Organelle-Targeted Nanocarriers for Cancer Therapy: Design Principles, Intracellular Trafficking, and Translational Barriers in Precision Drug Delivery.

The clinical translation of cancer nanomedicine remains constrained by inefficient intracellular delivery, poor subcellular specificity, and limited tumor accumulation, highlighting the need for more precise drug delivery strategies. Organelle-targeted nanocarriers have emerged as a promising platform for enhancing therapeutic efficacy by directing drugs to specific intracellular compartments, including the nucleus, mitochondria, lysosomes, and endoplasmic reticulum. However, the design principles governing efficient organelle-specific delivery and the barriers limiting clinical translation remain incompletely understood. This review provides a mechanistic framework linking nanoparticle physicochemical properties-including size, surface charge, ligand functionalization, and stimuli responsiveness to intracellular trafficking, organelle targeting, and therapeutic performance. We critically discuss the biological barriers encountered during delivery, including cellular uptake, endosomal escape, cytosolic transport, and organelle membrane penetration, together with current engineering strategies to overcome these challenges. Organelle-specific targeting approaches are comparatively evaluated to highlight their therapeutic advantages, limitations, and suitable clinical applications. Beyond summarizing recent advances, this review examines the major translational hurdles that impede clinical implementation, including non-specific biodistribution, manufacturing scalability, regulatory challenges, and the lack of standardized preclinical evaluation models. Emerging solutions such as hierarchical targeting, charge-reversal systems, size-transformable nanocarriers, and multifunctional theranostic platforms are discussed as strategies to improve clinical feasibility. Finally, we propose practical design guidelines and future research priorities that integrate nanomaterial engineering, predictive biological models, and scalable manufacturing to facilitate the development of clinically translatable organelle-targeted nanomedicines.