Waste‐Derived Nanocarriers for Tumor‐Targeted Anticancer Drug Delivery: Design Strategies, Functionalization, and Translational Challenges

Waste‐derived nanocarriers offer an opportunity to couple waste valorization with advanced drug delivery, but their clinical relevance cannot be established solely from precursor origin or green synthesis. This review critically evaluates how waste composition, synthesis route, and nanocarrier architecture influence drug loading, release, targeting, nano–bio interactions, toxicity, and therapeutic performance in anticancer applications. Carbon‐based, polymeric, mesoporous, and inorganic systems are compared with conventional nanocarriers with respect to physicochemical performance, reproducibility, biodegradation, manufacturing complexity, and cost. Particular emphasis is placed on ligand‐mediated targeting, stimuli‐responsive release, structure–property relationships, and quantitative biological evidence. Challenges associated with feedstock variability, scale‐up, impurity control, safety assessment, life‐cycle impacts, and regulatory translation are examined. Finally, opportunities for data‐driven design, precision nanomedicine, and scalable manufacturing are discussed to identify realistic pathways for advancing waste‐derived nanocarriers from laboratory proof‐of‐concept toward translational oncology.