Smart Cells Against Cancer: Advances in Cell-Based Drug Delivery and Diagnostics

Cell-based drug delivery has emerged as a powerful strategy to improve therapeutic targeting while reducing systemic toxicity. This approach is particularly valuable for anticancer agents, which are often limited by severe side effects arising from off-target activity and non-specific distribution. By using cells as carriers, drugs can evade immune clearance, achieve prolonged circulation, and improve pharmacokinetic profiles, ultimately enhancing therapeutic efficacy. This review surveys the current landscape of cell-mediated drug delivery in oncology, emphasizing both fundamental principles and practical applications. We discuss the design and preparation of cellular carriers, examine the unique characteristics of commonly used cell types, and highlight recent technological innovations that are expanding their theranostic potential, focusing on strategies for delivery to challenging anatomical sites, with a dedicated focus on the brain. By consolidating recent advances and insights, this review aims to provide a comprehensive perspective on the promise and future directions of cell-based drug delivery for cancer therapy.