Mesenchymal stem cells (MSC) differentiate towards multiple lineages that participate in bone formation and are often utilized for bone regeneration therapy. A 2019 review by Lee et al. explores the endogenous mechanical and biochemical environment of MSCs. Additionally, the article highlights the essential factors that lead to bone repair and how these factors can be leveraged to improve bone regeneration therapy.
Like all stem cells, MSCs depend on their native microenvironment for chemical and mechanical signals to initiate proliferation, differentiation, and maintain homeostasis. Signals from a healthy microenvironment include mechanical stressors, cytokines, and growth factors. As a result, it may be likely that transporting MSCs into an unfavorable microenvironment could have a negative impact on bone repair. Ideally, the microenvironment the MSCs are transplanted into would closely mimic their native microenvironment.
One critical component of the MSC microenvironment is the extracellular matrix (ECM), which is composed primarily of proteins and polysaccharides. The polysaccharide component of the ECM is emerging as a point of interest for osteogenesis research. Carbohydrate-based polymeric materials have structural and functional similarities to endogenous polysaccharides and have been used to regenerate bone in preclinical settings. They are also nontoxic, biodegradable, biocompatible, and soluble. Because of this, carbohydrate-based polymers may be an important material in the future of creating an ideal microenvironment for MSCs.
Despite the importance of the microenvironment, in a survey of over 700 clinical studies involving MSCs, a majority of the trials used ceramic-based carriers or injected MSC directly into patients without a carrier, giving little insight into or control over the microenvironment in which the MSC are transplanted. Going forward, creating an optimal microenvironment for MSCs in bone regeneration requires further attention, as the potential benefits of creating an ideal microenvironment are numerous. To learn more, refer to "Stem and progenitor cell microenvironment for bone regeneration and repair" (Lee 2019).
References
Lee CC, Hirasawa N, Garcia KG, Ramanathan D, Kim KD. Stem and progenitor cell microenvironment for bone regeneration and repair. Regen Med. 2019;14(7):693-702.