Delivery growth factors by layer-by-layer assembly in nanofibers for enhancing bone defect repairment along with...

In our daily life, bone defects with sensory losing caused by limb trauma, degenerative diseases, or tumor resection are very common. When the bone defect size exceeds the critical size, it cannot spontaneously heal. Therefore, clinical intervention and artificial bone materials are needed to repair damaged bone tissue and restore sensation. Here, we reported that Collagen (Col) and Chondroitin sulfate (CS) adsorbed into hydroxyapatite (HA) for long-time sustained release was used to prepare nanofibrous scaffolds (Col+CS)@HA through electrospining, fibroblast growth factor (FGF) and CS + Col as two layers were used to prepare (Col+CS)@HA-(FGF/CS + Col)₅ nanofiber scaffold through Layer-by-Layer (LBL) self-assembly technology. Interestingly, we found that neurogenesis could accelerate osteogenesis from RNA sequencing result. To confirm this result, we found that (Col+CS)@HA-(FGF/CS + Col)₅ scaffold could promote osteogenesis process in bone mesenchymal stem cells (BMSCs) regulated through extracellular regulated protein kinases 1/2 (Erk1/2) activated runt-related transcription factor 2 (Runx2) pathway. Furthermore, the transcriptional levels of downstream genes associated with osteogenesis were significantly elevated. Intriguingly, we also found that (Col+CS)@HA-(FGF/CS + Col)₅ scaffold could boost the differentiation of BMSCs into neurons and promote the transcriptional levels of neuron specific genes. As a result, we observed that new neuron was formed in Haversian canal in mice cranial defects area, which means (Col+CS)@HA-(FGF/CS + Col)₅ scaffold could not only promote osteogenesis, but also could enhance neurogenesis. Therefore, we believe this study is promising, as it provides new insights towards the process of bone defect repairment along with sensation restorement.