Abstract: The present invention relates to a non-viral method for the production of modified mesenchymal stem/stromal cells comprising the use of an additive rich in human-derived platelet growth factors, derived from platelet concentrates, aimed to promote the expansion of said cells. The method further comprises the phase of submitting the cells to electroporation and suspending said mixture in the growth-medium enriched in human-derived platelet growth factors and keeping in incubation. In this way, it is possible to achieve a chemical-physical, non-viral method in compliance with the Good Manufacturing Practice Guidelines (GMP) for advanced cell therapy products, allowing transiently or stably transfect/deliver gene constructs based on electric pulses administration to cells. Said production method is particularly simple and advantageous in terms of productivity and cost-effectiveness, when compared to methods involving viral vectors.