Over a decade after their discovery, induced pluripotent stem cells (iPSCs) have become a major biological model. The iPSC technology allows generation of pluripotent stem cells from somatic cells bearing any genomic background. The challenge ahead of us is to translate human iPSCs (hiPSCs) protocols into clinical treatment. To do so, we need to improve the quality of hiPSCs produced. In this study we report the reprogramming of multiple patient urine-derived cell lines with mRNA reprogramming, which, to date, is one of the fastest and most faithful reprogramming method. We show that mRNA reprogramming efficiently generates hiPSCs from urine-derived cells. Moreover, we were able to generate feeder-free bulk hiPSCs lines that did not display genomic abnormalities. Altogether, this reprogramming method will contribute to accelerating the translation of hiPSCs to therapeutic applications.

Mesenchymal stem cell secretome or conditioned medium (MSC-CM) is a combination of biomolecules and growth factors in cell culture growth medium, secreted by mesenchymal stem cells (MSCs), and the starting point of several derived products. MSC-CM and its derivatives could be applied after injuries and could mediate most of the beneficial regenerative effects of MSCs without the possible side effects of using MSCs themselves. However, before the clinical application of these promising biopharmaceuticals, several issues such as manufacturing protocols and quality control must be addressed. This review aims to underline the influence of the procedure for conditioned medium production on the quality of the secretome and its derivatives and highlights the questions considering cell sources and donors, cell expansion, cell passage number and confluency, conditioning period, cell culture medium, microenvironment cues, and secretome-derived product purification. A high degree of variability in MSC secretomes is revealed based on these parameters, confirming the need to standardize and optimize protocols. Understanding how bioprocessing and manufacturing conditions interact to determine the quantity, quality, and profile of MSC-CM is essential to the development of good manufacturing practice (GMP)-compliant procedures suitable for replacing mesenchymal stem cells in regenerative medicine.

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La découverte des cellules souches et de leurs potentialités a fait émerger de nouvelles formes de thérapies avec le développement de méthodes de bio-ingénierie cellulaire et tissulaire qui sous-tendent la médecine de demain. La disponibilité de cellules souches et leur conservation deviennent de ce fait un enjeu pour la santé de chacun. Parmi les différentes sources de cellules souches, celles de la pulpe dentaire présentent les avantages d’être pluripotentes, de pouvoir être cryopréservées et conservées durant de longues périodes sans perdre leur capacité de multiplication et de différenciation et enfin elles sont facilement accessibles. Les dents de sagesse ou les dents de lait extraites pour des raisons médicales sont une opportunité pour chacun de conserver des cellules souches pour un usage autologue. Des biobanques autorisées et spécialisées dans la préparation et la conservation des cellules souches pulpaires ouvrent l’accès à la médecine régénérative autologue de l’avenir.