The human body continuously relies upon its own tissue-resident stem cells to repair adult tissues and organs, and to oppose senescence-related processes. Human mesenchymal stem cells (hMSCs) exhibit self-renewal, multilineage differentiation, and can be isolated and expanded in vitro in virtually all organs, representing useful candidates for regenerative medicine approaches in the treatment of a variety of tissue injuries and degenerative disorders. hMSCs are usually expanded for multiple passages in vitro to increase cell yield prior to transplantation. Unfortunately, they undergo senescence both in vivo, contributing to the progressive decline in self-healing mechanisms, and in vitro during prolonged expansion. Today, hMSCs senescence represents a major drawback for successful outcomes in cell therapy approaches.

Within this context, in the last decades, the use of synthetic and natural molecules, as well as electromagnetic fields and mechanical vibrations, has contributed to the development of strategies that may counteract stem cell senescence allowing for the preservation of tissue homeostasis and our innate self-healing potential. On the other hand, although numerous studies have been conducted and many promising results have been reported, investigating new antisenescence strategies to achieve effective stem cell-based therapy remains crucial.

This Special issue therefore invites contributions from original research articles focusing on recent progress on the understanding of stem cell senescence mechanisms and on useful approaches in counteracting stem cell senescence in vivo and in vitro. Review articles which describe the current state of the art are also welcomed.

Potential topics include but are not limited to the following:

• Investigation of mechanisms at the basis of stem cell senescence
• Use of new chemicals able to counteract stem cell senescence
• Use of natural molecules able to counteract stem cell senescence
• Use of physical energy able to counteract stem cell senescence
• Methods to prolong stem cell cultures and to increase their expansion