BACKGROUND: Attachment of cells to fully hydrated hydrogel biomaterials, such as PEGDA, has proven challenging because of the hydrophobic cellular membrane. OBJECTIVE: To demonstrate undifferentiated human mesenchymal stem cells (hMSCs) and hMSC-derived chondrocytes infiltrated and attached to unmodified PEGDA hydrogel. METHODS: Human MSCs and MSC-Cys were cultured in and on PEGDA hydrogel. Attachment was verified by SEM and confocal microscopy and was accompanied by vinculin expression, indicating the presence of focal contacts. Infiltration was confirmed by H&E and fluorescence staining. RESULTS: Cells cultured on top of PEGDA hydrogel infiltrated the material on the order of micrometers. CONCLUSIONS: These findings will aid in understanding the cell-scaffold interaction for regenerative medicine constructs.