▎ 摘　　要

NOVELTY - Biomaterial-based composite ink composition comprises: at least one contrast agent comprising iron oxide, copper oxide, carbon nanotube, or graphene oxide; and at least one polysaccharide-based biomaterial comprising chitosan or its derivative. USE - The composition is useful for: endoscopic tattooing (claimed); and endoscopic imaging (including in colon tattooing) procedures to mark lesions or polyps in the colon for surgical resection or to guide follow-up procedures. ADVANTAGE - The composition: possesses strong contrast due to dark brown/black color; can retain localization at injection site for improved follow-up accuracy; induces low cytotoxic effects and low inflammatory response; possess enhanced mucoadhesivity to help retain localization in submucosal injection sites by interactions with connective tissue matrices, high contrast ratio visualization with high optical density, and carrier materials which are well established to have high biocompatibility and controllable degradability; and demonstrates high contrast towards endoscopic imaging and ability to retain the localized tattoo mark due to its inherent mucoadhesivity, and as consequence very low diffusion/transport compared to clinically used Spot-Ex ink(RTM: Darker tattoo). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: endoscopic tattooing comprising injecting the composition to tissue; and ynthesizing the composition comprising mixing the contrast agent.