The body is pretty good at repairing itself, but some parts of our anatomy struggle to bounce back after an injury.

One such material is cartilage – the spongy yet firm connective tissue that keeps our bones from rubbing and jarring against each other. Over time, the translucent or ‘hyaline’ components of cartilage can become heavily degraded, resulting in painful conditions like osteoarthritis and chondromalacia.

Scientists have been working on a way to regenerate hyaline cartilage for years, and now a team led by Northwestern University in the US has achieved a breakthrough. They have developed a biomaterial that, injected into damaged cartilage in living sheep, acted as a scaffold that promoted cartilage regrowth in active joints.

Helical foldamers are a class of artificial molecules that fold into well-defined helical structures like helices found in proteins and nucleic acids. They have garnered considerable attention as stimuli-responsive switchable molecules, tuneable chiral materials, and cooperative supramolecular systems due to their chiral and conformational switching properties.

Double-helical foldamers exhibit not only even stronger chiral properties but also unique properties, such as the transcription of chiral information from one chiral strand to another without chiral properties, enabling potential applications in higher-order structural control related to replication, like nucleic acids.

However, the artificial control of the chiral switching properties of such artificial molecules remains challenging due to the difficulty in balancing the dynamic properties required for switching and stability. Although various helical molecules have been developed in the past, reversal of twist direction in double-helix molecules and supramolecules has rarely been reported.