Every year, billions of dollars are spent on the discovery of new pharmaceuticals or technologies that offer safer and more effective treatments for diseases and ailments. Controlled-release materials (CRMs) offer a way to drastically improve currently available medications by controlling when, where, and how rapidly the active pharmaceutical ingredient (API) is released. CRMs are largely based on organic polymers, lipids, and metallic nanoparticles that rely on diffusion processes for drug uptake and release; however, this often leads to inconsistent and low drug loadings and rapid uncontrollable release.

 

Our research group targets non-porous coordination polymers (assemblies derived from organic linkers and metal nodes) as CRMs due to their high drug-loading capabilities and their inherent tunable physicochemical properties. In our approach, the API is directly incorporated into the framework during the synthetic procedure, allowing for exceptional drug wt% composition of the material, which we denote as Therapeutic Coordination Polymers (TCPs).

 

Drug release from the TCPs is degradation-based, which is mainly controlled by the strength of the metal-ligand interactions. With this understanding, the drug release rates can be easily tuned by changing the combination of metal ions and organic linkers, offering significant control over the release kinetics when compared to traditional CRMs. Additionally, our materials exhibit stimuli-responsive drug release, where the TCPs can release their payload under changes in pH, chemical triggers, and more recently, light irradiation. Research in this area resulted in a series of TCPs that were recently patented by our group which exhibited high drug loadings (60-70 wt%), biocompatibility, and excellent tuneability of drug release rates over three orders of magnitude.