title: The in vivo performance of CaP/PLGA composites with varied PLGA microsphere sizes and inorganic compositions.
abstract: Enrichment of calcium phosphate (CaP) bone substitutes with poly(lactic-co-glycolic acid) (PLGA) microspheres to create porosity overcomes the problem of poor CaP degradation. The degradation of CaP-PLGA composites can be customized by changing the physical and chemical properties of PLGA and/or CaP. However, the effect of the size of dense (solid rather than hollow) PLGA microspheres in CaP has not previously been described. The present study aimed at determining the effect of different dense (i.e. solid) PLGA microsphere sizes (small (S) ~20μm vs. large (L) ~130μm) and of CaP composition (CaP with either anhydrous dicalcium phosphate (DCP) or calcium sulphate dihydrate (CSD)) on CaP scaffold biodegradability and subsequent bone in-growth. To this end mandibular defects in minipigs were filled with pre-set CaP-PLGA implants, with autologous bone being used as a control. After 4weeks the autologous bone group outperformed all CaP-PLGA groups in terms of the amount of bone present at the defect site. On the other hand, at 12weeks substantial bone formation was observed for all CaP-PLGA groups (ranging from 47±25% to 62±15%), showing equal amounts of bone compared with the autologous bone group (82±9%), except for CaP with DCP and large PLGA microspheres (47±25%). It was concluded that in the current study design the difference in PLGA microsphere size and CaP composition led to similar results with respect to scaffold degradation and subsequent bone in-growth. Further, after 12weeks all CaP-PLGA composites proved to be effective for bone substitution.
authors.affiliation: Department of Biomaterials (309), Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Jan Willem M
authors.initials: JW
authors.lastname: Hoekstra
authors.forename: Jinling
authors.initials: J
authors.lastname: Ma
authors.forename: Adelina S
authors.initials: AS
authors.lastname: Plachokova
authors.forename: Ewald M
authors.initials: EM
authors.lastname: Bronkhorst
authors.forename: Marc
authors.initials: M
authors.lastname: Bohner
authors.forename: Juli
authors.initials: J
authors.lastname: Pan
authors.forename: Gert J
authors.initials: GJ
authors.lastname: Meijer
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
authors.forename: Jeroen J J P
authors.initials: JJ
authors.lastname: van den Beucken
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000032:analysis / Q000138:chemical synthesis* / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000737:chemistry*; D005260:Female; D007287:Inorganic Chemicals / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D008337:Mandibular Fractures / Q000473:pathology* / Q000628:therapy*; D008422:Materials Testing; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D013552:Swine; D013556:Swine, Miniature; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D007287:Inorganic Chemicals; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C020243:calcium phosphate