A novel porous bioceramics scaffold by accumulating hydroxyapatite spherulites for large bone tissue engineering in vivo. II. Construct large volume of bone grafts.
In vivo engineering of bone autografts using bioceramic scaffolds with appropriate porous structures is a potential approach to prepare autologous bone grafts for the repair of critical-sized bone defects. This study investigated the evolutionary process of osteogenesis, angiogenesis, and compressive strength of bioceramic scaffolds implanted in two non-osseous sites of dogs: the abdominal cavity and the dorsal muscle. Hydroxyapatite (HA) sphere-accumulated scaffolds with controlled porous structures were prepared and placed in the two sites for up to 6 months. Analyses of retrieved scaffolds found that osteogenesis and angiogenesis were faster in scaffolds implanted in dorsal muscles compared with those placed in abdominal cavities. The abdominal cavity, however, can accommodate larger bone grafts with designed shape. Analyses of scaffolds implanted in abdominal cavities [an environment of a low mesenchymal stem cell (MSC) density] further demonstrated that angiogenesis play critical roles during osteogenesis in the scaffolds, presumably by supplying progenitor cells and/or MSCs as seed cells. This study also examined the relationship between the volume of bone grafts and the physiological environment of in vivo bioreactor. These results provide basic information for the selection of appropriate implanting sites and culture time required to engineer autologous bone grafts for the clinical bone defect repair. Based on these positive results, a pilot study has applied the grafts constructed in canine abdominal cavity to repair segmental bone defect in load-bearing sites (limbs).
Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, 610031, China.
Wei
W
Zhi
Cong
C
Zhang
Ke
K
Duan
Xiaohong
X
Li
Shuxin
S
Qu
Jianxin
J
Wang
Zhuoli
Z
Zhu
Peng
P
Huang
Tian
T
Xia
Ga
G
Liao
Jie
J
Weng
D015901:Angiography, Digital Subtraction; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D016025:Bone Transplantation; D001842:Bone and Bones / Q000098:blood supply / Q000187:drug effects / Q000502:physiology*; D002516:Ceramics / Q000494:pharmacology*; D019245:Compressive Strength / Q000187:drug effects; D004285:Dogs; D017886:Durapatite / Q000494:pharmacology*; D009132:Muscles / Q000502:physiology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D016062:Porosity; D019919:Prosthesis Implantation; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
D001672:Biocompatible Materials; D017886:Durapatite
angiogenesis; bone graft; hydroxyapatite scaffold; in vivo bioreactor; osteogenesis