Nanocomposite hydrogel inks pioneering future of 3D bioprinting

• Nanotechnology-integrated ink transformed 3D bioprinting. • Nanomaterial-loaded ink exhibits good printability and structural integrity. • Nanomaterials help in controlling the mechanical properties of implants. • Nanomaterials-loaded ink supports cell growth and tissue regeneration. The intersection of nanotechnology with bioprinting has opened new frontiers in devising nanobiomaterials-based multifunctional inks for 3D (3-dimensional) bioprinters. We discuss recent developments in versatile inks that have been made possible by incorporating various nanomaterials, such as nanoparticles, nanofibers, carbon nanosheets, metals, silica, cellulose, ceramics, and different nanopolymers into hydrogels to fabricate nanocomposite hydrogel inks for 3D bioprinters. Given the recent developments, it is imperative to discuss the effects of nanomaterials on hydrogel-based inks in terms of their printability, printing fidelity, ability to release bioactive chemicals under regulated conditions, and the corresponding biological responsiveness. These inks mark a paradigm shift in creating intricate and functional scaffolds by combining the adaptability of hydrogels with the enhanced qualities of nanomaterials. We also highlighted the effective fabrication of various tissue/organ types, including skin, cartilage, nerve, bone, and vascular grafts. The challenges faced in achieving optimal print resolution, cell viability, and long-term functionality by critically examining recent studies are also discussed. The review also offers an overview of the future research directions and the potential for collaborations between interdisciplinary researchers.