Innovative chitosan-polyacrylic acid-MoS2 nanocomposite for enhanced and pH-responsive quercetin delivery

Cancer remains a global health challenge, with current treatments often leading to adverse side effects. Herein, a pH-sensitive, biocompatible nanocomposite composed of chitosan (CS), polyacrylic acid (PAA), and MoS2 nanosheets, loaded with quercetin (QCT) as a model anticancer drug has been synthesized via the water-oil-water (W/O/W) emulsification method, with the aim to be used for targeted breast cancer treatment. Characterization via Fourier-transform infrared spectroscopy (FT-IR) revealed strong interaction between the polymers via hydrogen bonding, and X-ray diffraction (XRD) showed a reduction in the level of crystallinity upon drug loading. Dynamic light scattering (DLS), zeta potential, and field-emission scanning electron microscopy (FE-SEM) tests revealed that the synthesized nanocarriers were spherical in shape and had a hollow structure, with a mean size of 484 nm and a high zeta potential of +44.3 mV, which confirms their high colloidal stability. The addition of MoS2 nanosheets to the polymeric mixture increased drug loading and encapsulation efficiency to 47% and 89%, respectively. The nanocomposite showed high potential as a pH-responsive drug delivery system, releasing 97% and 68% of QCT in acidic and neutral environments, respectively, over 96 hours. The biological performance was investigated using MTT and flow cytometry assays, which confirmed the efficiency of the nanocomposite for tumor cell removal.