Hydrodynamic radii of ranibizumab, aflibercept and bevacizumab measured by time-resolved fluorescence anisotropy


Purpose: To measure the hydrodynamic radii of intravitreal anti-VEGF drugs ranibizumab, aflibercept and bevacizumab with \(\mu\)s time-resolved fluorescence anisotropy.

Methods: Ruthenium-based dye Ru(bpy)\(_2\)(mcbpy-O-Su-ester)(PF\(_6\))\(_2\), whose lifetime of several hundred nanoseconds is comparable to the rotational correlation time of these drugs in buffer, was used as a label. The hydrodynamic radii were calculated from the rotational correlation times of the Ru(bpy)\(_2\)(mcbpy-O-Su-ester)(PF\(_6\))\(_2\)-labelled drugs obtained with time-resolved fluorescence anisotropy measurements in buffer/glycerol solutions of varying viscosity.

Results: The measured radii of 2.76\(\pm\)0.04 nm for ranibizumab,