FIGURE 4.
Thermoplastic polyurethane (TPU) discs with different surface modifications and corundum‐blasted titanium control discs were tested in vitro. TPU surface modifications included three different degrees of surface roughness combined with three degrees of biphasic calcium phosphate (BCP)‐coating; low Ra: low surface roughness Ra 0.12 μm; med Ra: medium surface roughness Ra 8.4 μm, high Ra: high surface roughness Ra 22.72 μm; TPU, BCP‐: uncoated TPU; TPU, BCP+: double BCP dip‐coated TPU; TPU, BCP++: eight times BCP dip‐coated TPU. HBMSCs were plated and (a) Twenty‐four hours after culture on proliferation medium cell viability was determined using a PrestoBlue assay. Results were normalized to the biomaterial‐free well. (b) Additional discs with seeded hBMSCs were either sampled directly, or cultured for 21 days in osteogenic medium and calcification on the discs of both time points was colorimetrically quantified using an alizarin red‐S assay. (a/b) Significant differences (p < .05) were determined using ANOVA and Bonferroni post hoc correction. A pair of similar alphabetic letters depicts a significant difference between two conditions