Isolation of cells or the like from bodily fluids

A method of providing beads adapted to the efficient isolation of cells from a bodily fluid or the like, which method comprises:

• providing spheroidal substrates having a size between about 5 μm and about 1000 μm,
• covering the entire outer surfaces of said substrates with a hydrophilic hydrogel prepolymer coating, which is an isocyanate-functional polymer containing residues of polyoxyalkylene diol and/or polyol reactants that are prepolymerized by urethane bonding to diisocyante and/or polyisocyanate molecules,
• binding sequestering agents directly or indirectly to said hydrogel via the isocyanate groups so that said sequestering agents retain their native 3-dimensional configuration and are present at least at or near exterior boundaries of said hydrogel coatings where they can contact and bind with ligands on the surfaces of target cells of interest, and
• completing polymerization of said coated prepolymer.

A method of providing beads adapted to the efficient isolation of cells from a bodily fluid or the like, which method comprises:

• providing a prepolymer in the form of an isocyanate-functional polymer that contains residues of PEG, PPG or a copolymer thereof having a MW between about 2,000 and 7,000 which residues are linked by urethane bonds to isocyanates, and that contains at least about 0.2 meq. of active isocyanate per gram,
• mixing sequestering agents or intermediate linkers with said prepolymer under conditions which cause said agents or linkers to covalently bind with isocyanate groups,
• forming said prepolymer mixture into spheroidal beads having a size between about 5 μm and about 500 μm, and
• optionally linking sequestering agents with said linkers when intermediate linkers are used,
• whereby the entire outer surface of said beads is a hydrophilic hydrogel where sequestering agents are present that retain their native 3-dimensional configuration so that they can contact and bind with ligands on the surfaces of target cells of interest.