title: Characterization and dissolution of functionalized amorphous calcium phosphate biolayers using single-splat technology.
abstract: New processing routes and characterization techniques underpin further growth of biomaterials for improved performance and multifunctionality. This study investigates the characteristics and solubility of amorphous calcium phosphate (ACP) printed splats. Splats made from 20 to 60 μm molten hydroxyapatite particles were classified for shape (rounded/splashed) and cracking. Recoil of the spread droplet created a bowl-shaped splat. This has previously not been observed and could be related to the longer solidification time associated with solidification to an ACP. A central depression was created from 20 μm particles, but a bowl-shaped splat from 60 μm particles. Cracking was more prevalent for splats that solidified with an edge discontinuity. Splats immersed in pH 7.3 tris buffer displayed dissolution followed by cracking. Cracking continued over a period of 15 min as dissolution induced more cracks. Further degradation occurred by delamination of splat segments. Delamination accelerated the process of splat removal. Applied to thermal spray coatings, this highlights topography and dissolution at the splat level. The use of separate splats can potentially be used as a biolayer where splats are separate, in a line or on top of each other.
authors.affiliation: Riga Biomaterials, Innovation and Development Centre, Riga Technical University, Latvia. kgross@rtu.lv
authors.forename: Karlis A
authors.initials: KA
authors.lastname: Gross
authors.forename: Cara J
authors.initials: CJ
authors.lastname: Young
authors.forename: Mardi A
authors.initials: MA
authors.lastname: Beck
authors.forename: Ezra W
authors.initials: EW
authors.lastname: Keebaugh
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Bronts
authors.forename: Saeed
authors.initials: S
authors.lastname: Saber-Samandari
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Riley
mesh_terms: D002021:Buffers; D002130:Calcium Phosphates / Q000032:analysis*; D017886:Durapatite / Q000032:analysis; D008422:Materials Testing / Q000379:methods*; D011208:Powders; D012995:Solubility
chemical_list: D002021:Buffers; D002130:Calcium Phosphates; D011208:Powders; C519480:amorphous calcium phosphate; D017886:Durapatite