Fig. 2
Stimuli-responsive degradation of nanocapsules. A The HPLC curve of 5-HT monomers (C5-HT = 500 μg/mL) and VCNCs (C5-HT = 5000 μg/mL) with different conditions for 72 h. B The samples at retention time (2–4 min) were collected and analyzed them using ESI–MS. C The release profile of VCNCs, CNCs, and VNCs at a concentration C5-HT = 50 μg/mL in different conditions (n = 3). XPS spectra of C 1 s, N 1 s, and O 1 s in D poly(5-HT), E 5-HT, and F degraded poly(5-HT)