The hypoxic and acidic microenvironment created by GelMA hydrogels enhances the stem-like characteristics of lung cancer cells by inhibiting the MAPK signaling pathway.

Gelatin methacryloyl (GelMA), a photosensitive biomaterial, can form three-dimensional (3D) structures with suitable mechanical strength to effectively support cell growth. In this study, the ability of GelMA hydrogels to generate a hypoxic and acidic microenvironment was supported by methods such as visual colorimetry, Western blot, and WST-8 assay. Lung cancer cells (A549) and lung epithelial cells (BEAS-2B) were encapsulated in GelMA hydrogels in a one-step process for 3D culture. CCK-8 assay and Calcein/PI staining results revealed that A549 cells cultured in the 3D system exhibited higher viability than BEAS-2B cells. Moreover, 3D culture promoted stemness acquisition in A549 cells, as evidenced by enhanced drug resistance, increased colony-forming capacity, and upregulated expression of stemness-associated marker genes. We further investigated the regulatory role of the MAPK signaling pathway in this microenvironment. RT-PCR and Western blot analyses confirmed that the GelMA hydrogel-based 3D culture system suppressed the MAPK signaling pathway. These findings suggest that the hypoxic and acidic 3D culture system constructed using GelMA hydrogel promotes both proliferation and stemness maintenance of lung cancer cells, and that inhibition of the MAPK signaling pathway likely contributes critically to this effect.