【作者】 王慧；

【导师】 王明礼；

【作者基本信息】 吉林大学 ， 临床医学硕士（外科学）（专业学位）， 2022， 硕士

【摘要】 1.1研究背景:对于骨关节面的软骨及软骨下骨损伤,骨软骨自体移植一直以来被认为是临床上最有效的治疗方法。该方法是将取自股骨负重较小的区域的骨块作为骨塞用来修补骨软骨缺损处。但是该项治疗方法同样存在弊端,例如患者供体部位的发病率增加以及昂贵的医疗费用。1.2研究目的:以往研究中对于软骨层的仿生效果欠佳,在以往研究中,软骨层支架多使用水凝胶或是强度较高的材料,过软或过硬的材料都不能完美的达到软骨层的仿生效果。此外,对于用于骨软骨损伤的双层支架,骨层支架与软骨层支架的衔接处不稳定是一个很棘手的问题,针对以上问题,制成更适合用于骨软骨损伤修复的支架是一个迫切需要被解决的问题。1.3研究方法:选取FDM型3D打印技术进行支架的打印,在选择材料时,众多高分子材料中,与其他材料相比,TPU的质较软更适合用作软骨层支架的支撑结构。通过选取质较软的TPU材料并在表面覆盖由明胶及海藻酸钠配制成的水凝胶作为软骨层材料来模拟支架的软骨层,并使用混有10%的羟基磷灰石(HA)的PLA作为骨层材料用作骨层材料,使用3D打印技术分别对两层支架进行打印,同时,利用3D打印时所需要的高温来使两层结构结合更加紧密,从而更有利于支架周围的骨及软骨的形成。并分别通过体内和体外实验来分别验证骨层支架及软骨层支架覆盖处的成骨及成软骨能力。1.4研究结果:骨层支架及软骨层支架的活-死及CCK实验证实了软骨层及骨层支架材料的生物相容性良好,此外,通过进行了骨层支架的茜素红染色及碱性磷酸酶(ALP)定量分析证实了骨层支架具有良好的成骨性能,并通过RT-q PCR实验进一步证实了骨层支架的成骨作用。此外,体内实验的结果表明双层支架植入兔的骨缺损模型后,8周及12周后,支架内部及周围的骨再生能力良好,并且实验组软骨层支架表面及周围由新生的软骨层覆盖,并且表面光滑度良好。1.5结论:含有10%HA的PLA材料及TPU材料很适合分别用于骨软骨支架的骨层及软骨层的3D打印,此外,TPU表面覆盖有明胶及海藻酸钠制成的复合水凝胶有利于增加再生软骨层的表面光滑度,从而达到更佳的仿生效果。更多还原

【Abstract】 1.1 Research backgroundFor articular cartilage and subchondral bone injury,osteochondral autograft is considered to be the most effective treatment.The method is to use the bone block from the area with small load of femur as a bone plug to repair the osteochondral defect.However,there are also drawbacks in using this treatment,such as the increased incidence rate of donor site and expensive medical expenses.1.2 research purposeIn previous studies,the biomimetic effect of cartilage layer was not good.In previous studies,cartilage scaffolds were mostly made of hydrogels or high strength materials.Soft or too hard materials could not perfectly imitate the cartilage layer.In addition,for the double-layer scaffold used for osteochondral injury,the instability of the junction between the osteochondral scaffold and the cartilage scaffold is a very difficult problem.In view of the above problems,it is an urgent problem to make a scaffold more suitable for the repair of osteochondral injury.1.3 research methodsAmong the polymer materials,TPU is softer than other materials and is more suitable to be used as the supporting structure of cartilage scaffold.The soft TPU material was selected and covered with gelatin and alginate as the cartilage layer to simulate the cartilage layer of the scaffold.And the PLA mixed with 10% hydroxyapatite(HA)is used as the bone layer material.3D printing technology is used to print the two-layer scaffolds respectively.The high temperature required for 3D printing is used to make the two-layer structure bond more closely,which is more conducive to the reconstruction of bone and cartilage around the scaffolds.The osteogenic and chondrogenic abilities of the double-layer scaffolds are verified by in vivo and in vitro experiments respectively.1.4 research resultsThe results of live-dead and CCK experiments of bone layer scaffolds and cartilage layer scaffolds confirmed that the biocompatibility of cartilage layer and bone layer scaffolds was well.In addition,Alizarin red staining and alkaline phosphatase of bone scaffolds(ALP)quantitative analysis confirmed that the bone layer scaffold had pretty osteogenic properties,and the osteogenic effect of the bone layer scaffold was further confirmed by RT q PCR experiment.In addition,the results of in vivo experiments showed that after the double-layer scaffold was implanted into the rabbit bone defect model,the bone regeneration inside and around the scaffold was good after 8 and 12 weeks,and the cartilage scaffold surface of the experimental group were covered with new smooth cartilage.1.5 conclusion10% HA containing PLA and TPU materials are suitable for 3D printing of bone and cartilage layers of osteochondral scaffolds respectively.In addition,the composite hydrogel made of gelatin and sodium alginate on the surface of TPU is beneficial to increase the surface smoothness of regenerated cartilage layer,so as to achieve better bionic effect.更多还原