title: Three-dimensional endothelial cell morphogenesis under controlled ion release from copper-doped phosphate glass.
abstract: Copper ions represent a promising angiogenic agent but are associated with cytotoxicity at elevated concentrations. Phosphate-based glasses (PGs) exhibit adjustable dissolution properties and allow for controlled ion release. This study examined the formation of capillary-like networks by SVEC4-10 endothelial cells (ECs) seeded in a three-dimensional (3D) type I collagen hydrogel matrix mixed with PG particles of the formulation 50P2O5-30CaO-(20-x)Na2O-xCuO (x=0 and 10 mol%). Copper and total phosphorus release decreased over time and was more sustained in the case of 10% CuO PG. Moreover, increasing the concentration of 10% CuO PG in collagen substantially delayed dissolution along with preferential release of copper. A 3D morphometric characterization method based on confocal laser scanning microscopy image stacks was developed in order to quantify EC network length, connectivity and branching. Network length was initially reduced in a concentration-dependent fashion by 10% CuO PG and, to a lesser extent, by 0% CuO PG, but reached values identical to the non-PG control by day 5 in culture. This reduction was attributed to a PG-mediated decrease in cell metabolic activity while cell proliferation as well as network connectivity and branching were independent of PG content. Gene expression of matrix metalloproteinases (MMP)-1 and -2 was up-regulated by PGs, indicating that MMPs did not play a critical role in network growth. The relationship between ion release and EC morphogenesis in 3D provided in this study is expected to contribute to an ultimately successful pro-angiogenic application of CuO-doped PGs.
authors.affiliation: Department of Mining and Materials Engineering, McGill University, Montreal, QC, Canada. Electronic address: christoph.staehli@mail.mcgill.ca.
authors.forename: Christoph
authors.initials: C
authors.lastname: Stähli
authors.affiliation: Department of Mining and Materials Engineering, McGill University, Montreal, QC, Canada. Electronic address: mark.james-bhasin@mail.mcgill.ca.
authors.forename: Mark
authors.initials: M
authors.lastname: James-Bhasin
authors.affiliation: Department of Mining and Materials Engineering, McGill University, Montreal, QC, Canada. Electronic address: showan.nazhat@mcgill.ca.
authors.forename: Showan N
authors.initials: SN
authors.lastname: Nazhat
mesh_terms: D000818:Animals; D002460:Cell Line; D003094:Collagen; D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005782:Gels; D015870:Gene Expression; D005898:Glass / Q000737:chemistry; D020782:Matrix Metalloproteinases / Q000235:genetics; D051379:Mice; D009024:Morphogenesis; D010078:Oxazines / Q000378:metabolism; D010084:Oxidation-Reduction; D010710:Phosphates / Q000737:chemistry / Q000494:pharmacology*; D010758:Phosphorus / Q000737:chemistry; D014966:Xanthenes / Q000378:metabolism
chemical_list: D005782:Gels; D010078:Oxazines; D010710:Phosphates; D014966:Xanthenes; C005843:resazurin; D010758:Phosphorus; D003300:Copper; D003094:Collagen; D020782:Matrix Metalloproteinases
keywords: Angiogenesis; Bioinorganics; Capillary-like network; Matrix metalloproteinase; RT-qPCR