Chromatography of living cells using supermacroporous hydrogels, cryogels

The preparative cell separation is an intrinsic requirement of various diagnostic, biotechnological and biomedical applications. Affinity chromatography is a promising technique for cell separation and is based on the interaction between a cell surface receptor and an immobilised ligand. Most of the currently available matrices have pore size smaller than the size of the cells and are not suitable for cell chromatography due to column clogging. Another problem encountered in chromatographic separation of cells is a difficulty to elute bound cells from affinity surfaces. Application of novel adsorbents, supermacroporous monolithic cryogels, allows overcoming these problems. Cryogels are characterised by highly interconnected large (10-100 microm) pores, sponge-like morphology and high elasticity. They are easily derivatised with any ligand of choice. Convective migration can be used to transport the cells through the matrix. Target cells bind to affinity ligands, while other cells pass through the cryogel column non-retained and are removed during a washing step. Because of the spongy and elastic nature of the cryogel matrices, the cells are efficiently desorbed by mechanical compression of cryogels, which provides high cell viability and yields. The release of affinity bound cells by mechanical compression of a cryogel monolithic adsorbent is a unique and efficient way of cell detachment. This detachment strategy and the continuous macroporous structure make cryogels very attractive for application in cell separation chromatography.