Coacervate-Filled Lipid Vesicles for Protein Delivery.

Macromolecularly crowded coacervate is useful in protein delivery for tissue engineering and regenerative medicine. However, coacervate tends to aggregate easily, which impedes their application. Here we present a method to prepare coacervate with enhanced stability. We assembled phospholipids on the surface of a coacervate to form lipocoacervate (LipCo). The resultant LipCo possessed a discrete spherical structure with a coacervate interior and phospholipid outer shell. The size of LipCo did not change over the four-week observation window, whereas coacervate coalesced into one bulk phase within 30 minutes. We used vascular endothelial growth factor-C (VEGF-C) and fibroblast growth factor-2 (FGF-2) as examples to test LipCo's ability to maintain protein bioactivity. The in vitro lymphangiogenesis assay demonstrated that human dermal lymphatic endothelial cells (LECs) formed increased network of cord in VEGF-C and FGF-2 loaded LipCo group compared to free proteins and proteins loaded in coacervate. Overall, LipCo could serve as a protein delivery vehicle with improved colloidal stability. This article is protected by copyright. All rights reserved.