Fibrin microbeads loaded with mesenchymal cells support their long-term survival while sealed at room temperature.

Efficient transfer of progenitor cells without affecting their survival is a key factor in any practical cell therapy. Fibrin microbeads (FMB) were developed as hard biodegradable cell carriers. The FMB could efficiently isolate mesenchymal stem cells (MSCs) from different sources and support the expansion of matrix-dependent cell types in a three-dimensional culture in slow rotation.

Visualization of immune response kinetics in full allogeneic chimeras.

Background: Donor Lymphocyte Infusion (DLI) is a well-recognized tool for augmentation of the anti-leukemia effect after mismatched bone marrow transplantation. Experimental results show, however, that DLI efficacy is strongly dependent on the number of donor hematopoietic cells persisting in recipient after transplantation. It is strong in mixed chimeras and relatively weak in full chimeras (FC) that replace host antigen-presenting cells by donor antigen-presenting cells.

Repair of bone defect using bone marrow cells and demineralized bone matrix supplemented with polymeric materials.

We present a novel, reverse thermo-responsive (RTR) polymeric osteogenic composite comprising demineralized bone matrix (DBM) and unmanipulated bone marrow cells (BMC) for repair of bone defects. The polymers investigated were low viscosity aqueous solutions at ambient temperature, which gel once they heat up and reach body temperature. Our goal to supplement DBM-BMC composite with RTR polymers displaying superior rheological properties, was to improve graft integrity and stability, during tissue regeneration.

Mesenchymal progenitor cells in red and yellow bone marrow.

Marrow cavities in all bones of newborn mammals contain haematopoietic tissue and stromal microenvironment that support haematopoiesis (haematopoietic microenvironment), known as red bone marrow (BM). From the early postnatal period onwards, the haematopoietic microenvironment, mainly in tubular bones of the extremities, is replaced by mesenchymal cells that accumulate lipid drops, known as yellow BM, whereas haematopoietic tissue gradually disappears. We analysed the ability of mesenchymal cell progenitors in red and yellow BM to produce bone and haematopoietic microenvironment in vivo after transplantation into normal or haematopoietically deficient (irradiated and old) recipients.

Conversion of red bone marrow into yellow - Cause and mechanisms.

Marrow cavities in all the bones of newborn mammals contain active hematopoietic tissue, known as red bone marrow. From the early postnatal period onwards, the hematopoietic tissue, mainly in the bones of the extremities, is gradually replaced by non-hematopoietic mesenchymal cells that accumulate lipid drops, known as yellow or fatty bone marrow. For its maintenance, hematopoietic tissue depends on the support of special mesenchymal cells in the bone marrow cavity, known as hematopoietic microenvironment.