Preparation and properties of a novel carbon nanotubes/poly(vinyl alcohol)/epidermal growth factor composite biological dressing

Wound dressings with drug delivery system have drawn increasing attention in skin damage recombination. Herein, a novel composite biological dressing was prepared and based on poly(vinyl alcohol) (PVA) combined with carbon nanotubes (CNTs) and epidermal growth factor (EGF) by electrospinning on gauze. The properties of the CNTs/PVA/EGF composite dressing were systemically investigated by general observation, and scanning electron microscopy (SEM). In vitro, the cytotoxicity of this dressing was investigated using a methyl thiazolyl tetrazolium (MTT) assay on L929 fibroblasts. In order to study the sustained release of EGF from this dressing, the concentration of EGF at different times was tested by ELISA. Furthermore, the biological activity of the released EGF was also evaluated using the MTT assay. Moreover, an in vivo experiment was conducted to observe whether this dressing was capable of improving healing in the model of wounded skin on rats. It was revealed that this dressing had a well‑distributed microstructure by SEM. Additionally, the grade of cytotoxicity was low, and the EGF had a sustained release rate from this dressing. Furthermore, a maximum accumulative release rate of 12.47% was identified at 12 h, and was retained at 9.4% after 48 h. Simultaneously, the relative growth rate of L929 fibroblasts in the 12 h experimental group and 48 h group was 291.24 and 211.3%, respectively. Next, the efficacy of these products was evaluated in vivo using Sprague‑Dawley rats with a skin injury model. The healing of wounded skin of rats was sped up by this dressing based on the gross and histological appearances. From 7 to 10 days, the wounds in the experimental group were almost healed. In conclusion, this CNTs/PVA/EGF dressing had a well‑distributed structure and an ability to release EGF at a sustained rate with the activity being favorable. On the basis of those results, a positive influence of designed dressing for accelerated wound healing was confirmed.