Amino-Functionalized Magnetic Composites And Their Applications For Targeted Drug Delivery And Mannich Reaction

Magnetic composite nano-materials carrying amino groups have attracted much interest due to their potential applications in the fields of catalysis, sensor, water purification, enzyme immobilization, DNA extraction, and targeted drug delivery. In this paper, Fe3O4 nanospheres were synthesized through the glycol reduction method. Parameters including reaction time, the volume ratio of glycol to water, the pH value and the polarity of the solvent were studied to understand the formation mechanism of the magnetic nanospheres. Fe3O4/PPy composite nanospheres were prepared in situ polymerization procedure after the magnetic cores were acidized and py monomers were added. In addition, Fe3O4 nanoparticles were synthesized by coprecipitation technique. For the synthesis of Fe3O4/PANI and Fe3O4/PPy composites, a surfactant-assisted in situ polymerization approach was employed. These samples were characterized with XRD, FT-IR, TEM, SEM, Zeta potential values, TGA/DSC, SQIM. Results of the tests explain that:(1) Amino-functionalized magnetic composites exhibit high magnetization, good water dispersibility, superparamagnetism.(2) The average size of core-shell structured Fe3O4/PPy composite nanospheres is 100 nm, which is meeting the demand of biorelated applications in vivo.A facile conjugation of fluorescein isothiocyanate and methotrexate (MTX) onto the dedoped Fe3O4/PPy composite nanospheres through the electrostatic interaction and the EDC/NHS coupling chemistry, respectively. Drug release kinetics of Fe3O4/PPy/FITC/MTX was studied under physiological conditions in vitro. Fe3O4, Fe3O4/PPy, Fe3O4/PPy/FITC, and Fe3O4/PPy/FITC/MTX were also examined in the cytotoxicity tests. Results of the tests explain that:(1) The desirable fluorescent Fe3O4/PPy/MTX with MTX loading of ca.109μg/mg was produced.(2) The as-obtained magnetic targeting drug exhibits controllable drug release.(3) Fe3O4, Fe3O4/PPy, and Fe3O4/PPy/FITC possess excellent cyto-compatibility. Fe3O4/PPy/FITC/MTX has specific targeting ability to HeLa cells overexpressing folate receptors.Amino-functionalized magnetic composites were coupled with p-hydroxy benzaldehyde. The total amount of surface amino groups of composite was measured according to the UV-Vis method. The magnetic composites as solid amine reacted with p-hydroxy benzaldehyde, diethyl acetamidomalonate through Mannich reaction to produce tyrosine. The results show that:(1) The content of surface amino groups of Fe3O4/PANI and Fe3O4/PPy composites is ca.246.1μmol/g and 300.1μmol/g, respectively.(2) The product synthesized through Mannich reaction is deduced to be tyrosine by the UV-Vis method and 1H NMR.(3) Solid amine could be recycled. The method is cost-effective and environmentally friendly compared with the conventional Mannich reaction to produce tyrosine.