pH-responsive chitosan/acrylamide/gold/nanocomposite supported with silver nanoparticles for controlled release of anticancer drug.

In this study, we prepared a pH-responsive nanocomposite hydrogel based on chitosan grafted with acrylamide monomer and gold nanoparticles using gamma irradiation method (Cs-g-PAAm/AuNPs). The nanocomposite was enhanced with a layer coating of silver nanoparticles to improve the controlled release of the anticancer drug fluorouracil while increasing antimicrobial activity and decreasing the cytotoxicity of silver nanoparticles in nanocomposite hydrogel by combining with gold nanoparticles to enhance the ability to kill a high number of liver cancer cells. The structure of the nanocomposite materials was studied using FTIR spectroscopy and XRD patterns, which demonstrated the entrapment of gold and silver nanoparticles within the prepared polymer matrix. Dynamic light scattering data revealed the presence of gold and silver in the nanoscale with the polydispersity indexes in the mid-range values, indicating that distribution systems work best. Swelling experiments at various pH levels revealed that the prepared Cs-g-PAAm/Au-Ag-NPs nanocomposite hydrogels were highly responsive to pH changes. Bimetallic pH-responsive Cs-g-PAAm/Au-Ag-NPs nanocomposites exhibit strong antimicrobial activity. The presence of AuNPs reduced the cytotoxicity of AgNPs while increasing their ability to kill a high number of liver cancer cells.Cs-g-PAAm/Au-Ag-NPs has a high amount of fluorouracil drug loaded at pH 7.4 reaching 95 mg/g with a maximum drug release of 97% within 300 min. Cs-g-PAAm/Au-Ag-NPs have been recommended to use as oral delivery of anticancer drugs because they secure the encapsulated drug in the acidic medium of the stomach and release it in the intestinal pH.