Fig. 5.

Transdermal light-triggered gelation and stiffening. (A) An alginate solution containing CaCl₂-loaded liposomes either with or without gold nanorods was injected s.c. into the dorsal region of a nude mouse. The region was irradiated for 5 min and gels were harvested for mechanical testing. (B) IR images of the mouse indicate significantly faster heating in gold nanorod-loaded liposomes. (C) Temperature profile over the course of irradiation. (D) Gold nanorod-loaded liposomes yielded gels that had significantly higher storage moduli than the ungelled alginate solution. (E) Photograph of mouse during irradiation (Top) and resulting gel after irradiation (Bottom). Scale bar, 5 mm. (F) Gels irradiated transdermally stiffened significantly compared with unirradiated controls.