含微納結(jié)構(gòu)且二級結(jié)構(gòu)可控的絲蛋白支架的研究
發(fā)布時間：2019-07-01 13:24
【摘要】：過去十年，由于其優(yōu)良的生物相容性、生物可降解性、低炎癥反應(yīng)和優(yōu)秀的機械性能，絲蛋白支架材料已經(jīng)從傳統(tǒng)的紡織纖維材料轉(zhuǎn)變成具有普適意義的天然生物材料和組織修復(fù)材料。但是不同組織的修復(fù)對材料有著不同的特定要求，如何進(jìn)一步提高支架的生物相容性和誘導(dǎo)性使其更有利于不同組織的修復(fù)是我們面臨的一項挑戰(zhàn)。細(xì)胞外基質(zhì)（ECM）的微納結(jié)構(gòu)為支架的設(shè)計包括支架多孔結(jié)構(gòu)的設(shè)計提供了良好的模板，通過模擬ECM的微納結(jié)構(gòu)構(gòu)建有利于細(xì)胞和組織生長的微環(huán)境為構(gòu)建具有生物活性的組織修復(fù)載體提供了全新的方向。 本文首先闡明了絲蛋白在水溶液環(huán)境下可控自組裝形成不同微納結(jié)構(gòu)對支架材料成孔性的調(diào)控機制，隨后研究了粘度、二級結(jié)構(gòu)和水作用力對成孔性的調(diào)控作用。實驗發(fā)現(xiàn)，溶液中納米線的形成對支架在凍干過程中多孔結(jié)構(gòu)的形成具有關(guān)鍵作用，是支架材料成孔的關(guān)鍵因素。 在此基礎(chǔ)上，本研究通過緩慢濃縮處理的方法自組裝形成納米纖維，并通過冷凍干燥法獲得具有仿細(xì)胞外基質(zhì)納米纖維結(jié)構(gòu)的絲蛋白多孔支架。經(jīng)上述方法制備的支架孔徑在200~250um之間、孔隙率達(dá)到99%以上，且隨著絲蛋白的逐漸降解和溶解，納米纖維會暴露到外部，在細(xì)胞體內(nèi)外培養(yǎng)中有利于細(xì)胞的吸附、增殖和遷移。隨后利用甲醇和水處理等不同方法實現(xiàn)對多孔支架晶體結(jié)構(gòu)的調(diào)控，使得支架材料具有不同的穩(wěn)定性和降解行為，以滿足不同組織再生的具體要求。其中，當(dāng)純水蒸氣處理時絲素的結(jié)晶結(jié)構(gòu)由無規(guī)向Silk I結(jié)構(gòu)轉(zhuǎn)變，隨著甲醇含量增多，絲素的結(jié)晶結(jié)構(gòu)由Silk I結(jié)構(gòu)逐漸轉(zhuǎn)變?yōu)镾ilk II結(jié)構(gòu)，熱力學(xué)穩(wěn)定性增強，降解速率降低，擴大了其在組織工程的不同應(yīng)用。 最后，通過體外細(xì)胞培養(yǎng)，用鹽析法制備的絲蛋白多孔支架作為對比，研究了該多孔材料對大鼠骨髓間充質(zhì)干細(xì)胞粘附、增殖的影響。激光共聚焦顯微鏡和DNA含量結(jié)果表明，同鹽析法絲蛋白支架相比，本研究所制備的仿生納米纖維化絲蛋白多孔支架對BMSC細(xì)胞的生長和增殖具有顯著的促進(jìn)作用。 綜上所述，，本文通過絲蛋白自組裝技術(shù)制備出孔結(jié)構(gòu)和二級結(jié)構(gòu)可控的含有仿生納米纖維結(jié)構(gòu)的絲蛋白多孔材料，為組織工程或組織修復(fù)提供一種具有生物活性的支架材料，可望滿足不同組織再生的要求和應(yīng)用。
[Abstract]:In the past decade, due to its excellent biocompatibility, biodegradability, low inflammatory reaction and excellent mechanical properties, silk protein scaffold materials have changed from traditional textile fiber materials to natural biomaterials and tissue repair materials with universal significance. However, the repair of different tissues has different specific requirements for materials. How to further improve the biocompatibility and inductivity of scaffolds to make them more conducive to the repair of different tissues is a challenge we face. The micro-nano structure of extracellular matrix (ECM) provides a good template for the design of scaffolds, including the design of porous structure of scaffolds. By simulating the micro-nano structure of ECM, the construction of microenvironment conducive to cell and tissue growth provides a new direction for the construction of bioactive tissue repair vector. In this paper, the regulation mechanism of different microstructures formed by controllable self-assembly of silk proteins in aqueous solution on the porosity of scaffolds was studied, and then the effects of viscosity, secondary structure and water force on the porosity of scaffolds were studied. It is found that the formation of nanowires in solution plays a key role in the formation of porous structure of scaffolds during freeze-drying, and is the key factor for pore formation of scaffolds. On this basis, the nanofibers were self-assembled by slow concentration treatment, and the silk protein porous scaffolds with extracellular matrix nanofiber structure were obtained by freeze-drying method. The pore size of the scaffold prepared by the above method is between 200~250um and the porosity is more than 99%. With the gradual degradation and dissolution of silk protein, the nanofibers will be exposed to the outside, which is beneficial to the adsorption, proliferation and migration of cells in vitro and in vivo. Then different methods such as methanol and water treatment are used to regulate the crystal structure of porous scaffolds, which makes the scaffolds have different stability and degradation behavior to meet the specific requirements of different tissue regeneration. Among them, when pure water vapor treatment, the crystal structure of silk fibroin changes from random to Silk I structure. With the increase of methanol content, the crystal structure of silk fibroin gradually changes from Silk I structure to Silk II structure, thermodynamic stability increases, degradation rate decreases, and its different applications in tissue engineering are expanded. Finally, the effect of porous silk protein scaffold prepared by salting out method on the adhesion and proliferation of rat bone marrow mesenchymal stem cells (BMSCs) was studied by cell culture in vitro. The results of laser confocal microscope and DNA content showed that the biomimetic nano-fibrosis silk protein porous scaffolds prepared in this study could significantly promote the growth and proliferation of BMSC cells compared with salting out silk protein scaffolds. In summary, silk protein porous materials with controllable pore structure and secondary structure containing biomimetic nanofiber structure were prepared by silk protein self-assembly technique, which provides a bioactive scaffold material for tissue engineering or tissue repair, which is expected to meet the requirements and applications of different tissue regeneration.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R318.08
本文編號：2508515
[Abstract]:In the past decade, due to its excellent biocompatibility, biodegradability, low inflammatory reaction and excellent mechanical properties, silk protein scaffold materials have changed from traditional textile fiber materials to natural biomaterials and tissue repair materials with universal significance. However, the repair of different tissues has different specific requirements for materials. How to further improve the biocompatibility and inductivity of scaffolds to make them more conducive to the repair of different tissues is a challenge we face. The micro-nano structure of extracellular matrix (ECM) provides a good template for the design of scaffolds, including the design of porous structure of scaffolds. By simulating the micro-nano structure of ECM, the construction of microenvironment conducive to cell and tissue growth provides a new direction for the construction of bioactive tissue repair vector. In this paper, the regulation mechanism of different microstructures formed by controllable self-assembly of silk proteins in aqueous solution on the porosity of scaffolds was studied, and then the effects of viscosity, secondary structure and water force on the porosity of scaffolds were studied. It is found that the formation of nanowires in solution plays a key role in the formation of porous structure of scaffolds during freeze-drying, and is the key factor for pore formation of scaffolds. On this basis, the nanofibers were self-assembled by slow concentration treatment, and the silk protein porous scaffolds with extracellular matrix nanofiber structure were obtained by freeze-drying method. The pore size of the scaffold prepared by the above method is between 200~250um and the porosity is more than 99%. With the gradual degradation and dissolution of silk protein, the nanofibers will be exposed to the outside, which is beneficial to the adsorption, proliferation and migration of cells in vitro and in vivo. Then different methods such as methanol and water treatment are used to regulate the crystal structure of porous scaffolds, which makes the scaffolds have different stability and degradation behavior to meet the specific requirements of different tissue regeneration. Among them, when pure water vapor treatment, the crystal structure of silk fibroin changes from random to Silk I structure. With the increase of methanol content, the crystal structure of silk fibroin gradually changes from Silk I structure to Silk II structure, thermodynamic stability increases, degradation rate decreases, and its different applications in tissue engineering are expanded. Finally, the effect of porous silk protein scaffold prepared by salting out method on the adhesion and proliferation of rat bone marrow mesenchymal stem cells (BMSCs) was studied by cell culture in vitro. The results of laser confocal microscope and DNA content showed that the biomimetic nano-fibrosis silk protein porous scaffolds prepared in this study could significantly promote the growth and proliferation of BMSC cells compared with salting out silk protein scaffolds. In summary, silk protein porous materials with controllable pore structure and secondary structure containing biomimetic nanofiber structure were prepared by silk protein self-assembly technique, which provides a bioactive scaffold material for tissue engineering or tissue repair, which is expected to meet the requirements and applications of different tissue regeneration.
【學(xué)位授予單位】：蘇州大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R318.08
【參考文獻(xiàn)】
相關(guān)期刊論文 前4條
1 王海寧;萬怡灶;李建;張勝男;何芳;黃遠(yuǎn);王玉林;;納米纖維組織工程支架及其納米效應(yīng)研究進(jìn)展[J];材料導(dǎo)報;2007年04期
2 徐軍;納米材料的研究現(xiàn)狀與發(fā)展[J];電鍍與涂飾;2001年06期
3 李明忠,吳徵宇,盧神州,張長勝,嚴(yán)灝景;多孔絲素材料的結(jié)構(gòu)與性能研究[J];東華大學(xué)學(xué)報(自然科學(xué)版);2001年02期
4 王身國;組織工程細(xì)胞支架及其相關(guān)技術(shù)研究[J];現(xiàn)代康復(fù);2001年16期
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