Linker-free conjugation and specific cell targeting of antibody functionalized iron-oxide nanoparticles

Abstract

Specific targeting is a key step to realize the full potential of iron oxide nanoparticles in biomedical applications, especially tumor-associated diagnosis and therapy. Here, we developed anti-GD2 antibody conjugated iron oxide nanoparticles for highly efficient neuroblastoma cell targeting. The antibody conjugation was achieved through an easy, linker-free method based on catechol reactions. The targeting efficiency and specificity of the antibody-conjugated nanoparticles to GD2-positive neuroblastoma cells were confirmed by flow cytometry, fluorescence microscopy, Prussian blue staining and transmission electron microscopy. These detailed studies indicated that the receptor-recognition capability of the antibody was fully retained after conjugation and the conjugated nanoparticles quickly attached to GD2-positive cells within four hours. Interestingly, longer treatment (12 h) led the cell membrane-bound nanoparticles to be internalized into cytosol, either by directly penetrating the cell membrane or escaping from the endosomes. Last but importantly, the uniquely designed functional surfaces of the nanoparticles allow easy conjugation of other bioactive molecules.

The responses of immune cells to iron oxide nanoparticles

“…The as-synthesized NPs were transferred from organic solvents to aqueous solution using a ligand exchange method (Xu et al, 2011(Xu et al, , 2014, where original hydrophobic coatings were replaced with hydrophilic ligands. Depending on the choice of the ligands, iron oxide NPs with selective surface functionalities and charges can be produced (Xu et al, 2011).…”

Anti-GD2 MABS and Next-Generation mAb-Based Agents for Cancer Therapy

“…Different nanoparticle formats that have been bioconjugated with anti-GD2 full size mAbs or Fab fragments include: liposomes, which have small diameter and are able to differentially accumulate and penetrate into solid tumors (with highly permeable capillaries) relative to normal tissue (with less permeable tight junctions) [121][122][123][124]; porous silica nanoparticles, which are inert, biodegradable, nontoxic and more stable due to uniform particle size [125]; gold nanorods and carbon nanotubes capable of absorbing near-infrared laser light leading to in vitro photothermal destruction of tumor cells [126,127]. ; and iron-based nanoparticles that enable direct delivery of drugs c arried by the nanoparticle [128].…”

Inorganic nanoparticles for biomedicine: where materials scientists meet medical research

“…Although targeting can also be achieved using small molecules, peptides, aptamers and other biomolecules [15], we focus in this section on the use of antibodies. Surface modifications of nanoparticle systems ranging from metal particles to polymer and micellar structures allows covalent attachment of antibodies via methods such as amide bonds using EDAC NHS chemistry [16][17][18], dopamine-mediated bonding [19], maleimide groups [20], disulfide bonds [21] and the use of a hydrazide alkyl linker [22]. Regardless of the linkage, the formation of a protein corona surrounding the nanoparticle is likely to take place, thereby blocking recognition of the functional groups.…”