Polymeric particles

1. Monodisperse magnetic hydrogel polymer particles comprising a nanoparticulate magnetic material and a polymer formed from (a) a hydrophilic vinylic monomer having a log P oct/wat (log P) of less than about 0.6, wherein the hydrophilic vinylic monomer comprises at least one hydrophilic vinylic monomer selected from a monomer comprising —C(O)NH 2 , —C(O)NHCH 3 , —C(O)NHCH 2 CH 3 , or —C(O)N(CH 3 ) 2 ; and (b) a crosslinker comprising at least two vinyl groups, wherein the crosslinker comprises at least one compound of formula (IIa):

wherein R 6 is selected from —C 1 -C 6 alkyl-, —C 1 -C 6 heteroalkyl-, —C 1 -C 6 cycloalkyl-, —C 1 -C 6 hydroxyalkyl-, —C 1 -C 6 ether-, or polyether comprising 2 to 100 C 2 -C 3 ether units, and R 7 and R 8 are each independently selected from —H, —C 1 -C 6 alkyl, —C 1 -C 6 heteroalkyl, —C 3 -C 6 cycloalkyl, —C 1 -C 6 hydroxyalkyl, or —C 1 -C 6 ether; or R 7 and R 8 are joined together to form —C 1 -C 6 alkyl-, —C 1 -C 6 heteroalkyl-, —C 1 -C 6 cycloalkyl-, —C 1 -C 6 hydroxyalkyl-, —C 1 -C 6 ether-, polyether comprising 2 to 100 C 2 -C 3 ether units, wherein the polymer particle further comprises a coating, wherein the coating is a polymer coating formed from at least one epoxide monomer or comprises silica.

2. The polymer particles of claim 1 , wherein the hydrophilic vinylic monomer comprises a monomer having an R atom according to the following formula:

R

atom

=

N

C

N

N

+

N

O

wherein N C is the number of carbon atoms, N N the number of nitrogen atoms, and N O the number of oxygen atoms in said hydrophilic vinylic monomer;

wherein R atom <2.75, when said hydrophilic vinylic monomer is an acrylamide.

3. The polymer particles of claim 1 , wherein the hydrophilic vinylic monomer is selected from or comprises acrylamide, methacrylamide, and 2-hydroxyethyl methacrylamide.

4. The polymer particles of claim 1 , wherein the crosslinker has a log P value of less than about 1.

5. The polymer particles of claim 1 , wherein the crosslinker is or comprises N,N′-(1,2-dihydroxyethylene)bisacrylamide, N,N′-methylenebis(acrylamide), N,N′-ethylenebis(acrylamide), piperazine diacrylamide, N,N′-((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))diacrylamide, polyethyleneglycol diacrylamide with a molecular weight ≤2000, 4-Arm PEG-Acrylamide with a molecular weight ≤2000, and/or N,N-bis(2-acrylamidoethyl)acrylamide, 1,2-dihydroxy bis-acrylamide, N,N′-((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))diacrylamide, polyethyleneglycol diacrylamide with a molecular weight MW ≤2000 and 4-Arm PEG-Acrylamide with a molecular weight MW ≤2000, or N,N′-((ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl))diacrylamide.

6. The polymer particles of claim 1 , wherein the polymer comprises pores and the pores comprise at least a portion of the magnetic material, wherein the magnetic material is substantially located in the pores.

7. The polymer particles of claim 6 , wherein the pores provide a polymer with a level of porosity of 40% to 95%.

8. The polymer particles of claim 1 , wherein the magnetic material is a superparamagnetic material, a metal oxide or alloy; a ferromagnetic material, or superparamagnetic iron oxide crystals.