gms | German Medical Science

Objectives: This study aims to develop a biomimetic engineered periosteum scaffold using MEW-fabricated PCL scaffold and bioprinting hydrogel scaffold to accelerate bone repair.

Methods: Our previous investigation determined that MEW-based PCL unidirectional scaffolds with a 30° angle between fibers exhibited superior performance in guiding cell growth compared to those with 70° and 90° angles [1]. A bidirectional scaffold was designed and fabricated by rotating the printing direction 90° after obtaining the single-layer unidirectional scaffold. Cell culture and mechanical experiments were performed on the PCL scaffolds. After 7, 14, and 21 days of incubation, the scaffolds were subjected to live-dead and Phalloidin/DAPI staining to observe cell growth. And then the optimized PCL scaffold, with or without collagen coating [1], was combined with two different hydrogel scaffolds [5% Alginate + 6% Gelatin (Alg/Gel) vs. 3% Alginate + 9% Methylcellulose in plasma (Alg/MC-Plasma)] to create hybrid periosteum scaffolds following our previously established method [2], [3]. After 1, 7, 14, and 21 days of incubation, the hybrid scaffolds were evaluated using live-dead and Phalloidin/DAPI staining to observe cell growth. Statistical analysis involved one-way ANOVA with Tukey's post hoc method for multiple group comparisons and t-tests for comparisons between 2 groups, with significance set at p < 0.05.

Results and conclusion: The unidirectional scaffold exhibited significantly greater deformation during the initial testing procedure and lower Fmax when the force was applied along the 150° direction than the unidirectional scaffold when the force was applied along the 30° direction and the bidirectional scaffold. While the Fmax of the unidirectional scaffold along the 30° showed no significant difference with the bidirectional scaffold group. In the cell experiments, it showed that bidirectional scaffolds exhibited superior and faster guidance of cells on PCL scaffolds in comparison of unidirectional scaffolds (Figure 1A [Fig. 1]). The outcomes of hybrid periosteum scaffolds showed that combining collagen-coated PCL scaffold with Alg/MC-Plasma scaffold yielded optimal cell activity and enhanced cell growth on the scaffolds (Figure 1B [Fig. 1]). In conclusion,the hybrid PCL-Alg/MC-Plasma scaffolds based on MEW and bioprinting techniques could be utilizedas a biomimic periosteum scaffold to repair bone defects.