Bi-functional carbonaceous hybrid nanocomposites with anticancer and antibacterial potential: synthesis, characterization, and cytotoxicity assessment.

Infectious diseases and cancers are the leading causes of mortality worldwide. Despite the discovery of antimicrobials and anticancer drugs, the mortality rate has not declined significantly. Hence, new novel agents with antibacterial and anticancer properties without toxicity are urgently needed. In the present study, carbonaceous hybrid nanocomposites multi-walled carbon nanotubes (MWCNT)/hydroxyapatite (HAp)/polyetheretherketone (PEEK)-MWCNT/HAp/PEEK were synthesized using Alphie 3D Tumbler Mixer (Synthesis Method-1), solid-state mixing (Synthesis Method-2), and chemical mixing and solvent casting (Synthesis Method-3). Synthesis Method-2 and Method-3 exhibited antibacterial activities at 250 and 500 µg/mL concentrations, and no antibacterial activity in the nanocomposite fabricated by Synthesis Method-1. However, nanocomposites prepared by Synthesis Method-1 demonstrated enhanced anticancer activity compared to Synthesis Method-2 and Synthesis Method-3. Moreover, these nanocomposites did not show any haemolytic activity at 250 and 500 µg/mL concentrations. These nanocomposites were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). SEM data demonstrated that nanocomposites fabricated by Synthesis Method-3 were a homogeneous, defect-free PEEK matrix with well-dispersed MWCNTs and HAp compared to Methods-1 and 2. EDS analysis showed that Synthesis Methods-2 and -3 exhibited enhanced PEEK and MWCNT dispersion. TGA analysis exhibited that Synthesis Method-3 led to the highest thermal stability. FTIR data demonstrated the presence of various functional groups in hybrid nanocomposites. XRD analysis confirmed that these nanocomposites were crystalline in nature. The TEM analysis confirms that amine-functionalized MWCNTs and HAp nanoparticles are well dispersed within the PEEK matrix. In conclusion, the synthesis strategy adopted has influenced and resulted in safe and bi-functional nanocomposites having antibacterial and anticancer activity in line with SDG-3.