The success of advanced cancer diagnosis and treatment relies on the localized enrichment of drugs or imaging agents at tumour sites. The technologies enable targeted delivery and on-demand activation represent an excellent solution to the issue in the battle of cancer. The tumour-targeted delivery and on-demand activation of prodrugs could enhance the concentration of active drugs selectively at tumour sites while sparing the exposure of toxic drugs to normal tissues, alleviating the adverse drug effects. There are several methodologies for on-demand activation. Among them, the light-responsive release, especially with near-infrared light of better tissue penetration depth and biocompatibility, provides a high degree of spatiotemporal precision. Also, bioorthogonal click-to-release reactions have been rapidly emerging in recent years because of its bioorthogonality and controlled bond-cleavage.
The objective of this research is to develop a novel cargo delivery avenue, enabling controlled prodrug release, e.g. the immunomodulatory molecule carbon monoxide (CO) and the chemotherapy drug doxorubicin, exclusively at tumour sites with spatiotemporal precision. The strategy proposed consists of single-walled carbon nanotubes (SWCNTs) and the prodrug cargos. The strategy will enable spatiotemporal control over prodrug activation via integrating the tumour-targeting property of SWCNTs, the stability and non-toxicity of the small molecule prodrugs and the on-demand activation of prodrugs at tumour sites. Besides, the lipid functionalized SWCNTs have shown biocompatibility, ultrahigh tumour uptake and relatively fast clearance and excretion from the health tissues, which impart the platform promising for in vivo application. The biocompatibility of the nanotool, the stability of the prodrug and the active drug release profile would be evaluated, followed by its dose- and time-dependent therapeutic potential on tumour treatment. We expect that this novel on-demand prodrug activation platform would enable significant improvements to the existing cancer treatment regimes in the near future.