5 research outputs found
Platinum-Triggered Bond-Cleavage of Pentynoyl Amide and N-Propargyl Handles for Drug-Activation.
The ability to create ways to control drug activation at specific tissues while sparing healthy tissues remains a major challenge. The administration of exogenous target-specific triggers offers the potential for traceless release of active drugs on tumor sites from antibody-drug conjugates (ADCs) and caged prodrugs. We have developed a metal-mediated bond-cleavage reaction that uses platinum complexes [K2PtCl4 or Cisplatin (CisPt)] for drug activation. Key to the success of the reaction is a water-promoted activation process that triggers the reactivity of the platinum complexes. Under these conditions, the decaging of pentynoyl tertiary amides and N-propargyls occurs rapidly in aqueous systems. In cells, the protected analogues of cytotoxic drugs 5-fluorouracil (5-FU) and monomethyl auristatin E (MMAE) are partially activated by nontoxic amounts of platinum salts. Additionally, a noninternalizing ADC built with a pentynoyl traceless linker that features a tertiary amide protected MMAE was also decaged in the presence of platinum salts for extracellular drug release in cancer cells. Finally, CisPt-mediated prodrug activation of a propargyl derivative of 5-FU was shown in a colorectal zebrafish xenograft model that led to significant reductions in tumor size. Overall, our results reveal a new metal-based cleavable reaction that expands the application of platinum complexes beyond those in catalysis and cancer therapy.EPSRC studentship for Benjamin Stenton
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Bioorthogonal Decaging Reactions for Targeted Drug Activation.
Bioorthogonal decaging reactions are highly selective transformations which involve the cleavage of a protecting group from a molecule of interest. Decaging reactions can be classified into subgroups depending on the nature of the trigger; they can be photo-, metal- or small molecule-triggered. Due to their highly selective and biocompatible nature, they can be carried out in living systems as they do not interfere with any endogenous processes. This gain-of-function allows controlled activation of proteins and release of fluorophores and drugs in vivo. Although there are many examples of fluorophore/protein release, this review focuses on the application of bioorthogonal decaging reactions for targeted drug activation. One strategy for targeted drug delivery is tissue-selective activation of prodrugs and antibody-drug conjugates (ADCs). Bioorthogonal decaging provides a highly selective, controllable method for activating prodrugs and ADCs, reducing toxicity due to the off-target drug release that occurs in endogenous activation strategies. Here we focus on the development of bifunctional linkers that enable studies of bioorthogonal chemistry for activation of ADCs