A series of reversible triblock poly(amino acid)s hydrogels with tunable pH-responsivity (pH 3.5–10.0) were synthesized by adjusting the ratio of the blocks. Attributing to the good biodegradability and low cytotoxicity of these triblock poly(amino acid)s, it is obvious that these poly(amino acid)s are potential novel materials in drug delivery and injectable hydrogels.

ABSTRACTA novel thermosensitive adhesive was synthesized by the esterification reaction of multihydroxyl Pluronic L-31 with 3,4-dihydroxy-l-phenylalanine and l-arginine. Pluronic L-31–DOPA–arginine derivative (PDA) gels, rapidly formed in situ with horseradish peroxidase and hydrogen peroxide, were used to explore the performance of efficient tissue adhesives. The results of their adhesive strength on porcine skin demonstrate that the structure of the polymers and temperature influenced the adhesiveness to tissue of the polymers. Compared with the PDAs at 25 °C, the PDAs at 37 °C showed superior adhesive strength. The attractive performance of the PDA gels were demonstrated by this study's results, which suggest biomedical applications in tissue-adhesive devices in the future. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44729.

The incorporation of L-3,4-dihydroxyphenylalanine (L-DOPA) residues in mussel-like biomimetic copolymers has drawn great attention due to their adhesive properties. In this work, a series of temperature-sensitive and hyperbranched poly(amino acid)s containing different functional side groups (catechol, guanidyl, mercapto and double bond) were designed and synthesized by the ring-opening polymerization of N-carboxy-α-amino acid anhydride (NCA), using a temperature-sensitive and multi-hydroxyl end pluronic L-31 as the initiator in this process. The tissue adhesive properties of these copolymers were evaluated by tensile strength tests on wet pork skin. We found that the topological structure, side groups of copolymers, adhesive temperature and cure time had influence on the wet adhesive strength, especially side groups. While only L-DOPA was incorporated into copolymeric chains, the wet adhesive strength was about 106 kPa. With guanidyl, mercapto and double bonds incorporated into copolymeric chains, an obvious increase in the wet adhesive strength was observed. Additionally, the wet adhesive strength improved by about 20 kPa at body temperature (37 °C) as compared to that at room temperature (25 °C). Meanwhile, we found that it has good biocompatibility and degradability through its cytotoxicity and degradation tests.