DOI
https://doi.org/10.25772/4B8M-XZ59
Defense Date
2020
Document Type
Thesis
Degree Name
Master of Science
Department
Physiology and Biophysics
First Advisor
Dr. Zhao Lin
Abstract
Periodontitis is an inflammatory disease caused by the imbalance between host immune response and bacterial infection. Strategies to manage the uncontrolled, excessive immune response and to promote tissue healing are in great demand. Therapies based on mesenchymal stem cells (MSCs) are promising and the clinical effects of MSCs are largely mediated by their secretome, especially exosomes. Previously, we isolated and purified exosomes secreted by human bone marrow mesenchymal stem cells (hBMSC). These exosomes have proliferative, chemotactic, anti-inflammatory and anti-osteoclastic function in vitro. In this study, we had two hypotheses: 1) hBMSC exosomes would prevent periodontal inflammation and alveolar bone loss with immunomodulatory function; 2) hBMSC exosomes would enhance 2 periodontal tissue regeneration. To test these hypotheses, we used a rodent ligature-induced experimental periodontitis model. In the preventative experiment, rats were treated with hBMSC exosomes concurrently with ligature placement. In the regenerative experiment, rats were treated with hBMSC exosomes for 3 weeks and 6 weeks after the experimental periodontitis was induced. Our results show that, in the preventive study, hBMSC exosome treatment led to less disease progression as evidenced by increased alveolar bone volume, decreased linear bone loss, and less lymphocyte infiltration in the subepithelial area. However, through micro-CT and gene expression analyses, no significant differences were seen between the exosome treatment and control in the regenerative study at both time points. In summary, hBMSC exosomes can ameliorate the development of periodontitis via an immunomodulatory effect. However, more studies are needed in the future to investigate their regenerative potential in periodontal tissues.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
4-29-2020