Researchers design dual light- and enzyme-triggered AND-gate prodrugs for selective senolytic therapy

A newly developed dual-trigger AND-gate prodrug strategy improves senolytic payload selectivity by requiring both 390 nm light irradiation and endogenous β-galactosidase activity for activation.

In a study published in Advanced Science, researchers developed a sequential light-enzyme AND-gate activation strategy to address off-target effects of senolytics.

The platform utilizes an o-nitrobenzyl photocage that blocks β-galactoside cleavage by senescence-associated β-galactosidase (SA-β-gal) until the compound is exposed to 390 nm light.

The researchers evaluated the system using a doxorubicin prodrug (LS-D) and an ARV-771-based PROTAC (LS-A), both of which demonstrated higher senolytic indices than their parent compounds in vitro across multiple senescence models.

In ex vivo patient-derived organoids of senescent lung cancer, the combination of LS-D and light increased organoid death, while either treatment alone showed minimal effect.

Targeting SA-β-gal alone can lead to unintended activation in healthy tissues where the enzyme is naturally expressed.

Adding a physical trigger (light) to a biochemical trigger (β-galactoside cleavage) provides spatial and temporal control over senolytic payload delivery.

The successful deployment of this AND-gate system with a PROTAC (LS-A) demonstrates that complex molecular degraders can be adapted for highly controlled local senolysis.

This approach could influence the design of localized senolytic treatments, particularly for accessible tissues such as the skin or in surgical/endoscopic oncology settings.

The therapeutic utility of the platform is constrained by the limited tissue penetration of 390 nm light, meaning systemic administration for deep-tissue senescence will require alternative trigger technologies.

The development of dual-gated systems represents a competitive evolution against first-generation, single-biomarker senolytic prodrug platforms.

Preclinical in vivo evaluation to establish the safety, biodistribution, and light-activation feasibility of these AND-gate prodrugs in animal models.