Nanobead-on-string composites for tendon tissue engineering

Tissue engineering holds great potential in the production of functional substitutes to restore, maintain or improve the functionality in defective or lost tissues. So far, a great variety of techniques and approaches for fabrication of scaffolds have been developed and evaluated, allowing researchers to tailor precisely the morphological, chemical and mechanical features of the final constructs. Electrospinning of biocompatible and biodegradable polymers is a popular method for producing homogeneous nanofibrous structures, which might reproduce the nanosized organization of the tendons. Moreover, composite scaffolds obtained by incorporating nanoparticles within electrospun fibers have been lately explored in order to enhance the properties and the functionalities of the pristine polymeric constructs. The present study is focused on the design and fabrication of biocompatible electrospun nanocomposite fibrous scaffolds for tendon regeneration. A mixture of poly(amide 6) and poly(caprolactone) is electrospun to generate constructs with mechanical properties comparable to that of native tendons. To improve the biological activity of the constructs and modify their topography, wettability, stiffness and degradation rate, we incorporated silica particles into the electrospun substrates. The use of nanosize silica particles enables us to form bead-on-fiber topography, allowing the better exposure of ceramic particles to better profit their beneficial characteristics. In vitro biocompatibility studies using L929 fibroblasts demonstrated that the presence of 20 wt% of silica nanoparticles in the engineered scaffolds enhanced cell spreading and proliferation as well as extracellular matrix deposition. The results reveal that the electrospun nanocomposite scaffold represents an interesting candidate for tendon tissue engineering.