Global population growth and climate change intensify the demand for sustainable crop improvement, thereby driving innovation in plant genetic transformation technologies. Conventional methods, including Agrobacterium-mediated transformation and biolistics, remain limited by host specificity, low transformation efficiency, tissue-culture dependence, and random DNA integration. Recently, nanomaterials, particularly carbon nanotubes (CNTs), have emerged as promising vehicles for biomolecule delivery into plant cells owing to their ability to penetrate the cell wall, transport diverse cargo, and enable transient delivery without necessarily requiring genome integration. In this review, we examine the potential of CNT-based platforms to overcome existing transformation barriers, enable transient delivery of DNA, RNA, and proteins, and expand gene-editing to recalcitrant crops with particular emphasis on CRISPR-Cas9 delivery in plasmid DNA, mRNA, and ribonucleoprotein (RNP) formats that may facilitate DNA-free genome editing. We also systematically discuss CNT synthesis, functionalization strategies, and structure-activity relationships that govern delivery efficiency, alongside a comparative analysis of established transformation methods. In addition, we assess the temporal and economic viability of CNT platforms and evaluate the evolving global regulatory landscape for nanomaterial-mediated crop editing. We conclude that CNT-mediated delivery represents a promising tool for sustainable crop engineering, though broader adoption will require standardized biosafety protocols, life-cycle assessments, and harmonized regulatory pathways to address nanotoxicological and environmental concerns. |
