Solid-state structure and anti­microbial and cytotoxicity studies of a cucurbit[6]uril-like Cu6L4 constructed from 3,5-bis­[(1H-tetra­zol-5-yl)meth­yl]-4H-1,2,4-triazol-4-amine

3,5-Bis[(1H-tetra­zol-5-yl)meth­yl]-4H-1,2,4-triazol-4-amine (H2L) associates under deprotonation with CuSO4 in aqueous medium to form a new waisted barrel-shaped M6L4 cluster, namely hexa­aqua­tetra­kis­{μ4-3,5-bis­[(1H-tetra­zol-5-yl)meth­yl]-4H-1,2,4- triazol-4-amine}-μ4-sulfato-hexa­copper(II) sulfate hydrate, [Cu6(SO4) (C6H6N12)4(H2O)6]SO4·nH2O (n = ∼23) (1). Cluster 1 resembles concave cucurbit[6]uril and has one disordered sulfate anion trapped inside the cage, which additionally stabilizes the Cu6 unit. The CuII ions have either a square-pyramidal or a distorted octa­hedral geometry. The equatorial positions are filled by N atoms from the L2− ligand, while the axial positions are occupied by coordinated water mol­ecules and O atoms of the sulfate counter-ion. In the solid state, the Cu6 clusters are connected through a large number of hydrogen bonds formed by uncoordinated water mol­ecules and an additional sulfate anion. The compound shows good anti­microbial activity against E. coli tested with the Kirby Bauer approach. In addition, the cell viability towards HeLa and L-929 cells was studied

Multi-parametric hydrogels support 3D in vitro bioengineered microenvironment models of tumour angiogenesis

Tumour microenvironment greatly influences the development and metastasis of cancer progression. The development of three dimensional (3D) culture models which mimic that displayed in vivo can improve cancer biology studies and accelerate novel anticancer drug screening. Inspired by a systems biology approach, we have formed 3D in vitro bioengineered tumour angiogenesis microenvironments within a glycosaminoglycan-based hydrogel culture system. This microenvironment model can routinely recreate breast and prostate tumour vascularisation. The multiple cell types cultured within this model were less sensitive to chemotherapy when compared with two dimensional (2D) cultures, and displayed comparative tumour regression to that displayed in vivo. These features highlight the use of our in vitro culture model as a complementary testing platform in conjunction with animal models, addressing key reduction and replacement goals of the future. We anticipate that this biomimetic model will provide a platform for the in-depth analysis of cancer development and the discovery of novel therapeutic targets

Synthesis of New Polyether Ether Ketone Derivatives with Silver Binding Site and Coordination Compounds of Their Monomers with Different Silver Salts

Polyether ether ketone (PEEK) is a well-known polymer used for implants and devices, especially spinal ones. To overcome the biomaterial related infection risks, 4-4′-difluorobenzophenone, the famous PEEK monomer, was modified in order to introduce binding sites for silver ions, which are well known for their antimicrobial activity. The complexation of these new monomers with different silver salts was studied. Crystal structures of different intermediates were obtained with a linear coordination between two pyridine groups and the silver ions in all cases. The mechanical and thermal properties of different new polymers were characterized. The synthesized PEEKN5 polymers showed similar properties than the PEEK ones whereas the PEEKN7 polymers showed similar thermal properties but the mechanical properties are not as good as the ones of PEEK. To improve these properties, these polymers were complexed with silver nitrate in order to “cross-link” with silver ions. The presence of ionic silver in the polymer was then confirmed by thermogravimetric analysis (TGA) and X-ray powder diffraction (XRPD). Finally, a silver-based antimicrobial compound was successfully coated on the surface of PEEKN5