Two Recent Research Progress on Polymers
- Sugar-Based Polymers from d-Xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release
Biodegradable bio-based polymers provide options for chemical recycling, and they can be used for storing and releasing useful molecules. Scientist Tae-Lim Choi and colleagues from Seoul National University, South Korea, have developed a class of sugar-based polymers that can be degraded by acid hydrolysis. The researchers also integrated “cargo” molecules in the polymer, which are designed to break apart after the polymer degrades. The study, published in the journal Angewandte Chemie, stated that degradable cargo polymers are very important for medical and sensor applications.
In this study, enyne monomers derived from D-xylose underwent living cascade polymerizations to prepare new polymers with a ring‐opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well-controlled and had living character, which enabled the preparation of high molecular weight polymers with narrow molecular weight dispersity values and a block copolymer. By tuning the type of acid-sensitive linkage (hemi-aminal ether, acetal, or ether functional groups), the researchers could change the degradation profile of the polymer and the identity of the resulting degradation products. For instance, the large difference in degradation rates between hemi-aminal ether and ether-based polymers enabled the sequential degradation of a block copolymer. Furthermore, we exploited the generation of furan-based degradation products, from an acetal-based polymer, to achieve the release of covalently bound reporter molecules upon degradation.
- Control of Crystallinity and Stereocomplexation of Synthetic Carbohydrate Polymers from d ‐ and l ‐Xylose
Scientists from from the University’s Centre for Sustainable and Circular Technologies have used xylose, the second most abundant sugar in nature, to make a sustainable polymer. This new nature-inspired material not only reduces the dependence on crude oil products, but also can easily control its properties to make the material flexible or crystalline. The research showed that polymers of the polyether family has a variety of applications, including being used as a base material for polyurethanes in mattresses and shoe soles, as an alternative to bio-derived polyethylene glycol, which is widely used in biomedicine; or to polyethylene oxide, sometimes used as an electrolyte in batteries.
In this study, the researchers reported the cocrystallisation of regio- and stereoregular polyethers derived from d- and l-xylose, leading to enhanced thermal properties compared to the enantiopure polymers. This is the first example of a stereocomplex between carbohydrate polymers of opposite chirality. In contrast, atactic polymers obtained from a racemic mixture of monomers are amorphous. The study also show that the polymer hydroxyl groups are amenable to post-polymerisation functionalization. These strategies afford a new family of carbohydrate polyethers, the physical and chemical properties of which can both be controlled, and which opens new possibilities for polysaccharide mimics in biomedical applications or as advanced materials.
About the author
CD Bioparticles is an established drug delivery company which provides customized solutions for developing and producing new, biocompatible drug delivery systems. We specialize in a range of formulation and drug delivery technologies, from conventional liposomes, PEGylated liposomes for drug delivery to polymer microspheres and nanoparticles for enhanced drug delivery. We are aiming to become the partner of choice as a leader in drug delivery, particularly in formulating challenging compounds with liposomes, polymers and other novel nano-enabled delivery technologies.
References
- Rizzo, Antonio, et al. Sugar‐Based Polymers from D‐xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release. Angewandte Chemie International Edition. 2021, 2: 849-855.
- McGuire, Thomas M., et al. Control of Crystallinity and Stereocomplexation of Synthetic Carbohydrate Polymers from d‐and l‐Xylose. Angewandte Chemie International Edition. 2021, 9: 4524-4528.