title: Calcium polyphosphate particulates for bone void filler applications.
abstract: This study investigates the characteristics of porous calcium polyphosphate particulates (CPPp) formed using two different processing treatments as bone void fillers in non- or minimally load-bearing sites. The two calcium polyphosphate particulate variants (grades) were formed using different annealing conditions during particulate preparation to yield either more slowly degrading calcium polyphosphate particulates (SD-CPPp) or faster degrading particulates (FD-CPPp) as suggested by a previous degradation study conducted in vitro (Hu et al., Submitted for publication 2016). The two CPPp grades were compared as bone void fillers in vivo by implanting particulates in defects created in rabbit femoral condyle sites (critical size defects). The SD-CPPp and FD-CPPp were implanted for 4- and 16-week periods. The in vivo study indicated a significant difference in amount of new bone formed in the prepared sites with SD-CPPp resulting in more new bone formation compared with FD-CPPp. The lower bone formation characteristic of the FD-CPPp was attributed to its faster degradation rate and resulting higher local concentration of released polyphosphate degradation products. The study results indicate the importance of processing conditions on preparing calcium polyphosphate particulates for potential use as bone void fillers in nonload-bearing sites. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 874-884, 2017.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.|Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Pilliar
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.|Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.|Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Rita A
authors.initials: RA
authors.lastname: Kandel
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.|Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Marc D
authors.initials: MD
authors.lastname: Grynpas
authors.affiliation: Division of Orthopedic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Theodoropoulos
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Youxin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.|Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Bedilu
authors.initials: B
authors.lastname: Allo
authors.affiliation: Lunenfeld Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.|Division of Orthopedic Surgery, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Adele
authors.initials: A
authors.lastname: Changoor
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry / Q000494:pharmacology; D005269:Femur / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects*; D011122:Polyphosphates / Q000737:chemistry / Q000494:pharmacology; D011817:Rabbits
chemical_list: D018786:Bone Substitutes; D011122:Polyphosphates
keywords: bone substitute; calcium phosphates; in vivo; orthopaedic; porous