The non-cross-linked polymer nanogels were disassembled when the temperature was lowered below the LCST, as described above (Figure ), but nanogels remained stable when cross-linked. When comparing the DLS traces of the cross-linked 5a4 nanogels at 37 °C and 25 °C, a size increase can be observed (93 ± 2 nm compared to 133 ± 9 nm). The slight size increase with decreasing temperature can be attributed to the thermo-responsive phase transition of the PNIPAM block, which switches from hydrophobic nature above the LCST to hydrophilic below the LCST. This could cause relaxation and water-induced swelling of the polymer chains, as previously observed in the literature. These networks are expected to swell and relax up to a limit determined by constraints imposed by the crosslinking, which will be dependent on the length and chemical structure of the peptide, and the cross-linking density.