A Glucose-Responsive Glucagon-Micelle for the Prevention of Hypoglycemia.

While glucose-responsive insulin delivery systems are in widespread clinical use to treat insulin insufficiency, the on-demand supplementation of glucagon for acute hypoglycemia treatment remains understudied. A self-regulated glucagon release material is highly desired to mitigate the potential risks of severe insulin-induced hypoglycemia. Here, we describe a glucose-responsive polymeric nanosystem with glucagon covalently grafted to the end-group.

Degradable polyisoprene by radical ring-opening polymerization and application to polymer prodrug nanoparticles.

Radical ring-opening polymerization (rROP) has received renewed attention to incorporate cleavable linkages into the backbones of vinyl polymers, especially from cyclic ketene acetals (CKAs). Among the monomers that hardly copolymerize with CKAs are (1,3)-dienes such as isoprene (I). This is unfortunate since synthetic polyisoprene (PI) and its derivatives are the materials of choice for many applications, in particular as elastomers in the automotive, sport, footwear, and medical industries, but also in nanomedicine.

Increasing the Hydrophilicity of Cyclic Ketene Acetals Improves the Hydrolytic Degradation of Vinyl Copolymers and the Interaction of Glycopolymer Nanoparticles with Lectins.

Radical ring-opening polymerization (rROP) of cyclic ketene acetals (CKAs) with traditional vinyl monomers allows the synthesis of degradable vinyl copolymers. However, since the most commonly used CKAs are hydrophobic, most degradable vinyl copolymers reported so far degrade very slowly by hydrolysis under physiological conditions (phosphate-buffered saline, pH 7.4, 37 °C), which can be detrimental for biomedical applications.

Degradable Glycopolyester-like Nanoparticles by Radical Ring-Opening Polymerization.

A small library of degradable polyester-like glycopolymers was successfully prepared by the combination of radical ring-opening copolymerization of 2-methylene-1,3-dioxepane as a cyclic ketene acetal (CKA) with vinyl ether (VE) derivatives and a Pd-catalyzed thioglycoconjugation. The resulting thioglycopolymers were formulated into self-stabilized thioglyconanoparticles, which were stable up to 4 months and were enzymatically degraded. Nanoparticles and their degradation products exhibited a good cytocompatibility on two healthy cell lines.

Degradable Polyampholytes from Radical Ring-Opening Copolymerization Enhance Cellular Cryopreservation.

Macromolecular cryoprotectants based on polyampholytes are showing promise as supplemental cryoprotectants alongside conventional DMSO-based freezing. Here we exploit radical ring-opening (ter)polymerization to access ester-containing cryoprotective polyampholytes, which were shown to be degradable. Using a challenging cell monolayer cryopreservation model, the degradable polyampholytes were found to enhance post-thaw recovery when supplemented into DMSO.

100th Anniversary of Macromolecular Science Viewpoint: Degradable Polymers from Radical Ring-Opening Polymerization: Latest Advances, New Directions, and Ongoing Challenges.

Radical ring-opening polymerization (rROP) allows facile incorporation of labile groups (e.g., ester) into the main chain of vinyl polymers to obtain (bio)degradable materials.

Degradable Copolymer Nanoparticles from Radical Ring-Opening Copolymerization between Cyclic Ketene Acetals and Vinyl Ethers.

2-Methylene-1,3-dioxepane (MDO) and different vinyl ether (VE) monomers were successfully copolymerized by free-radical radical ring-opening copolymerization (rROP) to yield P(MDO- co-VE) copolymers with M = 7 000-13 000 g·mol and high molar fractions of MDO ( F = 0.7-0.9).