In vivo biocompatibility studies on lipid nanoparticles.

Purpose. To assess the biocompatibility of polysorbate 80 coated cetyl palmitate nanoparticles (NPs), in vivo, using the chick chorioallantoic membrane (CAM) assay. Methods. Polysorbate 80 coated cetyl palmitate nanoparticles (NPs) were prepared using hot high pressure homogenization method (65°C, 1500 bar, 7 homogenization cycles). The obtained NPs were characterized for their process yield, dimensions (photon correlation spectroscopy), morphology (transmission electron microscopy, TEM), thermal behavior (differential scanning calorimetry) and physical stability. Biocompatibility studies were performed on chick embryos using the CAM assay. Practically, fertilized eggs were windowed 4 days after incubation and Derlin® containers were deposited on the chorioallantoic membrane at day 6. 24 hours later, the eggs were treated and monitored 1, 2 and 6 days after treatment. Results. Blank NPs, prepared in replicate of four to assess method reproducibility, showed a mean diameter of 185 ± 8 nm with a method yield of ≈92 %. The preparation was stable at 4°C for a period of 18 months. TEM analysis evidenced a spherical morphology with some aggregation probably due to sample preparation. CAM assay showed high biocompatibility. In fact, LNs, external phase (Polysorbate 80 solutions) and the raw material did not stimulate neither inflammatory reaction nor angiogenesis 1, 2 and 6 days after treatment. Conclusion. Polysorbate 80 coated cetyl palmitate NPs showed a very high biocompatibility, condition necessary for parenteral and, in particular, brain targeting applications.