Using mesenchymal stem cells as a therapy for bone regeneration and repairing

Bone is a unique tissue which could regenerate completely after injury rather than heal itself with a scar. Compared with other tissues the difference is that, during bone repairing and regeneration, after the inflammatory phase the mesenchymal stem cells (MSCs) are recruited to the injury site and differentiate into either chondroblasts or osteoblasts precursors, leading to bone repairing and regeneration. Besides these two precursors, the MSCs can also differentiate into adipocyte precursors, skeletal muscle precursors and some other mesodermal cells. With this multiline-age potentiality, the MSCs are probably used to cure bone injury and other woundings in the near future. Here we will introduce the recent developments in understanding the mechanism of MSCs action in bone regeneration and repairing

Bone Regulates Glucose Metabolism as an Endocrine Organ through Osteocalcin

Skeleton was considered as a dynamic connective tissue, which was essential for mobility, calcium homeostasis, and hematopoietic niche. However more and more evidences indicate that skeleton works not only as a structural scaffold but also as an endocrine organ, which regulates several metabolic processes. Besides osteoprotegerin (OPG), sclerostin (SOST), and Dickopf (DKK) which play essential roles in bone formation, modelling, remodelling, and homeostasis, bone can also secret hormones, such as osteocalcin (OCN), which promotes proliferation of cells, insulin secretion, and insulin sensitivity. Additionally OCN can also regulate the fat cells and male gonad endocrine activity and be regulated by insulin and the neural system. In summary, skeleton has endocrine function via OCN and plays an important role in energy metabolism, especially in glucose metabolism

Porous flexible polyaniline/polyvinylidene fluoride composite film for trace-level NH3 detection at room temperature

Flexible, highly sensitive, selective, and room temperature ammonia (NH3) sensor based on porous polyaniline/polyvinylidene fluoride (PANI/PVDF) composite film was developed by an in-situ chemical oxidative polymerization process. The obtained flexible PANI/PVDF film showed a three-dimensional and hierarchical porous structure, which greatly enhanced the sensing performance of the PANI film sensor. It exhibited an excellent selectivity to NH3 at 25 degrees C with 110% response towards 5 ppm. Furthermore, the PANI/PVDF film sensor can detect 1 ppm NH3 (Response = 27%) along with excellent stability and response reproducibility. To 0.2 ppm NH3, the PANI/PVDF showed 6.5% response at 25 degrees C. Furthermore, it also showed a good linearity relationship between the response and the concentration of NH3. Additionally, the PANI/PVDF film exhibited excellent bending stability, showing very little response value fluctuation at different bending angles. This work shows that the proposed PANI/PVDF film is promising for detecting trace-level NH3 at room temperature, and can be applied in real-time environmental monitoring. (C) 2020 Elsevier B.V. All rights reserved