title: Osteogenic properties of PBLG-g-HA/PLLA nanocomposites.
abstract: New development of biomaterial scaffolds remains a prominent issue for the regeneration of lost or fractured bone. Of these scaffolds, a number of bioactive polymers have been synthesized and fabricated for diverse biological roles. Although recent evidence has demonstrated that composite scaffolds such as HA/PLLA have improved properties when compared to either HA or PLLA alone, recent investigations have demonstrated that the phase compatibility between HA and PLLA layers is weak preventing optimal enhancement of the mechanical properties and making the composites prone to breakdown. In the present study, poly (γ-benzyl-L-glutamate) modified hydroxyapatite/(poly (L-lactic acid)) (PBLG-g-HA/PLLA) composite scaffolds were fabricated with improved phase compatibility and tested for their osteogenic properties in 18 Wistar female rats by analyzing new bone formation in 3 mm bilateral femur defects in vivo. At time points, 2, 4 and 8 weeks post surgery, bone formation was evaluated by µ-CT and histological analysis by comparing 4 treatment groups; 1) blank defect, 2) PLLA, 3) HA/PLLA and 4) PBLG-g-HA/PLLA scaffolds. The in vivo analysis demonstrated that new bone formation was much more prominent in HA/PLLA and PBLG-g-HA/PLLA groups as depicted by µ-CT, H&E staining and immunohistochemistry for collagen I. TRAP staining was also utilized to determine the influence of osteoclast cell number and staining intensity to the various scaffolds. No significant differences in either staining intensity or osteoclast numbers between all treatment modalities was observed, however blank defects did contain a higher number of osteoclast-like cells. The results from the present study illustrate the potential of PBLG-g-HA/PLLA scaffolds for bone tissue engineering applications by demonstrating favorable osteogenic properties.
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Nanchang, PR China; School of Stomatology, Nanchang University, Nanchang, PR China.
authors.forename: Lan
authors.initials: L
authors.lastname: Liao
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Yang
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Miron
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Nanchang, PR China.
authors.forename: Junchao
authors.initials: J
authors.lastname: Wei
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China; Department of Oral Implantology, School of Stomatology, Wuhan University, Wuhan, PR China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Nanchang, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D001861:Bone Regeneration / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation; D024042:Collagen Type I / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000293:injuries; D019344:Lactic Acid / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry / Q000627:therapeutic use* / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects* / Q000502:physiology; D011091:Polyesters; D011099:Polyglutamic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D015415:Biomarkers; D024042:Collagen Type I; D011091:Polyesters; D011108:Polymers; C003172:poly-gamma-benzyl-L-glutamate; D011099:Polyglutamic Acid; D019344:Lactic Acid; C033616:poly(lactide); D017886:Durapatite