Chitosan/montmorillonite nanocomposite film as anticancer drug carrier: A promising biomaterial to treat skin cancers

The solvent-evaporation approach was used to produce a chitosan (CS)/montmorillonite (MMT) nanocomposite film containing the anticancer drug 5-fluorouracil (5-FU). The physicochemical and morphological characteristics, drug release profile, cytotoxic and microbiological properties of the nanocomposite films were evaluated to verify their potential as a biomaterial for the treatment of tumors. X-ray diffraction (XRD) confirmed the formation of a CS-MMT/5-FU intercalated nanocomposite and Fourier transform infrared (FTIR) detected the characteristic 5- FU bonds in the CS/5-FU and CS-MMT/5-FU nanocomposite films, suggesting successful incorporation of the drug. The addition of 5-FU to chitosan increased the contact angle from 60.5° to 65.2°, which was compensated by the incorporation of MMT, resulting in a minimum contact angle of 42.7° (maximum hydrophilicity) for CS-MMT/5-FU. This result influenced the swelling degree and the in vitro release of 5-FU. The higher hydrophilicity of CS-MMT/5-FU promoted an increase in the swelling ratio compared to the CS/5-FU nanocomposite. CS-MMT/5-FU also showed a sustained, lower 5-FU release rate with antimicrobial activity against S. aureus, E. coli and C. albicans without inducing cytotoxicity or cell death. These results can be explained by the accommodation of the drug between the MMT lamellae, which maintains the 5-FU release without affecting its microbiological activity and reducing its toxicological effects. This work demonstrates that combining montmorillonite and chitosan in a nanocomposite film has the technological potential to control the release of 5-FU, resulting in a non-toxic antimicrobial drug carrier with promising potential for the treatment of skin malignancies.