The bone regenerative effect of chitosan microsphere-encapsulated growth hormone on bony consolidation in mandibular distraction osteogenesis in a dog model.
The purpose of this project was to study the effect of chitosan microsphere-encapsulated human growth hormone, which causes sustained release of chitosan and human growth hormone after implantation on early bony consolidation in distraction osteogenesis of a canine model. Forty-eight dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy, and the mandibular distraction was started 5 days after the operation at a rate of 1 mm/d up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan microsphere group (III), and chitosan microsphere-encapsulated human growth hormone group (IV). Normal saline was injected in group I. In group II, a 1-ml volume of hyaluronic acid solution was injected into the distracted area. In the group III, powder of chitosan microspheres and hGH were mixed with a 1-ml volume of hyaluronic acid to make an injectable form, and it was implanted into the distracted area. In group IV, powder of chitosan microsphere-encapsulated hGH was mixed with a 1-ml volume of hyaluronic acid. A total of 1-ml volume of the solution mix was implanted into the distracted area. Five dogs in each group (total of 20 dogs) were killed 3 weeks after completion of distraction. Twenty-eight dogs were killed at 6 weeks. Bone mineral density was 13.1% of the contralateral normal mandible at 3 weeks and 29.6% at 6 weeks in group I, 16.4% at 3 weeks and 40.4% at 6 weeks in group II, 16.6% at 3 weeks and 45.95% at 6 weeks in group III, and 29.6% at 3 weeks and 66.7% at 6 weeks in group IV. The mean three-point failure load was 16.1% in the control group, 34.7% in group II, 41.5% in group III, and 52.1% in group IV compared with the intact contralateral mandible, with statistical significance. In the histological findings, new bone was generated in all groups. In group IV, the formation of active woven bone was observed throughout the distracted area at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV, group III, group II, and the control group. In conclusion, these findings suggest that chitosan microsphere-encapsulated hGH seems to be quite effective in early bone consolidation in distraction osteogenesis.
Cho
Byung Chae
BC
Department of Plastic and Reconstructive Surgery, College of Medicine, Kyungpook National University, Daegu, Korea. bccho@knu.ac.kr
Kim
Jong Yeop
JY
Lee
Jong Hyup
JH
Chung
Ho Yun
HY
Park
Jae Woo
JW
Roh
Kyung Ho
KH
Kim
Go Un
GU
Kwon
Ick Chan
IC
Jang
Kwang Ho
KH
Lee
Dong-Sin
DS
Park
Nang Woon
NW
Kim
In San
IS
D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage*; D015519:Bone Density; D001861:Bone Regeneration / Q000187:drug effects*; D002686:Chitin / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D048271:Chitosan; D003799:Dental Stress Analysis; D004285:Dogs; D016503:Drug Delivery Systems; D019382:Human Growth Hormone / Q000008:administration & dosage*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008334:Mandible / Q000254:growth & development / Q000601:surgery*; D008863:Microspheres; D019647:Oral Surgical Procedures; D019857:Osteogenesis, Distraction; D018583:Pliability
D001672:Biocompatible Materials; D019382:Human Growth Hormone; D002686:Chitin; D007334:Insulin-Like Growth Factor I; D006820:Hyaluronic Acid; D048271:Chitosan