Cattle protein tailors drug carrier
doi:10.1038/nindia.2012.58 Published online 25 April 2012
New research has shown that ionic surfactant-modified unfolded bovine serum albumin (BSA) could help yield BSA-coated gold nanoparticles. BSA-coated gold nanoparticles are biocompatible and could therefore be useful for ferrying drugs to target cells and even brain cells across the blood–brain barrier.
Although bare nanoparticles have toxic effects on biological cells, capping them with suitable chemical agents can endow them with biocompatible properties.
Bovine serum albumin is a biocompatible protein that is widely used in biological studies. To make BSA-coated gold nanoparticles, the researchers used several ionic surfactants to unfold the structure of BSA, thus exposing reduced amino acids such as cysteine to temperatures of 20–70 °C.
The researchers compared the biocompatibility and toxicity of BSA-conjugated gold nanoparticles with that of surfactant-conjugated nanoparticles in studies with human red blood cells and rat brain tumour cells. The BSA-conjugated nanoparticles showed almost negligible haemolysis — a process in which the membranes of red blood cells are ruptured, releasing haemoglobin. The BSA coating rendered the surface of nanoparticles completely passive; the surface of the nanoparticles never comes in contact with the red blood cells.
In contrast, nanoparticles capped and stabilized by the surfactant exhibited significant haemolysis. Unlike surfactant-capped nanoparticles, the BSA-conjugated nanoparticles did not exhibit toxic effects on rat brain tumour cells.
"Besides the drug-delivery potential of BSA-coated nanoparticles, the study shows that nanopollutants, given the affinity of nanoparticles towards albumin, can form a complex with serum albumin circulating in bloodstream and hence will not be toxic," says lead researcher Mandeep Singh Bakshi.
The authors of this work are from: Department of Chemistry, Wilfrid Laurier University, Science Building, West, Waterloo, and Nanotechnology Research Laboratory, College of North Atlantic, Labrador City, Canada, Department of Chemistry, BBK DAV College for Women, and Department of Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, and Department of Chemistry, Kachchh University, Kachchh, Gujarat, India.
Khullar, P. et al. Bovine serum albumin bioconjugated gold nanoparticles: synthesis, hemolysis, and cytotoxicity toward cancer cell lines. J. Phys. Chem. C 116, 8834-8843 (2012) | Article