Figure 3.

Temperature-triggered self-assembly of an ELP block copolymers. a) An N-terminal hydrophilic ELP[V₁A₈G₇-n] gene and C-terminal hydrophobic ELP[V₅-n] gene are seamlessly fused together to create a gene that encodes an ELP block copolymer. When the size and ratio of the blocks are correctly selected, the ELP block copolymer self-assembles into a micelle close to body temperature. b) Hydrodynamic radius (R_h) and optical density profile at 350 nm of ELP[V₁A₈G₇-₆₄]/[[V₅-₉₀] block copolymer at 25 μm in PBS shows that ELPs exist as unimers (R_h of 5–10 nm) below CMT at 35 °C and form micelles (R_h 30–80 nm) above their CMT. c) Confocal fluorescence images of K562/α_vβ₃ cells treated with 10 μm ELP block copolymer with N terminal RGD ligand (green). Fluorescence images showed that there was no binding/uptake of RGD-ELP below the CMT but above the CMT there was significant binding/uptake of RGD-ELP due to the temperature-triggered multivalent display of RGD ligands. (a,b) Reproduced with permission.^[50] Copyright 2007, American Chemical Society. (c) Reproduced with permission.^[56] Copyright 2010, American Chemical Society.