Experimental study on the influence of PDA-modified PDMS on the biological behavior of mouse fibroblasts

Objective Polydimethylsiloxane (PDMS) is widely used across various fields due to its biocompatibility and chemical inertness. However, its surface hydrophobicity limits its application in cell culture. This study modifies PDMS surfaces with polydopamine (PDA) to mitigate hydrophobicity, evaluates fibroblast biocompatibility on modified substrates, and explores its potential for wound healing applications. Methods PDA-modified PDMS surfaces (0.05%, 0.1%, 0.2%, 0.3%, 0.4, and 0.5% PDA to modify PDMS surfaces and measured contact angles. Mouse L929 fibroblasts were co-cultured on these surfaces. The optimal PDA concentration for cell proliferation was determined using the CCK8 assay. Cell spreading, migration, and related gene expression were evaluated via FITC and DAPI staining, cell scratch assays, and qRT-PCR. Statistical analysis employed one-way ANOVA and t-tests. Results All PDA concentrations significantly reduced material contact angles (P < 0.01). At 48 h of composite culture, the 0.2% PDA-PDMS mixture exhibited the highest absorbance in CCK-8 assays, with significantly increased cell viability observed at 48 and 72 h (P < 0.05). The cell scratch assay showed that L929 had largely recovered by 36 hours post-scratch, with no significant difference compared to cells cultured on non-composite materials (P > 0.05). qRT-PCR analysis revealed relatively high expression of transforming growth factor-β1 (TGF-β1) and collagen α-1 (III) chain (COL3A1) at 24 and 36 hours post-cultivation (P < 0.05), while α-smooth muscle actin (α-SMA) showed elevated relative expression at 48 hours (P < 0.05). Conclusion PDA significantly improved the hydrophobicity of the PDMS surface and enhanced its wettability. PDA-modified PDMS at different concentrations generally exhibited varying cell proliferation capacities, with 0.2% PDA demonstrating the highest cell proliferation and good cell viability. PDA surface modification also enhanced cell migration ability, improved cell morphology and spreading, and increased the expression of related genes.