Integrating 3D printing of biomaterials with nitric oxide release.

The pivotal roles played by nitric oxide (NO) in tissue repair, inflammation, and immune response have spurred the development of a wide range of NO-releasing biomaterials. More recently, 3D printing techniques have significantly broadened the potential applications of polymeric biomaterials in biomedicine. In this context, the development of NO-releasing biomaterials that can be fabricated through 3D printing techniques has emerged as a promising strategy for harnessing the benefits of localized NO release from implantable devices, tissue regeneration scaffolds, or bandages for topical applications. Although 3D printing techniques allow for the creation of polymeric constructs with versatile designs and high geometric precision, integrating NO-releasing functional groups or molecules into these constructs poses several challenges. NO donors, such as S-nitrosothiols (RSNOs) or diazeniumdiolates (NONOates), may release NO thermally, complicating their incorporation into resins that require heating for extrusion-based 3D printing. Conversely, NO released photochemically from RSNOs effectively inhibits radical propagation, thus hindering photoinduced 3D printing processes. This review outlines the primary strategies employed to overcome these challenges in developing NO-releasing biomaterials via 3D printing, and explores future prospects in this rapidly evolving field.