Adipose-derived mesenchymal stem cells from solid tissue and lipoaspirates: A comparative study of phenotype, growth, and secretome.

[BACKGROUND] Mesenchymal stem cells (MSCs) are considered a promising therapy for various diseases due to their strong potential in regenerative medicine and immunomodulation. The tissue source of MSCs has gained attention for its role in influencing their function, accessibility, and readiness for clinical use.

[AIM] To identify the most suitable adipose source for MSC isolation and expansion for further applications.

[METHODS] We isolated MSCs from solid adipose tissue and liposuction aspirates using the enzyme method. The MSCs were examined for their expansion using population doubling time, differentiation capacity using multilineage differentiation induction, surface markers using flow cytometry, and stability of chromosomes using the karyotyping method. Growth factors and cytokines in MSC-conditioned media were analyzed using the Luminex assay.

[RESULTS] MSCs were isolated from solid adipose tissue and lipoaspirates and expanded from passage 0 to passage 2. All adipose-derived MSCs (AD-MSCs) exhibited the typical elongated, spindle-shaped morphology and comparable proliferation rate. They expressed positive surface markers [cluster of differentiation 73 (CD73): > 97%, CD90: > 98%, and CD105: > 95%], and negative markers (< 1%). All MSCs expressed similar levels of stemness genes (octamer-binding transcription factor 4, SRY-box 2, Krüppel-like factor, and MYC), colony-forming, and trilineage differentiation potential. Karyotyping analysis revealed normal chromosomal patterns in all samples, except one sample exhibiting a polymorphism (1qh+). Furthermore, the growth factors and cytokines of hepatocyte growth factor, vascular endothelial growth factor A, interleukin 6 (IL-6), and IL-8 were detected in all AD-MSC conditioned media; but fibroblast growth factor-2 and keratinocyte growth factor were selectively expressed in conditioned media from solid or lipoaspirate AD-MSCs, respectively.

[CONCLUSION] These findings indicate that AD-MSCs from both adipose sources possess all of the characteristic features of MSCs with source-specific secretome differences, which are suitable for further expansion and various clinical applications.