Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in different areas including drug delivery, tissue engineering, regenerative medicine and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)-block-undergo inverse thermogelation below a critical temperature by forming a reversible nanoscale worm-like network. The viscoelastic properties of the resulting gel can be conveniently tailored by the concentration and the polymer composition. Storage moduli of up to 110 kPa could be obtained while the material remains shear-thinning and retains rapid self-healing properties. We demonstrate 3D-printing of excellently defined and shape persistent 24-layered scaffolds at different aqueous concentrations to highlight its application potential e.g. in the research area of biofabrication. A mesoporous microstructure, which is stable throughout the printing process, could be confirmed via cryo-SEM analysis. The absence of cytotoxicity even at very high concentrations opens wide range of different applications for this first-in-class material in the field of biomaterials.

The synthesis and characterization of an ABA triblock copolymer based on hydrophilic poly(2-methyl-2-oxazoline) (pMeOx) blocks A and a modestly hydrophobic poly(2-iso-butyl-2-oxazoline) (piBuOx) block B is described. Aqueous polymer solutions were prepared at different concentrations (1–20 wt %) and their thermogelling capability using visual observation was investigated at different temperatures ranging from 5 to 80 °C. As only a 20 wt % solution was found to undergo thermogelation, this concentration was investigated in more detail regarding its temperature-dependent viscoelastic profile utilizing various modes (strain or temperature sweep). The prepared hydrogels from this particular ABA triblock copolymer have interesting rheological and viscoelastic properties, such as reversible thermogelling and shear thinning, and may be used as bioink, which was supported by its very low cytotoxicity and initial printing experiments using the hydrogels. However, the soft character and low yield stress of the gels do not allow real 3D printing at this point.

Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in different areas including drug delivery, tissue engineering, regenerative medicine and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)-block-poly(2-phenyl-2-oxazine)-block-poly(2-methyl-2-oxazoline) (PMeOx-b-PPheOzi-b-PMeOx) undergo inverse thermogelation below a critical temperature. The viscoelastic properties of the resulting gel can be conveniently tailored by the concentration and the polymer composition. Storage moduli of up to 110 kPa could be obtained while the material remains shear-thinning and retains rapid self-healing properties. We demonstrate 3D-printing of excellently defined and shape persistent 24-layered scaffolds at different aqueous concentrations to highlight its application potential e.g. in the research area of biofabrication. A mesoporous microstructure, which is stable throughout the printing process, could be confirmed via cryo-SEM analysis. The absence of cytotoxicity even at very high concentrations opens wide range of different applications for this first-in-class material in the field of biomaterials.<br>

Intraoperative bleeding and postoperative bleeding are major surgical complications. Tissue sealants, hemostats, and adhesives provide the armamentarium for establishing hemostatic balance, including the tissue sealant fibrin. Fibrin sealants combine advantages including instantaneous effect, biocompatibility, and biodegradability. However, several challenges remain. This review summarizes current fibrin product generations and highlights new trends and potential strategies for future improvement.

Bacterial phenazines react with diverse biogenic thiols and proteins under radical-forming conditions, revealing new biological roles based on conjugation and crosslinking of proteins.