UV-triggerable alginate beads decorated with basic proteinoid-coumarin conjugates.

UV-triggerable bead was prepared by coating the surface of alginate bead with a photo-responsive proteinoid. Epoxypropoxy coumarin (EPC) was covalently attached to a basic proteinoid composed of lysine and serine (PLS), and the PLS-EPC conjugate was used as a photo-responsive coat of the bead. EPC residues of PLS-EPC conjugate on the bead surface were photo-cross-linked upon the irradiation of λ = 365 nm, and then FITC-dextran was loaded as a fluorescence dye in the bead coated with photo-cross-linked PLS-EPC conjugate. Upon the irradiation of λ = 254 nm, the degree of release from the bead was enhanced possibly because the cross-linked network of PLS-EPC conjugate coating layer is photo-cleaved. The UV-triggerable bead developed in the present study could be applied to a UV-responsive drug carrier.