Sulfated glycopolymers were synthesized from diisocyanates and lactose containing diamines. Blood compatibility assays indicated highly sulfated glycopolymers with methylene bis(4-cyclohexyl isocyanate) backbones result in prolonged clotting times.

Abstract-

A lactose-containing monomer, N-(2-lactosylethyl)acrylamide, was synthesized and polymerized with N-hydroxyethyl acrylamide and 1 wt % of N, N'-methylenebis(acrylamide) and potassium persulfate as the initiator to produce hydrogels. The weight percent of N-(2-lactosylethyl)acrylamide were increased from 0 to 100% in increments of 10%. Hydrogels were successfully produced with up to 90 wt % of N-(2-lactosylethyl)acrylamide. Gelation was confirmed by inverted vial tests and rheology measurements. The as-prepared hydrogels were used for papain stabilization against heat burden and papain that was loaded into hydrogels showed 45% more activity after heating as compared to papain that was heated without hydrogel stabilization. This hydrogel stabilization technique has potential applications in preserving enzyme activity.

The tripodal amine chelate with two pyridyl groups and an α-hydroxy acid (AHA) group, Pyr-TPA-AHA, was synthesized. Different Fe(III) complexes form with this chelate depending upon the counterion of the Fe(III) source used in the synthesis. A dinuclear complex, Fe(III)(Pyr-TPA-AHA)(μ-O), 1, and mononuclear complexes Fe(III)(Pyr-TPA-AHA)X (X = Cl or Br, 2 and 3, respectively) were synthesized. 2 can be easily converted to 1 by addition of silver nitrate or a large excess of water. The structure of 1 was solved by X-ray crystallography (CHNOFe·13HO, a = 14.1236(6) Å, b = 14.1236(6) Å, c = 21.7469(15) Å, α = β = γ = 90°, tetragonal, P422, Z = 4). 2 and 3 each have simple quasireversible cyclic voltammograms with E (vs aqueous Ag/AgCl) = +135 mV for 2 and +470 for 3 in acetonitrile. The cyclic voltammogram for 1 in acetonitrile has a quasireversible feature at E = -285 mV and an irreversible cathodic feature at -1140 mV. All three complexes are photochemically active upon irradiation with UV light, resulting in cleavage of the AHA group and reduction of the iron to Fe(II). Photolysis of 1 results in reduction of both Fe(III) ions in the dinuclear complex for each AHA group that is cleaved, while photolysis of 2 and 3 results in reduction of a single Fe(III) for each AHA cleavage. The quantum yields for 2 and 3 are significantly higher than that of 1.