本文選題：磷酸鈣骨水泥 + PLGA　； 參考：《華南理工大學(xué)》2013年博士論文

【摘要】：采用定向冰晶-冷凍干燥法制備具有定向?qū)訝畲罂捉Y(jié)構(gòu)的磷酸鈣骨水泥（CPC）支架，通過灌注將聚乳酸羥基乙酸酯（PLGA）復(fù)合到CPC支架的孔壁表面后，獲得了具有較高強(qiáng)度和柔韌性的PLGA/CPC復(fù)合支架。本文對所制備的PLGA/CPC支架進(jìn)行了體外降解特性、細(xì)胞行為和體內(nèi)成骨性能的研究，并對支架的組成和結(jié)構(gòu)進(jìn)行了優(yōu)化，從而進(jìn)一步改善其力學(xué)性能、細(xì)胞反應(yīng)性和體內(nèi)成骨性。 顯微觀察表明，PLGA/CPC支架的孔壁表面覆蓋著PLGA膜，在體外降解過程中，PLGA膜首先降解，使骨水泥基體逐漸暴露，從而有利于提高材料與細(xì)胞和骨組織的反應(yīng)。PLGA/CPC支架的定向?qū)訝畲罂捉Y(jié)構(gòu)有利于細(xì)胞的長入和增殖。將PLGA/CPC支架植入兔子的股骨缺損后，新生的骨組織沿著定向的層狀大孔長入到支架的內(nèi)部。由于PLGA/CPC支架表面包覆著PLGA膜，導(dǎo)致細(xì)胞反應(yīng)性較差，植入初期，骨水泥骨傳導(dǎo)性好的優(yōu)點得不到發(fā)揮。為了改善PLGA/CPC支架的細(xì)胞反應(yīng)性，本研究在氨氣氣氛下對PLGA/CPC復(fù)合支架進(jìn)行等離子體表面處理，將膠原固定在PLGA/CPC支架孔壁PLGA膜的表面，改善支架的生物活性，得到Col/PLGA/CPC復(fù)合支架。經(jīng)膠原表面改性后的支架的細(xì)胞種植率、粘附、增殖和分化均得到顯著的提高。然而，植入兔子體內(nèi)后發(fā)現(xiàn)，膠原改性對提高PLGA/CPC支架的成骨能力幫助并不大。 為了適應(yīng)一些對支架強(qiáng)度有更高要求的應(yīng)用，本研究仿天然骨的皮質(zhì)骨/松質(zhì)骨雙層結(jié)構(gòu)制備了強(qiáng)度可控的核殼結(jié)構(gòu)磷酸鈣骨水泥基復(fù)合支架。通過設(shè)計模具，采用等靜壓處理的方法制備了致密的管狀骨水泥殼層。在致密殼層的空腔內(nèi)用定向冰晶-冷凍干燥法制備具有定向?qū)訝畲罂捉Y(jié)構(gòu)的多孔磷酸鈣骨水泥芯，并用PLGA進(jìn)行增強(qiáng)，然后用膠原進(jìn)行表面改性。外層致密、內(nèi)層多孔的骨水泥復(fù)合支架的強(qiáng)度可以通過改變致密層和多孔層的厚度比例調(diào)節(jié)（5~90MPa），以滿足不同骨缺損部位修復(fù)的要求。定向大孔主要在軸向上具有高度的連通性，橫向連通性較低。因此，致密的骨水泥外層對支架多孔芯的孔隙連通性沒有明顯的影響。細(xì)胞實驗表明，細(xì)胞在雙層骨水泥復(fù)合支架上粘附和增殖良好。 通過復(fù)合明膠微球改性PLGA/CPC支架的三維多孔結(jié)構(gòu)。PLGA/CPC支架經(jīng)過明膠微球（0%~30%）改性后，強(qiáng)度和孔隙率都有所變化，但分別保持在3.5~5MPa和62%~72%之間。經(jīng)明膠微球改性后，支架的定向?qū)訝畲罂妆环指顬槌叽巛^小的層狀大孔。此外，明膠微球溶解后原位留下80~200μm左右的等軸狀大孔。用20%明膠微球改性的支架的細(xì)胞種植率、增殖和分化改善效果最明顯。明膠微球的改性并沒有明顯影響支架的軸向連通性，，細(xì)胞仍然可以順利長入到支架的內(nèi)部。 將富血小板血漿（PRP）灌注到PLGA/CPC支架內(nèi)部，制備了PRP-PLGA/CPC復(fù)合體。結(jié)果表明，PRP的復(fù)合大大地改善了PLGA/CPC支架的細(xì)胞反應(yīng)。將PRP-PLGA/CPC復(fù)合支架植入到新西蘭大白兔的股骨缺損后發(fā)現(xiàn)，PRP的復(fù)合明顯促進(jìn)了骨組織長入到支架的內(nèi)部，加快血管的生成和材料的降解。此外，本研究首次將具有定向?qū)訝畲罂捉Y(jié)構(gòu)的PLGA/CPC支架用于修復(fù)新西蘭大白兔的橈骨節(jié)段性骨缺損。新生的骨組織沿著定向的層狀大孔長入支架的內(nèi)部，而沒有受到其三維連通性有限的影響。PRP的復(fù)合對PLGA/CPC支架修復(fù)橈骨的節(jié)段性骨缺損具有顯著的促進(jìn)作用。
[Abstract]:Calcium phosphate cement (CPC) scaffold with directional layered macroporous structure was prepared by directional ice crystal and freeze drying. The PLGA/CPC composite scaffold with high strength and flexibility was obtained by compounding the poly (lactic acid hydroxyacetate) (PLGA) to the pore wall surface of the CPC scaffold by perfusion. The PLGA/CPC scaffold prepared in this paper was carried out in this paper. The study of the properties of degradation, cell behavior and osteogenesis in vivo, and optimization of the structure and composition of the scaffolds to further improve their mechanical properties, cell reactivity and osteogenesis in the body.
The microscopic observation shows that the surface of the hole wall of the PLGA/CPC stent is covered with PLGA membrane. In the process of degradation in vitro, the PLGA film is degraded first and the bone cement matrix is exposed gradually. Thus, the reaction of the material to the cell and bone tissue is beneficial to the directional layered macroporous structure of the.PLGA/CPC scaffold which is beneficial to the growth of the cells. The PLGA/CPC scaffold is implanted into the scaffold. After the rabbit's femur defect, the new bone tissue grows into the interior of the scaffold along the directional layered large pore. Because the PLGA/CPC stents are coated with PLGA membrane, the cell reactivity is poor and the advantages of the good conductivity of the bone cement bone are not played at the early stage of implantation. In order to improve the cell reactivity of the PLGA/ CPC scaffold, this study is in the ammonia atmosphere. The PLGA/CPC composite scaffold was treated by plasma surface treatment. Collagen was immobilized on the surface of the PLGA membrane of the hole wall of the PLGA/CPC stent. The bioactivity of the scaffold was improved and the Col/PLGA/CPC composite scaffold was obtained. The cell implantation rate, adhesion, proliferation and differentiation of the scaffold after the collagen surface modification were significantly improved. However, the implanted rabbit was implanted in the rabbit. It was found that collagen modification did not help to improve the osteogenic potential of PLGA/CPC scaffolds.
In order to adapt to the application of a high requirement for the strength of the scaffold, a calcium bone cement composite scaffold with controllable core shell structure was prepared by imitating the double layer structure of the cortical bone / cancellous bone of the natural bone. The compact tubular bone cement shell was prepared by the method of isostatic pressure treatment. The porous calcium phosphate cement core with directional layered macroporous structure was prepared by the directional ice crystal and freeze drying method, and enhanced with PLGA, then the surface was modified with collagen. The outer layer was dense and the strength of the porous bone cement composite scaffold of the inner layer could be adjusted by changing the thickness ratio of the dense layer and the porous layer (5~90MPa) to meet the difference. The requirement of bone defect repair is that the directional macropores mainly have high connectivity in the axial direction, and the lateral connectivity is low. Therefore, the dense bone cement outer layer has no obvious influence on the pore connectivity of the porous core of the scaffold. Cell experiments show that the cells adhere and proliferate well on the double bone cement composite support.
The strength and porosity of the three-dimensional porous structure.PLGA/CPC scaffold modified by compound gelatin microspheres were modified by gelatin microspheres (0%~30%), and the strength and porosity were changed, but they were kept between 3.5~5MPa and 62%~72%. After the modification of gelatin microspheres, the directional layered macropores of the scaffold were divided into smaller layered macropores. In addition, gelatin was used. After the microspheres were dissolved, the ISO axial large pores were left around 80~200 mu m in situ. The cell implantation rate, proliferation and differentiation of the modified scaffold with 20% gelatin microspheres were most obvious. The modification of gelatin microspheres did not obviously affect the axial connectivity of the scaffold, and the cells could still grow into the inner of the scaffold.
Platelet rich plasma (PRP) was perfused into the internal PLGA/CPC scaffold and the PRP-PLGA/CPC complex was prepared. The results showed that the PRP composite greatly improved the cell response of the PLGA/CPC scaffold. The PRP-PLGA/CPC composite scaffold was implanted into the femur defect of New Zealand white rabbits and found that the recombination of PRP significantly promoted the bone tissue to grow into the inside of the scaffold. In addition, it is the first time that PLGA/CPC scaffolds with directional layered macroporous structures have been used for the first time to repair the radial segmental bone defect of New Zealand white rabbits. The new bone tissue grows into the stent along the directional layered macropores, and is not affected by the limited three-dimensional connectivity of the.PRP. It has a significant promoting effect on repairing the segmental bone defect of the radius with PLGA/CPC stent.
【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】：2013
【分類號】：R318.08

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 曹誼林;組織工程學(xué)的研究進(jìn)展[J];中國美容醫(yī)學(xué);2005年02期

2 董浩;葉建東;王秀鵬;楊娟娟;;磷酸鈣骨水泥大孔徑多孔組織工程支架的制備及其纖維增強(qiáng)[J];無機(jī)材料學(xué)報;2007年05期

3 鄭學(xué)斌,劉宣勇,丁傳賢;人體硬組織替代材料的研究進(jìn)展[J];物理;2003年03期

4 景元海;楊小玉;趙叢然;李恒;郭明峰;汪群;王強(qiáng);;經(jīng)皮椎體注入骨水泥治療老年脊椎骨質(zhì)疏松壓縮性骨折[J];中國組織工程研究與臨床康復(fù);2007年32期

5 潘朝暉,范清宇;促磷酸鈣骨水泥吸收的研究進(jìn)展[J];中國矯形外科雜志;2004年Z3期

6 孫磊;同種異體骨移植生物學(xué)[J];中國矯形外科雜志;1996年01期

7 戴紅蓮,閆玉華,曹獻(xiàn)英,李世普,賀建華,余國榮;磷酸鈣骨水泥的生物相容性[J];中國有色金屬學(xué)報;2002年06期

本文編號：2012177