Novel superparamagnetic core-shell nanoparticles for magnetic targeted drug delivery and hyperthermia treatment

The last few decades have witnessed a tremendous increase in the interest to use ferrofluids and ferrofluid-drug conjugates in magnetically guided drug delivery in loco regional treatment of cancer/tumor. In this paper, experiments on iron oxide (maghemite, /spl gamma/-Fe/sub 2/O/sub 3/)-gold superparamagnetic core-shell nanoparticles conjugated to human serum albumin-drug complex are presented. Coating these nanoparticles with gold varies the shell thickness resulting in particles with overall diameter from 15 to 30 nm thus pushing the gold shell plasmon resonance to 700 - 800 nm region . This in turn makes these particles suitable for use in laser induced hyperthermia. These core shell particles were also coated with serum albumin proteins to make them more resistant to auto immune response. When coated with bovine or human serum albumin, these particles can be further complexed with drugs such as emodin, quercetin dihydrate (anti-cancer) and anti-inflammatory ibuprofen. Since both tumor and inflammatory tissues are known to have slightly acidic pH, unlike healthy tissues, it is shown that on changing the pH from 8 to 6.4, the native form of drugs can be released from the composite particles in situ, thus ensuring drug delivery on target.