The regeneration of bone fractures, resulting from trauma, osteoporosis or tumors, is a major problem in our super-aging society. Bone regeneration is one of the main topics of concern in regenerative medicine. In recent years, stem cells have been employed in regenerative medicine with interesting results due to their self-renewal and differentiation capacity. Moreover, stem cells are able to secrete bioactive molecules and regulate the behavior of other cells in different host tissues. Bone regeneration process may improve effectively and rapidly when stem cells are used. To this purpose, stem cells are often employed with biomaterials/scaffolds and growth factors to accelerate bone healing at the fracture site. Briefly, this review will describe bone structure and the osteogenic differentiation of stem cells. In addition, the role of mesenchymal stem cells for bone repair/regrowth in the tissue engineering field and their recent progress in clinical applications will be discussed.

Lymphatic-vasculature function critically depends on extracellular matrix (ECM) and on its connections with lymphatic endothelial cells (LECs). However, the composition and the architecture of ECM have not been fully taken into consideration in studying the biology and the pathology of the lymphatic system. EMILIN1, an elastic microfibril-associated protein, is highly expressed by LECs in vitro and colocalizes with lymphatic vessels in several mouse tissues. A comparative study between WT and Emilin1 ؊/؊ mice highlighted the fact that Emilin1 deficiency in both CD1 and C57BL/6 backgrounds results in hyperplasia, enlargement, and frequently an irregular pattern of superficial and visceral lymphatic vessels and in a significant reduction of anchoring filaments. Emilin1-deficient mice also develop larger lymphangiomas than WT mice. Lymphatic vascular morphological alterations are accompanied by functional defects, such as mild lymphedema, a highly significant drop in lymph drainage, and enhanced lymph leakage. Our findings demonstrate that EMILIN1 is involved in the regulation of the growth and in the maintenance of the integrity of lymphatic vessels, a fundamental requirement for efficient function. The phenotype displayed by Emilin1 ؊/؊ mice is the first abnormal lymphatic phenotype associated with the deficiency of an ECM protein and identifies EMILIN1 as a novel local regulator of lymphangiogenesis.Lymphatic and blood vascular systems have distinct structural characteristics that reflect their specific and complementary functions. The lymphatic vasculature represents a second circulatory system and maintains tissue fluid homeostasis; it plays a major role in the absorption of dietary fat and in immune response, transporting lymphocytes and antigen-presenting cells to regional lymph nodes; finally, it provides routes for tumor metastasis (8). The lymphatic system consists of a complex network of lymphatic capillaries, which are uniquely adapted for the uptake of protein-rich lymph from tissue interstitium, and collecting lymphatic vessels that transport lymph back to the blood vascular system. The latter are surrounded by a basement membrane and smooth muscle cells, which are less organized than in blood vessels and, in addition, have intraluminal valves, which prevent lymph backflow (26). By contrast, lymphatic capillaries are blind-end vessels, lined by a single thin layer of overlapping lymphatic endothelial cells (LECs) directly connected to the surrounding extracellular matrix (ECM) by means of anchoring elastic filaments (18). These structures play a fundamental role in lymphatic-vessel function and represent one of the main distinguishing features between lymphatic and blood capillaries. When interstitial fluid pressure increases, anchoring filaments exert tension on LECs, thereby widening the capillary lumen and opening the overlapping cell junctions, which enable fluid and macromolecule uptake and cell entry. It is thought that abnormalities of anchoring filaments may reduce adsorption from the intersti...

Iron-doped superparamagnetic apatite nanoparticles are promising materials for magnetic drug delivery systems due to their ability to strongly bind the anticancer doxorubicin and provide an active control over the drug release by using a low-frequency pulsed electromagnetic field.