4.1. Materials

All starting materials were purchased from Sigma Aldrich (St. Louis, MO, USA), unless otherwise noted. DSPE-PEG₂₀₀₀-maleimide was purchased from Avanti Polar Lipids (Alabaster, AL, USA). Cy7-amine was purchased from the Lumiprobe corporation (Hunt Valley, MD, USA), and Cy7 mono-N-hydroxysuccinimide ester was purchased from GE Healthcare Life Sciences (Pittsburgh, PA, USA). Materials for cell culture, which include fetal bovine serum (FBS, Gibco, Gaithersburg, MD USA), penicillin-streptomycin (Gibco, USA), 2-mercaptoethanol (Gibco, USA), and PBS (Gibco, USA) were purchased from Thermo Fisher Scientific (Waltham, MA, USA). Dulbecco’s Modified Eagle’s Medium (DMEM) was purchased from Sigma Aldrich. WEHI-274.1 murine monocytes (ATCC# CRL-1679) were purchased from ATCC (Manassas, VA, USA) and subjected to mycoplasma testing.