Nanohybrid organic-inorganic chitosan/dopamine/TiO2 composites with controlled drug-delivery properties

In our present study, a series of nanohybrid composites of dopamine (DOP)/chitosan (CIS)@TiO2 were synthesized by sol-gel method and the drug release of the composites was investigated by using electrochemical determination and UV-vis absorbance techniques. DOP/CIS (10-40 wt%) composites were prepared by dissolving DOP in the chitosan aqueous solution. Then DOP/CIS composites were coated with different amounts of TiO2 (10-50 wt%) by using titanium tetra n-butoxide, as precursor. Formation of intercalated DOPICIS@TiO2 nanohybrid composites was characterized by FT-IR, FE-SEM, DSC, BET and XRD analysis. Zeta potential of the best DOPICIS@TiO2 nanohybrid composite was determined 45.0 and 59.1 mV. Compared to the DOP/CIS composites, incorporation of the TiO2 enhanced the drug entrapment considerably, and reduced the drug release. The DOP/CIS composites without TiO2 coating released the whole drug after 10 min in pH 7.4 solution while the TiO2 coated composites released the entrapped drug after 16 h. The results are very satisfactory and might be used in altering the DOP utilization from injection to oral. (C) 2015 Elsevier B.V. All rights reserved.