LAUSR

AbstractIn this study, a convenient method to synthesize cationic macromonomers containing branched poly(ε-caprolactone) (PCL) was developed, and stable materials were derived by photo-cross-linking reactions. In fact, a bromomethyl-terminated modification was carried out at the hydroxyl end groups of the starting PCL; then, the terminal groups reacted with 2,2′-dimethylaminoethyl methacrylate to afford the objective macromonomers, which had N,N′-dimethylmethacrylamino groups at the chain ends. The resulting PCL-based materials were cross-linked by UV light irradiation and were stable against exposure to organic solvents and heating above the softening points. The surface properties of the cationic, PCL, cross-linked membrane were evaluated by measuring the zeta potentials and performing anionic dye adsorption tests using Acid Red 87. As expected, the cationic, PCL, cross-linked membrane surfaces showed a positive charge and greater dye adsorption than the naked PCL, which depended on the cationic contents and temperature. Over the softening point, the positive charge steeply increased. The morphologies of adhered human mesenchymal stem cells on the PCL materials with lower cationic contents were preliminarily observed and shown to be well dispersed. The PCL-based materials in this study could enhance cell interaction and be useful for scaffold or mechanobiology studies.This study demonstrated convenient preparation methods for the introduction of cationic and cross-linkable moieties into 2-branched and 4-branched PCL and their corresponding stable materials. The cationic content and the ratio of 2-branched and 4-branched monomers could be simultaneously controlled by incorporating non-cationic macromonomers. Zeta potential measurements proved that the cationic charge could be controlled by changing the temperatures. Human MSC adhesion was observed on the PCL materials with different cationic contents and lower contents of cationic contents seem to be preferable. Consequently, such materials are promising for biomaterials research.