Chinese Journal of Tissue Engineering Research ›› 2019, Vol. 23 ›› Issue (18): 2806-2811.doi: 10.3969/j.issn.2095-4344.1732

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Supercritical bone defect repaired by composite bioscaffolds loaded with recombinant human bone morphogenetic protein 2/poly(lactic acid)

Zhou Sirui, Xiao Hongli, Huang Wenliang, Deng Jiang, Ye Peng
  

  1. First Ward of Orthopedics, the Third Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
  • Received:2019-02-18 Online:2019-06-28 Published:2019-06-28
  • Contact: Deng Jiang, Professor, Chief physician, Master’s supervisor, First Ward of Orthopedics, the Third Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
  • About author:Zhou Sirui, Master, Attending physician, First Ward of Orthopedics, the Third Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
  • Supported by:

    the Zunyi Science and Technology Bureau and Zunyi First People’s Hospital Joint Science and Technology Research and Development Project, No. (2018)162 (to ZSR); the National Natural Science Foundation of China, No. 81660367 (to ZSR); the Science and Technology Foundation of Guizhou Province, No. (2016)1420 (to ZSR)

Abstract:

BACKGROUND: Preliminary study has prepared the silk fibroin/chitosan/nano-hydroxyapatite composite bioscaffold and the recombinant human bone morphogenetic protein 2/polylactic acid sustained release system.
OBJECTIVE: To observe the effect of radial bone defect repairing in dogs with composite bioscaffold loaded with recombinant human bone morphogenetic protein 2/poly(lactic acid) sustained-release microspheres.
METHODS: Silk fibroin/chitosan/nano-hydroxyphosphorous bioscaffolds were prepared by vacuum freeze-drying and chemical crosslinking. Recombinant human bone morphogenetic protein 2/poly(lactic acid) sustained-release microspheres were prepared by compound emulsion volatilization, and then prepared the three-dimensional bioscaffold. Eight adult dogs (provided by the Experimental Animal Center of Zunyi Medical University) were used to make a critical bone defect model of the radius (3 cm in the middle radius). Four bone defects were implanted with the three-dimensional bioscaffold with sustained release microspheres and autologous cancellous bones (experimental group 1). The other four only implanted with autologous cancellous bone (control group 1). Another eight adult dogs were used to make a superficial bone defect model of the radius (5 cm in the middle radius). Four bone defects were implanted with the three-dimensional biological scaffold with sustained release microspheres and autologous cancellous bone (experimental group 2). The other four were implanted only with autologous cancellous bone (control group 2). X-ray examination was performed at postoperative 4, 8, and 12 weeks. At postoperative 12 weeks, the radius of the defect area was removed for histopathological observation. The study was approved by the Ethics Committee of Zunyi Medical University, approval number: (2016)2-071.
RESULTS AND CONCLUSION: (1)X-ray: at postoperative 12 weeks, the medullary cavity in the experimental group 1 was recanalized and the cortical bone was formed. The defect in the control group 1 was basically completely connected, but the medullary cavity recanalization and cortical bone shaping were incomplete. In the experimental group 2, the medullary cavity was basically recanalized, the cortical bone shaping and bone ingrowth were basically completed. The control group 2 appeared no bone connection, no cortical bone shaping. (2) Histological observation: in the experimental group 1, the bone defect was connected completely, and the cortical bone formation and complete medullary cavity recanalization were observed. In the control group 1, bone tissue was formed, and a large amount of fibrous tissues were observed, no cortical bone was formed, and the medullary cavity was not recanalized. In experimental group 2, the cortical bone formation and the completion of the medullary cavity were recanalized in the bone defect. The control group 2 showed a small amount of bones, no cortical bone formation and recanalization of the medullary cavity. The experimental group 1 has better bone repair effect than the experimental group 2. (3) These results imply that the three-dimensional bioscaffolds loaded with recombinant human bone morphogenetic protein 2/poly (lactic acid) sustained-release microspheres can effectively repair the critical and supercritical bone defects of canine tibia to some extent.

Key words: bone morphogenetic protein-2, bioscaffold, silk fibroin, chitosan, nano-hydroxyapatite, sustained release microspheres, supercritical bone defect;, autologous cancellous bone

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