Fig. 5
From: Polydopamine-coated double emulsion capsules for on-demand drug release with reduced passive leakage
On-demand drug release from PDA-coated DECs by NIR laser irradiation. (a) A custom-built laser system consists of a linear stage, a focusing lens, an NIR laser (808 nm), a thermal imaging camera, and a switchable sample holder. (b) Maximum temperatures of PDA-coated PCL films reached under 5 s of laser irradiation. Red and black dashed lines indicate the melting temperature (Tm) of PCL (62.7 °C) and the maximum temperature of the uncoated film (28.2 °C), respectively. (c) Surface morphology of films after 5 s of laser irradiation. The laser generated large holes on the PDA-coated film, while no visible change was observed on the uncoated film. (d) On-demand drug release using a PDA-coated DEC embedded within a soft tissue model (agarose gel). Three stages of DEC rupture: (i) intact DEC, (ii) DEC rupture by laser irradiation, and (iii) diffusion-based drug release from the ruptured DEC.
