Mixed-Mode Chromatography Membranes

Abstract

Described are composite materials and methods of using them for mixed-mode chromatography. In certain embodiments, the composite material comprises a support member, comprising a plurality of pores extending through the support member; and a multi-functional cross-linked gel. The multi-functional cross-linked gel possesses at least two of the following functions or characteristics: cationic, anionic, hydrophobic, hydrophilic, thiophilic, hydrogen bond donating, hydrogen bond accepting, pi-pi bond donating, pi-pi bond accepting, or metal chelating. The composite materials may be used in the separation or purification of a biological molecule or biological ion.

We claim: 
     
         1 . A composite material, comprising:
 a support member, comprising a plurality of pores extending through the support member; and   a cross-linked gel, wherein the cross-linked gel comprises a first functionality and a second functionality; the first functionality and the second functionality are cationic, anionic, hydrophobic, hydrophilic, thiophilic, hydrogen bond donating, hydrogen bond accepting, pi-pi bond donating, pi-pi bond accepting, or metal chelating; and the first functionality is different from the second functionality;   wherein the cross-linked gel is located in the pores of the support member.   
     
     
         2 . The composite material of  claim 1 , wherein the cross-linked gel is macroporous. 
     
     
         3 . The composite material of  claim 1 , wherein the cross-linked gel comprises a polymer derived from 2-(diethylamino)ethyl methacrylate, 2-aminoethyl methacrylate, 2-carboxyethyl acrylate, 2-(methylthio)ethyl methacrylate, acrylamide, N-acryloxysuccinimide, butyl acrylate or methacrylate, N,N-diethylacrylamide, N,N-dimethylacrylamide, 2-(N,N-dimethylamino)ethyl acrylate or methacrylate, N-[3-(N,N-dimethylamino)propyl]methacrylamide, N,N-dimethylacrylamide, ethyl acrylate or methacrylate, 2-ethylhexyl methacrylate, hydroxypropyl methacrylate, glycidyl acrylate or methacrylate, ethylene glycol phenyl ether methacrylate, methacrylamide, methacrylic anhydride, propyl acrylate or methacrylate, N-isopropylacrylamide, styrene, 4-vinylpyridine, vinylsulfonic acid, N-vinyl-2-pyrrolidinone (VP), acrylamido-2-methyl-1-propanesulfonic acid, styrenesulfonic acid, alginic acid, (3-acrylamidopropyl)trimethylammonium halide, diallyldimethylammonium halide, 4-vinyl-N-methylpyridinium halide, vinylbenzyl-N-trimethylammonium halide, methacryloxyethyltrimethylammonium halide, 3-sulfopropyl methacrylate, 2-(2-methoxy)ethyl acrylate or methacrylate, hydroxyethyl acrylamide, N-(3-methoxypropyl acrylamide), N-[tris(hydroxymethyl)methyl]acrylamide, N-phenyl acrylamide, N-tert-butyl acrylamide, or diacetone acrylamide. 
     
     
         4 . The composite material of  claim 1 , wherein the cross-linked gel comprises a polymer derived from more than one monomer. 
     
     
         5 . The composite material of  claim 2 , wherein the average pore diameter of the macropores is about 25 nm to about 1500 nm. 
     
     
         6 . The composite material of  claim 1 , wherein the composite material is a membrane. 
     
     
         7 . A method, comprising the step of:
 contacting at a first flow rate a first fluid comprising a substance with a composite material of  claim 1 , thereby adsorbing or absorbing a portion of the substance onto the composite material.   
     
     
         8 . The method of  claim 7 , wherein the first fluid further comprises a fragmented antibody, aggregated antibodies, a host cell protein, a polynucleotide, an endotoxin, or a virus. 
     
     
         9 . The method of  claim 7 , wherein the substance is a biological molecule or biological ion. 
     
     
         10 . The method of  claim 9 , wherein the biological molecule or biological ion is selected from the group consisting of albumins, lysozyme, viruses, cells, γ-globulins of human and animal origins, immunoglobulins of human and animal origins, proteins of recombinant and natural origins, polypeptides of synthetic and natural origins, interleukin-2 and its receptor, enzymes, monoclonal antibodies, trypsin and its inhibitor, cytochrome C, myoglobin, myoglobulin, α-chymotrypsinogen, recombinant human interleukin, recombinant fusion protein, nucleic acid derived products, DNA of synthetic and natural origins, and RNA of synthetic and natural origins. 
     
     
         11 . The method of  claim 1 , wherein the first fluid is a clarified cell culture supernatant. 
     
     
         12 . A method, comprising the step of:
 contacting at a first flow rate a first fluid comprising a substance and an unwanted material with a composite material of  claim 1 , thereby adsorbing or absorbing a portion of the unwanted material onto the composite material.   
     
     
         13 . The method of  claim 12 , wherein the unwanted material comprises a fragmented antibody, aggregated antibodies, a host cell protein, a polynucleotide, an endotoxin, or a virus. 
     
     
         14 . The method of  claim 12 , wherein substantially all of the unwanted material is adsorbed or absorbed onto the composite material. 
     
     
         15 . The method of  claim 12 , wherein the substance is a biological molecule or biological ion. 
     
     
         16 . The method of  claim 15 , wherein the biological molecule or biological ion is selected from the group consisting of albumins, lysozyme, viruses, cells, γ-globulins of human and animal origins, immunoglobulins of human and animal origins, proteins of recombinant and natural origins, polypeptides of synthetic and natural origins, interleukin-2 and its receptor, enzymes, monoclonal antibodies, trypsin and its inhibitor, cytochrome C, myoglobin, myoglobulin, α-chymotrypsinogen, recombinant human interleukin, recombinant fusion protein, nucleic acid derived products, DNA of synthetic and natural origins, and RNA of synthetic and natural origins. 
     
     
         17 . The method of  claim 12 , wherein the first fluid is a clarified cell culture supernatant. 
     
     
         18 . A method of making a composite material of  claim 1 , comprising the steps of:
 combining a first monomer, a photoinitiator, a cross-linking agent, and a solvent, thereby forming a monomeric mixture;   contacting a support member with the monomeric mixture, thereby forming a modified support member; wherein the support member comprises a plurality of pores extending through the support member, and the average pore diameter of the pores is about 0.1 to about 25 μm;   covering the modified support member with a polymeric sheet, thereby forming a covered support member; and   irradiating the covered support member for a period of time, thereby forming a composite material.