title: In vitro assessment of cell penetration into porous hydroxyapatite scaffolds with a central aligned channel.
abstract: There is a clinical need for synthetic scaffolds that promote bone regeneration. A common problem encountered when using scaffolds in tissue engineering is the rapid formation of tissue on the outer edge of the scaffold whilst the tissue in the centre becomes necrotic. To address this, the scaffold design should improve nutrient and cell transfer to the scaffold centre. In this study, hydroxyapatite scaffolds with random, open porosity (average pore size of 282+/-11microm, average interconnecting window size of 72+/-4microm) were manufactured using a modified slip-casting methodology with a single aligned channel inserted into the centre. By varying the aligned channel diameter, a series of scaffolds with channel diameters ranging from 170 to 421microm were produced. These scaffolds were seeded with human osteosarcoma (HOS TE85) cells and cultured for 8 days. Analysis of cell penetration into the aligned channels revealed that cell coverage increased with increasing channel diameter; from 22+/-3% in the 170microm diameter channel to 38+/-6% coverage in the 421microm channel. Cell penetration into the middle section of the 421microm diameter channel (average cell area coverage 121x10(3)+/-32x10(3)microm(2)) was significantly greater than that observed within the 170microm channel (average cell area coverage 26x10(3)+/-6x10(3)microm(2)). In addition, the data presented demonstrates that the minimum channel (or pore) diameter required for cell penetration into such scaffolds is approximately 80microm. These results will direct the development of scaffolds with aligned macroarchitecture for tissue engineering bone.
authors.affiliation: School of Pharmacy, Biomaterials and Tissue Engineering, University of Nottingham, Boots Science Building University Campus, Nottingham, Nottinghamshire NG7 2RD, UK. f.rose@nottingham.ac.uk
authors.forename: Felicity R
authors.initials: FR
authors.lastname: Rose
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Cyster
authors.forename: David M
authors.initials: DM
authors.lastname: Grant
authors.forename: Colin A
authors.initials: CA
authors.lastname: Scotchford
authors.forename: Steven M
authors.initials: SM
authors.lastname: Howdle
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Shakesheff
mesh_terms: D002455:Cell Division; D017886:Durapatite; D008855:Microscopy, Electron, Scanning; D023822:Tissue Engineering
chemical_list: D017886:Durapatite