Aim, shoot, kill pancreatic cancer
doi:10.1038/nindia.2011.45 Published online 30 March 2011
Researchers have designed new polymer nanoparticles that could selectively target and image pancreatic cancer cells. The nanoparticles could also be used to deliver drug molecules to target cancer cells.
In recent years, polyethylene glycol (PEG) has been used to prepare biocompatible and biodegradable polymer nanoparticles. The principal goal is to use PEG nanoparticles for biomedical applications such as drug delivery and tissue engineering. However, PEG nanoparticles are devoid of any reactive group on their surfaces, making them unsuitable for targeted tumour imaging and drug delivery.
To devise new layered polymer nanoparticles with reactive groups on their surfaces, the researchers produced PEG nanoparticles with inner cores of poly(lactide-coglycolide) (PLGA) tagged with a fluorescent dye. They then modified the nanoparticle surfaces using a cyclic peptide comprised of amino acids. The researchers wanted to discover the efficacy of these nanoparticles as selective imagers and drug carriers for pancreatic cancer, which is still incurable.
The peptide demonstrated an affinity for integrin, a cell surface protein that helps build the network of cancer cells. Thus, to find out the role of the peptide, the researchers cultured their nanoparticles with a specific type of brain tumour cells that contained integrin. The fluorescent polymer nanoparticles showed enhanced entry into the tumour cells. The researchers then carried out experiments to test how their nanoparticles behaved in the presence of pancreatic cancer cells.
Strong and stable fluorescence was maintained at the tumour site for several days, indicating that the high density of PEG in the nanoparticles may contribute to the long circulation time and subsequent targeting of the tumour site. The nanoparticles caused no apparent toxicity to blood composition in terms of liver and kidney functions.
"Because of the hydrophobic core formed by PLGA, most of the lipophilic anti-tumour drugs or other reagents can be encapsulated into the core of these nanoparticles," says Indrajit Roy, one of the researchers.
The authors of this work are from: The State University of New York, Buffalo, USA, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore and Department of Chemistry, University of Delhi, Delhi, India.