A nanocomposite theranostic system, consisting of AuNPs@MnCO3/Mn3O4 coated with PAA and integrated with folic acid, doxorubicin, and propidium iodide: Synthesis, characterization and examination for capturing of cancer cells

Design and construction of a nanocomposite system, containing targeted imaging and therapeutic agents is reported here. The nanoplatform, including AuNPs double coated by MnCO3/Mn3O4 and polyacrylic acid, [email protected]3/Mn3O4@PAA (as computerized tomography -scan and magnetic resonance imaging contrast agent), is constructed first. Then, the immobilized polyacrylic acid is conjugated with folic acid, and loaded with doxorubicin and propidium iodide (as targeting, therapeutic, and fluorescence agents), leading to construction of the [email protected]3/Mn3O4@PAA-FOA(Dox&PI)load system. Construction and physicochemical behavior of the system are followed by voltammetry, electrochemical impedance spectroscopy, and several surface and solution methods, from which the system is quantitatively characterized. The system performance is supported by the following findings: (i) Amount of loaded drug and loading efficiency, 56.33 and 84.50%, respectively, indicating high capability of the system for doxorubicin delivery. This is one of the important aspects of the current work, which in turn is understood to be related to the large amount of polyacrylic acid as the drug carrier immobilized onto the MnCO3/Mn3O4 nanoparticles. (ii) High ability of the system for capturing of the folate receptor overexpressed 4T1 breast cancer cells, in comparison with L929 normal cells, studied by electrochemical impedance spectroscopy in the presence of [Fe(CN)6]3−/4− redox probe. The large variations of charge transfer resistance against redox reaction of the probe at the [email protected]3/Mn3O4@PAA-FOA(Dox)load electrode, after incubation with the 4T1 cells (ΔRct = 217 kΩ, which is ~6 larger than that observed for L929 cells), supports ability of the [email protected]3/Mn3O4@PAA-FOA(Dox)load system for effective capturing of 4T1 cells.