doi:10.1038/nindia.2016.12 Published online 27 January 2016
Researchers have synthesized pH-sensitive, folic-acid-conjugated magnetic nanoparticles that can efficiently deliver the anticancer drug doxorubicin to target cancer cells. These nanoparticles are also capable of killing cancer cells by generating heat when an external magnetic field is applied. Furthermore, they are useful as contrast agents for magnetic resonance imaging and hence could potentially be used for both cancer diagnosis and anticancer therapies1.
The researchers prepared the magnetic nanoparticles using ferric chloride and ferrous chloride solutions and modified them with polyacrylic acid. They coated the modified nanoparticles with folic acid so that they will bind to cancer cell membrane receptors that have an affinity for folic acid.
The folic-acid-coated nanoparticles permeated the membranes of cervical cancer cells more efficiently than normal cells. The nanoparticles released more doxorubicin at low pH levels than at the higher pH levels that prevail in physiological environments. This suggests that undesired drug release from the nanoparticles can be restricted.
The doxorubicin-modified nanoparticles generated heat when exposed to a magnetic field, and this heat killed almost 90% of the cancer cells. The combination of doxorubicin and heat shrank the nuclei and damaged the DNA of the cancer cells, triggering their controlled death.
“Besides enhancing therapeutic efficacy, the modified nanoparticles could protect anticancer drugs from degradation by enzymes in the bloodstream,” says lead researcher Dhirendra Bahadur.
1. Gupta, J. et al. A pH-responsive folate conjugated magnetic nanoparticle for targeted chemo-thermal therapy and MRI diagnosis. Dalton Trans. (2016) doi: 10.1039/C5DT04135J