Time-dependent release of growth factors from implant surfaces treated with plasma rich in growth factors.

Plasma rich in growth factors (PRGFs) technology is an autologous platelet-rich plasma approach that provides a pool of growth factors and cytokines that have been shown to increase tissue regeneration and accelerate dental implant osseointegration. In this framework, the spatiotemporal release of growth factors and the establishment of a provisional fibrin matrix are likely to be key aspects governing the stimulation of the early phases of tissue regeneration around implants. We investigated the kinetics of growth factor release at implant surfaces functionalized either with PRGFs or platelet-poor plasma and correlated the results obtained with the morphology of the resulting interfaces.

Characterization of monoamine oxidases in mesenchymal stem cells: role in hydrogen peroxide generation and serotonin-dependent apoptosis.

Early death of grafted bone marrow mesenchymal stem cells (MSCs) represents a major limit to their use in cell therapy of solid organs. It is well known that oxidative stress plays a major role in cell death. We have recently shown that the serotonin-degrading enzyme monoamine oxidase A (MAO-A) generates large amount of hydrogen peroxide (H2O2) responsible for cell apoptosis.

Mesenchymal stem cells promote matrix metalloproteinase secretion by cardiac fibroblasts and reduce cardiac ventricular fibrosis after myocardial infarction.

Recent studies showed that mesenchymal stem cells (MSCs) transplantation significantly decreased cardiac fibrosis; however, the mechanisms involved in these effects are still poorly understood. In this work, we investigated whether the antifibrotic properties of MSCs involve the regulation of matrix metalloproteinases (MMPs) and matrix metalloproteinase endogenous inhibitor (TIMP) production by cardiac fibroblasts. In vitro experiments showed that conditioned medium from MSCs decreased viability, alpha-smooth muscle actin expression, and collagen secretion of cardiac fibroblasts.

Ex vivo pretreatment with melatonin improves survival, proangiogenic/mitogenic activity, and efficiency of mesenchymal stem cells injected into ischemic kidney.

Bone marrow mesenchymal stem cells (MSCs) have shown great potential in cell therapy of solid organs. Approaches to improving the ability of grafted MSCs to survive and secrete paracrine factors represent one of the challenges for the further development of this novel therapy. In the present study, we designed a strategy of ex vivo pretreatment with the pineal hormone melatonin to improve survival, paracrine activity, and efficiency of MSCs.