Biocompatible L-carrageenan-gamma-maghemite nanocomposite for biomedical applications - synthesis, characterization and in vitro anticancer efficacy

Background: Carrageenans are naturally occurring hydrophilic, polyanionic polysaccharide bioploymers with wide application in pharmaceutical industries for controlled drug delivery. Magnetic nanoparticles with their exceptional properties enable them to be an ideal candidate for the production of functional nanostructures, thus facilitating them for biomedical applications. The development of novel nanocomposite by coupling the synergistic effects of the sulfated polysaccharide (iota carrageenan) and a magnetic nanoparticle (maghemite) may offer new interesting applications in drug delivery and cancer therapy. The nanocomposite was characterized by ultraviolet-visible spectroscopy, high resolution scanning electron microscopy, dynamic light scattering analysis, Fourier transform infrared spectroscopy and powder XRD to highlight the possible interaction between the two components. Biocompatibility and the anticancer efficacy of the nanocomposite were assayed and analysed in vitro. Results: Results suggested that iota carrageenans have electrostatically entrapped the maghemite nanoparticles in their sulfate groups. Biocompatibility of the nanocomposite (at different concentrations) against normal cell lines (HEK-293 and L6) was confirmed by MTT assay. Hoechst 33342 and 7-AAD staining studies under fluorescent microscopy revealed that the nanocomposite is able to induce appoptosis as the mode of cell death in human colon cancer cell line (HCT116). Cell apoptosis here is induced by following the ROS-mediated mitochondrial pathway, combined with downregulation of the expression levels of mRNA of XIAP and PARP-1 and upregulation of caspase3, Bcl-2 and Bcl-xL. Conclusions: This novel nanocomposite is biocompatible with potential properties to serve in magnet aided targeted drug delivery and cancer therapy.