Cellular uptake of fluorophore-labeled glyco-DNA–gold nanoparticles

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2013-10, Vol.15 (10), p.1-12, Article 1992
• Main Authors: Witten, Katrin G., Ruff, Julie, Mohr, Anne, Görtz, Dieter, Recker, Tobias, Rinis, Natalie, Rech, Claudia, Elling, Lothar, Müller-Newen, Gerhard, Simon, Ulrich
• Format: Article
• Language: English
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cross-disciplinary physics: materials science; rheology; Deoxyribonucleic acid; DNA; Electronics; Exact sciences and technology; Fluorescence microscopy; Inorganic Chemistry; Lasers; Materials Science; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanotechnology; Optical Devices; Optics; Optoelectronic devices; Photonics; Physical Chemistry; Physics; Research Paper; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-013-1992-8

DNA-functionalized gold nanoparticles (AuNP–DNA) were hybridized with complementary di - N -acetyllactosamine-( di -LacNAc, [3Gal(β1-4)GlcNAc(β1-]2)-modified oligonucleotides to form glycol-functionalized particles, AuNP–DNA– di -LacNAc. While AuNP–DNA are known to be taken up by cells via scavenger receptors, glycol-functionalized particles have shown to be taken up via asialoglycoprotein receptors (ASGP-R). In this work, the interaction of these new particles with HepG2 cells was analyzed, which express scavenger receptors class B type I (SR-BI) and ASGP-R. To study the contribution of these receptors as potential mediators for cellular uptake, receptor-blocking experiments were performed with d -lactose, a ligand for ASGP-R, Fucoidan, a putative ligand for SR-BI, and a SR-BI blocking antibody. Labeling with Cy5-modified DNA ligands enabled us to monitor the particle uptake by confocal fluorescence microscopy and flow cytometry, in order to discriminate the two putative pathways by competitive binding studies. While SR-BI-antibody and d -lactose had no inhibiting effects on particle uptake Fucoidan led to a complete inhibition. Thus, a receptor-mediated uptake by the two receptors studied could not be proven and therefore other uptake mechanisms have to be considered.