(427g) Surface Modification of Bovine Red Blood Cells with Methoxypoly(Ethylene Glycol)

Methoxypolyethylene glycol
(mPEG) covalently bound to the surface of human red blood cells (hRBC) has been
shown to decrease immunological recognition of surface antigens.  Our goal is to similarly modify bovine
RBCs to reduce the demand on human blood donations needed for blood
transfusions.  We have modified the
surface of bovine red blood cells (bRBCs) with the succinimidyl ester of
methoxy poly(ethylene glycol) propionic acid (SPA-mPEG).  The oxygen binding properties of
PEGylated bRBCs remained unaltered with SPA-mPEG concentrations up to 4 mM when
reacted with bRBCs at a hematocrit of 12%.  Viscosity measurements of PEGylated bRBCs at a hematocrit of
40% show similar viscosities to hRBCs ~ 3 cp.  Studies on the meniscus packing in a capillary show some
altered deformability of PEGylated bRBCs, but blood flow through the capillary
appears to remain unhindered. Taken together, the results of this study
demonstrate the feasibility of PEGylating bRBCs to yield modified cells with
similar oxygen binding and flow properties similar to that of hRBCs.