Cell-free regenerative technologies for bone tissue repair in plastic surgery (review)

Abstract

The review contains data from modern literature on the use of cellular products and extracellular vesicles for the regeneration of bone tissue defects. Therapy based on mesenchymal stem cells (MSCs) is considered a potentially effective strategy for successful bone tissue regeneration. However, this technology has its drawbacks: phenotypic changes in tissues, immune rejection, potential oncogenicity, and low cell survival, which limits its widespread clinical application. The available data indicate that the positive biological effect of MSCs on tissue regeneration is largely due to the paracrine action of nanostructured extracellular vesicles (exosomes, vesicles), which can overcome the limitations of traditional MSC‑based treatment methods. Currently, all available studies have demonstrated the positive effect of MSCs and exosomes on the bone tissue remodeling process. Exosomes derived from MSCs, bone marrow cells, and other cell types transfer bone morphogenetic proteins, growth factors, and immunoregulatory microRNAs, triggering osteogenic processes. The type of cells from which they are derived is of great importance: MSCs from bone marrow typically produce exosomes with potent bone‑forming potential, while MSCs derived from adipose tissue produce exosomes with a better immunoregulatory effect. However, there are no clinical studies of their use in humans yet. Standardization of production remains the main problem, as current isolation methods are not scalable or reproducible, and the variability in dosage from batch to batch jeopardizes the stability of the exosome drug’s effect. Furthermore, standardization of exosome measurement units is required, as studies often use different measurement units, including those based on protein content, particle count, and total exosome mass, which hinders comparative analysis. To address this issue, it is necessary to develop consistent reporting standards that include both quantitative measurements and functional assessments relevant to therapeutic applications. Thus, the focus of future research should be on standardizing production, reducing its cost, and conducting thorough clinical trials; in this case, exosomes may become a safe and promising means of restoring damaged bones.