title: Enhanced bone formation in sheep vertebral bodies after minimally invasive treatment with a novel, PLGA fiber-reinforced brushite cement.
abstract: Injectable, brushite-forming calcium phosphate cements (CPC) show potential for bone replacement, but they exhibit low mechanical strength. This study tested a CPC reinforced with poly(l-lactide-co-glycolide) acid (PLGA) fibers in a minimally invasive, sheep lumbar vertebroplasty model.
  
  
  
  The study aimed to test the in vivo biocompatibility and osteogenic potential of a PLGA fiber-reinforced, brushite-forming CPC in a sheep large animal model.
  
  
  
  This is a prospective experimental animal study.
  
  
  
  Bone defects (diameter: 5 mm) were placed in aged, osteopenic female sheep, and left empty (L2) or injected with pure CPC (L3) or PLGA fiber-reinforced CPC (L4; fiber diameter: 25 µm; length: 1 mm; 10% [wt/wt]). Three and 9 months postoperation (n=20 each), the structural and functional CPC effects on bone regeneration were documented ex vivo by osteodensitometry, histomorphometry, micro-computed tomography (micro-CT), and biomechanical testing.
  
  
  
  Addition of PLGA fibers enhanced CPC osteoconductivity and augmented bone formation. This was demonstrated by (1) significantly enhanced structural (bone volume/total volume, shown by micro-CT and histomorphometry; 3 or 9 months) and bone formation parameters (osteoid volume and osteoid surface; 9 months); (2) numerically enhanced bone mineral density (3 and 9 months) and biomechanical compression strength (9 months); and (3) numerically decreased bone erosion (eroded surface; 3 and 9 months).
  
  
  
  The PLGA fiber-reinforced CPC is highly biocompatible and its PLGA fiber component enhanced bone formation. Also, PLGA fibers improve the mechanical properties of brittle CPC, with potential applicability in load-bearing areas.
authors.affiliation: Materials Science, Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Löbdergraben 32, Jena D-07743, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Maenz
authors.affiliation: Orthopedics, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany; Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Brinkmann
authors.affiliation: Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Kunisch
authors.affiliation: Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Victoria
authors.initials: V
authors.lastname: Horbert
authors.affiliation: Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gunnella
authors.affiliation: Institute of Laboratory Animal Sciences and Welfare, Jena University Hospital, Dornburger Str. 23, Jena D-07743, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Bischoff
authors.affiliation: Institute of Laboratory Animal Sciences and Welfare, Jena University Hospital, Dornburger Str. 23, Jena D-07743, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Schubert
authors.affiliation: Orthopedics, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Sachse
authors.affiliation: Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Long
authors.initials: L
authors.lastname: Xin
authors.affiliation: Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, Berlin D-12205, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Günster
authors.affiliation: Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, Berlin D-12205, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Illerhaus
authors.affiliation: Materials Science, Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Löbdergraben 32, Jena D-07743, Germany.
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Jandt
authors.affiliation: Materials Science, Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Löbdergraben 32, Jena D-07743, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Bossert
authors.affiliation: Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany. Electronic address: raimund.w.kinne@med.uni-jena.de.
authors.forename: Raimund W
authors.initials: RW
authors.lastname: Kinne
authors.affiliation: Orthopedics, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany; Experimental Rheumatology Unit, Department of Orthopedics, Jena University Hospital, Waldkrankenhaus "Rudolf Elle", Klosterlausnitzer Str. 81, Eisenberg D-07607, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Bungartz
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000009:adverse effects / Q000737:chemistry*; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry; D005260:Female; D019344:Lactic Acid / Q000737:chemistry; D010012:Osteogenesis; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012756:Sheep; D054854:Vertebroplasty / Q000009:adverse effects / Q000379:methods*
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C494366:calcium phosphate, dibasic, dihydrate
keywords: Bone regeneration; Calcium phosphate cement; Fiber reinforcement; In vivo; Large animal model sheep; Vertebroplasty