3D-printed holder devices: An alternative approach for cell culture assays

Cell culture experiments are difficult to reproduce due to variability in methods and in the materials used. To this end, a 3D printed holder device for cell culture assays is proposed. Four base materials were evaluated: two PolyJet photopolymer resins, VeroClear™ and MED610™ (Stratasys, USA), and two FFF/FDM thermoplastic filaments, Facilan™ C8 (3D4Makers, The Netherlands) and polylactic acid (PLA) (ROSA Filaments, Poland). Cytotoxicity was assessed using immortalized human gingival fibroblasts (hTERT) in direct contact with the printed holders (n = 10), with viability measured at days 1, 3, and 7 using a resazurin-based assay. Statistical analysis was performed using one-way ANOVA or Kruskal-Wallis tests with post-hoc comparisons (p < 0.05). Results are expressed as mean ± SD. At day 7, the PLA group exhibited significantly higher cell viability (71.1 ± 11.0%) than all other groups (p < 0.001) and was the only material remaining above the ISO 10993-5 cytotoxicity threshold; therefore, it was selected for exploratory characterization. PLA optical profilometry analysis showed arithmetic roughness (Ra) of 1.37 ± 0.12 μm. During 21 days in culture medium, PLA holders showed stable pH values comparable to controls, negligible mass variation (<0.55%), no relevant FTIR spectral changes, and only minor SEM surface alterations. These preliminary findings support PLA as a promising candidate for short-term holder fabrication in direct-contact cell culture assays.