Promoting bone regeneration in critical bony defects using HA/collagen composite with PRP

• Main Authors: Jr-Yuan Lin, 林志遠
• Other Authors: Che-Shoa Chang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/83791369892702511566

碩士 === 國立陽明大學 === 臨床牙醫學研究所 === 95 === Today the study of the bone regeneration is based on tissue engineering. The purpose of the study is to improve bone regeneration in critical-sized defects by the principle of tissue engineering: scaffolds, cells and growth factors. The goal we hope to achieve is the total regeneration of the bone on both functional and structure aspect. But we can't get complete bone regeneration just by PRP only. So we decide to combine the investigation of our facility: combined hydroxyapatite and collagen. The purpose of collagen is to retain more growth factors in PRP and combine with hydroxyapatite for attachment and migration of cells. We'll utilize the adult dog's tibia-animal model, a well-established model for bone biology study in our experimental group, to mimic the actual human condition. Five groups of adult mongrel dogs, average weighted 10 kg, are used for this study. Two 5-walls' bony cavities with volume of 18 mm x 10 mm x 10 mm are created on the either side of dog’s tibia heads, the cavity on the left side used as experimental group and the right side as control group. Implants as above-mentioned: hydroxyapaptite/collagen composite mixed with PRP using as carrier are placed into the experimental bone cavities, while cavities of control are packed with same amount of PRP mixed with using hydroxyapaptite as carrier. On each scheduled observing point, the sequential 1, 2, 4, 12, 24 weeks after surgery, five groups of dogs, which will be used for two different kinds of observation, will be sacrificed and bone block specimens harvested from the tibias will be observed under micro-CT for change of soft tissue, hard tissue and calcification under bone regeneration, Dual-energy X-ray absorptiometry for analysing the degree of osteogenesis and bone marrow density and scanning electron microscope for microarchitecture of neo-soft tissue and hard tissue in the bone defect. The results showed the 3-D collagen spongiosa may carry more growth factors from PRP and also capture more growth factors from the host's platelets and retain it more time at implant site. Therefore, using this experimental model may continuously promote the stem cell differentiation forming more osteoblosts. Then the large defect site will be expected to have a complete bone healing.