Isolation methods of exosomes derived from dental stem cells

Abstract

Mesenchymal stem cells are highly regarded for their potential in tissue repair and regenerative medicine due to their multipotency and self-renewal abilities. Recently, mesenchymal stem cells have been redefined as "medical signaling cells," with their primary biological effects mediated through exosome secretion. These exosomes, which contain lipids, proteins, RNA, and metabolites, are crucial in regulating various biological processes and enhancing regenerative therapies. Exosomes replicate the effects of their parent cells while offering benefits such as reduced side effects, low immunogenicity, excellent biocompatibility, and high drug-loading capacity. Dental stem cells, including those from apical papilla, gingiva, dental pulp, and other sources, are key contributors to exosome-mediated regenerative effects, such as tumor cell apoptosis, neuroprotection, angiogenesis, osteogenesis, and immune modulation. Despite their promise, clinical application of exosomes is limited by challenges in isolation techniques. Current methods face issues of complexity, inefficiency, and insufficient purity, hindering detailed analysis. Recent advancements, such as micro-electromechanical systems, alternating current electroosmosis, and serum-free three-dimensional cell cultures, have improved exosome isolation efficacy. This review synthesizes nearly 200 studies on dental stem cell-derived exosomes, highlighting their potential in treating a wide range of conditions, including periodontal diseases, cancer, neurodegenerative disorders, diabetes, and more. Optimized isolation methods offer a path forward for overcoming current limitations and advancing the clinical use of exosome-based therapies.

Fig. 1

The surface markers and tissue origins of various dental stem cells, confirming their mesenchymal lineage and regenerative potential. While all share core mesenchymal stem cell markers (CD44, CD73, CD90, CD105, STRO-1), unique markers including CD24, CD140a/β, and CD31/CD63 define specialized roles in tissue repair, regeneration, and immunomodulation

Fig. 2

Most utilized exosome isolation approaches. Traditional techniques for exosome isolation comprise differential ultracentrifugation (DUC) and size-exclusion chromatography (SEC). DUC focuses on the separation of exosomes through incrementally increasing centripetal acceleration. SEC employs biofluids as a mobile phase in conjunction with a porous stationary phase, allowing for the differential elution of molecules based on an inverse relationship with their size – specifically, larger particles elute prior to smaller ones, which, upon entering the pores, traverse a longer path resulting in extended elution times. Precipitation utilizes a solution to promote the formation of a polymer-encapsulated vesicle aggregate in substantial quantities. Immunoaffinity capture employs antibodies that target exosomal surface proteins, facilitating the isolation of specific vesicle subpopulations. The microfluidics approach utilizes chips designed for specific antibody-mediated interactions to efficiently capture exosomes. Ultrafiltration operates on the principle of using a filter with a defined pore size, resulting in a vesicle-rich filtrate tailored to the desired dimensions

Fig. 3

Methods for isolating DSC-Exos used in the 197 included studies

Fig. 4

A decision tree depicting the subpopulations and applications of DSC-Exos in different domains of medicine and dentistry utilizing different isolation methods