Boron Nitride Nanotubes for Drug Delivery: Toward Programmable Anisotropic Nanocarriers

Boron nitride nanotubes (BNNTs) have long been recognized as structurally robust, chemically inert, and electronically insulating one-dimensional nanomaterials, yet their role in drug delivery remains limited compared with carbon-based and spherical nanocarriers. This Perspective proposes that the underdevelopment of BNNTs in nanomedicine is not solely caused by intrinsic material limitations but also by a persistent conceptual mismatch in how these materials have been evaluated. BNNTs have often been judged using design paradigms developed for isotropic nanoparticles or electronically active carbon nanomaterials, which can obscure the opportunities created by their anisotropic geometry, polar B–N bonding framework, and tunable interfacial interactions. Here, BNNTs are reframed as programmable anisotropic delivery platforms in which geometry, surface chemistry, and interaction physics should be codesigned rather than optimized separately. Particular attention is given to three connected requirements for translation: rigorous material quality control, tunable BNNT–cargo and BNNT–biointerface interactions, and systematic evaluation of long-term biological fate, including degradation, organ accumulation, and clearance. By defining these requirements as experimentally actionable design principles, this Perspective aims to provide a clearer roadmap for future BNNT-based drug delivery studies and to distinguish established evidence from forward-looking opportunities in this emerging field.