Keratin-based electrospun nanofibers for biomedical applications in dental implants and bone regeneration

Electrospinning is a simple method to produce nanofibres with high specific surface. Keratin is a biocompatible and biodegradable protein [1], it supports fibroblasts [2] and osteoblasts [3] growth. Moreover, electrospun keratin-based nanofibers (EKNs) were made insoluble to water by a thermal treatment inducing cross-linking [4]. For dental applications, pure keratin has been electrospun from solutions of formic acid to deposit nanofibers onto titanium substrates. The aim is the improvement of soft tissue adhesion avoiding epithelial down-growth and bacterial infiltration on the collar. Water stability of EKNs was evaluated by 28 days soaking. EKNs were found to greatly improve fibroblast cells growth already at 24h. In bone regeneration, nano-hydroxyapatite (HAp) was used in composite EKNs. Unfortunately, HAp particles are not stable in acids; therefore, water was used as solvent to produce HAp-EKNs. Better processability was attained by blending keratin with polyethylene oxide (PEO). PEO is an amphiphilic and water-soluble polymer added as a sacrificial material. HAp-EKNs were subjected to heating and washing to obtain pure keratin nanofibres. HAp-EKNs have been tested for osteoblasts cells adhesion and growth, showing biocompatibility by cell viability assay and SEM.