壳聚糖-胶原支架的降解性及生物相容性的研究

Study on degradability and histocompatibility of chitosan-collagen scaffolds

目的:将壳聚糖(Chi)与胶原(Col)制备成复合支架作为牙周组织工程材料,研究支架降解情况及生物相容性,探讨Chi-Col支架作为引导牙周骨组织再生材料的可行性,为临床治疗牙周骨组织缺损提供实践依据。方法:采用冷冻干燥法制备Chi-Col支架,将支架植入兔背部皮下,分别于2、4、6、8周后处死,取出支架及切除支架周围组织分别进行扫描电镜和HE染色,观察支架超微结构变化和周围组织变化,同时经溶菌酶体外降解实验测定其体外降解率,计算质量损失百分率。结果:扫描电镜观察可见,Chi-Col支架具有良好的多孔网状结构,孔径100μm左右,支架的孔与孔之间相互联通构成了通孔。在体内经过一段时间后支架孔径逐步表现为增多增大,结构破坏,部分降解,经体外降解计算质量损失百分率在2、4、6、8周时分别为17.52%、29.13%、40.49%、52.68%。HE染色周围组织早期可见炎症反应,继而炎症逐渐减轻,未见不良反应。结论:通过冷冻干燥法制备的Chi-Col支架,其生物学行为符合牙周组织工程的要求。Chi-Col支架可发生降解,没有观察到组织排斥反应,生物相容性好,因此有可能成为牙周组织工程的支架材料。

Objective:To study degradation and biocompatibility of the chitosan(Chi)-collagen(Col)scaffolds as the periodontal tissue engineering material and to investigate feasibility of the Chi-Col scaffolds as a material for guiding periodontal bone regeneration,in order to provide a practical basis for clinical treatment of periodontal bone defects.Methods:The Chi-Col scaffolds were prepared by the freeze-drying method,and then were implanted into the back of rabbits subcutaneously.These animals were sacrificed 2,4,6,and 8 weeks later.The scaffolds were removed,and the tissues surrounding the scaffolds were excised and examined by scanning electron microscopy(SEM)and HE staining.The ultrastructural changes of the scaffolds and changes in surrounding tissues were observed.Further,the in vitro degradation rate was determined by lysozyme in vitro degradation test,and the percentage of mass loss was calculated.Results:SEM showed that the Chi-Col scaffolds had a good porous network structure with a pore size of about 100μm,and the pores within the scaffold were connected with each other.After being implanted for a period of time,the scaffolds could be partially degraded with gradually increased pore size and damaged structure.Through the in vitro degradation test,the calculated percentages of mass loss 2,4,6,and 8 weeks after implantation were 17.52%,29.13%,40.49%,and 52.68%,separately.Some inflammatory reactions could be seen in the early HE-stained surrounding tissues,and then was gradually reduced.No adverse reactions were observed.Conclusions:The biological behaviors of the Chi-Col scaffolds prepared by the freeze-drying method meets the requirements of periodontal tissue engineering.The Chi-Col stent scaffolds can be degraded with no observed tissue rejection reactions and good biocompatibility.Therefore,they may become the scaffold material for the periodontal tissue engineering.