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

Available for download on Thursday, April 29, 2021

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