Challenges in the processing and preservation of adipose-derived stem cell subpopulations for clinical use

The beneficial roles of distinct adipose-derived stem cell (ASC) immunophenotypical subpopulations, defined by the unique combination of cell surface markers, have been investigated in various therapeutic contexts [1]. For example, the varied differentiation potentials of ASC subpopulations, such as CD29^pos, CD34^pos, CD90^pos, CD34^posCD90^pos, can be selected for targeted treatments – bone, cartilage, or vascular tissue regeneration [2–8]. Subpopulations with potent immunomodulatory or angiogenic properties, such as CD248^pos, CD106^pos enhance the overall regenerative capacity of ASCs, making them more effective in treating complex wounds and inflammatory conditions [9,10]. Based on these promising outcomes, ASC subpopulations will be at the forefront of precise treatment in personalized interventions.

Extensive studies have investigated the preparations of optimal ASC products for clinical use, which focus on key processes such as harvest, expansion, and cryopreservation. In contrast, preparing ASC subpopulations involves different steps, as it requires identifying and sorting the targeted populations together with the subsequent expansion and cryopreservation. However, the effects of these procedures on ASC subpopulations remain poorly understood. Several crucial research questions remain: Are the sorted populations homogeneous enough to achieve the specific or expected clinical outcomes? Are there simpler or more efficient ways to identify or sort these populations? In clinical applications, additional expansion and cryopreservation are necessary – how do these procedures impact the immunophenotypes and functions of sorted ASC subpopulations? Moreover, do the changes in immunophenotype, probably caused by the additional steps, inevitably lead to predetermined functional changes in sorted ASC subpopulations?

The success of these subpopulation-based treatments depends highly on a thorough understanding of the cellular composition within the ASC subpopulations, as well as the establishment of reliable methodologies for accurately identifying and targeting desired subpopulations. Additionally, the development of scalable manufacturing and cryopreservation techniques that preserve the functions of the ASC subpopulation is essential. It is also imperative to understand how closely the functions are associated with specific immunophenotypes.

Therefore, I will analyze the aforementioned research questions. Of note, due to the limited number of studies available, my discussion will focus on presenting ideas and potential solutions based on currently available evidence. The primary goal here is to encourage further reflection, dialogue, or research on these topics.