Journal: Polymers

Article Title: Osteoinductive and Biocompatibility Assessment of a 3D-Printed Polymeric–Hydroxyapatite Composite Interference Screw

doi: 10.3390/polym18101239

Figure Lengend Snippet: Scanning electron microscopy characterization of mesenchymal stem cell attachment and proliferation on three biomaterial compositions. Top panels ( A – C ): Biomaterial surfaces prior to cell seeding, showing the characteristic surface morphology of Group 1 (PCL + HA, 60/40) ( A ), Group 2 (PCL + PLGA, 50/50) ( B ), and Group 3 (PCL + PLGA + HA, 30/30/40) ( C ) respectively. Bottom panels ( D – F ): Mesenchymal stem cells after 21 days of culture in osteogenic differentiation medium, demonstrating robust cell attachment, spreading, and surface colonization on Groups 1 ( D ), 2 ( E ), and 3 ( F ), respectively. Panel ( G ): Higher magnification view (×3500) illustrating characteristic elongated morphology of healthy, proliferative mesenchymal stem cells with extensive filopodia and lamellipodia formation extending across the Group 3 biomaterial surface, indicating strong cell–substrate interactions and active synthetic activity.

Article Snippet: Human bone marrow-derived mesenchymal stem cells were obtained from PromoCell (Heidelberg, Germany) and cultured in Mesenchymal Stem Cell Growth Medium MSC2 according to the manufacturer’s instructions.

Techniques: Electron Microscopy, Cell Attachment Assay, Activity Assay

Journal: Polymers

Article Title: Osteoinductive and Biocompatibility Assessment of a 3D-Printed Polymeric–Hydroxyapatite Composite Interference Screw

doi: 10.3390/polym18101239

Figure Lengend Snippet: Alamar Blue assay evaluating mesenchymal stem cell metabolic activity on three 3D-printed biomaterial compositions over time. ( A ) Line graph showing percentage of cell metabolic activity measured at days 3, 7, 14, and 21 on PCL + HA (60/40), PCL + PLGA (50/50), and PCL + PLGA + HA (30/30/40) substrates. Days 3, 7, 14, and 21 refer to the duration of osteogenic differentiation culture, defined as Day 0 of osteogenic induction initiated after 3 days of proliferation medium pre-culture. ( B ) Corresponding bar graph representation of metabolic activity for each composition at individual time points (D3, D7, D14, D21). Data are presented as mean ± SEM (n = 3 biological replicates per group per timepoint). Statistical annotations indicate comparisons between material groups as follows: * comparison between PCL + PLGA + HA and PCL + HA; # comparison between PCL + PLGA + HA and PCL + PLGA in A. Normality of residuals was assessed using the Shapiro–Wilk test, and homogeneity of variances was assessed using Levene’s test; assumptions were met for all groups (Shapiro p > 0.05; Levene p > 0.05). Statistical differences were evaluated by two-way ANOVA, followed by Tukey multiple comparisons with Bonferroni correction.#: PCL + PLGA + HA vs. PCL + PLGA (# p < 0.05, ## p < 0.01, (n = 3 per group)) *: PCL + PLGA + HA vs. PCL + HA ( p < 0.05 (*), p < 0.01 (**), p < 0.001 (***)).

Article Snippet: Human bone marrow-derived mesenchymal stem cells were obtained from PromoCell (Heidelberg, Germany) and cultured in Mesenchymal Stem Cell Growth Medium MSC2 according to the manufacturer’s instructions.

Techniques: Alamar Blue Assay, Activity Assay, Comparison

Journal: Polymers

Article Title: Osteoinductive and Biocompatibility Assessment of a 3D-Printed Polymeric–Hydroxyapatite Composite Interference Screw

doi: 10.3390/polym18101239

Figure Lengend Snippet: Relative gene expression of osteogenic markers in MSCs cultured on Implant A and Implant B 3D-printed PCL + PLGA + HA (30/30/40) composite scaffolds at days 14 and 21 of osteogenic differentiation. Days 14 and 21 refer to the duration of osteogenic differentiation culture, initiated after 3 days of proliferation medium pre-culture. Implant A: surface-coated PCL + PLGA + HA (30/30/40); Implant B: uncoated PCL + PLGA + HA (30/30/40) control. ( A ) Alkaline phosphatase (ALP), ( B ) Runt-related transcription factor 2 (RUNX2), and ( C ) Bone gamma-carboxyglutamate protein (BGLAP). Gene expression was normalized to GAPDH using the 2 −ΔΔCt method. Data are presented as mean ± SD (n = 4 biological replicates, each analyzed with three technical replicates). Normality of residuals was assessed using the Shapiro–Wilk test, and homogeneity of variances was assessed using Levene’s test; assumptions were met for all genes (Shapiro p > 0.05; Levene p > 0.05). Statistical differences were evaluated gene-by-gene using a two-way ANOVA (Time_Point: Day 14 vs. Day 21; Condition: Implant A vs. Implant B) including the interaction term (Time_Point × Condition), followed by Tukey/emmeans post hoc multiple comparisons with Bonferroni correction. Significance is indicated as follows: p < 0.05 (*) and p < 0.001 (***).

Article Snippet: Human bone marrow-derived mesenchymal stem cells were obtained from PromoCell (Heidelberg, Germany) and cultured in Mesenchymal Stem Cell Growth Medium MSC2 according to the manufacturer’s instructions.

Techniques: Gene Expression, Cell Culture, Control