Poly(tert‐butoxycarbonylaminomethylacrylate) (PtBAMA), a derivative of polydehydroalanine (PDha), is synthesized using free radical polymerization (FRP) and nitroxide mediated polymerization (NMP). Due to the presence of orthogonal protective groups, the resulting polymers can be selectively deprotected to yield either a polyanion (poly(tert‐butoxycarbonylaminoacrylic acid), PtBAA) or a polycation (poly(aminomethylacrylate), PAMA). Deprotection of both the amino‐ and the carboxyl‐functionality in a sequential manner leads to the potential polyzwitterion polydehydroalanine (PDha). The pH‐dependent solution behavior of PtBAA, PAMA, and PDha are examined in aqueous solution by potentiometric and turbidimetric titrations as well as ζ‐potential measurements.

The controlled nonviral delivery of genetic material using cationic polymers into cells has been of interest during the past three decades, yet the ideal delivery agent featuring utmost transfection efficiency and low cytotoxicity still has to be developed. Here, we demonstrate that multicompartment micelles from stimuli-responsive triblock terpolymers, polybutadiene-block-poly(methacrylic acid)-block-poly(2-(dimethylamino)ethyl methacrylate) (BMAAD), are promising candidates. The structures exhibit a patchy shell, consisting of amphiphilic (interpolyelectrolyte complexes, MAA and D) and cationic patches (excess D), generating a surface reminiscent to those of certain viruses and capable of undergoing pH-dependent changes in charge stoichiometry. After polyplex formation with plasmid DNA, superior transfection efficiencies can be reached for both adherent cells and human leukemia cells. Compared to the gold standard PEI, remarkable improvements and a number of advantages were identified for this system, including increased cellular uptake and an improved release of the genetic material, accompanied by fast and efficient endosomal escape. Furthermore, high sedimentation rates might be beneficial regarding in vitro applications.

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We report on the coating of superparamagnetic iron oxide nanoparticles using polyanionic or polyzwitterionic materials based on polydehydroalanine. The resulting core–shell hybrid nanoparticles exhibit shells of different charge and thickness.

This work examines the fabrication regime and the properties of polymer-enzyme thin-films adsorbed onto conductive substrates (graphite or gold). The films are formed via two-steps, sequential adsorption of poly(n-butylmethacrylate)-block-poly(N,N-dimethylaminoethyl methacrylate) (PnBMA-b-PDMAEMA) diblock copolymer micelles (1st step of adsorption), followed by the enzyme choline oxidase (ChO) (2nd step of adsorption). The solution properties of both adsorbed components are studied and the pH-dependent step-by-step fabrication of polymer-enzyme biosensor coatings reveals rather drastic differences in their enzymatic activities in dependence on the pH of both adsorption steps. The resulting hybrid thin-films represent highly active biosensors for choline with a low detection limit of 30 nM and a good linearity in a range between 30 nM and 100 μM. The sensitivity is found to be 175 μA mM(-1) cm(-2) and the operational stability of the polymer-enzyme thin-films can be additionally improved via enzyme-to-enzyme crosslinking with glutaraldehyde.

We report on the synthesis of thiol-terminated, polyether-based block copolymers featuring a crosslinkable block and their use as ligands for Au-nanoparticles in organic solvents.

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