Cartilage and bone tissue engineering using adipose stromal/stem cells spheroids as building blocks

Scaffold-free techniques in the developmental tissue engineering area are designed to mimic in vivo embryonic processes with the aim of biofabricating,in vitro,tissues with more authentic properties.Cell clusters called spheroids are the basis for scaffold-free tissue engineering.In this review,we explore the use of spheroids from adult mesenchymal stem/stromal cells as a model in the developmental engineering area in order to mimic the developmental stages of cartilage and bone tissues.Spheroids from adult mesenchymal stromal/stem cells lineages recapitulate crucial events in bone and cartilage formation during embryogenesis,and are capable of spontaneously fusing to other spheroids,making them ideal building blocks for bone and cartilage tissue engineering.Here,we discuss data from ours and other labs on the use of adipose stromal/stem cell spheroids in chondrogenesis and osteogenesis in vitro.Overall,recent studies support the notion that spheroids are ideal"building blocks"for tissue engineering by“bottom-up”approaches,which are based on tissue assembly by advanced techniques such as three-dimensional bioprinting.Further studies on the cellular and molecular mechanisms that orchestrate spheroid fusion are now crucial to support continued development of bottom-up tissue engineering approaches such as three-dimensional bioprinting.

ZnO Nanorods Produced by the Method of Arc Discharge

ZnO nanorods are fabricated by arc discharge with ZnO powder as source materials. The sample is characterized by x-ray diffraction, Raman scattering spectra, scanning electron microscopy and high-resolution transmission electron microscopy. The ZnO nanorods exhibit single crystals with the hexagonal wurtzite structure. Many of them are tetrapod-like. The diameters range from several nanometres to about lOOnm, and the main diameters of the nanorods is around 20nm. The length-to-diameter ratio is more than 5, and the grown directions are along the [001] axis. Photoluminescence spectra show a narrow ultraviolet emission at around 389nm and a broad green emission at around 520 nm. The growth process can be interpreted by the vapour-solid mechanism.

Assembly of Three Scandium-containing Heteropolytungstates Based on a Building-block Synthetic Strategy

Three novel scandium-containing heteropolytungstates[Sc3(H2O)3NO(PW9O34)2]^10(1a)Scs(H2O)2(GeW6O34)2(GeW6O26)2]^12(2a)and[Sc11(W6O10)2(OH)2(H2O)16(BiW9O33)6]^27(3a)were synthesized by reactions of Sclllions with trilacunary Keggin precursors,[A-a-XW9O34]^n(X=P,Ge,n=9,10)or[B-a-BiW9O33]^9,in NaOAc/HOAc buffer solution under conventional synthetic condition,respectively.All the three compounds were characterized by means of single-crystal X-ray diffraction(XRD),Fourier transform-infrared(FTIR)spectroscopy ultraviolet-visible(UV-Vis)spectroscopy,elemental analysis,and thermogravimetric analysis.The aqueous solutior stability of the sandwich polvanion[Sc3(H2O)3(pw9O34)2]^10-was also verified by electrospray ionization mass Spectrometry(ESI-MS)due to its good solubility in water.