Synthesis of lightly crosslinked zwitterionic polymer-based bioinspired adhesives for intestinal tissue sealing

In this report, we have developed a new bioinspired medical adhesive capable of providing a leak-proof barrier for application to intestinal anastomoses. The newly synthesized adhesive is a terpolymer possessing three different repeating units: (1) A zwitterionic polymer, poly(sulfobetaine methacrylate) (polySBMA), for increased hydrophilicity and biocompatibility, (2) a 3,4-dihydroxy-L-phenylalanine (DOPA) segment which contains the catechol group, and (3) poly(ethylene glycol) dimethacrylate (PEGDMA) for light crosslinking, which will be used to strengthen the polymer adhesion properties by providing debonding resistance. The chemical structure of the terpolymer, poly(N-methacryloyl-3,4-dihydroxyl-L-phenylalanine-co-sulfobetaine methacrylate-co-poly(ethylene glycol) dimethacrylate) (poly(MDOPA-co-SBMA-co-PEGDMA)), synthesized following a convenient and reproducible radical polymerization was clearly confirmed by H-1 NMR. The terpolymer adhesive displayed the optimal adhesion properties when containing 1.5-2.5 mol % of crosslinker, PEGDMA, according to the measured maximum adhesion strength and work of adhesion, characterized by lap shear strength tests utilizing porcine skin. The adhesive did not show cytotoxicity when tested with human embryonic kidney (HEK293A) cells. Ex vivo anastomosis experiments using porcine intestine demonstrated that the new poly(MDOPA-co-SBMA-co-PEGDMA) is a promising biomedical adhesive which successfully prevents leakage from the sutured intestinal tissue. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1564-1573