Excellent biocompatibility of semiconductor quantum dots encasedin multifunctional poly(N-isopropylacrylamide) nanoreservoirsand nuclear specific labeling of growing neurons

Quantum dots (QDs) have received attention for labeling biomolecules; however, toxicity of these nanostructures in the intracellular environment has prevented a biomedical breakthrough. Here we report biocompatibility of a QD based multifunctional system on neuronal cells. Moreover, the designed nanostructures bind with high affinity in the cell nucleus. Nucleus specific binding and enhanced biocompatibility, coupled with no deleterious effects on neurite outgrowth, even at high dosages ( 500 μ g / ml sphere conc.) suggest increased therapeutic potential of this system for specific targeting followed by controlled release of drugs in treating neurodegenerative disorders.