Copolymerization of 2,3-Dihydropyran and Ethyl Vinyl Ether with Maleic Anhydride

Sequence-Controlled Polyurethane Block Copolymer Displays Differentiated Immunoglobulin-G Adsorption That Influences Human Monocyte Adhesion and Activity

The ability to specify an adsorbed protein layer through the polymer chemistry design of immunomodulatory biomaterials is important when considering a desired immune response, such as reducing pro-inflammatory activity. Limited work has been undertaken to elucidate the role of monomer sequence in this process, when copolymeric systems are involved. In this study, we demonstrate the advantage of an alternating radical copolymerization strategy as opposed to a random statistical copolymerization to order monomers in the synthesis of degradable polar-hydrophobic-ionic polyurethanes (D-PHI), biomaterials originally designed to reduce inflammatory monocyte activation. A monomer system consisting of a vinyl-terminated polyurethane cross-linker, maleic acid (MA), and ethyl vinyl ether (EVE), not only generated a diverse chemical environment of polar, hydrophobic, and ionic functional groups, but also formed a charge transfer complex (CTC) reactive to alternating polymerizations. Conversion of MA and EVE occurred in a constant proportion regardless of monomer availability, a phenomenon not observed in conventional D-PHI formulations. For feeds with unequal molar quantities of MA and EVE, the final conversion was limited and proportional to the limiting reagent, leading to an overall higher polyurethane cross-linker content. The presence of a reactive CTC was also found to limit the monomer conversion. Compared to a D-PHI with random monomer arrangement using methacrylic acid (MAA) and methyl methacrylate (MMA), a reduction in Fab region exposure from adsorbed immunoglobulin G and a reduction in average adherent monocyte activity were found in the sequence-controlled version. These results represent the first example of using an alternating copolymerization approach to generate regularly defined polymer chemistries in radical chain-growth biomaterials for achieving immunomodulation, and highlight the importance of considering sequence control as a design strategy for future immunomodulatory biomaterial development.

Partial Esters of Alternating Copolymers of Maleic Anhydride and Alkyl Vinyl Ethers for Pharmaceutical Applications

The synthesis, characterization, and reactivity of alternating copolymers of maleic anhydride (MA) with new vinyl ethers of mono-O-methyl oligoethylene glycol (MePegnVE, degree of oligomerization n = 1-4) are described. The linear MA/PegnVE copolymers were partially esterified with alcohols such as methanol, ethanol, n-butanol, methoxyethanol, and n- dodecanol. Depending upon the nature of the two reactive components, the degree of esterification was between 10 and 70%. Semiquantitative indications on the relative reactivity of both polymeric materials and alcohols are pro vided. The potential of this new class of functional polymers is to provide am phiphilic polymeric ionomers as candidates for drug controlled release, based on their biocompatibility.