin soon after an injury. Skin substitutes have crucial role in the management of deep dermal and full thickness wounds. At present, there is no skin substitute in the market that can replace all the functions of skin ‘and the research is still continuing for a better alternative. This review is an attempt to recollect and report the past efforts including skin grafting and recent trends like use of bioengineered smart skin substitutes in wound care. Incorporation functional moieties like antimicrobials and wound healing agents are also described.