Nanomaterials for Subcellular Organelle Targeting: Unlocking New Avenues for Enhanced Therapeutic Effectiveness

Subcellular organelle targeting is changing the way nanomedicine is designed, moving the field beyond simple cellular entry toward more precise intracellular localization, controlled cargo release, and functional activity within disease-relevant compartments. This review critically discusses nanomaterial-based strategies for targeting the nucleus, mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus, and cytoskeleton-associated trafficking pathways. Its main novelty is the use of a cross-organelle, mechanism-based framework that links nanocarrier physicochemical properties with intracellular transport biology, rather than examining each organelle or delivery platform separately. Lipid nanoparticles, polymeric carriers, dendrimers, inorganic nanomaterials, biomimetic systems, and engineered extracellular vesicles are compared according to their targeting mechanisms, cargo compatibility, therapeutic potential, and translational limitations. Particular attention is given to nuclear import mediated by NLS-, CPP/TAT-, and aptamer-based strategies; mitochondrial delivery shaped by membrane potential, membrane fusion, and redox-responsive release; lysosomal targeting for pH- and enzyme-activated therapies; and ER/Golgi-directed delivery through retrograde trafficking, retention motifs, and modulation of stress-related pathways. The review also brings together several emerging directions, including stimuli-responsive release, biomimetic surface engineering, extracellular vesicle scalability, CRISPR/Cas delivery, base and prime editing, and targeted protein degradation, all of which may support more programmable forms of intracellular therapy. Importantly, it separates true organelle localization from transient trafficking or nonspecific perinuclear accumulation, emphasizing the need for stronger and more reliable validation methods. Key barriers remain, including inefficient endosomal escape, off-target intracellular accumulation, organelle-specific toxicity, long-term safety concerns, reproducibility, scalable manufacturing, and regulatory classification. Overall, this review frames organelle-directed nanomedicine as a rational design strategy for improving therapeutic precision, while also stressing that clinical translation will depend on clear evidence of durable, safe, and measurable therapeutic benefit at the organelle level.