本文選題：磷酸八鈣　切入點：離子摻雜　出處：《華南理工大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：作為生物磷灰石礦物的一種前驅(qū)相,OCP有良好的骨傳導(dǎo)性和生物降解性,可用作骨替代修復(fù)材料,具有很好的臨床應(yīng)用價值。OCP具有促進成骨細胞分化、誘導(dǎo)破骨細胞形成以及促進新骨形成的能力,這些都與其特定的物理化學(xué)特性密切相關(guān)。本課題從骨礦物組成仿生的角度出發(fā),選取OCP作為磷酸鈣礦物研究模型,在生物活性礦物離子(Fe~(3+)或Sr~(2+))環(huán)境下,通過研究具有不同組成、形貌和結(jié)構(gòu)的OCP的相關(guān)物理化學(xué)特性對生物蛋白分子交互作用和干細胞響應(yīng)的影響機理,深入模擬研究摻雜活性Fe或Sr離子的OCP的骨傳導(dǎo)性和生物降解性。同時,通過摻雜活性離子的方式提高OCP材料的生物活性,為其在骨修復(fù)領(lǐng)域中的應(yīng)用作鋪墊。研究表明,通過尿素水解介導(dǎo)的化學(xué)均相沉淀法合成的OCP晶體純度高,結(jié)晶度好,呈典型的板片狀結(jié)構(gòu)。當反應(yīng)溫度高于70℃時,尿素水解反應(yīng)的劇烈程度才足夠提供控制體系pH值的動力。反應(yīng)過程中的溫度與pH值是沉淀合成反應(yīng)的關(guān)鍵參數(shù),可通過控制尿素濃度、反應(yīng)初始pH值、反應(yīng)溫度和反應(yīng)時間綜合控制。獲得高純OCP產(chǎn)物的較佳條件為:尿素濃度0.5 M,初始pH值5.9,反應(yīng)溫度90oC和反應(yīng)時間2 h。與其他用此法合成的磷酸鈣材料相比,合成的OCP材料具有更好的細胞親和性和黏附性能,以及較好或相近的細胞增殖活性和成骨分化能力。通過溫和的化學(xué)均相沉淀法分別將Fe~(3+)和Sr~(2+)成功地引入到OCP的結(jié)構(gòu)中,且均引起相應(yīng)的晶格膨脹,這源于Ca2+在原位分別被半徑更大的Fe(OH)_2+/Fe(OH)2+或Sr~(2+)替代。Fe/Sr摻雜并未明顯改變OCP晶體的形貌和結(jié)構(gòu),但特別地,Fe-OCP晶體表面誘導(dǎo)了納米磷酸鐵鹽顆粒的沉積。Fe/Sr摻雜顯著改變了OCP材料的表面物理化學(xué)特性包括比表面積、表面電負性和粗糙度,具有更好的BSA和LSZ的吸附性能。Fe/Sr摻雜材料均能誘導(dǎo)體外磷灰石形成,且在礦化過程中能持續(xù)穩(wěn)定地分別釋放出Fe~(3+)和Sr~(2+)。相比于空白樣,Fe/Sr摻雜材料均具有更好的細胞親和性,能顯著上調(diào)整合素基因的表達,有利于細胞黏附鋪展,明顯促進細胞的增殖活性;顯著上調(diào)干細胞成骨分化相關(guān)蛋白和基因的表達;提高胎牛血清總蛋白的吸附量。在作用機理上,Fe/Sr摻雜通過改變材料表面物理化學(xué)性質(zhì),影響了材料的初始的蛋白交互作用、細胞膜-材料表面電荷識別以及材料拓撲結(jié)構(gòu)的刺激響應(yīng);同時,動態(tài)釋放的活性Fe~(3+)和Sr~(2+)參與了細胞的礦化鈣結(jié)節(jié)過程,促進了細胞的體外鈣化行為,而Fe~(3+)/Sr~(2+)也具有刺激細胞響應(yīng)的積極作用。以上兩者協(xié)同介導(dǎo)了干細胞的響應(yīng)。通過摻雜量調(diào)控Fe~(3+)/Sr~(2+)的釋放動力學(xué),根據(jù)Fe/Sr系列摻雜材料的生物相容性,評估Fe~(3+)/Sr~(2+)的安全有效劑量濃度,其中,Fe的摻雜量控制應(yīng)在15 mol.%以內(nèi),過高則有一定的毒副作用,而Sr在低于25 mol.%范圍內(nèi)均有益于干細胞響應(yīng)。此外,從高溫熱穩(wěn)定性和溫和溶液環(huán)境穩(wěn)定性的角度,控制Fe/Sr摻雜材料的處理條件,獲得各種OCP-HA轉(zhuǎn)化狀態(tài)的OCP材料。這些不同的轉(zhuǎn)化產(chǎn)物均比相應(yīng)的對照樣具有相對更活躍的表面,因而會積極地刺激干細胞的響應(yīng)。此外,相對于空白樣,Fe-OCP和Sr-OCP分別具有更低和更高的穩(wěn)定性。穩(wěn)定性的差異會分別影響相應(yīng)的離子溶出動力學(xué)尤其是早期的溶出行為,較高劑量的Fe~(3+)溶出會有一定的毒副作用,而較為穩(wěn)定的Sr~(2+)釋放則能顯著促進干細胞的響應(yīng)。因而需要從表面物理化學(xué)特性和活性離子的角度綜合衡量有益于Fe/Sr摻雜OCP材料生物活性的處理方法和條件。通過綜合控制OCP-HA轉(zhuǎn)化可得到高生物活性的活性離子摻雜磷酸八鈣材料,從而提高了其臨床骨再生修復(fù)的應(yīng)用價值。同時,從生物成分仿生的角度,在礦物離子參與的條件下,也能更全面和準確地理解OCP-HA轉(zhuǎn)化機制,及其與OCP基生物材料生物相容性的相關(guān)性。
[Abstract]:As a precursor to biological apatite mineral phase, OCP bone conductivity and good biodegradability, can be used as bone repair material, has good clinical application value of.OCP can promote osteoblast differentiation, induce osteoclast formation and promote bone formation ability, these are their specific physical chemistry the characteristics are closely related. This topic from the perspective of bionic bone mineral composition, OCP is selected as a model of calcium phosphate minerals, the biological activity of mineral ions (Fe~ (3+) or Sr~ (2+)) environment, through research with different composition, morphology and structure of OCP related physical and chemical properties of biological effect mechanism protein molecular interaction and stem cell response, bone conduction and biodegradability of deep simulation on the activity of Fe or Sr ion doped OCP. At the same time, improve the biological activity of OCP materials by doping the active ion mode , in order to pave the way for its application in bone repair in the field. The results show that the chemical urea hydrolysis mediated by homogeneous precipitation of OCP crystals synthesized by high purity, good crystallinity, a typical plate-like structure. When the reaction temperature is higher than 70 DEG C, the severe degree of urea hydrolysis reaction is enough to provide control power system pH value. In the process of reaction temperature and pH value are the key parameters of precipitation reaction, by controlling the concentration of urea, the initial pH value, comprehensive control of reaction temperature and reaction time. The optimum conditions to obtain high purity OCP product is urea concentration 0.5 M, initial pH 5.9, reaction 90oC temperature and reaction time of 2 h. compared with other synthetic method of calcium phosphate materials, synthetic OCP material has better cell affinity and adhesion, and cell proliferation activity better or similar and osteogenic differentiation ability. Through chemical and temperature are Precipitation method respectively, Fe~ (3+) and Sr~ (2+) is successfully introduced into the structure of OCP, and cause the corresponding lattice expansion, which originates from the Ca2+ in situ were greater radius of Fe (OH) _2+/Fe (OH) 2+ or Sr~ (2+) morphology and structure instead of.Fe/Sr doping no obvious change of OCP crystal, but in particular, the surface of Fe-OCP crystal induced by nano iron phosphate particles deposition of.Fe/Sr doping significantly changed the surface physical and chemical properties of OCP materials including specific surface area, surface roughness and electronegativity, the adsorption properties of.Fe/Sr doped material has better BSA and LSZ can induce apatite the formation, and in the mineralization process can consistently respectively release Fe~ (3+) and Sr~ (2+). Compared with the blank sample, Fe/Sr doped materials have better cell affinity, can significantly adjust the expression of CYP genes, is conducive to cell adhesion and spreading, significantly promote cell Proliferation; up-regulated expression of stem bone differentiation related gene and protein in cells; improve the adsorption amount of total protein in fetal bovine serum. The mechanism of action, by changing the physical and chemical properties of Fe/Sr doped material surface, the effect of initial protein interaction materials, cell membrane surface charge and material topology recognition at the same time, the activity of stimulus response; dynamic release of Fe~ (3+) and Sr~ (2+) participate in the mineralization of calcium nodule cells, promote cell behavior in vitro calcification, while Fe~ (3+) /Sr~ (2+) also has a positive role to stimulate cell rings. The above two collaborative mediated stem cell response by doping. The regulation of Fe~ (3+) /Sr~ (2+) release kinetics, according to the compatibility of Fe/Sr series doped materials, biological evaluation of Fe~ (3+), /Sr~ (2+) safe and effective dose of concentration, the doping amount of Fe should be controlled within 15 mol.%, high Have certain side effects, while Sr in less than 25 in the range of mol.% are beneficial to stem cell response. In addition, the thermal stability and the stability of mild solution environment angle, processing condition control of Fe/Sr doped materials, to obtain a variety of OCP-HA transformed state OCP materials. These different transformation products all have relatively more active surface than that of the control sample accordingly, thus actively stimulate stem cell response. In addition, compared with the blank sample, Fe-OCP and Sr-OCP respectively with lower and higher stability. The stability of the difference will affect the corresponding ion dissolution kinetics especially the dissolution behavior of the early, the higher dose of Fe~ (3+) dissolution there will be some side effects, and more stable Sr~ (2+) release could significantly promote stem cell response. Therefore need from the surface physical and chemical properties and active ion angle comprehensive measure is beneficial to Fe/Sr The methods and conditions of processing materials doped OCP biological activity. The activity of ion doped phosphate can have high biological activity of eight calcium materials by means of comprehensive control of OCP-HA conversion, so as to improve the application value of the clinical repair of bone regeneration. At the same time, from the view of Bionics in biological components, mineral ions in the conditions, can be more comprehensive and accurate understanding of OCP-HA transformation mechanism and biological OCP based biomaterials correlation.

【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TQ132.32;R318.08
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本文編號：1634611