The biocompatibility of apoferritin-encapsulated PbS quantum dots

The biocompatibility of a nanocomposite based on a Pbs quantum dots (QD) entrapped in the hollow core of an apoferritin protein cage is examined. This offers a water-soluble hybrid construct with stable and tunable fluorescence emission at wavelengths larger than 1000nm. Native polyacrylamide gel-electrophoresis studies show that the PbS QDs do not alter the external surface of apoferritin or its migratory behavior. Apoferritin is obtained from ferritin molecules by reductive dissolution of its iron oxide core. MTT assays were performed on normal and cancer cell lines and recorded the cell viability after treatment with AFt-PbS at different concentrations and up to 72-hour. Cells were cultured under optimum conditions in RPMI nutrient medium supplemented with 10 fetal bovine serum, and subcultivated twice weekly to maintain logarithmic growth. Cells were seeded into 96-well microtiter plates at a density of 5 � 103 per well and allowed 24-hour to adhere before AFt, PbS QDs and AFt-PbS composites were introduced with final concentrations of QDs