We have developed a technology that facilitates the targeted delivery of glucocorticoids to arthritic joints thereby side-stepping systemic immune suppression while potentially improving efficacy. Our technology loads phototherapeutics inside of red blood cell (RBC) carriers. This ensures that the inactive, RBC-contained phototherapeutic drug is transported throughout the body and released from the RBC carrier only after triggered release by long-wavelength light. We have demonstrated that medications bound to vitamin B12 can be photo-released from RBCs using tissue penetrating, longwavelength red, far-red, and near infrared light in the collagen antibody-induced arthritis model.