(a) Ultrasound (US) enhanced recombinant MMP-9 triggered release of contents from MMP-9 cleavable ELIPs. (b) Ultrasound (US) enhanced redox triggered release of contents from polymer coated disulfide cross-linked ELIPs [Reproduced with permission from [76]]. In both the figures, the olive, blue, orange, and magenta colored bars represents the passive release in absence of any trigger, release due to US only, release due to other triggers (MMP-9 or redox) only, and the release with simultaneous application of US and the other trigger respectively.