Association between Donor Age and Osteogenic Potential of Human Adipose Stem Cells in Bone Tissue Engineering

Abstract

Adipose stem cells (ASCs) have multilineage differentiation capacity and hold great potential for regenerative medicine. Compared to bone marrow-derived mesenchymal stem cells (bmMSCs), ASCs are easier to isolate from abundant sources with significantly higher yields. It is generally accepted that bmMSCs show age-related changes in their proliferation and differentiation potentials, whereas this aspect is still controversial in the case of ASCs. In this review, we evaluated the existing data on the effect of donor age on the osteogenic potential of human ASCs. Overall, a poor agreement has been achieved because of inconsistent findings in the previous studies. Finally, we attempted to delineate the possible reasons behind the lack of agreements reported in the literature. ASCs represent a heterogeneous cell population, and the osteogenic potential of ASCs can be influenced by donor-related factors such as age, but also gender, lifestyle, and the underlying health and metabolic state of donors. Furthermore, future studies should consider experimental factors in in vitro conditions, including passaging, cryopreservation, culture conditions, variations in differentiation protocols, and readout methods.

Keywords: ASC; aging; osteoblast; osteogenic potential; regenerative medicine; tissue engineering.

Figure 1

Schematic representation of the natural bone repair process. Immune cells associated with hematoma are formed in the first phase. In the second phase, MSCs are recruited and differentiated into chondroblasts and osteoblasts that help the formation of soft cartilage callus. VEGFs promote vascularization in this phase. In the third phase, soft cartilage is replaced by hard bone facilitated by osteoblasts, osteoclasts, chondroclasts, and chondroblasts. The final step involves the continuous remodeling of newly formed bone. The figure was modified from Pfeiffenberger et al. [1], licensed under a Creative Common Attribution (CC BY) 4.0 Generic License, https://creativecommons.org/licenses/by/4.0/) (accessed on 24 November 2023). Created with BioRender.com (accessed on 24 November 2023).

Figure 2

Flowchart demonstrating the selection process in this review.

Figure 3

The osteogenic potential of ASC is influenced by both donor-related and experimental factors. Created with BioRender.com (accessed on 24 November 2023).