Nanocomposite GelMA Bioinks: Toward Next-Generation Multifunctional 3D-Bioprinted Platforms

The convergence of nanotechnology and bioprinting is redefining the landscape of tissue engineering, with nanocomposite gelatin methacryloyl (GelMA) bioinks emerging as a transformative platform for the biofabrication of multifunctional tissue-specific constructs. GelMA, a photocrosslinkable hydrogel, has rapidly gained attention due to its intrinsic bioactivity, tunable mechanical properties, and compatibility with living cells. However, despite its wide applicability regenerating muscle, cartilage, bone, vascular, cardiac, and neural tissues, native GelMA suffers from limited mechanical strength and insufficient biofunctionality to recapitulate the complexity of specialized tissues. To overcome these shortcomings, recent strategies have focused on the incorporation of nanomaterials into GelMA matrices, ranging from inorganic and carbon-based to metallic, polymeric, and lipidic nanomaterials. These nanocomposite bioprinted scaffolds impart critical enhancements, including improved mechanical robustness, electrical conductivity, stimuli-responsiveness, and bioactivity, while also enabling advanced functionalities such as controlled drug release and real-time responsiveness to the cellular microenvironment. This review examines the bioprinting parameters, material synergies, and design strategies governing the performance of nanocomposite GelMA bioinks. By integrating the tunability of photocrosslinkable bioinks with the multifunctionality of nanomaterials, nanocomposite GelMA bioinks represent a next-generation platform capable of addressing the complex demands of tissue repair and regeneration.