ROS act as a “double-edged sword” inducing either tissue repair or necrosis depending on their concentration. ROS are generated by various factors; in particular, excessive ROS during radiation therapy for head and neck cancer cause severe damage to salivary glands (SGs). Thus, developing ROS-suppressive biomaterials is essential for successful SG repair. In this study, we developed a GSH-gelatin hybrid protein. This material exhibits high antioxidant capacity while overcoming the short half-life of GSH. To facilitate clinical application, we fabricated stable AdMSC spheroid capsule using blue light. Consequently, this cell capsule effectively scavenged ROS, suppressing oxidative stress and accelerating tissue regeneration through the localized spheroid delivery. Our findings suggest that this multi-functional cell capsule holds great promise as a next-generation platform for treating tissue injuries requiring both oxidative stress suppression and targeted cell delivery.