Determination of the Serum Concentrations of the Monoclonal Antibodies Bevacizumab, Rituximab, and Panitumumab Using Porous Membranes Containing Immobilized Peptide Mimotopes

Effective monoclonal antibody (mAb)
therapies require a threshold
mAb concentration in patient serum. Moreover, the serum concentration
of the mAb Bevacizumab should reside in a specific range to avoid
side effects. Methods for conveniently determining the levels of mAbs
in patient sera could allow for personalized dosage schedules that
lead to more successful treatments. This work utilizes microporous
nylon membranes functionalized with antibody-binding peptides to capture
Bevacizumab, Rituximab, or Panitumumab from diluted (25%) serum. Modification
of the capture-peptide terminus is often crucial to creating the affinity
necessary for effective binding. The high purity of eluted mAbs allows
for their quantitation using native fluorescence, and membranes are
effective in spin devices that can be used in any laboratory. The
technique is effective over the therapeutic range of Bevacizumab concentrations.
Future work aims at further modifications to develop rapid point-of-care
devices and decrease detection limits.