title: Biocompatibility of calcium phosphate bone cement with optimised mechanical properties: an in vivo study.
abstract: This work establishes the in vivo performance of modified calcium phosphate bone cements for vertebroplasty of spinal fractures using a lapine model. A non-modified calcium phosphate bone cement and collagen-calcium phosphate bone cements composites with enhanced mechanical properties, utilising either bovine collagen or collagen from a marine sponge, were compared to a commercial poly(methyl methacrylate) cement. Conical cement samples (8 mm height × 4 mm base diameter) were press-fit into distal femoral condyle defects in New Zealand White rabbits and assessed after 5 and 10 weeks. Bone apposition and tartrate-resistant acid phosphatase activity around cements were assessed. All implants were well tolerated, but bone apposition was higher on calcium phosphate bone cements than on poly(methyl methacrylate) cement. Incorporation of collagen showed no evidence of inflammatory or immune reactions. Presence of positive tartrate-resistant acid phosphatase staining within cracks formed in calcium phosphate bone cements suggested active osteoclasts were present within the implants and were actively remodelling within the cements. Bone growth was also observed within these cracks. These findings confirm the biological advantages of calcium phosphate bone cements over poly(methyl methacrylate) and, coupled with previous work on enhancement of mechanical properties through collagen incorporation, suggest collagen-calcium phosphate bone cement composite may offer an alternative to calcium phosphate bone cements in applications where low setting times and higher mechanical stability are important.
authors.affiliation: School of Mechanical and Aerospace Engineering, Ashby Building, Queen's University of Belfast, 121 Stranmillis Road, Belfast, BT9 5AH, UK.
authors.forename: Iwan
authors.initials: I
authors.lastname: Palmer
authors.affiliation: Institute for Global Food Security, School of Biological Sciences, Medical Biology Centre, Queen's University of Belfast, Lisburn Road, Belfast, BT9 7BL, UK.
authors.forename: John
authors.initials: J
authors.lastname: Nelson
authors.affiliation: KliniPharm GmbH, Stephan Strasse 10, Frankfurt am Main, 60313, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schatton
authors.affiliation: School of Mechanical and Manufacturing Engineering, Stokes Building, Dublin City University, Collins Avenue, Dublin 9, Ireland.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Dunne
authors.affiliation: School of Mechanical and Aerospace Engineering, Ashby Building, Queen's University of Belfast, 121 Stranmillis Road, Belfast, BT9 5AH, UK. f.buchanan@qub.ac.uk.
authors.forename: Fraser
authors.initials: F
authors.lastname: Buchanan
authors.affiliation: School of Nursing and Midwifery, Medical Biology Centre, Queen's University of Belfast, Lisburn Road, Belfast, BT9 7BL, UK.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Clarke
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001843:Bone Cements / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002417:Cattle; D003094:Collagen / Q000737:chemistry; D019245:Compressive Strength; D005264:Femoral Fractures / Q000628:therapy; D017102:Fracture Healing; D007249:Inflammation; D008422:Materials Testing; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011161:Porifera; D011817:Rabbits; D013314:Stress, Mechanical
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; D003094:Collagen; D019904:Polymethyl Methacrylate; C020243:calcium phosphate