LAYER BY LAYER ASSEMBLY ON THE SURFACE OF NANOPARTICLE FOR CHEMOTHERAPEUTIC DRUG LOADING

In the present investigation, fluorescently labelled sulfated polystyrene beads were coated with oppositely charged polyelectrolytes {i.e. Poly diallyl dimethyl ammonium chloride, Poly (sodium 4-styrene sulfonate)} through an electrostatic interaction by using layer by layer assembly method. Doxorubicin is a model anticancer drug with protonatable amine group that acquires net positive charge in an acidic environment. The positively charged doxorubicin was electrostatically bound onto the surface of polystyrene beads coated with Poly (sodium 4-styrene sulfonate) as an outer layer. This model drug loaded nanocarrier was characterized by optical spectroscopy. In addition, gel electrophoresis principle was used to track the polyelectrolyte coating on the surface of the negatively charged polystyrene beads. The layer by layer method of coating drug molecule on the surface of polyelectrolyte coated nanoparticles was also confirmed with size and zeta potential measurements by using dynamic light scattering. The correlation between the movement of polyelectrolytes coated nanoparticles in gel electrophoresis and size of the nanoparticles measured by dynamic light scattering were also studied. The results suggest that layer by layer method can be used as a versatile method to load drug molecule on the nanoparticles surface.