Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases.

Anti-tuberculosis agent rifampicin is extensively used for its effectiveness. Possible complications of tuberculosis and prolonged rifampicin treatment include kidney damage; these conditions can lead to reduced efficiency of the affected kidney and consequently to other diseases. Bone marrow-derived mesenchymal stem cells (BMMSCs) can be used in conjunction with rifampicin to avert kidney damage; because of its regenerative and differentiating potentials into kidney cells. This research was designed to assess the modulatory and regenerative potentials of MSCs in averting kidney damage due to rifampicin-induced kidney toxicity in Wistar rats and their progenies. BMMSCs used in this research were characterized according to the guidelines of International Society for Cellular Therapy. The rats (male and female) were divided into three experimental groups, as follows: Group 1: control rats (4 males & 4 females); Group 2: rats treated with rifampicin only (4 males & 4 females); and Group 3: rats treated with rifampicin plus MSCs (4 males & 4 females). Therapeutic doses of rifampicin (9 mg/kg/day for 3-months) and MSCs infusions (twice/month for 3-months) were administered orally and intravenously respectively. At the end of the three months, the animals were bred together to determine if the effects would carry over to the next generation. Following breeding, the rats were sacrificed to harvest serum for biochemical analysis and the kidneys were also harvested for histological analysis and quantification of the glomeruli size, for the adult rats and their progenies. The results showed some level of alterations in the biochemical indicators and histopathological damage in the rats that received rifampicin treatment alone, while the control and stem cells treated group showed apparently normal to nearly normal levels of both bio-indicators and normal histological architecture. Intravenous administration of MSCs yielded sensible development, as seen from biochemical indicators, histology and the quantitative cell analysis, hence implying the modulatory and regenerative properties of MSCs.