Dendritic cell microrobots target spinal cord regeneration in vivo

Acute spinal cord injury (SCI) has a high disability rate, with neural remodeling crucial for recovery. However, the over-activated immune response and deficiency of growth factors in post-injury significantly hinder nerve remodeling and axonal regeneration during recovery. Low targeting efficacy, delayed onset of action and side effects (e.g., infection or femoral head necrosis) are bottleneck issues of currently adopted approaches such as peripheral injection immunotherapy and drug delivery. Regarding these issues, vaccines based on dendritic cells (DCs) provide a promising solution in modulating immune responses while treating various central nervous system (CNS) diseases in clinical situations owing to the activation of antigen-specific T-cell responses. Recently, biocompatible cell-based microrobots have been arising for targeted drug delivery and precision therapy, relying on their controllability in motion. Magnetic microrobots can quickly and accurately target the lesion area. In this study, we developed a DC microrobot (DC robot) to serve as a DC vaccine for SCI treatment. Controlled by rotating magnetic fields, these microrobots effectively regulate immune responses and deliver neurotrophic factors, promoting axonal regeneration and functional recovery in SCI mouse models. This approach highlights the potential of cell-based microrobots as a precise and safe strategy for treating SCI and other CNS diseases.