Transcriptome analysis revealed the symbiosis niche of 3D scaffolds to accelerate bone defect healing

3D printed scaffolds have been shown to be superior in promoting tissue repair, but the cell-level specific regulatory network activated by 3D printing scaffolds with different material components to form a symbiosis niche have not been systematically revealed. Here, three typical 3D printed scaffolds, including natural polymer hydrogel (Gelatin-methacryloyl, GelMA), synthetic polymer material (Polycaprolactone, PCL) and bioceramic (β-tricalcium phosphate, β-TCP), were fabricated to explore the regulating effect of the symbiotic microenvironment during bone healing. Enrichment analysis showed that hydrogel promotes tissue regeneration and reconstruction by improving blood vessel generation by enhancing oxygen transport and red blood cell development. The PCL scaffold regulates cell proliferation and differentiation by promoting cellular senescence, cell cycle and DNA replication pathways, accelerating the process of endochondral ossification and the formation of callus. The β-TCP scaffold can specifically enhance the expression of osteoclast differentiation and extracellular space pathway genes to promote the differentiation of osteoclasts and promote the process of bone remolding. In these processes, specific biomaterial properties can be used to guide cell behavior and regulate molecular network in the symbiotic microenvironment to reduce the barriers of regeneration and repair.研究表明，3D打印支架在促进组织修复方面性能更优，但由不同材料组分制备的3D打印支架所激活的、用于构建共生生态位的细胞层面特异性调控网络，尚未得到系统性阐释。本研究制备了三类典型3D打印支架，分别为天然高分子水凝胶（明胶甲基丙烯酸酯，Gelatin-methacryloyl，GelMA）、合成高分子材料（聚己内酯，Polycaprolactone，PCL）与生物陶瓷（β-磷酸三钙，β-tricalcium phosphate，β-TCP），旨在探究骨愈合过程中共生微环境的调控作用。富集分析结果显示，该水凝胶可通过增强氧气运输与红细胞生成，促进血管生成，进而推动组织再生与重构。聚己内酯（PCL）支架可通过激活细胞衰老、细胞周期及DNA复制通路，调控细胞增殖与分化，加速软骨内骨化进程与骨痂形成。β-磷酸三钙（β-TCP）支架可特异性上调破骨细胞分化与细胞外空间通路相关基因的表达，从而促进破骨细胞分化与骨重塑进程。在此过程中，可通过特定生物材料特性引导细胞行为、调控共生微环境中的分子网络，从而降低再生修复的阻碍。