The pluripotency (e.g., self-renewal, self-proliferation, and multilineage differentiation ability) and pleiotropic properties (e.g., immune-modulation, tissue regeneration, and tumor tropism) of mesenchymal stem cells (MSCs) in vitro and in vivo make them powerful tools for tissue engineering, drug delivery, or cancer therapy. Importantly, MSCs have been isolated from most tissues investigated so far in sufficient quality and quantity without any obvious risk for the donor or ethical constraints afflicted with other types of stem cells (e.g., embryonic stem cells).

In regenerative medicine, MSCs from different tissue and organ sources are able to feature similar phenotypic characteristics (e.g., capacity of plastic adherence, differentiation potential, and surface marker profiles). For instance, MSCs can be applied to bone reconstruction in combination with bioactive factors (e.g., BMPs) and biomaterial-based scaffolds of organic (e.g., collagen, HA) or inorganic (e.g., PGA, PLA) origin.

Beyond their potential uses in regenerative medicine, an emerging field of research aims to utilize MSCs for anticancer treatment. This growing interest is based on the fact that some defined subpopulations are able to inhibit tumor growth by inhibiting survival signaling such as Wnt and Akt pathway but also owing to their remarkable ability of MSCs to localize and integrate into tumor stroma and deliver anticancer agents (e.g., cytokines, oncolytic viruses, and TRAIL). Paradoxically, there is increasing evidence that MSCs have the ability to migrate and engraft into tumor sites and exert stimulatory effects on cancer cell growth, invasion, and even metastasis through direct and/or indirect interaction with tumor cells by regulating immune surveillance, growth, and angiogenesis. Friends or enemies, MSCs are de facto a crucial segment of the tumor surroundings, and their confirmed tumor tropism is assumed to be an open gateway for the design of promising drug delivery systems (e.g., engineered MSCs).

It is now obvious that heterogeneity exists between different MSC populations depending on their origin, isolation, propagation procedures, and their status of differentiation, meantime opening up many recherché perspectives, but precise characterization of MSC subpopulations is crucial for ensuring efficacy and safety before translating breakthrough discoveries from bench to bedside.

This special issue invites researchers, industrials, biomedical engineers, technologists, and healthcare professionals specialized in oncology, regenerative medicine, pharmacy, nanomedicine, and biotechnology to share their knowledge by contributing original basic and applied research articles, clinical studies, and review articles.

The manuscripts shall be of high quality and shall emphasize the impact of MSCs on cancers, regenerative medicine, and drug delivery.

Potential topics include but are not limited to the following:

• Engineered MSCs for targeted actions
• Nanomedicine
• Roles and mechanisms of action
• Effects of the microenvironment
• MSCs-cells interactions
• Global analyses using OMICS technology
• Translational medicine
• Therapeutic efficacy and safety