High stability porous metal oxide spherules used for one-step antibody purifications
The present invention describes the use of porous metal oxides for the preparative purification of antibodies and biomolecules within a range of particle physical characteristics. Typically, particles from 15 to 100 microns in average diameter with pores sizes ranging from 400 to 600 angstroms and surface areas from 10 to 50 square meters per gram, and pore volumes from 0.1 to 0.4 mL/gram can be used for purification processes. The metal oxide particles that fall within this range of physical properties show enhanced utility and greater chromatographic capacity for antibodies than materials oxide particles falling outside of this range. Metal oxides such as zirconia, titania and alumina can all be modified with a multi-Lewis base moiety such as an organophosphate ethylenediamine-N,N-tetra(methylenephosphonic) acid (EDTPA), to produce a bio-compatible purification media for, biomolecules.
1. A chromatographic material comprising:
a porous metal oxide particle having a diameter of about 15 to 100 microns, a surface area of about 10 to 50 m.sup.2/g, and a pore size of about 200 to 600 Å; and
a multi-Lewis base moiety incorporated onto the surface of the particle, wherein the multi-Lewis base moiety is an amount sufficient enough to impart cation-exchange characteristics to the particle for separations.
2. The chromatographic material of claim 1 , wherein the porous metal oxide comprises a material selected from the group consisting of zirconia, titania, and alumina.
3. The chromatographic material of claim 1 , wherein the multi-Lewis base moiety is a phosphate.
4. The chromatographic material of claim 3 , wherein the phosphate comprises about 0.5 to 15% by weight of the chromatographic material.
5. The chromatographic material of claim 3 , wherein the phosphate is derived from phosphoric acid.
6. The chromatographic material of claim 3 , wherein the phosphate is an inorganic phosphate.
7. The chromatographic material of claim 1 , wherein the multi-Lewis base moiety is ethylenediamine-N,N-tetra(methylenephosphonic acid).
8. The chromatographic material of claim 1 , wherein the chromatographic material is substantially stable in an aqueous solution of a pH of about 1 to 14.
9. The chromatographic material of claim 1 , wherein the porous metal oxide particle is a spherule.