2015 ISAKOS Biennial Congress ePoster #402
Local rhBMP-4 Release From Regenerative Silk Fibroin Coated Polyethylene Terephthalate Scaffold for Potential Enhanced Artificial Graft-Bone Healing
Fang Wan, MD, PhD, Shanghai CHINA
Jia Jiang, MD, PhD, Shanghai CHINA
Peng Zhang, PhD, Shanghai CHINA
Jun Chen CHINA
Shiyi Chen, MD, PhD, Prof., Shanghai CHINA
Huashan Hospital, Fudan University, Shanghai, Shanghai, CHINA
FDA Status Cleared
Summary: We prepared a regenerative silk fibroin coating with a local rhBMP-4 release system that coated on polyethylene terephthalate (PET) scaffold and investigate its potential on artificial graft-bone healing. We hypothesize that the coated scaffold can enhance artificial graft to bone healing and the result supports our hypothesis.
To prepare a regenerative silk fibroin (RSF) coating with a local rhBMP-4 release system that coated on polyethylene terephthalate (PET) scaffold and investigate its potential on artificial graft-bone healing.
20µg recombinant human BMP-4 was added into 10ml 4% RSF solution that was prepared by previous method. The surface of PET scaffold received plasma treatment (50V, 2mA) for 3 minutes, and then it was soaked in an SF solution for 1 hour. It was processed with methanol and dried. Multiple characterizations were proceeded on those scaffolds. Mice osteoblast (MC3T3-E1) was cultured in the uncoated-PET material (control group), RSF coating-PET scaffold (RSF group) and RSF with local rhBMP-4 release coating-PET scaffold (RSF+rhBMP-4 group). Subsequently, scanning electron microscope (SEM), methyl thiazolyl tetrazolium (MTT), cell cycle analysis, ALP activity, DNA content and living confocal laser scanning microscopy was detected. These scaffolds were also implanted into proximal tibia in New Zealand rabbits for the animal model of graft-bone healing. Biomechanical pull-out tests, µ-CT scan and histological examination were proceeded to evaluate the healing progress after 4 weeks.
Characterizations showed there are significant differences between coated and uncoated group. The results of SEM, MTT ,cell cycle and DNA content analysis showed both RSF+rhBMP-4 group and RSF group could significantly improve the proliferation and adhesion of mice osteoblast (MC3T3-E1) (P<0.05). Meanwhile, RSF+rhBMP-4 group showed better performance than RSF group (P<0.05). All of above were proved by living confocal laser scanning microscopy. ALP activity and analysis showed that RSF+rhBMP-4 had significant osteogenesis activity than both SF group and control group (P<0.05). 4 weeks after the build of graft-bone healing model, RSF+rhBMP-4 group and RSF group exhibited significantly higher maximum loads of 42.9 ± 4.6 N and 36.3 ± 5.4 N, respectively, compared with the control group (20.9 ± 3.4 N) (P<0.05), respectively; In µ-CT scan, as expected, significantly more bone volume in the bone tunnel can be observed in RSF+rhBMP-4 scaffolds compared with those in RSF group or control group following a 4-week healing period. In histologic examination, as compared with RSF group or uncoated PET scaffold, substantial new bone tissue could be observed within the bone tunnel from RSF+rhBMP-4 scaffolds both at the periphery and in the center of the tunnel, as well as an increased number of osteoblastic cells and matrix.
Local rhBMP-4 release from regenerative silk fibrin coated polyethylene terephthalate scaffold was successfully prepared. It could improve proliferation and adhesion of osteoblastic cells and also increase its osteogenesis activity. It had the potential of enhancing artificial graft-bone healing.