C-H bond activation of 2-methoxyethylamino-bis(phenolate)-yttrium catalysts allowed the synthesis of BAB block copolymers comprised of 2-vinylpyridine (2VP; monomer A) and diethylvinylphosphonate (DEVP; monomer B) as the A and B blocks, respectively, by rare-earth-metal-mediated group-transfer polymerization (REM-GTP). The inherent multi-stimuli-responsive character and drug-loading and -release capabilities were observed to be dependent on the chain length and monomer ratios. Cytotoxicity assays revealed the biocompatibility and nontoxic nature of the obtained micelles toward ovarian cancer (HeLa) cells. The BAB block copolymers effectively encapsulated, transported, and released doxorubicin (DOX) within HeLa cells. REM-GTP enables access to previously unattainable vinylphosphonate copolymer structures, and thereby unlocks their full potential as nanocarriers for stimuli-responsive drug delivery in HeLa cells. The self-evident consequence is the application of these new micelles as potent drug-delivery vehicles with reduced side effects in future cancer therapies.

Tailor-made, multi-responsive micellar AB and ABB′ block copolymers show a pH-sensitivity and a tunable LCST within an expanded temperature range.

COMMUNICATION This journal isPost combustion carbon dioxide capture with aqueous polymer solutions is a field of major interest. Via acylation of commercially available polyethylenimine (b-PEI) with butyric anhydride, lower critical solution temperature (LCST) behaviour together with a reversible pH shift was found in water as well as in CO 2 containing aqueous solutions. As expected, a low CO 2 absorption capability of the acylated thermosensitive b-PEI was measured in a stirred tank reactor. However, the observed improved CO 2 release in the desorption process associated with the LCST behaviour of the polymer is a "green" tool to face high efficiency loss in standard CO 2 capturing processes.