摘要
目的通过双侧颈总动脉墨汁灌注法观察组织工程大鼠颅骨极量骨缺损修复过程中骨形成、血管生成与陶瓷降解之间的关系及血供来源和走行。方法28只成年雄性SD大鼠随机分成实验组和对照组,在全麻及无菌条件下离断其左侧股、胫骨,将骨髓冲入α-MEM培养基中诱导培养大鼠的自体骨髓基质细胞。实验组将已分化的成骨细胞复合含孔磷酸钙陶瓷修复与所取细胞对应的大鼠颅骨极量骨缺损,对照组植入无成骨细胞的陶瓷。于术后第4、8、12、16、20、24及28周每组各处死2只大鼠,取材前行双侧颈总动脉墨汁灌注,制成脱钙切片和不脱钙磨片,光学显微镜下观察。结果实验组大鼠颅骨缺损修复过程中,动脉血供主要来源于周围骨床,纵横直行并呈离心性分布,静脉回流蜿蜒迂曲呈向心性分布。术后16～28周,血管密集处大部分陶瓷已降解并被新骨所取代。对照组虽有大量血管杂乱地渗入陶瓷孔隙,也可见陶瓷降解,但除邻接植骨床处有新骨爬行长入外,其中央部始终无新骨形成。结论在以含孔磷酸钙陶瓷为支架的组织工程骨修复过程中,陶瓷内部交通的孔隙有利于血管生成和新骨形成;血管生成与新骨形成及陶瓷降解关系密切。
Objective To observe angiogenesis, osteogenesis and ceramic biodegradation in reconstruction of rat critical-sized calvarial defects with autogenous osteoblasts loaded porous calcium phosphate ceramic. Methods Twenty-eight male adult Sprague-Dawley rats were randomly assigned into experimental and control groups. Bone marrow was obtained from left femurs and tibias of all rats under general anesthesic and sterile condition. In experimental group, autogenous osteoblasts derived from bone marrow stromal cells (MSCs) were differentiated and proliferated in vitro and then seeded and subcultured on porous calcium phosphate ceramics. The cell-ceramic compounds were used to repair critical-sized (8 mm in diameter) calvarial defects in the corresponding rats. In control group, the solitary ceramic without cell loading was used. Lab animals were sacrificed postoperatively at four-week interval till the 28th week and India ink was injected intravascularly into two rats in both groups each time. All involved samples were retrieved and examined microscopically after decalcified or undecalcified grinded section. Results Histomorphometrically, the relationships between angiogenesis, osteogenesis and biodegradation of the ceramics were closely relevant throughout the whole defect areas during reconstruction in experimental group. India ink intravascular injections demonstrated that the arterial supplies to the bone substitute predominantly came from surrounding bone beds, and invaded horizontally or longitudinally into ceramic pores in a centrifugal way, whereas venous drainage mainly flowed centripetally. Most parts of ceramic were replaced by newly formed bone when abundant blood vessel bundles permeated into ceramic pores from 16th to 28th week postoperatively. In contrast, calvarial defects in control group were bridged primarily by fibrous connective tissue even though a lot of blood vessels that arranged in a mess invaded the ceramic pores. Conclusion Porous structure of calcium phosphate ceramic and osteoblast loading helps angiogenesis and osteogenesis. Blood vessels penetration and osteogenesis are of significant relationship with ceramic biodegradation.
出处
《中华骨科杂志》
CAS
CSCD
北大核心
2003年第5期295-298,共4页
Chinese Journal of Orthopaedics
基金
国家自然科学基金资助项目(30070818)
