Reactive and Functional Polymers

This study describes the novel procedure for synthesizing an aldehyde-containing polyrotaxane (PRβCD1) composed of β-cyclodextrin (βCD) monoaldehyde and polypropylene glycol, and the preparation of atelocollagen threads with enhanced mechanical properties through the use of PRβCD1 as a crosslinker (Col-PRβCD1). For the selective introduction of the aldehyde groups into βCD of the PRβCD1, the comparative study on the oxidation method was initially performed with Dess-Martin Periodinane (DMP) and a redox couple between the (2,2,6,6-tetramethylpiperidin-1-yl)oxyl and iodobenzene derivatives. NMR measurements performed after oxidation of βCD with the DMP indicated the presence of both ketone and aldehyde, while the selective production of the aldehyde groups was achieved by the proposed redox couple. After further improvement of the reaction conditions, the water-soluble PRβCD1 containing aldehyde groups as the only crosslinkable sites was successfully synthesized. Interestingly, the fracture strain and stress, and toughness of the atelocollagen threads were enhanced after crosslinking with PRβCD1. The observed mechanical properties of Col-PRβCD1 reflect the slidering features of the polyrotaxane. Overall, this study provides important insights into the synthesis of crosslinkable polyrotaxanes and their applicability as biomaterials.