Sustainable Production and Activity Determination of Serum-Free Conditioned Medium from Menstrual Blood-Derived Endometrial Stem Cells.

Mesenchymal stem cells (MSCs) have exhibited great potential as a regenerative medicine, and MSC-derived paracrine effects, mainly including the secretion of various bioactive factors, play critical roles in MSC-based therapies. MSC-derived serum-free conditioned medium (MSC-CM) is defined as the secretome of MSC-derived bioactive factors and is considered a new cell-free therapeutic agent for disease treatment. However, the MSC-CM used in previous studies was prepared by a nearly disposable method that the MSCs were discarded after preparing MSC-CM, and the preparation time was variable; simultaneously, the viability changes of MSCs after MSC-CM preparation are still unknown. Therefore, this study takes MenSCs as a research project and aims to explore the suitable period of sustainable MenSC-CM preparation rather than using a disposable method. As expected, our results confirmed that MenSC-CM improves viability of both naïve targeted cells and H2O2-injured targeted cells, and suggested that 36 h is suitable for sustainable MenSC-CM preparation in which the angiogenic factors almost reach to the peak. Simultaneously, the MenSCs used to prepare the MenSC-CM for 36 h also maintained preferable cell viability and could be sustainably used for further MenSC-CM preparation. Moreover, the in vivo results further confirmed the improvement of MenSC-CM on promoting skin wound healing. Consequently, our results not only provide support for optimizing MSC-CM sustainable preparation based on various MSCs but also promote the comprehensive application of MenSCs in the clinic.