Nano-inks for tissue-engineering

Bioprinting strategies can combine materials and cells to create automated and high-fidelity relevant three-dimensional (3D) structures. Although bioprinting can mimic some tissues' features that cannot be achieved using classic scaffolding strategies, there are still challenges to overcome. Despite few successful examples of ink development for microtissues fabrication, the bioprinting of complex tissues and organs is still a mirage. Naturally derived hydrogels are attracting significant interest owing to their biocompatible and biodegradable properties and their similarity to the tissues' extracellular matrix. Even so, hydrogels present some limitations, because of their low mechanical properties. Exploring the combination of 3D printing and nanotechnology, complex structures with functional features and improved mechanical performance have been obtained. In particular, nanocomposite inks have emerged as a promising approach to producing complex biofunctional and stimuli-responsive environments that can deliver specific therapeutics crucial for tissue engineering. Here, we discuss the challenges and developments involving nano inks for tissue engineering applications.