溶胶凝胶氧化硅纳米材料及其生物功能因子传输性能研究

发布时间：2018-01-10 19:08

本文关键词：溶胶凝胶氧化硅纳米材料及其生物功能因子传输性能研究　出处：《浙江大学》2017年博士论文　论文类型：学位论文

【摘要】：组织创伤和肿瘤等疾病严重影响着人们的身体健康和生活质量。随着生物医学技术的发展,用于各种疾病治疗的生物功能因子被研制和应用。但也同样面临一些挑战和困难,蛋白类药物稳定性差、膜通透性差、生物半衰期短等缺点影响了蛋白质功能因子的治疗效果。临床上使用的化疗药物分子溶解度低、选择性差,在体内一般呈全身分布,大大降低药物的疗效甚至是危害病人的身体健康。因此,设计能够高效传输组织修复蛋白功能因子/肿瘤等疾病治疗的功能药物载体材料是解决上述问题的关键所在。较为理想的传输载体不仅要求其自身具有良好的生物相容性以及对生物功能因子有较高的负载率,而且能选择性地将其作用于病变部位,并且能精确地控制释放动力学,延长作用时间,发挥其治疗修复效果。其中,氧化硅纳米材料具有大的比表面积、可调的孔结构、高的孔容、丰富的表面化学基团和良好的生物相容性等优点,获得兼具较高生物功能因子装载率与可控释放动力学氧化硅纳米材料在生物医药与组织工程领域具有重要应用前景。本课题以氧化硅为基体,通过对其进行功能化复合与表面化学构象调控,研究了其在骨组织修复以及肿瘤治疗领域中的应用。本文的研究内容概括为以下几个部分:1.采用溶胶凝胶结合静电纺丝方法制备出不同水解程度(H2O/TEOS摩尔比)的四组活性氧化硅纳米纤维。随着水解程度增加,Si-O-Si网络结构完整性增强,在模拟体液(SBF)中活性依次减弱。通过两种不同的加载方式:BSA溶液加载以及BSA/SBF溶液加载,研究发现四组活性氧化硅纤维通过BSA/SBF方法具有高量BSA加载,持续的释放性能。其中,水解程度最低的活性氧化硅纤维具有最大的加载量与最稳定的释放性能。2.在不同水解程度的活性氧化硅前驱体溶液中加入具有上转换发光性能的CaTiO3:Er,Yb纳米颗粒,通过静电纺丝技术制备出具有上转换发光的活性氧化硅复合纤维。体外骨髓基质干细胞毒性实验表明发光活性氧化硅复合纤维具有较好的生物相容性。在980 nm激发下,能发射出绿光(～550 nm)以及红光(～660 nm)。研究发现上转换发光强度变化与活性氧化硅纤维在模拟体液(SBF)中矿化程度存在对应关系,即表面矿化物形成的越快,诱导发光猝灭越快;同时研究还发现,表面矿化物除去后发光现象能够恢复。因而可以利用光学信号来监测骨支架纤维材料的表面矿化活性大小。3.首次采用原位的溶胶凝胶方法在介孔氧化硅(MSNs)的介孔结构中生长CaF_2:Tm,Yb纳米晶,制备出了具有上转换发光性能的CaF_2:Tm,Yb@mSiO_2纳米颗粒。通过对前驱体溶液中乙醇和正硅酸四乙酯的体积比,实现了对CaF_2:Tm,Yb@mSiO_2颗粒尺寸的调控。进一步利用抗癌药物DOX研究了所得纳米颗粒的装载、释放与抗肿瘤性能。研究发现小尺寸(～65nm)的CaF_2:Tm,Yb@mSiO_2具有较高的药物加载量,持续的药物释放功能以及较强的抗肿瘤效果。随后,对小尺寸的CaF_2:Tm,Yb@mSiO_2颗粒进行氨基改性用于大分子蛋白的输送,研究发现氨基改性后,促进了 BSA分子的加载量及更持续的释放行为,实现了细胞内大分子蛋白的有效输送。4.通过对CaF_2:Tm,Yb@mSiO_2纳米颗粒表面进行PAA分子改性,实现了 pH与NIR(808nm)双触发的药物释放功能,而且能够对其药物释放动力学过程进行实时的光学监测。由于PAA与DOX较强的静电作用使得DOX的加载效率提高到～92%。系统研究了不同pH(7.4,5.8和4.7)条件下释放动力学特征,随着pH值降低,药物释放速率明显加快。由于DOX分子对材料的蓝光发射区域存在荧光共振能量转移效应,而对红光发射区域无吸收的特性,可以根据蓝光与红光强度的比值((1478/1660)变化来实时监测药物释放动力学过程。NIR(808nm)光照射后,药物的释放速率加快,进而促进了对肿瘤细胞杀伤效果。5.一种结合发光氧化硅(PLMSNs)和光热支架材料的新型局部释控系统(PGC-PLMSNs)被系统的研究。通过对PLMSNs载体表面嫁接聚多巴胺(PD A),实现了其pH响应释放动力学特征,一旦被肿瘤细胞吞噬后,将会在细胞内释放出DOX药物分子。将发光氧化硅(PLMSNs)纳米颗粒通过静电力结合到具有光热效应的聚己内酯/明胶/碳纳米颗粒(PCL/Gel/CNP,PGC)纤维膜表面来构建植入型的局部释放系统(PGC-PLMSNs)。研究发现,与颗粒载体相比,PGC-PLMSNs载体展现出了优良的细胞吞噬与抗肿瘤性能。经NIR(808nm,0.6W/cm2)照射后,PGC支架的温和光热效应弱化了 PLMSNs与PGC纤维的静电力,使得PLMSNs从复合纤维膜表面释放,进而被肿瘤细胞吞噬。初期的细胞实验表明,PGC-PLMSNs复合纤维膜在NIR(808nm,0.6W/cm2)照射后,能诱导最高的细胞吞噬效率以及较强的抗肿瘤效果。
[Abstract]:Tissue trauma and tumor diseases seriously affect people's health and quality of life. With the development of biomedical technology for the treatment of diseases of biological functional factors have been developed and applied. But it also faces some challenges and difficulties, protein drugs with poor stability, poor membrane permeability, short half-life of shortcomings of protein function factor treatment. Chemotherapy drugs in clinical use of low solubility, poor selectivity, in vivo is systemic distribution, greatly reducing the effect of drugs and even endanger the health of patients. Therefore, the design can function as drug carrier material efficient transmission of tissue repair protein functional factors / diseases such as cancer treatment is the key to solve the above the problem of transmission. An ideal carrier requires not only its compatibility and biological function of good biological factor The load rate is high, and can be selectively applied to the lesion, and can accurately control the release kinetics, prolong action time and exert their therapeutic effect of repair. Among them, silicon oxide nano materials have large surface area, tunable pore structure, high Kong Rong, biocompatibility of surface chemical groups rich and good biological and biological functions get both high factor loading rate and controlled release kinetics of silicon oxide nano materials have important application prospects in the field of biomedicine and tissue engineering. The silica matrix by functional composite and surface chemical conformation of its regulation, discussed its application in bone tissue repair and in the field of tumor therapy. The research contents of this paper are summarized as follows: 1. by sol gel prepared with different degree of hydrolysis (H2O/TEOS Moore electrospinning method Four) than group activated silica nanofibers. With the hydrolysis degree increased, Si-O-Si network structure integrity enhancement in simulated body fluid (SBF) activity decreased successively. Through two different modes of loading: BSA solution and BSA/SBF solution loading loading, the study found that the four groups active silica fibers by BSA/SBF method with high the amount of BSA loading, sustained release performance. Among them, fiber activated silica was the lowest with the largest amount of loading and release properties of the most stable.2. in active silica precursor solution with different hydrolysis degree added with luminescent properties on the conversion of CaTiO3:Er, Yb nanoparticles were prepared by electrospinning with the conversion of active silica fiber composite luminescence. Bone marrow stromal stem cells in vitro toxicity test indicated that light activated silica composite fiber has good biocompatibility. In 980 nm laser Next, can emit green light (~ 550 nm) and red (~ 660 nm). The study found that the upconversion intensity and activity of silica fiber luminescence in simulated body fluid (SBF) in the relationship between the degree of mineralization, the faster surface mineralization formation, induced luminescence quenching more rapidly; at the same time, the study also found that the phenomenon of surface mineralization can be restored after removal of light. So we can monitor the surface activity of mineralized bone scaffold size.3. fiber material for the first time by sol-gel method in situ in mesoporous silica using optical signal (MSNs) of the mesoporous structure in the growth of CaF_2:Tm, Yb nanocrystals were prepared with upconversion luminescence properties CaF_2:Tm, Yb@mSiO_2 nanoparticles. The ethanol in the precursor solution and the volume ratio of ethyl silicate is four, the realization of CaF_2:Tm, control the size of the Yb@mSiO_2 particles. The further use of anticancer drugs on DOX nanoparticles Particle loading, release and anti-tumor properties. The study found that the small size (~ 65nm) of CaF_2:Tm, Yb@mSiO_2 has high drug loading, sustained drug release function and antitumor effect of strong. Then, on the small size of the CaF_2:Tm, the Yb@mSiO_2 particles of amino modified for delivery of large molecule protein, found amino modified, promotes the loading amount of BSA molecules and more sustained release behavior, to achieve the effective delivery of proteins of.4. cells by CaF_2:Tm, the surface of Yb@mSiO_2 nanoparticles by PAA molecular modification, the pH and NIR (808nm) - triggered drug release function, and the the kinetics of drug release process of optical monitoring in real time. The electrostatic interaction of PAA and DOX strong increase to the loading efficiency of DOX 92%. of different pH (7.4,5.8 and 4.7) under the conditions of release kinetics The characteristics, with the decrease in pH, the drug release rate was significantly accelerated. Because DOX molecules of the material of blue light emission region fluorescence resonance energy transfer effect, and no absorption characteristics of the red emission region, according to the ratio of blue and red intensity ((1478/1660) changes to real-time monitoring of drug release kinetics of.NIR (808nm) light after irradiation, the drug release rate was accelerated, and then promote the tumor cell killing effect of.5. combined with a luminescent silicon oxide (PLMSNs) and photothermal scaffold materials for new local delivery systems (PGC-PLMSNs) are systematically studied. Based on the PLMSNs vector surface grafting polydopamine (PD A), realizes the pH release response dynamic characteristics, once the tumor cells after phagocytosis, DOX will release the drug molecules in the cells. The luminescence of silicon oxide (PLMSNs) nanoparticles to have the photothermal effect together by electrostatic. Caprolactone / gelatin / carbon nano particles (PCL/Gel/CNP, PGC) on membrane surface to construct local release system implantation type (PGC-PLMSNs). The study found that, compared with the particle vector, PGC-PLMSNs vector showed excellent cell phagocytosis and antitumor properties. The NIR (808nm 0.6W/ cm2) after irradiation, mild photothermal effect the PGC scaffold has weakened the electrostatic PLMSNs and PGC fiber, the PLMSNs release from the composite fiber membrane surface, and then by tumor cells. The initial experiment indicates that cell phagocytosis, PGC-PLMSNs composite fiber membrane in NIR (808nm, 0.6W/cm2) after irradiation could induce the highest phagocytic efficiency and strong anti-tumor effect.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB383.1;R318.08

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