Cell-Based Drug Delivery Systems: Innovative Drug Transporters for Targeted Therapy.

Significant progress has been made in developing cell-based drug delivery systems that utilize the intrinsic biological properties of various cell types-erythrocytes, leukocytes, platelets, stem cells, and even spermatozoa-to improve drug targeting, bioavailability, and biocompatibility. This review presents an integrative analysis of the latest advances in cell-based drug delivery systems, focusing on their design, pharmacokinetics, cellular interactions, and therapeutic potential. We specifically focus on hybrid microrobots and membrane-coated nanocarriers as emerging biohybrid platforms. Despite these advances, translation to the clinical phase remains constrained by persistent limitations, such as immune clearance, loss of membrane integrity during cargo loading, limited tissue penetration of carrier cells, and manufacturing challenges. Finally, we highlight future directions, including CAR-cell combinations and artificial cell engineering, that promise to expand the clinical utility of cell-based drug delivery systems in oncology, infectious diseases, and regenerative medicine.