Metal-Free CO-Releasing Compounds with pH and ROS Triggers

The patent employs pH-sensitive and oxidation-sensitive triggers that change the molecular parameters of CO-releasing compounds in response to physiological conditions. The compounds remain stable under normal conditions but undergo structural changes at elevated pH or high ROS levels, enabling controlled CO release specifically at disease sites such as inflammatory tissues and cancer cells.

The patent creates compounds with different stability profiles for different locations in the body. The CO-releasing molecules are designed to be stable in healthy tissues with normal pH and ROS levels, but become activated and release CO selectively in disease sites characterized by elevated pH and reactive oxygen species, thereby achieving local therapeutic effect without systemic toxicity.

The patent replaces expensive and potentially harmful metal-based CO prodrugs with organic, metal-free alternatives that achieve the same CO-release function through pH-sensitive and oxidation-sensitive mechanisms. These organic compounds are designed to be biocompatible, non-toxic, and capable of controlled CO release without the immunogenicity associated with metal-based systems.

The patent designs composite molecular structures that integrate CO-releasing moieties with pH-sensitive and oxidation-sensitive trigger groups. These composite molecules combine multiple functional elements into a single molecular entity, enabling responsive CO release through physiological stimuli while maintaining reasonable molecular complexity for drug development and synthesis.