Casual cell surface remodeling using biocompatible lipid-poly(ethylene glycol)(n):: Development of stealth cells and monitoring of cell membrane behavior in serum-supplemented conditions

Control of the cell surface allows modulation of the cell's biological response, producing practical applications and satisfying scientific interests. Consequently, to meet such goals and interests, diverse approaches were developed in cell surface engineering techniques. Poly(ethylene glycol) (PEG) intermediates were widely employed to modify proteins, enzymes, artificial surfaces, liposomes, and drugs for practical usage. PEGylation was also used for modification of cell surface properties. A method was recently developed for the rapid incorporation of proteins into mammalian cell membranes using lipid-PEG(n) derivatives under physiological conditions. This is a rapid and homogeneous method to incorporate lipid-PEG(n), which was used as a model to study the modification of cellular properties and cell-cell interactions. Because the stability of molecules incorporated into the cell surface shows the usefulness of the anchoring technique, it was also investigated whether potential factors such as time, the concentration of the incorporated lipid-PEG(n), and the type of medium affect this incorporation. At concentrations greater than 10 p,M, when dual typed lipid-PEG(n) was incorporated into erythrocytes, antigenic recognition was dramatically attenuated, resulting in the successful development of stealth cells. (C) 2004 Wiley Periodicals, Inc.