title: The influence of target stoichiometry on early cell adhesion of co-sputtered calcium-phosphate surfaces.
abstract: The nature of the initial interaction between calcium phosphate (Ca-P) thin films and osteoblasts can be influenced by a number of different properties including the phase, crystallinity, stoichiometry and composition of the surface. There is still a strong interest in developing and studying Ca-P surfaces that have the ability to accurately control the osteoblast response. Radio frequency (RF) magnetron sputtering is a technique that allows for accurate control of the properties of deposited Ca-P coatings and has been studied extensively because of this fact. In this work, Ca-P coatings were co-deposited using RF magnetron sputtering in order to study the effect of changing the target stoichiometry on the initial in vitro behavior of MG63 osteoblast-like cells. The samples produced were analysed both as-deposited and after thermal annealing to 500 °C. After annealing XPS analyses of the samples co-deposited using tricalcium phosphate (TCP) materials gave a Ca/P ratio of 1.71 ± 0.01, as compared to those co-deposited from hydroxyapatite (HA) materials, with a Ca/P of 1.82 ± 0.06. In addition to this, the curve fitted XPS data indicated the presence of low levels of carbonate in the coatings. Despite this the XRD results for all of the annealed coatings were shown to be characteristic of pure HA with a preferred 002 orientation. The atomic force microscopy results also highlighted that both types of coatings had surface features of a similar size (200-220 nm). Both surfaces exhibited a degree of surface degradation, even after 1 h of cell culture. However, the TCP derived surfaces showed an enhanced osteoblastic cell response in terms of cell adhesion and cell proliferation in the earlier stages of cell culture than the surfaces deposited from HA. An improvement in the initial cell attachment and a potential for increased cell proliferation rates is viewed as a highly advantageous result in relation to controlling the osteoblast response on these surfaces.
authors.affiliation: Nanotechnology and Integrated Bioengineering Centre (NIBEC), School of Engineering, University of Ulster, Shore Road, Newtownabbey, Co. Antrim, BT37 0QB, Northern Ireland, UK, ar.boyd@ulster.ac.uk.
authors.forename: A R
authors.initials: AR
authors.lastname: Boyd
authors.forename: C
authors.initials: C
authors.lastname: O'Kane
authors.forename: P
authors.initials: P
authors.lastname: O'Hare
authors.forename: G A
authors.initials: GA
authors.lastname: Burke
authors.forename: B J
authors.initials: BJ
authors.lastname: Meenan
mesh_terms: D000293:Adolescent; D001672:Biocompatible Materials / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D002448:Cell Adhesion / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D003460:Crystallization; D006801:Humans; D008280:Magnetics; D008297:Male; D010006:Osteoblasts / Q000166:cytology*; D011208:Powders; D011846:Radio Waves; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D016596:Vinculin / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D011208:Powders; D016596:Vinculin; C020243:calcium phosphate; D014025:Titanium; C018392:tricalcium phosphate
references.citation: J Biomed Mater Res. 1995 Feb;29(2):269-76
references.pmid: 7738075
references.citation: J Mater Sci Mater Med. 1997 Nov;8(11):683-90
references.pmid: 15348819
references.citation: J Biomed Mater Res. 2002 Mar 15;59(4):697-708
references.pmid: 11774332
references.citation: Biomaterials. 1997 Aug;18(15):1037-41
references.pmid: 9239465
references.citation: Biomaterials. 2006 Nov;27(32):5512-7
references.pmid: 16872671
references.citation: J Biomed Mater Res A. 2008 Mar 1;84(3):682-90
references.pmid: 17635019
references.citation: J Colloid Interface Sci. 1997 Jul 15;191(2):489-97
references.pmid: 9268533
references.citation: Biomaterials. 2010 Jan;31(3):515-22
references.pmid: 19864018
references.citation: J Biomed Mater Res. 1997 Mar 15;34(4):507-17
references.pmid: 9054534
references.citation: Biomaterials. 2005 Jun;26(16):2947-56
references.pmid: 15603789
references.citation: Colloids Surf B Biointerfaces. 2010 Jul 1;78(2):283-90
references.pmid: 20392613
references.citation: J Bone Joint Surg Br. 1988 Jan;70(1):17-22
references.pmid: 2828374
references.citation: J Biomed Mater Res. 1998 Feb;39(2):176-83
references.pmid: 9457545
references.citation: J Biomed Mater Res. 2000 Feb;49(2):155-66
references.pmid: 10571901
references.citation: Biomaterials. 2002 Mar;23(5):1383-9
references.pmid: 11804294
references.citation: Calcif Tissue Int. 1987 Feb;40(2):64-70
references.pmid: 3032379
references.citation: Acta Biomater. 2010 Apr;6(4):1561-8
references.pmid: 19903542
references.citation: J Mater Sci Mater Med. 2007 Jun;18(6):1061-9
references.pmid: 17268873
references.citation: Acta Biomater. 2010 Aug;6(8):3234-41
references.pmid: 20188868
references.citation: J Mater Sci Mater Med. 2010 Jan;21(1):173-81
references.pmid: 19672562
references.citation: Bone. 2001 Dec;29(6):547-52
references.pmid: 11728925
references.citation: J Mater Sci Mater Med. 2008 Feb;19(2):485-98
references.pmid: 17607520
references.citation: Biomaterials. 1997 Apr;18(7):551-7
references.pmid: 9105595