Inspired by marine mussel adhesive proteins, polymers with catechol side groups have been extensively explored in industrial and academic research. Here, Pluronic L-31 alcoholate ions were used as the initiator to prepare a series of polypeptide-Pluronic-polypeptide triblock copolymers via ring-opening polymerization of l-DOPA-N-carboxyanhydride (DOPA-NCA), l-arginine-NCA (Arg-NCA), l-cysteine-NCA (Cys-NCA), and ε-N-acryloyl lysine-NCA (Ac-Lys-NCA). These copolymers demonstrated good biodegradability, biocompatibility, and thermoresponsive properties. Adhesion tests using porcine skin and bone as adherends demonstrated lap-shear adhesion strengths up to 106 kPa and tensile adhesion strengths up to 675 kPa. The antibleeding activity and tissue adhesive ability were evaluated using a rat model. These polypeptide-Pluronic copolymer glues showed superior hemostatic properties and superior effects in wound healing and osteotomy gaps. Complete healing of skin incisions and remodeling of osteotomy gaps were observed in all rats after 14 and 60 days, respectively. These copolymers have potential uses as tissue adhesives, antibleeding, and tissue engineering materials.

In this study, thermoresponsive and mussel-inspired polypeptides were synthesized using ring-opening polymerization of α-amino acid derivatives of N-carboxyanhydride (NCA). The tissue adhesive properties of these polypeptides were evaluated using in vitro adhesive strength tests on porcine skin and bone. The results indicated that the species of the functional polypeptide side groups and the adhesive temperature have a significant influence on the adhesion strength. The maximum of the lap-shear adhesion strength on porcine skin was 101.2 kPa, and the maximum of tensile adhesion strength on bone was 603 kPa. The in vivo antibleeding activity and tissue adhesive ability were also evaluated using a rat model. These polypeptides exhibited superior hemostatic properties and healing effects in the skin incision and osteotomy gap, and the skin incision healing and osteotomy gap remodeling were completed in all rats after 2–9 weeks. These polypeptides are expected to be good candidates for surgical tissue adhesives, tissue engineering materials, and antibleeding materials, etc.

The adhesive strength of poly(amino acid)s can be improved by clicking a cross-link, forming a disulfide bond and so on. In addition, the adhesion strength becomes better on grafting with different monomers at 37 °C.

A series of hyperbranched, thermo-responsive and mussel-inspired polypeptides were synthesized and used for surgical adhesion, hemostasis and interventional embolization.

A series of biodegradable linear–hyperbranched barbell‐like poly(ethylene glycol) (PEG)‐supported poly(lactic‐ran‐glycolic acid) (PLGA) copolymers were synthesized with PEG, d,l‐lactic acid aqueous solution, glycolic acid and gluconic acid (Glu) under bulk conditions. The branching density of the hyperbranched section was varied by controlling the molar ratio of Glu to hydroxyl‐terminal groups of PEG ([Glu]/[OH] = 1, 3.5, 6.0, 8.5). Chemical structures of these copolymers were confirmed using NMR spectroscopy. The molecular weights were determined using 1H NMR group analysis and gel permeation chromatography, both results being consistent with one another. The results of hydrolytic degradation indicate that these copolymers can degrade completely in no more than three weeks. The thermal properties were evaluated using differential scanning calorimetry and thermogravimetric analysis. The results indicate that the glass transition temperatures and melt temperatures of these copolymers are not above 50 °C. The self‐assembly behavior of the copolymers on hydrophilic surfaces was also investigated. The morphology of self‐assembly films made of the copolymers was observed using atomic force microscopy, and the results indicate that these copolymers exhibit more inhomogeneous and rough structural orientated films on a silicon wafer substrate with increasing branching densities. Due to the favorable biodegradability and biocompatibility of the PLGA and PEG, the results suggest new possibilities for these novel structural amphiphilic linear–hyperbranched barbell‐like copolymers as potential biomaterials. © 2013 Society of Chemical Industry