Figure 1.
An ultrasound-based mechanism termed acoustic droplet vaporization (ADV) was used to release basic fibroblast growth factor (bFGF) from an acoustically-responsive scaffold (ARS). A) bFGF was encapsulated within a phase-shift double emulsion (PDSE). At subthreshold acoustic pressures (P < PADV), the perfluorocarbon (PFC) phase within the PSDE remains a liquid. At suprathreshold acoustic pressures (P > PADV), the PFC phase is vaporized into a gas bubble, which causes release of bFGF. Depending on the molecular weight of the PFC, the generated bubble either is stable and continues to grow in size due to in-gassing or is transient and recondenses back into liquid PFC. B) ARSs were generated by incorporating the PSDE into a fibrin hydrogel. The ARSs were exposed ex situ to four different spatial patterns of ADV and then implanted subcutaneously in mice. As demonstrated with immunohistochemical staining, angiogenesis correlated with the pattern of ADV. The figure was created with BioRender.com