1 research outputs found
Recognition of Dextran–Superparamagnetic Iron Oxide Nanoparticle Conjugates (Feridex) via Macrophage Scavenger Receptor Charged Domains
Dextran-coated superparamagnetic iron oxide nanoparticles
(dextran–SPIO
conjugates) offer the attractive possibility of enhancing MRI imaging
sensitivity so that small or diffuse lesions can be detected. However,
systemically injected SPIOs are rapidly removed by macrophages. We
engineered embryonic cells (HEK293T) to express major macrophage scavenger
receptor (SR) subtypes including SR-AI, MARCO, and endothelial receptor
collectin-12. These SRs possess a positively charged collagen-like
(CL) domain and they promoted SPIO uptake, while the charge neutral
lipoprotein receptor SR-BI did not. In silico modeling indicated a
positive net charge on the CL domain and a net negative charge on
the cysteine-rich (CR) domain of MARCO and SR-AI. In vitro experiments
revealed that CR domain deletion in SR-AI boosted uptake of SPIO 3-fold,
while deletion of MARCO’s CR domain abolished this uptake.
These data suggest that future studies might productively focus on
the validation and further exploration of SR charge fields in SPIO
recognition