Nanospheres from UV-absorbing chitosan derivatives

Abstract

In this work, four groups of UV-absorbing chitosan derivatives were synthesized. They include 1) UVB filter cinnamoylchitosan (CC) 2) UVA filter 2,4,5-trimethoxycinnamoylchitosan (245CC) 3) UVA filter 4-hydroxy-3-methoxycina malidene succinylchitosan (43CSC) and 4) UVB filter 2,4-dimethoxybenzalidenesuc cinylchitosan (24BSC). Fabrication of nanoparticles from the obtained derivatives was carried out by solvent displacement method. It was found that the size of the particles varied with degree of cinnamoyl substitution. 2,4,5-Trimethoxycinnamoyl chitosan and 2,4-dimethoxybenza lidenesuccinylchitosan are more photostable than cinnamoylchitosan and 4-hydroxy-3-methoxycinnamalidenesuccinylchitosan, respectively. In addition, 2,4-dimethoxybenzalidenesuccinylchitosan possess similar UVB filtering efficiency to the popularly used UVB filter 2-ethylhexyl-4- methoxycinnamate.