Hand-ground nanoscale Zn^II -based coordination polymers derived from NSAIDs: Cell migration inhibition of human breast cancer cells

Abstract

Increased levels of intracellular prostaglandin E₂ (PGE₂) have been linked with the unregulated cancer cell migration that often leads to metastasis. Non-steroidal anti-inflammatory drugs (NSAIDs) are known inhibitors of cyclooxygenase (COX) enzymes, which are responsible for the increased PGE₂ concentration in inflamed as well as cancer cells. Here, we demonstrate that NSAID-derived Zn^II-based coordination polymers are able to inhibit cell migration of human breast cancer cells. Various NSAIDs were anchored to a series of 1D Zn^II coordination polymers through carboxylate–Zn coordination, and these structures were fully characterized by single-crystal X-ray diffraction. Hand grinding in a pestle and mortar resulted in the first reported example of nanoscale coordination polymers that were suitable for biological studies. Two such hand-ground nanoscale coordination polymers NCP1 a and NCP2 a, which contained naproxen (a well-studied NSAID), were successfully internalized by the human breast cancer cells MDA-MB-231, as was evident from cellular imaging by using a fluorescence microscope. They were able to kill the cancer cells (MTT assay) more efficiently than the corresponding mother drug naproxen, and most importantly, they significantly inhibited cancer cell migration thereby displaying anticancer activity.