Evaluation of recombinant human vascular endothelial growth factor VEGF₁₂₁-loaded poly-l-lactide microparticles as a controlled release delivery system

Authors: SUNIL ABRAHAM, SRINIVASA PRASAD RANGASWAMY, AMUTHA CHINNAIAH

Abstract: Vascular endothelial growth factor A (VEGF-A) is an important growth factor that plays a major role in angiogenesis. With different isoforms distributed in various tissues, the shortest isoform of VEGF-A is VEGF₁₂₁, one of the physiologically functional variants next to VEGF₁₆₅. It is well known that VEGF has a shorter half-life, and the stability of the protein must be considered in therapeutic aspects. Poly-l-lactide (PLA) microparticles can release the encapsulated protein in a sustained release mode. In this study, the VEGF₁₂₁ gene was cloned and expressed in a prokaryotic expression system (Escherichia coli). The recombinant VEGF121 was encapsulated with PLA microparticles and studied in vitro and ex ovo for the sustained release mechanism. The PLA-VEGF microparticles and the recombinant VEGF₁₂₁ were explored for their bioactivity in human umbilical vein endothelial cells (HUVEC). VEGF released in vitro from PLA microparticles on days 1, 20, and 30 showed remarkable biological activity compared to PBS-loaded PLA microparticles such as the ability of the cells to proliferate, migrate, and form tubes similar to recombinant VEGF₁₂₁. Besides, PLA-VEGF microparticles and the recombinant VEGF₁₂₁ were also tested for their proangiogenic action in embryonated eggs by chicken chorioallantoic membrane assay (CAM), and the effect was observed in both forms. This study suggests that PLA-loaded VEGF microparticles in a sustainable release format can be effectively used in proangiogenic therapy and reduce the adverse effects caused due to multiple dosages.

Keywords: VEGF, purification, poly-l-lactide, human umbilical vein endothelial cells, proliferation, cell migration, CAM assay, sustained release

Full Text: PDF