This study develops a novel strategy for regenerative therapy of musculoskeletal soft tissue defects using a dual-phase multifunctional injectable gelatin-hydroxyphenyl propionic acid (Gtn-HPA) composite. The dual-phase gel consists of stiff, degradation-resistant, ≈2-mm diameter spherical beads made from 8 wt% Gtn-HPA in a 2 wt% Gtn-HPA matrix. The results of a 3D migration assay show that both the cell number and migration distance in the dual-phase gel system are comparable with the 2 wt% mono-phase Gtn-HPA, but notably significantly higher than for 8 wt% mono-phase Gtn-HPA (into which few cells migrated). The results also show that the dual phase gel system has degradation resistance and a prolonged growth factor release profile comparable with 8 wt% mono-phase Gtn-HPA. In addition, the compressive modulus of the 2 wt% dual-phase gel system incorporating the 8 wt% bead phase is nearly four-fold higher than the 2 wt% mono-phase gel (5.3 ± 0.4 kPa versus 1.5 ± 0.06 kPa). This novel injectable dual-phase Gtn-HPA composite thus combines the advantages of low-concentration Gtn-HPA (cell migration) with high-concentration Gtn-HPA (stiffness, degradation resistance, slower chemical release kinetics) to facilitate effective reparative/regenerative processes in musculoskeletal soft tissue.

中文翻译：

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一种可注射的多功能双相珠增强明胶基质，允许间充质干细胞浸润，用于肌肉骨骼软组织修复

本研究开发了一种使用双相多功能可注射明胶-羟苯基丙酸 (Gtn-HPA) 复合材料再生治疗肌肉骨骼软组织缺损的新策略。双相凝胶由坚硬、抗降解、直径约 2 毫米的球形珠子组成，由 8 重量% Gtn-HPA 在 2 重量% Gtn-HPA 基质中制成。3D 迁移测定的结果表明，双相凝胶系统中的细胞数量和迁移距离均与 2 wt% 的单相 Gtn-HPA 相当，但明显高于 8 wt% 的单相 Gtn -HPA（少数细胞迁移到其中）。结果还表明，双相凝胶系统具有与 8 wt% 的单相 Gtn-HPA 相当的抗降解性和延长的生长因子释放曲线。此外，包含 8 wt% 珠相的 2 wt% 双相凝胶系统的压缩模量比 2 wt% 单相凝胶高近四倍（5.3 ± 0.4 kPa 对 1.5 ± 0.06 kPa）。因此，这种新型可注射双相 Gtn-HPA 复合材料结合了低浓度 Gtn-HPA（细胞迁移）和高浓度 Gtn-HPA（刚度、抗降解性、较慢的化学释放动力学）的优点，以促进有效的修复/再生过程在肌肉骨骼软组织中。