Preparation of Hybrid Fe 3 O 4 @SiO 2 Biopolymer Core-Shell Anticancer Drug Carrier for Sustainable Release of Doxorubicin

Abstract

Magnetic core-shell drug-carrier microcapsules were prepared and investigated using doxorubicin (Dox) as an anticancer drug model. First, superparamagnetic iron oxide nanoparticles (Fe₃O₄), were prepared and coated with silica SiO₂ using a sol-gel method. Next, the Fe₃O₄@SiO₂ nanoparticles were functionalized using the (3-aminopropyl) ethoxy silane (APS), to obtain the Fe₃O₄@SiO₂-NH₂. Afterward, the (Dox) was added to form the Fe₃O₄@SiO₂-NH₂-(Dox), and then the nanoparticles were wrapped in a polymer matrix by adding a chitosan/CaCl₂ aqueous solution. The presence of divalent Ca²⁺ cations ensured hydrogel chain reticulation and the Fe₃O₄@SiO₂-NH₂-(Dox) encapsulation into the polymer matrix. The chitosan was chosen to shrink the hydrogel microcapsules' pores and limit the drug diffusion in acidic pH. Finally, a solution of dextran and polyvinyl pyrrolidone in chloroform was added to form the outermost shell structure. This core-shell magnetic drug-carrier microcapsule was noted system (A). The second drug-carrier microcapsule noted (B), was obtained by adding the (Dox) to the outermost polymer shell. The two-hybrid core-shell, drug carriers A, and B were observed by scanning electron microscopy (SEM) and characterized by ATR-FTIR spectroscopy, and their magnetic characteristics were confirmed. The drug diffusion kinetic study revealed that (A) had a greater drug release efficiency than (B), with an enhanced drug release effect at pH 5.8 and 7.4 associated with cancer cell environments, rather than pH 4.9 associated with healthy cell environments. Therefore, the magnetic drug carrier (A) was selected as a promising candidate for cancer cell targeting therapy.