Extracellular Vesicles-Loaded Fibrin Gel Supports Rapid Neovascularization for Dental Pulp Regeneration

• Published in: International journal of molecular sciences Vol. 21; no. 12; p. 4226
• Main Authors: Zhang, Siyuan, Thiebes, Anja Lena, Kreimendahl, Franziska, Ruetten, Stephan, Buhl, Eva Miriam, Wolf, Michael, Jockenhoevel, Stefan, Apel, Christian
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13-06-2020; MDPI
• Subjects: Angiogenesis; Apoptosis; Bioaccumulation; Cell adhesion & migration; Cell growth; Cell Movement; Cell Proliferation; Coculture Techniques; Collagen (type I); Collagen - metabolism; Dental pulp; Dental Pulp - cytology; Dental Pulp - physiology; dental pulp regeneration; Dental restorative materials; Deposition; Endothelial cells; Extracellular vesicles; extracellular vesicles (EVs); Extracellular Vesicles - metabolism; Fibrin; Fibrin - chemistry; Human Umbilical Vein Endothelial Cells - cytology; Humans; hydrogel; Hydrogels; Hydrogels - chemistry; Laser microscopy; Mesenchymal Stem Cells - cytology; Mesenchymal Stem Cells - metabolism; Mesenchyme; Microscopy, Confocal; Proteins; rapid vascularization; Regeneration; Stem cells; Stromal cells; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - metabolism; Vascularization; VEGF; Vesicles; Wound healing; dental pulp regeneration; extracellular vesicles (EVs); rapid vascularization; hydrogel; VEGF; angiogenesis
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21124226

Rapid vascularization is required for the regeneration of dental pulp due to the spatially restricted tooth environment. Extracellular vesicles (EVs) released from mesenchymal stromal cells show potent proangiogenic effects. Since EVs suffer from rapid clearance and low accumulation in target tissues, an injectable delivery system capable of maintaining a therapeutic dose of EVs over a longer period would be desirable. We fabricated an EV-fibrin gel composite as an in situ forming delivery system. EVs were isolated from dental pulp stem cells (DPSCs). Their effects on cell proliferation and migration were monitored in monolayers and hydrogels. Thereafter, endothelial cells and DPSCs were co-cultured in EV-fibrin gels and angiogenesis as well as collagen deposition were analyzed by two-photon laser microscopy. Our results showed that EVs enhanced cell growth and migration in 2D and 3D cultures. EV-fibrin gels facilitated vascular-like structure formation in less than seven days by increasing the release of VEGF. The EV-fibrin gel promoted the deposition of collagen I, III, and IV, and readily induced apoptosis during the initial stage of angiogenesis. In conclusion, we confirmed that EVs from DPSCs can promote angiogenesis in an injectable hydrogel in vitro, offering a novel and minimally invasive strategy for regenerative endodontic therapy.