【作者】 王波；

【导师】 许燕；

【作者基本信息】 新疆大学 ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 目前组织工程骨是针对临床骨缺损修复的重要途径,由于组织工程骨存在生物惰性,使得成骨速度慢以及与骨组织结合较差等问题,现阶段的研究主要集中在如何提升组织工程骨的生物活性来提高成骨速度,但较少关注覆有骨膜所具备的电学微环境。研究发现去除原始骨膜的骨髓会导致新骨生成减少73%,但天然骨膜存在移植困难的问题。研究具有特定功能的仿生骨膜,来促进骨组织的修复与再生具有重要研究意义。本文将极化后具有压电效应β相聚偏氟乙烯(PVDF)以及具有良好亲水性能的聚乙烯醇(PVA)材料共混复合,利用分子动力学分析材料之间的作用机制,初步采用湿法相转化法探究PVA对于PVDF共混复合膜的改性效果,并通过静电纺丝方法优化复合膜的压电性能(β相含量)、亲水性能、力学性能,使得制备出的基础复合膜满足仿生骨膜的基本使用要求。首先,通过分子动力学对不同聚合物建模以及相关模拟,直观解释实验无法观察到结构内部的物理现象,加速理论与实验研究的进程。初步探究PVDF分别与亲水性聚合物聚乙二醇(PEG)以及PVA的可混性,并研讨不同聚合度对于其溶度参数影响,筛选出最优聚合度。通过分析径向分布函数以及扩散系数筛选出最佳溶剂,在保证最优聚合度下,探究PVDF-PVA不同共混质量比的相容性,得到最佳共混比90/10。其次,利用实验验证模拟筛选的最佳溶剂和最优共混比,采用湿法相转化法探究PVA对于PVDF共混复合膜的改性效果,对其性能进行分析发现,红外光谱显示PVA与PVDF的共混只是物理共混,并未发生化学反应,共混复合膜水接触角相较于纯PVDF提升了40.25%,亲水性能得到了提升,复合膜的孔隙率也提升了74.64%,但PVA的引入使得压电性能(β相含量)降低。最后,针对PVA-PVDF共混复合膜的亲水性能得到提升,但其压电性能(β相含量)降低,通过理论模拟分析发现,添加剂加入以及单轴拉伸可以提升β相含量,静电纺丝制备方法及收集装置转速的提升可以增加单轴拉伸概率。通过静电纺丝制备共混纳米纤维膜,添加剂的加入促进了溶剂的挥发,纳米纤维膜表面形貌规整度较好,β相含量增加,亲水性能略有降低。随着转速的提升,纤维排列更有取向性,纳米纤维膜比共混复合膜β相含量最高提升10.25%,亲水性能更优异,力学性能得到改善,拉伸强度最高为3.8MPa满足天然骨膜使用要求。更多还原

【Abstract】 At present,tissue engineering bone was an important way for clinical bone defect repair,due to the biological inertia of tissue engineering bone,made the osteogenesis rate slow and poor combination with bone tissue,etc.,the current stage of research mainly focuses on how to enhanced the biological activity of tissue engineering bone to improved the rate of osteogenesis,but less attention was paid to the electrical microenvironment covered with periosteum.Studies have found that removing the bone marrow from the original periosteum leads to a 73% reduction in new bone production,but the natural periosteum has the problem of difficult grafting.It is of great significance to study the bionic periosteum with specific functions to promote the repair and regeneration of bone tissue.Polarized polyvinylidene difluoride(PVDF)with a piezoelectric effect β phase and polyvinyl alcohol(PVA)with good hydrophilic properties material blending and compounding,using molecular dynamics to analyzed the mechanism of action between materials,and preliminarily using wet phase conversion method to explored the modification effect of PVA on PVDF blending composite membrane.And through the electrospinning method,the piezoelectric properties(β phase content),hydrophilic properties and mechanical properties of the composite membrane are optimized,so that the prepared basic composite membrane to meet the basic requirements of the bionic periosteum.Firstly,through molecular dynamics modeling of different polymers and related simulations,it intuitively explains the physical phenomena inside the structure that cannot be observed by experiments,and accelerates the process of theoretical and experimental research.The mixability of PVDF with the hydrophilic polymers polyethylene glycol(PEG)and PVA was preliminarily investigated,and the influence of different polymerization degrees on its solubility parameters was studied,and the optimal polymerization degree was screened.By analyzing the radial distribution function and diffusion coefficient,the optimal solvent was selected,and the compatibility of different blend mass ratios of PVDF-PVA was explored under the guarantee of optimal polymerization,and the optimal blend ratio of 90/10 was obtained.Secondly,the best solvent and optimal blend ratio of the simulated screening were verified experimentally,and the modification effect of PVA on the PVDF blend composite film was explored by wet phase conversion method,and its performance was analyzed and found,and the infrared spectroscopy was displayed The blending of PVA and PVDF is only a physical blend,and no chemical reaction occurs,and the water contact angle of the blend composite membrane is increased by 40.25% compared with pure PVDF,the hydrophilic performance has been improved,and the porosity of the composite film has also increased by 74.64%,but the introduction of PVA has reduced the piezoelectric performance(β phase content).Finally,the hydrophilic properties of the PVA-PVDF blend composite membrane are improved,but their piezoelectric performance(β phase content)is reduced,which is simulated theoretically the analysis found that the addition of additives and uniaxial stretching can increased the β phase content,and the increased in the speed of electrospinning preparation method and collection device can increased the probability of uniaxial stretching.By prepared the blended nanofiber film by electrospinning,the addition of additives promotes the volatilization of the solvent,the surface morphology of the nanofiber membrane is better,the β phase content is increased,and the hydrophilic properties are slightly reduced.With the increase of rotational speed,the fiber arrangement is more oriented,and the β phase content of nanofiber film is increased by up to 10.25% compared with the blended composite film.The hydrophilic properties are more excellent,the mechanical properties are improved,and the tensile strength is up to3.8MPa to meet the requirements of natural periosteum.更多还原