A team of researchers from NYU Abu Dhabi's (NYUAD) chemistry program and colleagues from the University's biology program have developed and studied the biological activity of five new metal-organic hybrid knotted molecules termed metal-organic trefoil knots (M-TKs). These molecules can effectively deliver metals to cancer cells, demonstrating the potential to act as a new category of anti-cancer agents.

Research scientists from NYUAD, Farah Benyettou and Thirumurugan Prakasam from the Trabolsi Research Group, led by NYUAD Associate Professor of Chemistry Ali Trabolsi Have reported that this nanoscale, water-soluble M-TKs revealed high potency in vitro against six cancer cell lines and in vivo in zebrafish embryos. Zebrafish-related studies were performed by NYUAD Postdoctoral Associate Anjana Ramdas Nair from the Sadler Lab. The team published the results of the research in the journal Chemical Science.

Generated by metal-templated self-assembly of a simple pair of chelating ligands, the M-TKs was well tolerated in vitro by non-cancer cells but were significantly more potent than cisplatin, a conventional chemotherapy medication in both human cancer cells, including those that were cisplatin-resistant, and in zebrafish embryos. In cultured cells, M-TKs introduce reactive oxygen species (ROS) that damage the mitochondria of cancer cells, but not the nuclear DNA or the plasma membrane.

According to Trabolsi, the cytotoxicity and ample scope for structural variation of M-TKs indicate the potential of synthetic metal-organic knots as a new field of chemical space for pharmaceutical design and development. Explaining further, Trabolsi noted that there is a significant promise for developing new cancer therapies that can complement the existing chemotherapy options that are currently used to treat nearly half of all cancer patients undergoing chemotherapy.

The NYUAD Research explained that the NYUAD Research Scientist Thirumurugan Prakasam synthesized the M-TKs from the Trabolsi Research Group and discovered, in many cases, to have a higher potency than has been previously reported in cisplatin and other metal complexes.

Scientist Farah Benyettou said that the main delivery routes were macropinocytosis and both caveolin and clathrin-mediated endocytosis, which are all more active in cancer cells than in healthy cells. Cisplatin and other small molecules penetrate cells by diffusion, which is less cancer-selective in vitro. The team hypothesized that the molecules they have developed are less toxic to healthy cells because they are internalized less.

Moving forward in developing M-TKs, research efforts will focus on the mechanism of action of the M-TKs to determine whether their ROS-mediated toxicity involves specific intracellular targets.

The confirmation of these findings is the viability of studying the effects of these compounds in whole vertebrates, as the M-TKs were well tolerated by zebrafish and appeared to attack dividing cells selectively.