Figure 5.

Stimuli-induced assembly events. (A) Cartoon illustrating a generic assembly event in which an uncaging event occurs (loss of red blocking unit) to enable the assembly of many unimers (blue octagons). Note that we define an assembly event as a unimer or ill-defined structure assembling into a much larger stucture of higher order. Aggregation is a related process in which unimers or disordered phases assemble into larger, amphorphous aggregates. (B) Chemical structures depicting a literature example of an o-nitrobenzyl “caged” amphiphilic peptide that becomes amphiphillic and self-assembles into hydrogel-forming fibers upon removal of the caging group (i.e., the red oval in scheme A) by 350 nm light. (C) Photograph of the caged amphiphile and the hydrogel formed after removal of the o-nitrobenzyl cage. (D) Transmission electron microscopy images of the system before and after exposure to UV light. Panels B–D are adapted from Muraoka et al.¹¹⁷ with permission from John Wiley and Sons Ltd.