Nowadays, the design of functional polymer materials that can mimic natural phenomena, e.g., self-healing of skin cuts, has got a tremendous interest in materials science and engineering. Recently, 1,2,4-triazoline-3,5-dione (TAD)...
Correction for ‘An injectable hyaluronic acid/PEG hydrogel for cartilage tissue engineering formed by integrating enzymatic crosslinking and Diels–Alder “click chemistry”’ by Feng Yu et al., Polym. Chem., 2014, 5, 1082–1090.
By using click chemistry, a hexacationic cage was synthesized. The cage contains two triscationic π-electron–deficient trispyridiniumtriazine (TPZ3+) platforms that are bridged in a face-to-face manner by three ethylene-triazole-ethylene linkers. A diversity of π-electron–rich guests can be recognized within the pocket of the cage, driven by host-guest π-π interactions. The cage cavity acts as a protecting group, preventing an anthracene guest from undergoing Diels-Alder reaction. Under ultraviolet (UV) light, the pyridinium C─N bonds in TPZ3+ platforms are polarized and weakened, resulting in the occurrence of cage decomposition via β-elimination. Guest recognition could help to prevent this UV-stimulated cage decomposition by suppressing the excitation of the TPZ3+ units.