Therapeutic coordination polymers: tailoring drug release through metal-ligand interactions.

Developing tunable materials which exhibit sustained drug release is a considerable challenge. Herein, we report the concept of Therapeutic Coordination Polymers (TCPs); non-porous coordination polymers constructed from biocompatible components which demonstrate tunable zero-order drug release kinetics upon degradation of metal-ligand bonds. TCPs were constructed from three principal components: (i) a cationic metal center (M = Mg2+, Mn2+, Zn2+, or Cu2+); (ii) an anionic drug (Diclofenac); and (iii) an alkyl bis-imidazole organic ligand which behaves as a "linker" between metal centers. Most drug-release materials, such as amorphous polymer dispersions, or metal-organic frameworks rely on a diffusion-based mechanism for drug release, but the degradation-controlled release of drugs from non-porous one-periodic coordination polymers has been largely unexplored. TCPs described herein exhibit a high wt% of pharmaceutical (>62%), tailorable zero-order drug release rate kinetics which span over three orders of magnitude, and stimuli-responsive drug release behavior making them well suited for extended drug-release applications.

Natural Health Products (NHP's) and Natural Compounds as Therapeutic Agents for the Treatment of Cancer; Mechanisms of Anti-Cancer Activity of Natural Compounds and Overall Trends.

Most cancer therapeutics, such as tubulin-targeting chemotherapy drugs, cause cytotoxic, non-selective effects. These harmful side-effects drastically reduce the cancer patient's quality of life. Recently, researchers have focused their efforts on studying natural health products (NHP's) which have demonstrated the ability to selectively target cancer cells in cellular and animal models. However, the major hurdle of clinical validation remains. NHP's warrant further clinical investigation as a therapeutic option since they exhibit low toxicity, while retaining a selective effect. Additionally, they can sensitize cancerous cells to chemotherapy, which enhances the efficacy of chemotherapeutic drugs, indicating that they can be utilized as supplemental therapy. An additional area for further research is the investigation of drug-drug interactions between NHP's and chemotherapeutics. The objectives of this review are to report the most recent results from the field of anticancer NHP research, and to highlight the most recent advancements in possible supplemental therapeutic options.