【摘要】：目前研究認(rèn)為在磷酸鈣生物陶瓷骨誘導(dǎo)性潛能中發(fā)揮作用的材料特性包括:化學(xué)成分、宏觀及微觀幾何結(jié)構(gòu)和孔隙率。此外,生物體的種屬及植入部位也會(huì)影響材料的骨誘導(dǎo)活性。盡管對(duì)磷酸鈣生物陶瓷骨誘導(dǎo)現(xiàn)象的生物機(jī)制進(jìn)行了大量的研究,卻仍缺乏對(duì)這些機(jī)制的系統(tǒng)性理解,這限制了生物陶瓷在臨床骨再生治療中的廣泛應(yīng)用。本研究綜合考慮磷酸鈣生物陶瓷的宏觀孔隙結(jié)構(gòu)和微結(jié)構(gòu)表面特性在異位骨形成中的作用,以及生理環(huán)境下應(yīng)力刺激對(duì)骨發(fā)生、發(fā)育及動(dòng)態(tài)平衡起到的重要作用,從體內(nèi)應(yīng)力環(huán)境、支架孔隙結(jié)構(gòu)和支架內(nèi)細(xì)胞受到的力學(xué)刺激之間的相關(guān)性角度入手,基于生物力學(xué)調(diào)控理論,對(duì)生物材料通過(guò)自身結(jié)構(gòu)特征調(diào)控骨誘導(dǎo)發(fā)生的機(jī)制進(jìn)行探討。為深入研究磷酸鈣生物陶瓷與骨誘導(dǎo)發(fā)生的相關(guān)性機(jī)制提供新途徑,并對(duì)優(yōu)化設(shè)計(jì)可控骨誘導(dǎo)性的磷酸鈣生物陶瓷提供實(shí)驗(yàn)和理論依據(jù)。包括以下內(nèi)容:(1)將具有不同宏觀孔隙形狀和尺寸的羥基磷灰石顆粒堆積支架(HA spheres accumulating scaffolds, HASAs)和羥基磷灰石顆粒造孔支架(HAporogen-pore scaffolds,HAPPs)植入狗的背肌和腹腔,系統(tǒng)比較宏孔形狀和尺寸對(duì)支架異位成骨能力的影響。并構(gòu)建三維支架理論模型,對(duì)支架內(nèi)微流體動(dòng)力環(huán)境進(jìn)行流動(dòng)仿真模擬,探討材料的宏觀結(jié)構(gòu)因素通過(guò)微流體動(dòng)力途徑轉(zhuǎn)換為骨誘導(dǎo)調(diào)控信號(hào)的相關(guān)性。研究表明宏孔尺寸和形狀對(duì)HA多孔支架骨誘導(dǎo)性有顯著的影響,并且這種影響是兩種結(jié)構(gòu)變量共同作用的結(jié)果。流體仿真計(jì)算結(jié)果表明微流體動(dòng)力環(huán)境影響支架內(nèi)新骨形成和分布。研究發(fā)現(xiàn)微流體動(dòng)力環(huán)境是材料的宏孔結(jié)構(gòu)因素轉(zhuǎn)換為骨誘導(dǎo)生物調(diào)控信號(hào)的重要途徑。(2)通過(guò)調(diào)節(jié)溶膠-凝膠體系中HA/Chitin的質(zhì)量比制備具有不同表面微形貌(粗糙度、比表面積和微孔隙率)的HA球形顆粒。體外細(xì)胞實(shí)驗(yàn)結(jié)果證實(shí)材料表面微形貌對(duì)BM-MSCs的生物行為有明顯影響,多孔粗糙表面在與BM-MSCs復(fù)合初期更有利于細(xì)胞的增殖,后期則利于細(xì)胞骨向分化。細(xì)胞在與致密光滑表面復(fù)合初期因增殖很快受限,因此提前促進(jìn)了 BM-MSCs的骨向分化�？傮w來(lái)說(shuō)多孔粗糙表面對(duì)BM-MSCs具有更好的促增殖和分化作用。每種表面都具有良好的細(xì)胞相容性。體內(nèi)動(dòng)物實(shí)驗(yàn)結(jié)果表明,本研究所用的具有不同表面微形貌的HA多孔顆粒支架均具有良好的生物相容性,而粗糙表面更利于支架植入體內(nèi)非骨部位后的異位骨形成。(3)在體外構(gòu)建生理-微振動(dòng)應(yīng)力環(huán)境,研究微振動(dòng)應(yīng)力刺激(振幅≤50μm、強(qiáng)度1×g、頻率范圍在1-100Hz的極低幅度、低強(qiáng)度、低頻率的力學(xué)環(huán)境,MV)對(duì)羥基磷灰石多孔支架材料上復(fù)合的BM-MSCs成骨分化和細(xì)胞外基質(zhì)礦化的影響,探討微振動(dòng)對(duì)羥基磷灰石生物活性及生物力學(xué)性能的影響,以及與羥基磷灰石陶瓷骨誘導(dǎo)性之間的關(guān)聯(lián)性。研究發(fā)現(xiàn)微振動(dòng)應(yīng)力環(huán)境能提升HA多孔支架生物礦化能力,有利于構(gòu)建成骨環(huán)境;微振動(dòng)應(yīng)力環(huán)境通過(guò)三維多孔支架發(fā)生力學(xué)信號(hào)轉(zhuǎn)換誘導(dǎo)BM-MSCs成骨分化;并且微振動(dòng)應(yīng)力環(huán)境和HA多孔支架協(xié)同提高了 BM-MSCs成骨相關(guān)基因Cbfal/Runx2、Col-I、ALP、OC的表達(dá)和成骨特征性蛋白ALP的表達(dá)。(4)將HA顆粒堆積支架(HASAs)植入實(shí)驗(yàn)動(dòng)物腹腔內(nèi)構(gòu)建體內(nèi)組織工程骨移植物,修復(fù)自體股骨節(jié)段性骨缺損,以探討利用多孔貫通生物材料支架在體內(nèi)自然生理環(huán)境異位培養(yǎng)組織工程化骨移植物修復(fù)大節(jié)段承重骨缺損的可能性。同時(shí),也探討腹腔作為自體生物反應(yīng)器構(gòu)建特定形狀、大體積的組織工程骨移植物的可能性。研究證明腹腔內(nèi)低血供、低應(yīng)力負(fù)荷和缺少干細(xì)胞源性物質(zhì)的生理環(huán)境具有作為體內(nèi)生物反應(yīng)器構(gòu)建組織工程化骨移植物的可能。并成功將腹腔中構(gòu)建的具有自體骨組織的骨移植物應(yīng)用于節(jié)段性承重骨缺損修復(fù)。
[Abstract]:Current studies have shown that the material properties that play a role in the bone induction potential of calcium phosphate bioceramics include chemical composition, macroscopic and microscopic geometric structures and porosity. However, there is still a lack of systematic understanding of these mechanisms, which limits the wide application of Bioceramics in clinical bone regeneration therapy. Dynamic balance plays an important role in bone induction. Based on the theory of biomechanical regulation, the mechanism of biomaterials regulating bone induction through their own structural characteristics is discussed from the point of view of the correlation between stress environment in vivo, pore structure of scaffolds and mechanical stimulation of cells in scaffolds. This study provides a new way to optimize the design of bone-inducible calcium phosphate bioceramics, including: (1) HA spheres accumulating scaffolds (HASAs) and hydroxyapatite particles with different macroporous shapes and sizes. Haporogen-pore scaffolds (HAPPs) were implanted into the dorsal and abdominal muscles of dogs to compare the effects of macropore shape and size on the ectopic osteogenesis of the scaffolds. A three-dimensional scaffold model was constructed to simulate the microhydrodynamic environment in the scaffolds and explore the macrostructural factors of the scaffolds through the microhydrodynamic pathway. Studies have shown that macropore size and shape have a significant effect on the osteoinductivity of HA porous scaffolds, and this effect is the result of the interaction of two structural variables. Force environment is an important way to convert macroporous structural factors into bone-induced biological signals. (2) HA spherical particles with different surface micromorphologies (roughness, specific surface area and microporosity) were prepared by adjusting the mass ratio of HA/Chitin in sol-gel system. Biological behavior of BM-MSCs was significantly influenced by porous rough surfaces, which were more conducive to cell proliferation at the early stage of BM-MSCs compounding, but more conducive to cell bone differentiation at the later stage. The results of in vivo animal experiments showed that HA porous particle scaffolds with different surface micromorphologies had good biocompatibility, and rough surfaces were more conducive to heterotopic bone formation after implantation in non-bone sites in vivo. To study the effect of micro-vibration stress stimulation (amplitude < 50 micron, intensity 1 xg, frequency range 1-100Hz, mechanical environment of low amplitude, low strength, low frequency, MV) on the osteogenic differentiation and extracellular matrix mineralization of BM-MSCs on porous scaffolds, and to explore the effect of micro-vibration on the formation of hydroxyapatite. It was found that the micro-vibration stress environment could enhance the biomineralization ability of HA porous scaffolds and facilitate the construction of osteogenic environment, and the micro-vibration stress environment could induce BM-MSCs osteogenic differentiation through mechanical signal transformation of three-dimensional porous scaffolds. The expression of BM-MSCs osteogenesis-related genes Cbfal/Runx2, Col-I, ALP, OC and the expression of osteogenic characteristic protein ALP were enhanced by microvibration stress and HA porous scaffolds. (4) HA granular accumulation scaffold (HASAs) was implanted into the abdominal cavity of experimental animals to construct in vivo tissue-engineered bone grafts to repair segmental bone defects of the femur. The possibility of repairing large segmental load-bearing bone defects with tissue-engineered bone grafts in heterotopic culture in vivo using porous perforated biomaterial scaffolds was also discussed. The possibility of constructing large-scale tissue-engineered bone grafts in the abdominal cavity as an autologous bioreactor was also discussed. It is possible to construct tissue-engineered bone grafts in vivo as bioreactor under mechanical loading and lack of stem cell-derived materials. Bone grafts with autogenous bone tissue from abdominal cavity were successfully used to repair segmental load-bearing bone defects.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：R318.08

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 張波;楊利娟;丁寧;許田恩;郭來(lái)威;孟會(huì)強(qiáng);汪靜;王翠芳;安麗萍;馬靖琳;夏亞一;;震蕩流體剪切力通過(guò)ERK5信號(hào)通路促進(jìn)成骨細(xì)胞增殖[J];中國(guó)骨質(zhì)疏松雜志;2016年10期

2 季僑丹;何成奇;;不同機(jī)械力學(xué)刺激對(duì)骨成骨作用的研究進(jìn)展[J];中國(guó)骨傷;2016年04期

3 羅品風(fēng);智偉;張靜微;匙峰;段可;汪建新;魯雄;翁杰;;基于Micro-CT不同多孔結(jié)構(gòu)陶瓷支架的建模及其貫通性與液流分布分析[J];無(wú)機(jī)材料學(xué)報(bào);2015年01期

4 陶飛飛;吳繼功;馬華松;宋淑軍;劉俊麗;邵水霖;張樂(lè)樂(lè);陶有平;高博;李海俠;;變頻振動(dòng)在模擬微重力環(huán)境下對(duì)成骨細(xì)胞增殖和分化的影響[J];中國(guó)骨質(zhì)疏松雜志;2014年05期

5 趙婧;李金雨;智偉;魯雄;賈治彬;翁杰;;蠟球造孔法制備多孔HA陶瓷支架及其性能優(yōu)化[J];無(wú)機(jī)材料學(xué)報(bào);2013年01期

6 ;Expression of Bone-related Genes in Bone Marrow MSCs after Cyclic Mechanical Strain: Implications for Distraction Osteogenesis[J];International Journal of Oral Science;2009年03期

7 查丁勝;陳建庭;鄧軒庚;孫學(xué)剛;佟麗;王建鈞;翁科捷;金大地;;不同頻率振動(dòng)應(yīng)變對(duì)成骨細(xì)胞增殖及分化能力的影響[J];中國(guó)骨質(zhì)疏松雜志;2008年05期

8 梁偉;茍三懷;齊進(jìn);魏立;歐陽(yáng)躍平;劉巖;;低強(qiáng)度脈沖超聲波對(duì)體外培養(yǎng)的兔骨髓基質(zhì)細(xì)胞成骨作用的影響[J];第二軍醫(yī)大學(xué)學(xué)報(bào);2007年06期

相關(guān)碩士學(xué)位論文 前1條

1 郭來(lái)陽(yáng);孔隙結(jié)構(gòu)互補(bǔ)的磷灰石多孔支架的研究[D];西南交通大學(xué);2010年

，

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