Table 1.
Effect of different EVs on dental tissue regeneration
| Regeneration tissue | EVs source | Delivery strategy | Study model | EVs concentration/dose | Outcome in vivo | References |
|---|---|---|---|---|---|---|
| Maxillofacial tissue | ADMSCs | Intravenous injection | Rat BRONJ model | 1 µg/kg | After treatment with ADMSC-EVs, bone parameters, including BV/TV, Tb·N, Tb·Th were increased, whereas Tb·Sp declined. Moreover, fewer necrotic bones but more osteoclasts were found in the EVs group. There were also more collagen and vessels in the EVs group. | [45] |
| BMMSCs | Intravenous injection | Rat BRONJ model | 30 µg | In a rat BRONJ model, some genes in maxillary, such as p21 and pRB were upregulated. Moreover, osteoclasts in the EVs group were not apoptosis, which showed opposite results in the control group. | [46] | |
| BMMSCs | Injection for each limb | Rat proximal tibial condyles | 19.2 µg | In a rabbit proximal tibial condyles implanting EVs model for three days, the bone density was higher by 47.2% than that in control groups on average. | [47] | |
| DPSCs | Collagen | Rat jaw-bone defect model | 100 µg | In a rat mandibula defect model, rats treated with DPSC-EVs showed an increase in bone mineral density, and the thickness of the buccal-lingual increased as well. | [48] | |
| SCAPs | Injection locally | Mouse palatal gingiva wound healing model | 40 µg | In the defect area of mice gingiva, after injecting SCAP-EVs, it formed newly epidermis and connective tissues, with high expressions of COL1 and fibronectin. Furthermore, there formed new blood vessels in the defect area. | [50] | |
| GMSCs | SIS-ECM laden with EVs | Rat critical-sized tongue defect model | Not mentioned | In a rat critical-sized tongue defect model, rat treated with SIS-ECM laden with GMSC-EVs facilitate recovery of epithelial layers and the regeneration of taste buds. | [41] | |
| EPI-NCSCs | Not mentioned | Rat FNI model | Not mentioned | The FNI rat recovered eyelid-buccal synkinesis, and the group treated with EPI-NCSCs showed higher amplitude during the blink reflex in the rats’ left buccal territory. | [49] | |
|
Periodontal tissue Dental-pulp |
ADMSCs | Injection locally | Rat periodontitis model | 80–150 µg | In a rat periodontitis model, rat injected ADMSC-EVs showed cementum, periodontal fibers and alveolar bone formation. Moreover, newly formed alveolar bone showed various reversal lines and new osteoid tissue. | [57] |
| ADMSCs | PLGA/pDA | Rat subcutaneous transplantation with the tooth root slice model | Not mentioned | Periodontitis rats treated with ADMSC-EVs showed a few high-density spots and bone nodules on the edge of the defect area. Meanwhile, osteogenesis related genes such as ALP, RUNX2, OCN were upregulated. | [58] | |
| BMMSCs | Collagen | Rat periodontitis model | 40 mg EVs/sponge | Periodontitis rats treated with BMMSC-EVs showed oriented periodontal fibers span between the newly-formed bone and root surface, and higher BV/TV was seen compared with the other groups. | [54] | |
| BMMSCs | Hydrogel | Rat periodontitis model | 500 µg/ml | In a rat periodontitis model, rats treated with BMMSC-EVs on hydrogel had fewer TRAP positive cells with lower OPG/RANKL ratio, and fibers destruction and alveolar bone loss were lower as well. | [55] | |
| DPSCs | Chitosan hydrogel | Mouse periodontitis model | 50 µg | Mice treated with DPSC-EVs showed a lower alveolar bone loss in experiment groups. Additionally, it showed the thicker epithelial tissue layers on periodontal bone. | [61] | |
| DPSCs | Injection locally | Mouse periodontitis model | 1 million cells secretory EVs | In a mouse periodontitis model, injecting 3D-cultured EVs arose more alveolar bone and less inflammatory cells, which occurred less osteoclasts in the periodontium. In addition, proinflammatory genes including IL-1a, IL-1 β, Ccl12, TNF were downregulated. | [62] | |
| DPSCs | Injection locally | Mouse periodontitis model | 75 million particles | In a mouse periodontitis model, EVs-treated group showed the least alveolar bone loss, while TRAP staining showed EVs inhibited osteoclast-like colonies. | [60] | |
| DPSCs | Gelatin | Mouse subcutaneous transplantation with the tooth root slice model | 250 µl/scaffold | In contrast with the control group, more dentin and collagen were observed. Moreover, the account of DMP positive cells was higher. | [97] | |
| DFCs | Collagen | Rat periodontitis model | Not mentioned | New bone formation and newly bone showed denser outcomes compared to other groups. In addition, the higher thickness of trabecular was seen in the EVs-treatment group. | [64] | |
| DFCs (LPS-preconditioned) | Hydrogel | Rat periodontitis model | 500 µg/ml | After treated DFC-EVs, the distance from the cementoenamel junction to the alveolar bone crest was shortened significantly, with obviously alveolar bone formation and periodontal tissue arranged in a dense. | [72] | |
| DFCs | Collagen | Mouse periodontitis model | 40 µg | Rats treated with DFC-EVs had increased BV/TV, with more trabecular bone continuously and completely. Moreover, more staining for OCN, OPN were found and more osteogenesis-gene expressed (such as ALP, MMP-2). | [65] | |
| DFCs (LPS-preconditioned) | HA | Dog periodontitis model | 200 µg | In a dog periodontitis model, HA carried DFC-EVs formed denser, more regular and wider periodontal ligaments, attaching new fibers to the cementum layer. Also significantly enhanced the bone parameters, including BV/TV and Tb·Sp. | [71] | |
| Dendritic cells |
Injection locally/ intravenous injection |
Mouse periodontitis model | 200 million particles | Mice with periodontal diseases treated with EVs from dendritic cells by local injection promoted soft tissues covered on the alveolar bone better. | [59] | |
|
GMSCs (TNF-α treated) |
Injection locally | Mouse periodontitis model | 200 µg | In a mouse periodontitis model, mice injected GMSC-EVs had less bone resorption and fewer TRAP-positive cells. | [39] | |
| GMSCs | PLGA | Rat periodontitis model | “full” EVs in PLGA | On the one hand, GMSC-EVs upregulated the expression of IL-10 and TGF-β significantly, whereas they downregulated the level of TNF-α. On the other hand, the defect area of rats’ alveolar bone was significantly increased. Furthermore, osteogenic makers such as BMP2, RUNX2 and OCN were highly expressed. | [66] | |
| M2-Macrophages | Injection locally | Mouse periodontitis model | 30 µl | In a mouse periodontitis model, after injecting EVs derived from M2-macrophage, less bone loss was found compared with the no EVs group. | [56] | |
| PDLSCs | β-TCP | Rat periodontitis model | 150 µg/µl | In a rat periodontitis model, β-TCP carried EVs to the defect area had positive functions, in which the surface of the alveolar bone was more smooth, the periodontal fiber was more regular, also more collagen formation. The gene expression levels of OCN and RUNX2 were upregulated. | [68] | |
| PDLSCs | Gel-Alg Hydrogel | Rat alveolar bone defect model | 2 µg/µl | Rats treated with PDLSC-EVs formed more new bones. Similarly, the bone parameter of BV/TV in EVs groups was higher than that in no-treatment groups. | [67] | |
| SCAPs | Injection locally | Mouse periodontitis model | 5 µg | Periodontitis mice injected with SCAP-EVs showed less bone resorption. In the periodontal tissue, the level of TNF-α and IL-8 also decreased. | [63] | |
| SHEDs | β-TCP | Rat periodontal defect model | 2 µg/µl | Periodontal rats treated with β-TCP/EVs had gained more newly-bone and more collagen accompanied by new blood vessels than the control group. EVs also enhanced COL1, and increased BV/TV. | [69] | |
| Salivary | Injection locally | Mouse periodontitis model | Not mentioned | Exosomal miR-25-3p treatment group showed lower CD4+and CD8+T cells from TNF-α or IL-17, taking effect on developing diabetes-associated periodontitis. | [37] | |
| DPSCs | Collagen | Mouse tooth root slice model | 1.25 million cells’ EVs in 1cm2 collagen membrane | In the root slice model, collagen membrane immobilized with DPSC-EVs increased odontogenic markers, such as DMP1, DPP on explant sections. The osteogenesis markers and angiogenesis markers such as vWF, BMP2, TGF-β, PDGF, RUNX2 were upregulated. | [76] | |
| DPSCs (LPS-preconditioned) | Peptide-hydrogel | Rat dental pulp removed model | 200 µg/ml | In a pulp-removing rat model, treated by DPSC-EVs facilitated more blood vessels and newly connective tissue formation. | [79] | |
| DPSCs |
1) Implantation; 2) Injection locally |
(1) Mouse subcutaneous transplantation with the tooth root slice model; (2) Dog dental pulp removed model |
Not mentioned | In the model of nude mice implanted tooth scaffold under dorsum, EV-treatment groups showed dentin-like tissue with higher vessel density; in the dog dental pulp removed model, after injecting EVs locally, it showed dental-pulp like tissue formation with high expression of DSPP and DMP-1. | [81] | |
| DPTs/DPCs | Collagen with SCAPs | Mouse in vivo implant model based on TDM | 160 µg/ml | Pre-dentin-like tissue appeared with a number of blood vessels, and formed some odontoblast-like cells and dense fibers. Furthermore, more polarizing odontoblast-like cells were shown after DPT-EVs were treated. | [80] | |
| Hertwig’s epithelial root sheath cells | Collagen | Mouse subcutaneous transplantation with the tooth root slice model | 2 mg/ml | It formed newly predentin-like tissue and odontoblast-like cells with collagen fibers, new blood and nerve nearby. Moreover, gene expressions of DSPP, DMP1 and β-catenin in the soft tissue around dentin also increased. | [78] | |
| Schwann cells | Collagen | Rat subcutaneous transplantation with the tooth root slice model | 4 mg/ml | Mice treated with EVs from Schwann cells had significantly more blood vessels and pre-dentin-like tissues, and formed odontoblast-cells. Some proteins such as DSPP and DMP1 led to odontogenic differentiation were increased. | [77] | |
| SCAPs | Collagen | Mouse subcutaneous transplantation with the tooth root slice model | 2 mg/ml | In a subcutaneous transplantation model with tooth root slice transplanted, EVs delivered by collagen formed newly regenerated tissues such as polarizing odontoblast-like cells, pre-dentin-like cells, collagen fibers with new blood vessels and nerves. Genes expression of DSPP, DMP1, β-catenin between dentin and soft fiber enhanced as well. | [35] | |
| SHEDs | Implantation locally | Mouse subcutaneous transplantation with the tooth root slice model | Not mentioned | After implanting SHED-EVs, there appeared continuous dentin layers with new blood vessels, which showed the regeneration of the dentin-pulp complex. | [75] | |
| Dental hard tissues | Ameloblasts | – | – | – | EVs secreted from ameloblasts mediated biomineralization of enamel, showing more enamel crystals formation. Compared with the control group, the width of the enamel was increased, and the distance of the interrod was decreased. | [84] |
| DPSCs (in odontogenic differentiation media) | PEG-PLGA-PEG | Rat Pulpotomy Model | 1.25 mg/scaffold | In a rat-pulpotomy model, DPSC-EVs implanted into the pulp interface induced more complete dentin formation while showing special dentin-tubes and mineral tissues stained with abundant collagen. | [86] | |
| DPSCs | Implantation locally | Mini-pig pulp repair model | 1 mg/µl | The group treated with EVs from DPSCs cooperated with treated dentin matrix showing the thickest mineralized layers of dentin, and appeared dentin-bridge. Moreover, osteoid dentin also be observed nearby the pulp tissue. | [87] | |
| M2-Macrophages | Intravenous injection | Mouse mechanical force induced OTM model | 100 µg | In a mechanical force-induced orthodontic tooth movement model, in comparison with other phenotypes macrophages, treated with M2-macrophage EVs induced cementoblast mineralization formation, which showed highly-expressions of BSP, OCN and OSX. | [88] | |
| Incisor epithelium and mesenchyme cells | - | - | - | In a knocked-down Rab27a/b CD1 mouse tooth organ reconstitution model, which reduces the secretion of EVs from epithelial and mesenchyme cells, weaker dentinogenesis compared with control groups was seen. | [89] | |
| TMJOA | EBCs | Injection locally | Rat TMJOA model | 100 µg | In a TMJOA model, EBC-EVs displayed significant functions in bone parameters, including BV/TV, Tb·Th. The height, thickness and cellularity of cartilage were also significantly improved. | [92] |
EVs, extracellular vesicles; ADMSCs, adipose mesenchymal stem cells; BMMSCs, bone marrow mesenchymal stem cells; DPSCs, dental pulp stem cells; DFCs, dental follicle cells; GMSCs, gingival mesenchymal stem cells; PDLSCs, periodontal ligament stem cells; SCAPs, stem cells from apical papilla; EPI-NCSCs, hair follicle epidermal neural crest stem cells; SHEDs, human exfoliated deciduous teeth stem cells; CM, serum-free conditioned medium; DPTs, dental pulp tissues; DPCs, dental pulp cells; EBCs, embryonic stem cell; LPS, lipopolysaccharide; SIS-ECM, small intestinal submucosa–extracellular matrix; PLGA, poly (lactic-co-glycolic acid); PLA, poly (lactic acid); HA, hyaluronic acid; β-TCP, β-tricalcium phosphate; Gel-Alg Hydrogel, gelatin-sodium alginate hydrogel; PEG-PLGA-PEG, polyethylene glycol-poly (lactic-co-glycolic acid)-polyethylene glycol; BRONJ, bisphosphonate related osteonecrosis of the jaw; TDM, treated dental matrix; FNI, facial nerve injury; OTM, orthodontic tooth movement; TMJOA, temporomandibular joint osteoarthrosis; BV/TV, bone volume/total volume; Tb·N, trabecular number; Tb·Th, trabecular thickness; Tb·Sp, trabecular separation; COL1, collagen 1; ALP, alkaline phosphatase; RUNX2, runt-related transcription factor 2; OCN, osteocalcin; TRAP, tartrate resistant acid phosphatase; OPG, osteoprotegerin; RANKL, receptor activator of nuclear factor-κB ligand; IL-1, interleukin-1; TNF, tumor necrosis factor; DMP-1, dentin matrix protein-1; OPN, osteopontin; MMP-2, matrix metalloproteinases-2; HA, hydroxyapatite; TGF, transforming growth factor; DPP, dentin phosphoprotein; vWF, vonWillebrandfactor; PDGF, platelet-derived growth factor; DSPP, dentin sialophosphoprotein; BSP, bone sialoprotein; OSX, osterix.