發(fā)布時(shí)間：2018-05-17 18:42

  本文選題：大段骨缺損 + 鈦酸鋇　； 參考：《第四軍醫(yī)大學(xué)》2017年博士論文

【摘要】：研究背景當(dāng)今社會中,由于感染、創(chuàng)傷、骨腫瘤骨病切除等往往造成骨組織的缺損,對于常規(guī)的骨缺損,經(jīng)過積極治療后常常能夠獲得較理想的治療效果,但是對于大段骨組織的缺失(等于或者大于長骨直徑的1.5倍),即使經(jīng)過積極治療也難以獲得良好的治療效果,尤其是負(fù)重部位的大段骨缺損,更是困擾著醫(yī)學(xué)研究人員。雖然目前已經(jīng)有較多人工骨移植材料被研發(fā),但是它們或多或少存在一定的缺陷,例如移植材料的強(qiáng)度有限或者雖具有較好的強(qiáng)度但是缺乏活性,甚至既具有了好的強(qiáng)度也有了不錯(cuò)的生物活性但是仍然難以滿足臨床上的應(yīng)用。近年來,多孔鈦合金技術(shù)的發(fā)展給大段骨缺損的治療帶來了新的治療思路,多孔鈦合金具有良好的生物相容性、耐腐蝕性、高的機(jī)械強(qiáng)度,同時(shí)其整體彈性模量可以根據(jù)骨的彈性模量通過調(diào)節(jié)孔徑大小、連通徑大小以及孔隙率的高低來做出調(diào)整。而且,多孔結(jié)構(gòu)不僅能夠作為營養(yǎng)物質(zhì)運(yùn)輸?shù)挠行ǖ?而且為新生骨組織的長入也提供了良好的空間,因此將多孔鈦合金作為治療負(fù)重部位大段骨缺損的基底材料不失為一種不錯(cuò)的選擇。但是,多孔鈦合金屬于生物惰性材料,其植入體內(nèi)后,不能很好地誘導(dǎo)骨組織長入,骨與材料界面難以達(dá)到理想的整合效果。因?yàn)闄C(jī)體內(nèi)一切生命活動(dòng)都有賴于微弱生物電活動(dòng),因此提高多孔鈦合金的生物電活性或許能夠改善其成骨活性。目前,壓電陶瓷是一種良好的力-電轉(zhuǎn)換材料,在其受到外界力的作用并發(fā)生形變時(shí)(即使是極其微小的形變)在其周圍會產(chǎn)生微弱的電流;而當(dāng)其處在電場中時(shí),其亦會發(fā)生形變,從而實(shí)現(xiàn)力-電之間的互相轉(zhuǎn)換。因此,如果能將壓電陶瓷作為涂層制備于多孔鈦合金表面,其在力的作用下能夠很好的改善多孔鈦合金的生物電活性。目前,醫(yī)學(xué)領(lǐng)域中對壓電陶瓷已有了大量研究,但是只有鈦酸鋇壓電陶瓷研究和應(yīng)用的最為廣泛,而且其作為涂層的制備工藝也更為成熟。鈦酸鋇壓電陶瓷具有良好的生物相容性和壓電特性,作為涂層的制備方法包括等離子噴涂、火焰噴涂等,但是這些方法所制備的涂層厚度和分布多不夠均勻,涂層結(jié)合多不牢固。水熱合成法通過化學(xué)合成的方法,能在多孔鈦合金表面原位生成厚薄均勻的鈦酸鋇涂層,并且結(jié)合穩(wěn)定牢固。低強(qiáng)度脈沖超聲波已經(jīng)被美國食品和藥品管理局(FDA)批準(zhǔn)用于治療臨床上新鮮骨折以及骨不連等,證明低強(qiáng)度脈沖超聲波本身能夠促進(jìn)骨組織的再生。另外,低強(qiáng)度脈沖超聲波作為一種微弱的機(jī)械力,其作用于壓電陶瓷后,能夠使其發(fā)生形變從而產(chǎn)生壓電效應(yīng),壓電效應(yīng)所產(chǎn)生的微電流進(jìn)一步刺激新骨的形成。因此,本實(shí)驗(yàn)將鈦酸鋇壓電陶瓷涂層制備于多孔Ti6Al4V支架表面后,并將低強(qiáng)度脈沖超聲波作用于涂層修飾后的支架,觀察和評估了體外的細(xì)胞學(xué)效應(yīng)和體內(nèi)修復(fù)大段骨缺損的效果。研究目的將鈦酸鋇壓電陶瓷涂層制備于多孔Ti6Al4V支架表面,對修飾后支架的自身特性和表面特性與單純多孔Ti6Al4V支架進(jìn)行對比;檢測低強(qiáng)度脈沖超聲波作用于修飾前支架和修飾后支架對于體外細(xì)胞生物學(xué)特性的影響;檢測低強(qiáng)度脈沖超聲波作用于修飾前支架和修飾后支架對于體內(nèi)大段骨缺損治療效果,包括骨量增長的多少和骨與支架的整合程度。研究方法1)通過電子束熔融技術(shù)制備兩種不同規(guī)格的多孔Ti6Al4V支架,即體外細(xì)胞實(shí)驗(yàn)所用支架直徑12mm,高2mm和體內(nèi)動(dòng)物實(shí)驗(yàn)所用支架直徑5mm,高13mm,孔徑大小設(shè)計(jì)為700μm,孔隙率為70%,橫梁直徑為380μm。通過水熱合成法在支架表面制備鈦酸鋇壓電陶瓷涂層,并利用掃描電鏡、普通能譜分析和X射線光電子能譜分析檢測涂層是否制備成功。通過水接觸角和表面粗糙度比較涂層修飾前后,多孔Ti6Al4V支架表面特性的變化。通過Micro-CT掃描比較了修飾前后多孔Ti6Al4V支架的孔徑、連通徑、孔隙率以及橫梁大小的變化。通過力學(xué)測試評價(jià)涂層修飾前后,多孔Ti6Al4V支架彈性模量和強(qiáng)度的變化。2)將低強(qiáng)度脈沖超聲波作用于涂層修飾前后的多孔Ti6Al4V支架,并將兔骨髓間充質(zhì)干細(xì)胞種植于支架表面。根據(jù)超聲波條件的加載與否,實(shí)驗(yàn)被分為BaTiO_3/pTi+LIPUS組、BaTiO_3/pTi組、LIPUS+pTi組和pTi組四組。并在培養(yǎng)4天和7天時(shí)利用CCK-8檢測了細(xì)胞的增殖活性;在4天時(shí)利用SEM,在4天和7天時(shí)利用熒光染色觀察了細(xì)胞的基本形態(tài)和黏附活性;在4天時(shí)利用流式細(xì)胞儀,在4天和7天時(shí)利用細(xì)胞死活熒光染色分析了細(xì)胞的死亡和凋亡情況;在7天和14天時(shí),分別利用堿性磷酸酶活性和成骨相關(guān)基因的PCR結(jié)果評估了細(xì)胞的成骨分化情況。3)建立新西蘭大白兔橈骨中段大段骨缺損的模型,并將鈦酸鋇壓電陶瓷涂層修飾前后的多孔Ti6Al4V支架分別移植于骨缺損處,術(shù)后給予低強(qiáng)度脈沖超聲波刺激。根據(jù)是否加載超聲刺激,實(shí)驗(yàn)同樣被分為BaTiO_3/pTi+LIPUS組、BaTiO_3/pTi組、LIPUS+pTi組和pTi組四組。在術(shù)后6周和12周分別取材,通過影像學(xué)X線平片和Micro-CT掃描分析了材料內(nèi)部骨組織的再生情況,通過熒光標(biāo)記計(jì)算了骨礦化沉積率的快慢,通過組織學(xué)切片VG染色進(jìn)一步分析了新生骨組織的生長狀況和骨-支架界面的骨整合情況,通過生物力學(xué)檢測了最大拔出力。研究結(jié)果1)通過SEM、SEM自帶的能譜分析儀和XPS檢測,發(fā)現(xiàn)鈦酸鋇壓電陶瓷涂層被成功制備于多孔Ti6Al4V支架表面;水接觸角結(jié)果顯示,鈦酸鋇壓電陶瓷涂層改善了多孔Ti6Al4V支架表面的親水性;表面粗糙度結(jié)果表明,鈦酸鋇涂層修飾后的支架有了更好的表面粗糙度;Micro-CT掃描結(jié)果表明,涂層修飾前后支架的孔徑、連通徑、孔隙率和橫梁直徑均無統(tǒng)計(jì)學(xué)意義上的變化;力學(xué)測試結(jié)果顯示,涂層修飾前后支架的彈性模量和力學(xué)強(qiáng)度均無明顯變化。2)CCK-8結(jié)果表明,在4天和7天時(shí),BaTiO_3/pTi+LIPUS組與其它三組比較有了更好的細(xì)胞增殖活性(*p0.05 vs.pTi組,#p0.05 vs.BaTiO_3/pTi組,+p0.05 vs.LIPUS+pTi組),LIPUS+pTi組和BaTiO_3/pTi組的細(xì)胞增殖活性高于pTi組(*p0.05)。掃描電鏡發(fā)現(xiàn)BaTiO_3/pTi+LIPUS組細(xì)胞形態(tài)不僅更為飽滿,伸展?fàn)顟B(tài)良好,而且在支架表面形成的細(xì)胞層,LIPUS+pTi組和BaTiO_3/pTi組的細(xì)胞狀態(tài)要好于pTi組。熒光染色后,細(xì)胞總面積與細(xì)胞核面積之比顯示在4天和7天時(shí),BaTiO_3/pTi+LIPUS組的值均高于LIPUS+pTi組(P0.05)、BaTiO_3/pTi組(P0.05)和pTi組(P0.05),而LIPUS+pTi組和BaTiO_3/pTi組的值僅在7天時(shí)在統(tǒng)計(jì)學(xué)上高于pTi組(P0.05)。黏著斑蛋白的表達(dá)顯示,在4天和7天時(shí),Ba TiO_3/pTi+LIPUS組均有較高的表達(dá)(*p0.05 vs.pTi組,#p0.05 vs.Ba TiO_3/pTi組,+p0.05 vs.LIPUS+pTi組),LIPUS+pTi組的表達(dá)均高于pTi組(P0.05),BaTiO_3/pTi組只在7天時(shí)高于pTi組(P0.05)。流式細(xì)胞儀細(xì)胞凋亡指數(shù)和細(xì)胞死活染色結(jié)果結(jié)果顯示,在4天和7天時(shí),BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組。堿性磷酸酶活性結(jié)果顯示,在7天和14天時(shí),BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組。成骨基因RNA表達(dá)結(jié)果顯示,在7天和14天時(shí),對于ALP、RUNX2和COL-1基因的表達(dá)來說,Ba TiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組,但是,對于OPN基因表達(dá)來說,Ba TiO_3/pTi組在7天和14天時(shí)均大于其他三組(*p0.05,#p0.05,+p0.05),而LIPUS+pTi組和BaTiO_3/pTi組僅在14天時(shí)大于pTi組(P0.05)。3)影像學(xué)檢查發(fā)現(xiàn),在6周和12周時(shí),新生骨組織長入的量,BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組。骨礦化沉積率的計(jì)算結(jié)果表明,對于新骨生長速度來說,BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組。組織學(xué)VG染色結(jié)果與影像學(xué)和熒光標(biāo)記結(jié)果相一致,BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組,另外,BaTiO_3/pTi+LIPUS組、LIPUS+pTi組、Ba TiO_3/pTi組這三組骨整合均較pTi組好。最大拔出力的結(jié)果與影像學(xué)和組織學(xué)保持一致,BaTiO_3/pTi+LIPUS組(*p0.05,#p0.05,+p0.05)LIPUS+pTi組(*p0.05)BaTiO_3/pTi組(*p0.05)pTi組。研究結(jié)論1)成功在多孔Ti6Al4V支架表面制備了鈦酸鋇壓電陶瓷涂層,而且該涂層在改善多孔Ti6Al4V支架表面的親水性和表面粗糙度的基礎(chǔ)上,并未影響支架本身的特性,包括孔徑、連通徑、孔隙率、彈性模量、力學(xué)強(qiáng)度。2)在體外研究中,鈦酸鋇壓電陶瓷涂層作為獨(dú)立因素能夠改善多孔Ti6Al4V支架上細(xì)胞的形態(tài)、黏附、增殖和分化;低強(qiáng)度脈沖超聲波同樣可以作為獨(dú)立的因素改善多孔Ti6Al4V支架上細(xì)胞的生物學(xué)表現(xiàn);當(dāng)?shù)蛷?qiáng)度脈沖超聲波作用于鈦酸鋇壓電陶瓷涂層時(shí),其改善孔Ti6Al4V支架上細(xì)胞生物行為學(xué)的能力進(jìn)一步被提高。3)在體內(nèi)研究中,鈦酸鋇壓電陶瓷涂層能夠作為獨(dú)立因素提高多孔Ti6Al4V支架內(nèi)新生骨組織的長入并且促進(jìn)骨與支架之間的整合;低強(qiáng)度脈沖超聲波同樣可以作為獨(dú)立因素改善多孔Ti6Al4V支架內(nèi)新生骨組織的生成量和骨整合能力;鈦酸鋇壓電陶瓷涂層在低強(qiáng)度脈沖超聲波的作用下,其促進(jìn)骨再生的能力和骨與支架整合的能力進(jìn)一步被加強(qiáng),相較于單純多孔Ti6Al4V支架來說,骨組織的生成量增加了10%-20%。4)多孔Ti6Al4V支架、鈦酸鋇壓電陶瓷涂層、低強(qiáng)度脈沖超聲波的結(jié)合能顯著提高負(fù)重部位大段骨缺損的修復(fù)效能,為臨床應(yīng)用提供了理論基礎(chǔ)。但是,其修復(fù)機(jī)制尚未完全明了,有待進(jìn)一步的探究。
[Abstract]:Research background today, infection, trauma, bone tumor resection often cause bone tissue defects. For conventional bone defects, after active treatment, they often get better therapeutic effects, but the loss of large bone tissue is equal to or greater than 1.5 times the diameter of the long bone, even after active treatment. It is difficult to obtain good therapeutic effects, especially large segment bone defects in the weight bearing area, which is more perplexing medical researchers. Although many artificial bone graft materials have been developed, there are more or less defects, such as the limited strength of the graft material, the better strength but the lack of activity, and the lack of activity. In recent years, the development of porous titanium alloy technology has brought new treatment ideas for the treatment of large bone defects. Porous titanium alloys have good biocompatibility, corrosion resistance, high mechanical strength, and the overall elastic modulus of the porous titanium alloy. The volume can be adjusted according to the modulus of elasticity of the bone, the size of the diameter and the porosity of the bone. Moreover, the porous structure can not only serve as an effective channel for the transport of nutrients, but also provide a good space for the growth of the new bone tissue. Therefore, porous titanium alloy is used as a large part of the treatment of weight bearing parts. The base material of bone defect is a good choice. However, porous titanium alloy is a biological inert material. After implantation, it can not induce bone tissue to grow well. The bone and material interface can not achieve the ideal integration effect. Because all life activities in the body depend on weak bioelectrical activity, so the porous titanium is improved. The bioelectrical activity of an alloy may improve its osteogenic activity. At present, a piezoelectric ceramic is a good force - electric conversion material, which produces a weak current around it when it is subjected to external forces and is deformed (even extremely small); and when it is in an electric field, it will also be deformed, thus realizing force - Therefore, if the piezoelectric ceramic can be prepared as a coating on the surface of the porous titanium alloy, it can improve the bioelectrical activity of the porous titanium alloy very well. At present, a lot of research has been done on the piezoelectric ceramics in the medical field, but only barium titanate piezoelectric ceramics are the most widely used in the field of research and application. The preparation technology of the coating is also more mature. Barium titanate piezoelectric ceramics have good biocompatibility and piezoelectric properties. The preparation methods of the coating include plasma spraying, flame spraying, etc. but the thickness and distribution of the coating are not uniform enough and the coating is not solid. The hydrothermal synthesis method is passed. The method of chemical synthesis can produce a thick and uniform barium titanate coating on the surface of porous titanium alloy, and it is stable and stable. Low intensity pulsed ultrasound has been approved by the US Food and Drug Administration (FDA) for clinical fresh fractures and bone nonunion. It is proved that low intensity pulse ultrasound can promote bone group itself. In addition, the low strength pulse ultrasonic as a weak mechanical force, which acts on the piezoelectric ceramic, can cause the deformation to produce the piezoelectric effect. The micro current produced by the piezoelectric effect further stimulates the formation of the new bone. Therefore, this experiment has prepared the barium titanate piezoelectric ceramic coating on the surface of the porous Ti6Al4V scaffold. The effect of the in vitro cytological effect and the repair of large bone defects in the body was observed and evaluated in vitro by using low intensity pulsed ultrasound as a scaffold. The purpose of this study was to prepare barium titanate piezoelectric ceramic coating on the surface of porous Ti6Al4V scaffold. The self and surface properties of the modified scaffold and the simple porous Ti6Al4V branch were studied. The effects of low intensity pulsed ultrasound on the biological characteristics of the cells in vitro, and the effect of low intensity pulsed ultrasound on the treatment of large bone defects in the body, including the amount of bone mass growth and the integration of bone and scaffold, was detected by the effect of low intensity pulsed ultrasound on the biological characteristics of the cells in vitro. Degree. Method 1) two kinds of porous Ti6Al4V scaffolds with different specifications were prepared by electron beam melting technique, that is, the diameter of scaffold used in vitro cell experiment 12mm, high 2mm and the diameter of scaffold used in the animal experiment in vivo, 5mm, high 13mm, the diameter of 700 u m, the porosity of 70%, and the diameter of the transverse beam of 380 mu on the surface of the scaffold. Barium titanate piezoelectric ceramic coating was prepared. The coating was successfully prepared by scanning electron microscopy, ordinary energy spectrum analysis and X ray photoelectron spectroscopy. The surface properties of porous Ti6Al4V scaffolds were compared before and after the coating modified by water contact angle and surface roughness. The porous Ti6Al4V scaffolds before and after the modification were compared by Micro-CT scanning. Pore size, connection diameter, porosity and change of beam size. Through mechanical tests, the elastic modulus and strength of the porous Ti6Al4V scaffold were evaluated before and after the coating modified.2). The low intensity pulsed ultrasound was applied to the porous Ti6Al4V scaffold before and after the coating, and the rabbit bone marrow mesenchymal stem cells were planted on the surface of the scaffold. The experiment was divided into four groups, BaTiO_3/pTi+LIPUS group, BaTiO_3/pTi group, LIPUS+pTi group and pTi group. CCK-8 was used to detect cell proliferation activity by CCK-8 for 4 days and 7 days. The basic morphology and adhesion activity of the cells were observed by SEM at 4 days and 4 and 7 days by fluorescence staining, and the flow cytometry was used at 4 days. Cell death and apoptosis were analyzed by cell dead fluorescence staining at 4 and 7 days. At 7 and 14 days, PCR results of alkaline phosphatase activity and osteogenic related genes were used to evaluate the osteogenic differentiation of cells.3). A model of large bone defect in the middle segment of the radius of New Zealand white rabbit was established and barium titanate piezoceramic was used. The porous Ti6Al4V scaffold before and after the coating was transplanted to the bone defect and was given low intensity pulse ultrasonic stimulation after operation. The experiment was also divided into four groups, group BaTiO_3/pTi+LIPUS, group BaTiO_3/pTi, group LIPUS+pTi and group pTi according to whether the ultrasonic stimulation was loaded. The regeneration of bone tissue in the material was analyzed by scanning, and the rate of bone mineralization deposition was calculated by fluorescence labeling. The growth status of the new bone tissue and the bone integration of the bone scaffold interface were further analyzed by the histological section VG staining. The maximum pulling force was detected by the biomechanics. The results of the study were 1) by SEM and SEM. The energy spectrum analyzer and XPS test showed that barium titanate piezoelectric ceramic coating was successfully prepared on the surface of porous Ti6Al4V stent, and the water contact angle showed that barium titanate piezoelectric ceramic coating improved the hydrophilicity of the porous Ti6Al4V stent surface, and the surface roughness results showed that the scaffold after the barium titanate coating had better surface roughness. The results of Micro-CT scan showed that the diameter, diameter, porosity and diameter of the scaffold were no significant changes before and after the coating. The results of mechanical test showed that the modulus of elasticity and mechanical strength of the scaffolds were not significantly changed by.2) CCK-8 results showed that in 4 and 7 days, the BaTiO_3/pTi+LIPUS group and the other three were the other three. The group had better cell proliferation activity (group *p0.05 vs.pTi, #p0.05 vs.BaTiO_3/pTi group, +p0.05 vs.LIPUS+pTi group), and the cell proliferation activity of LIPUS+pTi group and BaTiO_3/pTi group was higher than that of group pTi (*p0.05). The cell morphology of BaTiO_3/pTi+LIPUS group was not only more full, well stretched, but also formed on the surface of the scaffold. Cell layer, LIPUS+pTi group and BaTiO_3/pTi group were better than group pTi. After fluorescent staining, the ratio of total area to cell nuclear area was higher than that of group LIPUS+pTi (P0.05), BaTiO_3/pTi group (P0.05) and pTi group (P0.05) at 4 days and 7 days, while the value of LIPUS+pTi group and BaTiO_3/pTi group was only 7 days. The expression of macula protein was higher than that of pTi group (P0.05). The expression of macula protein showed that at 4 and 7 days, the Ba TiO_3/pTi+LIPUS group had higher expression (*p0.05 vs.pTi group, #p0.05 vs.Ba TiO_3/pTi group, +p0.05 vs.LIPUS+pTi group), and the expression of LIPUS+pTi group was higher than that of the group. The results of apoptotic index and cell death staining showed that at 4 and 7 days, group BaTiO_3/pTi+LIPUS (*p0.05, #p0.05, +p0.05) group LIPUS+pTi (*p0.05) BaTiO_3/pTi group (*p0.05) pTi group. The results of alkaline phosphatase activity showed that the BaTiO_3/pTi+ LIPUS group was in the 7 and 14 days. 5) pTi group. The expression of osteogenic gene RNA showed that at the 7 and 14 days, the expression of ALP, RUNX2 and COL-1 genes, Ba TiO_3/pTi+LIPUS group (*p0.05, #p0.05, +p0.05) LIPUS+pTi group (*p0.05) group, but, for 7 and 14 days, the group was larger than the other three groups. .05, +p0.05), and group LIPUS+pTi and BaTiO_3/pTi only 14 days longer than pTi group (P0.05).3) imaging examination found that the amount of new bone tissue in the 6 and 12 weeks, BaTiO_3/pTi+LIPUS group (*p0.05, #p0.05, +p0.05) LIPUS+pTi group. Speed, group BaTiO_3/pTi+LIPUS (*p0.05, #p0.05, +p0.05) group LIPUS+pTi (*p0.05) BaTiO_3/pTi group (*p0.05) pTi group. Histology VG staining results are consistent with the results of imaging and fluorescence labeling. The three groups of bone integration in group Ba TiO_3/pTi were better than those in group pTi. The results of maximum pulling force were consistent with imaging and histology. Group BaTiO_3/pTi+LIPUS (*p0.05, #p0.05, +p0.05) LIPUS+pTi group (*p0.05) BaTiO_3/pTi group (*p0.05) pTi group. Conclusion 1) barium titanate piezoelectric ceramic coating was successfully prepared on the surface of porous scaffold. On the basis of improving the hydrophilicity and surface roughness of the surface of the porous Ti6Al4V scaffold, the coating does not affect the characteristics of the scaffold itself, including the pore size, the diameter, the porosity, the modulus of elasticity and the mechanical strength.2) in the study. The barium titanate piezoelectric ceramic coating can improve the morphology and adhesion of the cells on the porous Ti6Al4V scaffold as an independent factor. Proliferation and differentiation; low intensity pulsed ultrasound can also be an independent factor to improve the biological performance of cells on the porous Ti6Al4V scaffold; when low intensity pulsed ultrasound acts on barium titanate piezoelectric ceramic coating, the energy of cell biobehavior on the porous Ti6Al4V scaffold is further improved by.3) in the body study, titanic acid Barium piezoelectric ceramic coating can increase the growth of the new bone tissue in the porous Ti6Al4V scaffold and promote the integration of the bone and the scaffold as an independent factor. The low intensity pulse ultrasound can also improve the formation and the bone integration of the new bone tissue in the porous Ti6Al4V scaffold as an independent factor; barium titanate piezoelectric ceramic coating is low Under the action of intensity pulse ultrasound, the ability to promote bone regeneration and the ability to integrate the bone with the scaffold is further strengthened. Compared with the simple porous Ti6Al4V scaffold, the formation of bone tissue is increased by 10%-20%.4) porous Ti6Al4V scaffold, barium titanate piezoelectric ceramic coating, and the combination of low intensity pulsed ultrasonic wave can significantly increase the weight negative part. The repair efficiency of large segmental bone defects provides a theoretical basis for clinical application. However, its repair mechanism is not yet fully understood and needs further investigation.
【學(xué)位授予單位】：第四軍醫(yī)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：R68;R318.08
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本文編號：1902437