Poly[lactic-co-glycolic] acid (PLGA) targeting nanoparticles AFP/PLGA/Dt386, loaded with Dt386 plasmid of
diphtheria toxin gene, modified by
Alpha fetoprotein (AFP)
monoclonal antibody, is prepared. Its physical and chemical properties and its effect on HepG2 cells are studied. Firstly, Dt386 expression plasmid pET11a/Dt386 is constructed and PLGA nanoparticles are prepared by
emulsion solvent evaporation (ESE). Scanning electron microscope (SEM) is used to observe its morphology.
Laser Particle Sizer is used to measure the particle size. In addition, the encapsulation efficiency,
drug loading and in vitro release rate of PLGA nanoparticles are measured. Carboxy
fluorescein and
rhodamine fluorescein are used to double label
IgG/PLGA/Dt386 and AFP/PLGA/Dt386
nanospheres, respectively, the entry of
nanospheres into HepG2 cells are observed at 3 h and 12 h. The effect of AFP/PLGA/Dt386
nanospheres on the migration of HepG2 cells is examined by wounding healing assay. Transwell chamber experiment is used to detect the effect of AFP/PLGA/Dt386
nanospheres on the invasion of HepG2 cells. MTT method is utilized to determine the inhibitory activity of nanoparticles on HepG2 cell proliferation. After treated with
IgG/PLGA/Dt386 and AFP/PLGA/Dt386 nanoparticles for 48 hours, flow cytometry is used to detect the apoptosis rate and cell cycle of HepG2 cells in each group. The results show that the prepared
nanospheres have regular morphology, flat surface, average particle size of 265.72±12.46 nm, zeta potential of -18.15 mV. The average entrapment efficiency and
drug loading are 78.48±1.71% and 3.16±0.35%, respectively. The nanoparticles release slowly and stably in vitro. At the 10th day, the release rate reaches 75.13%. PLGA
nanospheres can effectively protect
DNA from nuclease degradation. The results show that AFP/PLGA/Dt386
nanospheres have
biological targeting effect and can be enriched in cells. AFP/PLGA/Dt386 nanoparticles can significantly inhibit the migration, invasion and proliferation of HepG2 cells, and promote apoptosis.