Researchers develop novel nanoparticle that efficiently and selectively kills cancer cells

Many chemotherapeutic agents used to treat cancers are associated with side-effects of varying severity, because they are toxic to normal cells as well as malignant tumors. This has motivated the search for effective alternatives to the synthetic pharmaceuticals with which most cancers are currently treated.

The use of calcium phosphate and citrate for this purpose has been under discussion for some years now, since they lead to cell death when delivered directly into cells, while their presence in the circulation has little or no toxic effect. The problem consists in finding ways to overcome the mechanisms that control the uptake of these compounds into cells, and ensuring that the compounds act selectively on the cells one wishes to eliminate.

Researchers in the Department of Chemistry at LMU, led by Dr. Constantin von Schirnding, Dr. Hanna Engelke and Prof. Thomas Bein, now report the development of a class of novel amorphous nanoparticles made up of calcium and citrate, which are capable of breaching the barriers to uptake, and killing tumor cells in a targeted fashion.

Both calcium phosphate and citrate are involved in the regulation of many cellular signaling pathways. Hence, the levels of these substances present in the cytoplasm are tightly controlled, in order to avoid disruption of these pathways.

Crucially, the nanoparticles described in the new study are able to bypass these regulatory controls. "We have prepared amorphous and porous nanoparticles consisting of calcium phosphate and citrate, which are encapsulated in a lipid layer," von Schirnding explains. The encapsulation ensures that these particles are readily taken up by cells without triggering countermeasures.