We report on the use of visible light as the driving force for the intramolecular dimerization of pendant anthracene groups on a methacrylic polymer to induce the formation of single-chain nanoparticles (SCNPs). Using a 532 nm green laser light source and platinum octaethylporphyrin as a sensitizer, we first demonstrated the use of TTA-UC to dimerize monomeric anthracene, and subsequently applied this concept to dilute poly((methyl methacrylate)-stat-(anthracenyl methacrylate)) samples. A combination of triple-detection size-exclusion chromatography, atomic force microscopy, and UV-visible spectroscopy confirmed the formation of the SCNPs. This report pioneers the use of TTA-UC to drive photochemical reactions in polymeric systems, and showcases the potential for TTA-UC in the development of nanoobjects.
Polymer vesicles, also known as polymersomes, have garnered a lot of interest even before the first report of their fabrication in the mid‐1990s. These capsules have found applications in areas such as drug delivery, diagnostics and cellular models, and are made via the self‐assembly of amphiphilic block copolymers, predominantly with soft, rubbery hydrophobic segments. Comparatively, and despite their remarkable impermeability, glassy polymersomes (GPs) have been less pervasive due to their rigidity, lack of biodegradability and more restricted fabrication strategies. GPs are now becoming more prominent, thanks to their ability to undergo stable shape‐change (e.g., into non‐spherical morphologies) as a response to a predetermined trigger (e.g., light, solvent). The basics of block copolymer self‐assembly with an emphasis on polymersomes and GPs in particular are reviewed here. The principles and advantages of shape transformation of GPs as well as their general usefulness are also discussed, together with some of the challenges and opportunities currently facing this area.
Polymersomes have gained a lot of attention in recent years. Their compartmentalized, hollow nature, stability and ability to transport both hydrophilic and hydrophobic cargo has made them attractive for increasingly complex applications in various fields of biomedicine, catalysis and diagnostics. Progress in these fields would therefore benefit from improvements in polymersome functionality. Recently, morphological control of polymersomes, namely the fabrication of various non-spherical morphologies, has emerged as a means to enhance the usefulness of the polymersomes. In the present review, we highlight the most topical trends in this field and how these developments and the newly acquired knowledge about their nature can be leveraged towards applications.
We used osmotic pressure changes to induce shape transformation in glassy polymersomes from crosslinkable ABA triblock copolymers. We observed that both the speed of osmotic pressure changes and order of crosslinking affect shape change behavior.
Mechanochemistry refers to the study of the evolution of the formation and disruption of chemical bonds upon application of an external force. In this chapter, the roles of mechanical forces in different biological systems are highlighted along with mechanisms and mechanotransduction pathways showing how complex biological systems can provide inspiration for materials design. Examples of how mechano-based systems have been mimicked by other scientists are also discussed including self-healing systems.
In article number https://doi.org/10.1002/smll.201802734, Yoan C. Simon and co‐workers review the fabrication and usefulness of glassy polymersomes. Capitalizing on their noteworthy impermeability, rigidity, versatile assembly behavior, and readily available shape transformation, many groups have embarked on an exciting scientific journey to generate unique vesicular constructs, which could one day serve as cell mimics.
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