Preparation of CD3 Antibody-Conjugated, Graphene Oxide Coated Iron Nitride Magnetic Beads and Its Preliminary Application in T Cell Separation

Abstract

Immunomagnetic beads (IMBs) for cell sorting are universally used in medical and biological fields. At present, the IMBs on the market are ferrite coated with a silicon shell. Based on a new type of magnetic material, the graphene coated iron nitride magnetic particle (G@FeN-MP), which we previously reported, we prepared a novel IMB, a graphene oxide coated iron nitride immune magnetic bead (GO@FeN-IMBs), and explored its feasibility for cell sorting. First, the surface of the G@FeN-MP was oxidized to produce oxygen-containing groups as carboxyl, etc. by the optimized Hummers’ method, followed by a homogenization procedure to make the particles uniform in size and dispersive. The carboxy groups generated were then condensed and coupled with anti-CD3 antibodies by the carbodiimide method to produce an anti-CD3-GO@FeN-IMB after the coupling efficacy was proved by bovine serum albumin (BSA) and labeled antibodies. Finally, the anti-CD3-GO@FeN-IMBs were incubated with a cell mixture containing human T cells. With the aid of a magnetic stand, the T cells were successfully isolated from the cell mixture. The isolated T cells turned out to be intact and could proliferate with the activation of the IMBs. The results show that the G@FeN-MP can be modified for IMB preparation, and the anti-CD3-GO@FeN-IMBs we prepared can potentially separate T cells.