Non-enzymatic automated closed-cycle process to isolate mesenchymal stromal cells for drug delivery applications

Mesenchymal stromal cells (MSCs) can be easily isolated from several human organs and tissues and, because of their self-renewing capacity and multipotent differentiation properties; they are important tools for treating immune disorder and for tissue repair. To ensure reproducibility, efficacy and safety for clinical uses, these procedures have to be compliant with Good Manufacturing Practices (GMP). Techniques for harvesting and processing human adipose tissue have rapidly evolved in the last years, and, among them, Lipogems represents an innovative approach to obtain micro-fragmented adipose tissue in a short time, without expansion and/or enzymatic treatment. The aim of this study was to assess the presence of Adipose Tissue Mesenchymal Stromal Cells (AT-MSCs) in the drain bag of the device after the standard processing, and the possibility to use these cells as drug delivery agents. We used a Lipogems Processor Prototype (PLG-P) to wash and process the lipoaspirate in a standardized condition. The waste fluid was analyses for the presence of mesenchymal stromal cells that were expanded in flask , characterized by CD analysis and differentiation ability. The ability of these cells to uptake Paclitaxel was evaluated by using a previous standardized procedure. The activity of paclitaxel released by drug loaded AT MSCs were tested in vitro against cancer cells. We found that the drain bag contain red blood cells and oil residues but also significant amount of single isolated cells easy to expand and having the typical characteristics of AT-MSCs. These AT-MSCS were also able to uptake Paclitaxel and then release it in amount active in vitro against the proliferation of a human pancreatic cancer cell line. Our findings suggest the possibility to develop a new integrated in-line device, implying neither enzymatic treatment, nor centrifugation, which can isolate and expand AT-MSCs in an intrinsically closed system, highly simplifying GMP compliance effort. This system could be used to obtain AT-MSCs not only for regenerative purposes, but also for drug loading procedure, as a new and innovative cell mediated drug-delivery system.