骨修复用SMPU电纺薄膜的制备、响应性能及其对成骨细胞生长行为的影响

发布时间：2018-06-18 11:12

本文选题：骨修复 + 形状记忆聚氨酯　；参考：《西北农林科技大学》2012年硕士论文

【摘要】：随着组织工程学的兴起，以生物医用材料来制作骨移植替代物，，是目前治疗大面积骨组织损伤的研究热点。采用普通骨移植材料进行手术时，会在骨修复部位形成应力遮挡，并且植入的人工骨通常与缺损骨的两端因为接触不紧密而造成骨不连。形状记忆聚氨酯（Shape memory polyurethane, SMPU）是一类新型功能高分子材料，将SMPU应用于骨组织修复时，可以同时解决骨不连和应力遮挡的难题。静电纺丝可以制备具有极大比表面积、高孔隙率和相互连通的网状结构的材料，这些特点使得电纺纤维膜可以在一定程度上仿生物细胞外基质的结构与功能，为细胞提供生长、增殖以及分化的理想微环境。采用该方法时，需要确保电纺溶液具有一定的可纺性，同时制得的初始纤维材料具有在温和环境下进一步交联的潜能。由于有上述条件限制，目前关于形貌稳定、可逆，具有微纳米纤维结构SMPU材料的制备及其对细胞生长行为研究的报道还很少。本研究克服静电纺丝技术的难点，成功制得了具有微纳米纤维结构的SMPU电纺薄膜。首先，表征了SMPU电纺薄膜的形状记忆性以及微形貌的稳定性；然后对比了同尺寸SMPU电纺薄膜和本体薄膜响应回复性能的差异。最后，将成骨细胞与两种材料复合培养，考察了成骨细胞在两种薄膜上生长行为的差异。研究取得了如下结果： 1.以聚己内酯（PCL）、4,4'-二苯基甲烷二异氰酸酯（MDI）、γ-氨丙基三乙氧基硅烷（APS）为原料，利用溶液聚合法得到的预聚体-ASPU的结构进行分析，推断出其可能分子结构；SEM结果显示，SMPU本体薄膜表面致密，无孔洞；手动拉伸测试和DMA测定均表明，SMPU本体薄膜具有较好的形状记忆性，其Rf和Rr均接近于100%。通过DSC分析了材料的热学性能，发现嵌段共聚物的形成影响了SMPU本体薄膜可逆相PCL的结晶。 2.通过采取特殊的步骤1和2，利用静电纺丝的方法，成功制得了形状记忆性良好的SMPU电纺薄膜。SEM结果表明：SMPU电纺薄膜表面具有微纳米纤维形貌，且该形貌经过连续三次的“拉伸-回复”过程仍可稳定保持；同尺寸两种薄膜响应回复情况结果表明：SMPU电纺薄膜较先响应回复，且响应回复时间短，响应的优势至少可以保持三次循环。通过两种薄膜DSC分析，推断出SMPU电纺薄膜较SMPU本体薄膜响应回复的优势主要与其微纳米结构有关。SMPU电纺薄膜具有微纳米纤维堆积的无纺布结构，比表面积大，孔隙率高，使得其热传递较SMPU本体薄膜快，可先达到其相变温度，最终表现出较早、较快的响应回复趋势。 3.分别将成骨细胞与SMPU电纺薄膜和本体薄膜复合培养，考察了成骨细胞在两种薄膜上黏附情况、铺展以及增殖活力的不同。结果表明：经DiI细胞膜红色染料标记后的成骨细胞形态良好，标记率达100%，是一种研究细胞在支架材料上生长规律的简单、有效、及时的观测手段；成骨细胞在SMPU电纺薄膜表面的黏附、铺展以及增殖活力都优于SMPU本体薄膜。说明具有三维网络结构的SMPU电纺薄膜较本体薄膜更利于成骨细胞早期的生长，其生物相容性前景更好。本研究采用静电纺丝方法克服了静电纺丝技术中的难点，成功制得了形貌稳定的具有微纳米纤维结构的SMPU电纺薄膜，其较SMPU本体薄膜在响应回复以及成骨细胞早期生长方面都具有一定的优势。这就为下一步利用SMPU进行骨修复的研制提供理论基础及前期准备。同时，也为开发其他形状记忆材料治疗骨组织缺损的研究奠定基础。
[Abstract]:With the rise of tissue engineering, the use of biomedical materials to make bone graft substitutes is a hot spot in the treatment of large area bone tissue injury. Bone nonunion. Shape memory polyurethane (SMPU) is a new type of functional polymer material. The application of SMPU to bone tissue repair can solve the problem of bone nonunion and stress shielding at the same time. Electrospun fibers can prepare materials with large surface area, high porosity and interconnected network structure. The electrospun fiber membrane can mimic the structure and function of the extracellular matrix to a certain extent and provide the ideal microenvironment for cell growth, proliferation and differentiation. In this method, the spinnability of the electrospun solution must be ensured, and the initial fiber material has the potential to further cross linking in a mild environment. Because of the above conditions, there are few reports on the preparation of SMPU materials with micro nanofiber structure and the study of cell growth behavior.
In order to overcome the difficulty of the electrospinning technology, the SMPU electrospun film with micronanofiber structure was successfully prepared. First, the shape memory of the SMPU electrospun film and the stability of the micromorphology were characterized. Then, the differences in the response of the same size SMPU electrospun film and the bulk film were compared. Finally, the osteoblasts and the two species were formed. The growth behavior of osteoblasts on two kinds of films was investigated.
1. with polyhexyl ester (PCL), 4,4'- two phenyl methane diisocyanate (MDI), gamma amyl triethoxy silane (APS) as raw material, the structure of prepolymer -ASPU obtained by solution polymerization was analyzed and its possible molecular structure was deduced. The results of SEM showed that the surface of SMPU was compact and non porous; both manual tensile test and DMA determination were used. It is shown that the SMPU film has better shape memory, and its Rf and Rr are close to the thermal properties of 100%. through DSC, and the formation of block copolymers affects the crystallization of the reversible phase PCL in the SMPU bulk film.
2. by taking special steps 1 and 2, the SMPU electrospinning film with good shape memory was successfully prepared by electrostatic spinning method. The results showed that the surface of the SMPU electrospun film had the morphology of the micro nanofiber, and the morphology was still stable after three consecutive "tensile recovery" processes, and the response responses of the two kinds of thin films in the same size were recovered. The results show that the SMPU electrospun film is responsive to the response first, and the response time is short, and the advantage of the response can be kept at least three times. Through the analysis of two kinds of thin film DSC, it is concluded that the advantage of SMPU electrospun film in response to the response of the SMPU film is mainly related to the micronano structure of the.SMPU electrospun film with micro nanofiber accumulation. The non-woven fabric with large specific surface area and high porosity makes the heat transfer faster than the SMPU film. The phase transition temperature can be reached first, and the response trend is earlier and faster.
3. the osteoblasts were cultured with the SMPU electrospun film and the bulk film respectively. The adhesion of osteoblasts on the two kinds of films, spreading and proliferating activity were investigated. The results showed that the form of osteoblasts marked by the red dye of the DiI cell membrane was good and the labeling rate reached 100%. It was a kind of cell growth on the scaffold material. The regularities are simple, effective and timely observation. The adhesion, spreading and proliferation of osteoblasts on the surface of SMPU electrospun film are better than that of SMPU. It shows that the SMPU electrospun film with three-dimensional network structure is more beneficial to the early growth of osteoblast than that of the bulk film, and its biocompatibility is better.
In this study, the electrospun method was used to overcome the difficulties in the electrospinning technology. The SMPU electrospun film with a micro nanofiber structure with stable morphology has been successfully prepared. It has a certain advantage over the response recovery and early growth of osteoblasts compared with the SMPU bulk film. This is the next step of using SMPU for bone repair. It provides a theoretical basis and preliminary preparation, and lays the foundation for the development of other shape memory materials in the treatment of bone tissue defects.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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