Exosomes are a kind of membrane vesicles that encapsulate proteins, RNAs and other substances selected and isolated in cells, which can regulate the biological reactions of distal cells and tissues through the circulatory system, and have a good application prospect in the regeneration of oral and maxillofacial tissues. This article reviews the new progress of exosomes in the field of oral and maxillofacial tissue regeneration engineering such as dental pulp, periodontium, bone, skin, and nerve, and summarizes the experience of oral and maxillofacial tissue regeneration and functional reconstruction based on the research of exosomes in recent years. The purpose of this article is to provide reference for research in this field and to look forward to the clinical translation and application prospect of exosome-based oral and maxillofacial tissue regeneration technology.

Objective:To explore the effect of mesenchymal stem cell (MSC) derived exosomes induced by strontium on osteogenic differentiation and angiogenesis, providing a new idea for the repair of vascularized bone defects. Methods:Strontium was added to bone marrow mesenchymal stem cell (BMSC) and strontium-exosomes were then extracted by ultracentrifugation, using untreated BMSC exosomes as control. The cell internalization was observed by fluorescent labeling of exosomes. Alkaline phosphatase (ALP) staining, ALP activity determination and qRT-PCR analysis were used to study the effects of exosomes on the osteogenic differentiation of BMSC. The effects of exosomes on vascular formation of endothelial cells in vitro were evaluated by wound healing assay, transwell assay, tube formation assay and other methods. Finally, the potential mechanism of strontium-exosomes in promoting osteogenesis and angiogenesis was discussed by the miRNA sequencing. Results:The stimulation of strontium ion could not affect the secretion of exosomes by BMSC, and the strontium-exosomes could be internalized by BMSC. Strontium-exosomes could enhance the ALP activity of BMSC and up-regulate the transcription of osteogenesis-related genes ALP and runt-related transcription factor 2 (Runx2). Strontium-exosomes could also promote the migration and the tubule formation of endothelial cells, and significantly increase the transcription of angiogenic-related genes of VEGF, ANG1 and FGF. The miRNA sequencing analysis revealed that the stimulation of strontium ions induced the differential expression of miRNA in exosomes derived from BMSC. The up-regulated expression of miR-125b-5p, miR-132-3p, miR-31a-5p and miR-450b may be then involved in promoting osteogenic differentiation and angiogenesis of cells. Conclusions:The strontium-exosomes have dual functions of promoting angiogenesis and osteogenic differentiation.

Objective:?To develop a novel strategy for the construction and cultivation of three-dimensional cell spheroids from dental pulp stem cells (DPSCs) with coaxial-electrospray method. Methods:?DPSCs were isolated from clinically collected teeth and then identified through flow cytometry. Core-shell microcapsules were constructed. By adjusting the concentration and flow rates of internal and external phase solutions and cell density, the morphology and size of the microcapsules were observed to get the best preparation condition. Cell viability was detected through live/dead staining and CCK-8 assay, and the spheroids was observed using cytoskeletal staining. Results:?DPSCs were successfully isolated and cultured. Cell-laden microcapsule with alginate layer and carboxymethylcellulose core structure was fabricated. When the cell density within microcapsules reached 1×108 cells/mL, the DPSCs within a single microcapsule formed a spheroid spontaneously with a diameter of (101.93±10.11) μm within 24 hours. Live/dead staining showed the cell survival rate did not decrease within 7 days(P>0.05). CCK-8 assay revealed an increase in cell proliferation rate to (114.91%±7.70%) after 4 days of culture (P<0.05), which further grew to (169.05%±5.29%) at 7 days (P<0.001). Cytoskeletal staining revealed that the cultured cells formed dense spheroids. Conclusions:? These core-shell microcapsules could promote the formation of DPSCs cell spheroids and maintain their long-term survival.

Objective:To investigate the effects of Krüppel-like factor 4 (KLF4) in a high glucose and inflammatory environment on mitochondrial energy metabolism and osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). Methods:The localization and expression of KLF4 in hPDLSCs was investigated under high glucose inflammatory environment using immunofluorescence and western blot. ALP staining and alizarin red staining were used to study osteogenic differentiation of hPDLSCs in hyperglycemic inflammatory environment. Lentivirus knockdown and overexpression techniques were used to detect the expression of KLF4 after virus infection by qRT-PCR and Western blot. CUT&RUN technique was used to analyze the changes of KLF4 binding DNA and related signaling pathways in hPDLSCs under high glucose inflammatory environment. The impact of KLF4 on oxidative respiratory capacity of hPDLSCs was explored using a Seahorse energy metabolism analyzer. Results:KLF4 expression was downregulated under high glucose inflammatory conditions, accompanied by reduced ALP activity, calcium nodule formation (all P<0.001), and expression of RUNX2 and OCN (P<0.001). Knockdown of KLF4 resulted in a significant decrease in ALP activity (P<0.001) and reduced calcium nodule formation (P<0.001) in hPDLSCs, while overexpression of KLF4 promote osteogenic differentiation. Under high glucose inflammatory environment, the downstream regulatory genes of KLF4 were enriched in energy metabolism, osteogenesis and other related pathways. KLF4 knockdown reduced OCR levels and increased ECAR levels in hPDLSCs, while KLF4 overexpression increased OCR levels and decreased ECAR levels. Conclusions:In a high glucose inflammatory environment, the osteogenic differentiation ability of hPDLSCs was compromised, and KLF4 may enhance the mitochondrial oxidative phosphorylation capacity to restore this ability.

Objective:?To investigate the role of has_circ_0008717 during the process that human amnion-derived mesenchymal stem cells (hAMSCs) promote angiogenesis of human umbilical vein endothelial cells (HUVECs). Methods:?Wound healing assay, Transwell migration and tube formation were used to confirm the pro-angiogenic capacity of conditioned medium from hAMSCs (hAMSC-CM) on HUVECs, qRT-PCR and were used to detect the change of level of the potential pro-angiogenic relative circRNAs and genes in HUVECs after treated with hAMSC-CM, among them, has_circ_0008717 and VEGFA attracted our attention. siRNAs specially targeted has_circ_0008717 were used to down-regulate the level of has_circ_0008717 in HUVECs treated with hAMSC-CM, and then qRT-PCR was used to detect were used to evaluate the change of level of VEGFA caused by down-regulation of has_circ_00087, afterwards,wound healing assay, Transwell migration and tube formation were used to assess the effects of down-regulation of has_circ_0008717 on HUVECs treated with hAMSC-CM. Results: Enhanced migration and tube formation in HUVECs induced by hAMSC-CM were observed (P＜0.05). And has_circ_0008717 been the mostly up-regulated circRNA among several potential pro-angiogenic relative circRNAs was selected for further investigation (P＜0.05). Increased expression of vascular endothelial growth factor A (VEGFA) was observed among a few pro-angiogenic relative genes (P＜0.05). Furthermore, these can be inhibited by silencing has_circ_0008717 in HUVEC treated with hAMSC-CM (P＜0.05). Conclusion: has_circ_0008717 might be involved in the pro-angiogenic role of hAMSC-CM in HUVECs.

Objective:To investigate the role of Hedgehog pathway in the mice osteoarthritis (OA). Methods:10-week-old male C57BL/6J mice were subjected to destabilization of the medial meniscus (DMM) surgery. The left hindlimb knee was the experimental group, with right hindlimb knee as control. Mice were sacrificed 8 weeks after the surgery and knee joints were harvested for subsequent experiments. Stereomicroscope was used to observe the damage degree of knee joint. Micro-CT was used to detect the meniscus calcification. Safranin O-Fast Green staining, toluidine blue staining, hematoxylin-eosin (HE) staining and immunofluorescence staining of Col2 were used to observe the changes of cartilage extracellular matrix and chondrocytes. The expression of genes related to articular cartilage homeostasis (Col2, Sox9, Mmp13) and Hedgehog signaling pathway (Smo, Gli1, Ptch1) were detected by RT-qPCR. ATDC5 cell model of OA was established using IL-1β, treated with NVP-LDE225 as Smo inhibition. RT-qPCR was used to detect the expression of Smo, Gli1, Ptch1, Col2, Sox9 and Mmp13. Results:Mouse OA model was established successfully after the DMM surgery. The experimental mice present knee joint enlargement, destroyed cartilage layer, higher meniscus calcification volume, knee cartilage deformation, decreased content of extracellular matrix proteoglycan and disordered arrangements of the chondrocytes. The immunofluorescence staining of Col2 indicated an aberrant extracellular matrix. In contrast, Col2 and Sox9 were significantly downregulated. Mmp13 and Hedgehog related genes (Smo, Ptch1, Gli1) was significantly increased in the OA model mice（P＜0.05）. Besides, inhibition of Smo in ATDC5 cell OA model antagonized the downgraded gene expression of Col2 and Sox9 and upgraded gene expression of Mmp13, Smo, Ptch1 and Gli1 induced by IL-1β, thus attenuating the severity of OA（P＜0.05）. Conclusions:Hedgehog signaling was activated in OA and Hedgehog signaling might be involved in the occurrence and development of OA.

Objective:?To analyze the clinical effect of implant-supported prosthetic rehabilitation after reconstruction with fibular muscle flap for mandibular defect. Methods:?Fifteen patients who underwent mandibular defect reconstruction with fibular muscle flap due to tumor or inflammation were included. Evaluate the retention rate of implants, marginal bone level of implants, depth of soft tissue exploration, and modified sulcus bleeding index 2 years after implant restoration. Results: A total of 62 implants were included, and the implant retention rate was 100% after 2 years of functional use. There was no statistically significant difference in the marginal bone level of the implant, and there was no statistically significant difference in the depth of soft tissue exploration around the implant and the modified sulcus bleeding index (P＞0.05). When the depth of implant probing is greater than 4 mm, the modified sulcus bleeding index significantly increases (P＜0.05). Conclusions:?The reconstruction of mandibular defect with fibular muscle flap and implantation of dentures has achieved good clinical efficacy. Implants with a soft tissue depth of less than 4 mm around the implant exhibit better stability.

Post-translational modifications (PTMs) are essential for developmental biology and homeostasis of bone and are closely associated with bone disease occurrence. This article reviews the role of several common forms of PTMs in fracture healing, providing some reference for the therapy of fracture healing.

The cross-dermal interaction and secretion of related signaling molecules drived cell differentiation and organogenesis. From pattern formation, morphogenesis, to functional differentiation of teeth, various cross-dermal signaling molecules were involved. In recent years, with the application of novel technologies such as single-cell transcription profiling, some unique cell subpopulations and intercellular interactions have been reported, promoting further research on tooth development. This article reviews new findings in the use of single-cell transcriptome sequencing to study tooth development processes in recent years, with a focus on advances in cross-dermal intercellular signaling.

In recent years, several studies have shown that long non-coding RNA (lncRNA) plays crucial roles at multiple levels, such as epigenetic level, transcriptional and post-transcriptional levels. lncRNA is extensively involved in the biological behavior of PDLSCs, including proliferation, inflammatory immune response, and multidirectional differentiation. A great number of lncRNAs are significantly differentially expressed in healthy periodontal tissues and tissues affected by periodontitis, and the differential expression of lncRNAs is closely related to the abnormal biological behavior of PDLSCs. This paper reviews the mechanisms by which lncRNA regulates the biological behavior of PDLSCs affected by periodontitis.