Biocompatible polymeric monoliths for protein and peptide separations

The concept of biocompatibility with reference to chromatographic stationary phases for separation of biomolecules (including proteins and peptides) is introduced. Biocompatible is a characteristic that indicates resistance to nonspecific adsorption of biomolecules and preservation of their structures and biochemical functions. Two types of biocompatible polymeric monoliths [i.e., polyacrylamide and poly(meth)acrylate-based monoliths] used for protein and peptide separations are reviewed in detail, with emphasis on size exclusion, ion exchange, and hydrophobic interaction chromatographic modes. Biocompatible monoliths for enzyme reactors are also included. The two main synthetic approaches to produce biocompatible monoliths are summarized, i.e., surface modification of a monolith that is not inherently biocompatible and direct copolymerization of hydrophilic monomers to form a biocompatible monolith directly. Integration of polyethylene glycol into the poly(meth)acrylate monolith network is becoming popular for reduction of non-specific protein interactions.