Multiwalled Carbon Nanotubes Decorated with Fe₃O₄ Nanoparticles for Efficacious Doxycycline Delivery

Multiwalled carbon nanotubes (MWCNTs) based nanovectors have flourished when we furnish them with iron oxide (Fe3O4) nanoparticles (NPs) and an antibiotic, doxycycline (Doxy), as Doxy-MWCNTs/Fe3O4 conjugates. Doxycycline is a broad-spectrum antibiotic prescribed worldwide for treating a variety of infectious agents. However, limited drug bioavailability with unacceptable efficacy and safety profiles are the prime drawbacks of Doxy. To combat these pitfalls, we have employed and appraised the developed conjugates. Magnetic measurement studies have revealed superparamagnetic behavior of Fe3O4 NP-embellished MWCNTs. Successful loading of Doxy onto the Fe3O4 NP-embellished MWCNTs’ exterior have been imparted by transmission electron microscope image and Raman spectra. While Fourier transform-infrared and ultraviolet–visible spectrographs have corroborated composition and explored the probable mechanism of conjugation between Doxy and MWCNTs/Fe3O4. Zeta-potential studies demonstrated surface charges of constituents of Doxy-MWCNTs/Fe3O4 conjugates. When extrapolated to bactericidal potential, results suggest that conjugates have inhibited growth of the Gram-negative bacterium, Eschericia coli and Gram-positive bacterium, Bacillus subtilis more efficiently even at a lower concentration of drug loading. In these antibacterial studies the fate of conjugates was directed by magnetism, a targeted and prompt cellular uptake with enhanced bioavailability has substantially ameliorated the efficacy of Doxy. The drug release profile proved that Doxy-MWCNTs/Fe3O4 conjugates have much better sustained drug-release property than the conventional Doxy. The extended drug release time will reduce the dosing frequency as well.