【摘要】：論文基于靜電紡絲技術(shù)，制備出PLA(polylactic acid)基支架材料：溶液靜電紡PLA纖維支架，熔融靜電紡PLA纖維支架及溶液靜電紡PLA紗線支架。 探討了溶液靜電紡成纖過程中紡絲液射流運(yùn)動(dòng)過程：超過臨界電壓后，紡絲液射流所受電相斥力與表面張力的相互作用，決定著射流從直線區(qū)域進(jìn)入到鞭動(dòng)區(qū)域時(shí)刻。而正是射流在鞭動(dòng)區(qū)域的運(yùn)動(dòng)引起直徑劇減，形成超細(xì)纖維�；诖�，介入不同成分與組分的溶劑，，以干涉紡絲液射流在運(yùn)動(dòng)過程所受的電相斥力對(duì)射流在運(yùn)動(dòng)過程，特別是鞭動(dòng)區(qū)域的運(yùn)動(dòng)構(gòu)成影響，成功調(diào)控制備出直徑分布差異的溶液靜電紡PLA纖維支架材料及溶液靜電紡PLA紗線支架材料。分別借助Fridrikh S V模型與Rutledge G C模型，進(jìn)一步探討了不同溶劑成分與組分對(duì)溶液靜電紡PLA纖維直徑差異的調(diào)控機(jī)制。 借助高速相機(jī)在紡絲過程中拍攝的射流照片，探討了熔融靜電紡成纖過程中聚合物射流的運(yùn)動(dòng)過程：超過臨界電壓后，噴絲口處聚合物熔滴從球形被拉伸成錐形，形成泰勒錐，射流向收集端作加速運(yùn)動(dòng)；射流運(yùn)動(dòng)過程中，表面張力與電相斥力之間的相互競(jìng)爭(zhēng)作用決定了射流的鞭笞穩(wěn)定性，進(jìn)而決定了射流成纖時(shí)的細(xì)化程度。并基于熔融靜電紡絲技術(shù)，制備出高度定向排列熔融靜電紡PLA纖維支架材料。 采用表面沉積的方法，分別對(duì)溶液靜電紡PLA纖維支架和熔融靜電紡PLA纖維支架進(jìn)行表面Ti/Cu沉積處理。形貌觀察發(fā)現(xiàn)：對(duì)于溶液靜電紡PLA纖維支架，表面Ti/Cu沉積造成了纖維表面凹凸不平的類似多孔結(jié)構(gòu)；而對(duì)于熔融靜電紡PLA纖維支架，Ti/Cu以納米級(jí)的顆粒沉積在纖維表面的部分區(qū)域，并在纖維表面呈島狀生長(zhǎng)。接觸角測(cè)試表明：溶液靜電紡制備的PLA纖維支架具有一定的疏水性，而熔融靜電紡PLA纖維支架則具有一定的親水性；表面Ti/Cu沉積使溶液靜電紡和熔融靜電紡PLA纖維均具有較好的親水性，特別是表面Ti沉積的熔融靜電紡PLA纖維，親水性大大增加，1s時(shí)間內(nèi)，完全潤(rùn)濕。結(jié)合形貌觀察結(jié)果，探討Ti/Cu金屬顆粒在PLA纖維基表面生長(zhǎng)機(jī)理發(fā)現(xiàn)：在表面Ti/Cu沉積初始階段，金屬顆粒主要以核生長(zhǎng)型在靜電紡PLA纖維基表面進(jìn)行生長(zhǎng)。 分別針對(duì)溶液靜電紡PLA纖維支架材料，表面Ti/Cu沉積熔融靜電紡PLA纖維支架材料以及靜電紡PLA紗線支架材料的細(xì)胞相容性進(jìn)行了研究。MTT (4-甲偶氮唑藍(lán))檢測(cè)結(jié)果發(fā)現(xiàn)：NIH3T3細(xì)胞在表面Ti沉積的浸提液中，細(xì)胞活力隨著培養(yǎng)時(shí)間的推移而增大，在72h時(shí)甚至超過未處理支架材料；體外毒性評(píng)定發(fā)現(xiàn)，表面Ti沉積樣品，在24h時(shí)，具有輕微毒性，而到72h時(shí)，毒性逐漸消失至0級(jí)。而NIH3T3細(xì)胞在表面Cu沉積熔融靜電紡PLA纖維支架材料浸提液中，細(xì)胞活力隨培養(yǎng)時(shí)間推移稍有降低。體外毒性評(píng)定發(fā)現(xiàn)，24h，48h及72h時(shí)，Cu沉積熔融靜電紡PLA纖維支架材料均表現(xiàn)出輕微毒性。 對(duì)不同直徑范圍的溶液靜電紡PLA纖維/紗線支架材料的增殖與粘附結(jié)果表明：纖維基支架材料均比澆鑄膜支架材料更有利于NIH3T3細(xì)胞的粘附和增殖；培養(yǎng)72h后，NIH3T3細(xì)胞在所有PLA纖維基支架材料上以不同的增長(zhǎng)率進(jìn)行了增殖；紗線的加捻結(jié)構(gòu)，對(duì)細(xì)胞在PLA纖維支架材料上的增殖有著較大影響；基于纖維之間孔隙結(jié)構(gòu)差異，孔隙率等因素，無(wú)論是在不同直徑分布的PLA纖維支架材料，還是紗線支架材料上，難以單獨(dú)從細(xì)胞粘附和增殖，判斷纖維直徑對(duì)細(xì)胞生長(zhǎng)情況的影響。
[Abstract]:Based on electrospinning technology, PLA (polylactic acid) based scaffolds were prepared: solution electrospinning PLA fiber scaffolds, melt electrospinning PLA fiber scaffolds and solution electrospinning PLA yarn scaffolds.
The process of jet motion in electrospun spinning process was discussed. The interaction between the repulsive force and the surface tension of the jet after exceeding the critical voltage determines the time when the jet enters the whipping region from the linear region. The electrospun PLA fiber scaffolds and the electrospun PLA yarn scaffolds with different diameter distributions were successfully prepared by interfering with the influence of the electro-repulsive force on the motion of the jet, especially in the whipping region, by intervening the solvents with different composition and composition. Drikh S V model and Rutledge G C model were used to investigate the mechanism of different solvent composition on the diameter difference of electrospun PLA fibers.
With the aid of jet photographs taken by high-speed camera during spinning, the movement process of polymer jet in the process of melt electrospinning was discussed. After exceeding the critical voltage, the polymer droplets at the nozzle were stretched from sphere to cone, forming Taylor cone, and the jet flowed to the collector for accelerated motion. Competition between repulsive forces determines the stability of the jet whip and the fineness of the jet fibers. Based on the melt electrospinning technology, the highly oriented melt electrospun PLA fiber scaffolds were prepared.
Surface Ti/Cu deposition was carried out on solution electrospun PLA fiber scaffolds and melt electrospun PLA fiber scaffolds by surface deposition method. Ti/Cu nanoparticles were deposited on part of the fiber surface and grew in island shape on the fiber surface. Contact angle test showed that the PLA fiber scaffolds prepared by solution electrospinning had certain hydrophobicity, while the melt electrospinning PLA fiber scaffolds had certain hydrophilicity; Ti/Cu deposition on the surface made the solution electrospinning and melting static static static. The electrospun PLA fibers have good hydrophilicity, especially the melt electrospun PLA fibers deposited on the surface of Ti. The hydrophilicity of the electrospun PLA fibers is greatly increased, and the PLA fibers are completely wetted within 1 s. Combining with the morphology observation, the growth mechanism of Ti/Cu metal particles on the surface of PLA fibers is discussed. It is found that at the initial stage of Ti/Cu deposition, the metal particles are mainly nucleated. It grows on the surface of electrospinning PLA fiber.
The cell compatibility of solution electrospun PLA fiber scaffolds, melt electrospun PLA fiber scaffolds deposited on Ti/Cu surface and electrospun PLA yarn scaffolds was studied. MTT (4-methazolyl blue) test results showed that the cell viability of NIH3T3 cells in the extract of surface Ti deposition increased with the time of culture. In vitro toxicity assessment showed that Ti deposited on the surface had slight toxicity at 24 h and gradually disappeared to grade 0 at 72 h. However, the cell viability of NIH3T3 cells deposited melt electrospun PLA fiber scaffold extract on the surface of Cu decreased slightly with the passage of culture time. In vitro toxicity assessment showed that Cu deposited electrospun PLA fiber scaffolds exhibited slight toxicity at 24h, 48h and 72h.
The results of proliferation and adhesion of electrospun PLA fiber/yarn scaffolds with different diameters showed that fiber-based scaffolds were more conducive to the adhesion and proliferation of NIH3T3 cells than cast-membrane scaffolds. Twisting structure has a great influence on cell proliferation on PLA fiber scaffolds. Based on the differences of pore structure and porosity between fibers, it is difficult to judge the effect of fiber diameter on cell growth by cell adhesion and proliferation on PLA fiber scaffolds or yarn scaffolds. Influence.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：R318.08

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 徐佳;纖維組織工程支架的制備及性能研究[D];吉林大學(xué);2009年

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