Cellular uptake of magnetic nanoparticle is mediated through energy-dependent endocytosis in A549 cells

• DOI: 10.4142/jvs.2006.7.4.321
• Publication Date: 2011-08-18T07:59:33Z
• Authors: Jun-Sung Kim; Tae-Jong Yoon; Kyeong-Nam Yu; Mi Suk Noh; Minah Woo; Byung-Geol Kim; Kee-Ho Lee; Byung-Hyuk Sohn; Seung-Bum Park; Jin-Kyu Lee; Myung-Haing Cho
• Keywords: Sucrose; Lung Neoplasms; Microscopy, Confocal; Temperature; Biocompatible Materials; Endosomes; 02 engineering and technology; Endocytosis; 3. Good health; Drug Delivery Systems; Microscopy, Electron, Transmission; Cell Line, Tumor; Humans; Nanoparticles; Original Article; Macrolides; Sodium Azide; 0210 nano-technology

Biocompatible silica-overcoated magnetic nanoparticles containing an organic fluorescence dye, rhodamine B isothiocyanate (RITC), within a silica shell [50 nm size, MNP@SiO2(RITC)s] were synthesized. For future application of the MNP@SiO2(RITC)s into diverse areas of research such as drug or gene delivery, bioimaging, and biosensors, detailed information of the cellular uptake process of the nanoparticles is essential. Thus, this study was performed to elucidate the precise mechanism by which the lung cancer cells uptake the magnetic nanoparticles. Lung cells were chosen for this study because inhalation is the most likely route of exposure and lung cancer cells were also found to uptake magnetic nanoparticles rapidly in preliminary experiments. The lung cells were pretreated with different metabolic inhibitors. Our results revealed that low temperature disturbed the uptake of magnetic nanoparticles into the cells. Metabolic inhibitors also prevented the delivery of the materials into cells. Use of TEM clearly demonstrated that uptake of the nanoparticles was mediated through endosomes. Taken together, our results demonstrate that magnetic nanoparticles can be internalized into the cells through an energy-dependent endosomal-lysosomal mechanism.