Human VEGFA mRNA

Vascular endothelial growth factor A (VEGFA) plays an important role in skin wound healing. Here, researchers developed nucleoside-modified VEGFA-encoding mRNA-encapsulated ionizable lipid nanoparticles (LNPs) to promote angiogenesis and improve wound healing rates. First, VEGFA mRNA was synthesized by an in vitro transcription (IVT) method. Then, VEGFA mRNA-LNPs were prepared by encapsulating mRNA in ionizable lipid-based nanoparticles using a microfluidic mixer. The physicochemical properties of VEGFA mRNA-LNPs were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The results showed that VEGFA mRNA-LNPs had a regular spherical morphology with an average particle size of 112.67 nm and a negative Zeta potential of −3.43 mV. The LNP delivery system had good lysosomal escape ability and high transfection efficiency. ELISA and Western Blot analysis showed that mRNA-LNPs were able to express VEGFA protein in human umbilical vein endothelial cells (HUVECs). In addition, endothelial tube formation experiments, cell proliferation experiments, and scratch experiments also showed that VEGFA mRNA-LNP promoted angiogenesis, cell proliferation, and cell migration by expressing VEGFA protein. Finally, a skin wound model of C57BL/6 mice was established, and VEGFA mRNA-LNP was intradermally injected for treatment. The results showed that VEGFA mRNA-LNP could significantly accelerate wound healing.

To evaluate the effect of VEGFA mRNA-LNP on HUVEC, the researchers characterized the levels of cell proliferation, migration, and tube formation. Cell migration is the basis of angiogenesis and fibrosis. The effect of VEGFA mRNA-LNP on cell migration was examined using an inverted microscope. A scratch assay was performed to evaluate the migration of HUVEC at different time points. As shown in Figure 1A, the motility of HUVEC was significantly enhanced after treatment with VEGFA mRNA-LNP or VEGFA mRNA-lipo3000 compared with the control group. The cell migration rate in the scratch healing area was quantified, as shown in Figure 1B. After 24 hours of treatment, the cell fusion rate in the VEGFA mRNA-LNP group was the highest (73.08%), while the fusion rate in the control group was 45.66%. In contrast, the cell fusion rate of VEGFA mRNA-lipo3000 was 68.08%. The above results indicate that VEGFA mRNA-LNP can more effectively promote cell migration to the wound surface. The cell survival rate of VEGFA mRNA-lipo3000 was maintained above 110%, indicating that its promoting effect on HUVEC proliferation was weak (Figure 1C). These results indicate that LNP encapsulated VEGFA mRNA can promote cell proliferation. Compared with the control group and VEGFA mRNA group, the number of tubular structures of HUVEC treated with VEGFA mRNA-LNP increased at 2 and 6 h (Figure 1D). These studies confirm that VEGFA mRNA-LNP has good biosafety and can activate endothelial cell proliferation, migration and tubular structure formation.

Figure 1. The effect of VEGFA mRNA-LNP on cell proliferation and migration in vitro. (Dong S, et al., 2023)