Restoration of critical-size defects in the rabbit mandible using porous nanohydroxyapatite-polyamide scaffolds.
Composite nanohydroxyapatite/polyamide (n-HA/PA) biomaterials have been indicated for bone defect reconstruction, where PA is added to enhance the toughness of n-HA. However, a comprehensive understanding of the biological performance of this implant material remains to be determined. In this study, the biological activity of n-HA/PA biomaterials was characterized in vitro by assessing the growth of bone marrow stromal cells (BMSCs), and in an in vivo rabbit model. To evaluate the n-HA/PA performance under different osteogenic conditions in vivo, implants were inserted to critical-size bone defects in the angle and body of the rabbit mandible. To determine the necessity of ectogenic BMSC-n-HA/PA hybrids at different implantation sites, both raw n-HA/PA materials and BMSC-seeded n-HA/PA hybrids were implanted. Bone formation was detected by radiology and histological studies. The results showed that n-HA/PA composites had great bioactivity, demonstrating significant BMSC proliferation, active alkaline phosphatase secretion, and stimulating the expression of osteogenic proteins (bone morphogenetic protein 2 [BMP2], osteoprotegerin [OPG], osteopontin [OPN], collagen type I [Col I], and osteocalcin [OCN]), in comparison to the control (polyethylene). At marrow-rich implantation sites (mandibular body), the amount of new bone formation was significant, but was not enhanced by the presence of BMSCs in the BMSC-n-HA/PA hybrids. However, the BMSC-n-HA/PA hybrids were essential for promoting bone formation in marrow-poor sites (mandibular angle). In conclusion, n-HA/PA biomaterials, which offer the advantage of enhanced mechanical performance over n-HA, exhibit significant bioactivity, including the capacity for bone regeneration at marrow-poor sites when implanted in combination with BMSCs.
State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, P.R. China.
Jun
J
Guo
Zhaosong
Z
Meng
Gang
G
Chen
Dan
D
Xie
Yali
Y
Chen
Hang
H
Wang
Wei
W
Tang
Lei
L
Liu
Wei
W
Jing
Jie
J
Long
Weihua
W
Guo
Weidong
W
Tian
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D015519:Bone Density / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D001861:Bone Regeneration / Q000187:drug effects; D058250:Dental Restoration Repair / Q000379:methods*; D017886:Durapatite / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D020007:Implants, Experimental; D008334:Mandible / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009757:Nylons / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D019919:Prosthesis Implantation; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D054457:Tissue Scaffolds / Q000737:chemistry*; D055114:X-Ray Microtomography
D001672:Biocompatible Materials; D009757:Nylons; D017886:Durapatite; D000469:Alkaline Phosphatase