Encapsulation mechanism of molecular nanocarriers based on unimolecular micelle forming dendritic core-shell...

A series of dendritic core-shell structural polymers with different shell densities were synthesized based on dendritic polyester Boltorn H40 and were demonstrated to form unimolecular micelles in chloroform. The encapsulation mechanism study using Congo red as a guest molecule by fluorescence and UV-vis methods showed that the interaction of Congo red with hydroxyl groups in the dendritic core-shell polymer led to encapsulation. Moreover, the results also indicated that the dendrimer with 43.4% hydroxyl groups end-capped by the long alkyl chains showed the best encapsulation capacity. However, lower and higher alkyl densities both led to lower encapsulation capacities. The former was attributed to the poor compatibility of the polymer with chloroform, and the later was caused by less location sites for the guest molecule inside the core-shell polymer.