Polymeric particles

1 . Monodisperse coated hydrogel polymer particles comprising 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; and a coating; 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; and wherein the coating comprises an organic coating formed from at least one epoxide monomer or comprises silica.

2 . The polymer particles of claim 1 , 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 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 ether-, polyether comprising 2 to 100 C 2 -C 3 ether units.

3 . The polymer particles of claim 1 , wherein R 6 is (CH 2 ) r (OCH 2 CH 2 ) n O(CH 2 ) s , wherein r and s are each independently 2 or 3, and n is an integer from 1 to 100.

4 . The polymer particles of claim 1 , wherein the polymer particles have an average diameter of from 0.5 μm to 10 μm, and/or wherein the coefficient of variation (CV) is less than 20%.

5 . The polymer particles of claim 1 , wherein the hydrophilic vinylic monomer is selected from or comprises acrylamide, methacrylamide, hydroxymethyl acrylamide, [tris(hydroxymethyl)methyl]acrylamide, (3-aminopropyl)methacrylamide, and 2-hydroxyethyl methacrylamide.

6 . 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, NN the number of nitrogen atoms, and No the number of oxygen atoms in said hydrophilic vinylic monomer;

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

7 . The polymer particles of claim 1 , wherein the crosslinker 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, N,N-bis(2-acrylamidoethyl)acrylamide, 1,2-dihydroxy bis-acrylamide, or polyethyleneglycol diacrylamide with a molecular weight MW≤2000 and.

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

9 . The polymer particles of claim 1 , wherein the polymer comprises pores.

10 . The polymer particles of claim 9 , wherein the pores provide a polymer with a level of porosity of 40% to 95%.