The Effect of the Epidermal Growth Factor(EGF) on the Healing of the Injured Anterior Cruciate Ligament of the Knee in Dog: in Vivo Study

Kim, Yong Sik; Chung, Do Hyun; Chung, Jin Wha; Woo, Young Kyun; Lim, Young Wook; Lee, Hwa Sung; Kwon, Soon Yong

Abstract

PURPOSE
The purpose of this study is to find out the possibilities of the new treatment via continuous stimulation by photo-immobilization of growth factor in the anterior cruciate ligament(ACL) injury.
MATERIALS AND METHODS
Photo-reactive epidermal growth factor(EGF-Az) synthesized by conjugating EGF with N-(4-azidobenzoyloxy)succinimide was immobilized onto biodegradable tissue-regenerative mesh(Bio-Mesh(R)) using UV irradiation. We sutured the BioMesh containing photo-reactive EGF on the artificial defect area of ACL in the left knee of beagle dogs and sutured the BioMesh that was not treated with EGF-Az on the defect area of ACL in the right knee. Four weeks later, we obtained the tissues from the defect area of both ACLs and compared the results of HE stain, immunohistochemistry and RT-PCR in both tissues.
RESULTS
In results of HE stain and immunohistochemistry, we observed better cellular proliferation and more definite spindle shape of cells in EGF-immobilized area than in non-EGF defect area. Also cellular density was higher in EGF-immobilized area. On the other hand, cells had shaped more round and cellular density was lower in non-EGF defect area. In results of RT-PCR of GAPDH(Glyceraldehyde-3-phosphate dehydrogenase), COL I(Collagen type I), COL III and EGF, except for TGF-beta1(Transforming growth factor-beta 1), we also observed more definite expressions in EGF-immobilized area than in non-EGF defect area.
CONCLUSION
We were able to confirm rapid cellular proliferation via artificial stimulation effect induced by photo-immobilized EGF. If EGF is immobilized onto biodegradable materials for clinical application, it will contribute to the treatment of ACL injury.