In vitro cytotoxicity evaluation of a CMC-SA edible packaging film for migration and safety assessment

Edible raw materials have gained attention as sustainable food packaging films, which are often considered a priori safe for human consumption. However, cytotoxicity issues may arise due to the incorporation of additives or modifications of film functionality during the manufacturing process. This study introduces an integrated methodology for the evaluation of potential migration of cytotoxic substances from materials used for the development of conventional and biodegradable food packaging. Carboxymethyl cellulose (CMC) and sodium alginate (SA) were tested as raw materials of an edible (CMC-SA) film, while a low-density-polyethylene (LDPE) film was tested as a conventional material. The CMC-SA film exhibited higher water vapor transmission rate and water vapor permeability, and lower hydrophobicity compared to LDPE (WVTR_CMC-SA=1457.87 vs. WVTR_LDPE=3.43 g×m^-2×day^-1, WVP_CMC-SA=43.24 vs. WVP_LDPE=0.0048 g×m^-2×mm×day^-1×kPa^-1 and CA_CMC-SA=52.05 vs. CA_LDPE=94.28°, respectively). An analytical protocol based on EU Regulation 10/2011 was introduced, to evaluate the potential migration of cytotoxic packaging substances into food simulants, using different human cells. Caco2 cells were used to simulate human intestine, whereas Huh7 and Immortalized Human Hepatocytes (IHH) cells simulated human liver. Cell viability assays and gene expression results indicated that substances migrating from the tested packaging materials neither produced cell cytotoxicity, nor induced oxidative stress to Caco2 cells.