多壁碳納米管論文：可降解高分子-碳納米管復合電紡纖維的制備及其性能研究

1、 多壁碳納米管論文：可降解高分子/碳納米管復合電紡纖維的制備及其性能研究【中文摘要】本論文使用靜電紡絲法制備了無規(guī)取向和定向?qū)щ娋廴樗崽技{米管(PLA/MWCNTs)復合纖維支架和載藥(茶多酚)的聚己內(nèi)酯碳納米管(PCL/MWCNTs)復合纖維支架。其中,所采用的聚乳酸和聚己內(nèi)酯高分子可生物降解,無毒,具有良好的生物相容性；多壁碳納米管(MWCNTs)具有優(yōu)異的力學性能、導電性及良好的生物相容性。因此,可以預見,我們制備的纖維支架在組織工程和藥物控制釋放方面具有廣闊的應用前景。首先,對于PLA/MWCNTs導電復合電紡纖維支架,我們使用掃描電子顯微鏡(SEM),透射電子顯微鏡(TEM),萬能材

2、料力學實驗機,超高阻微電流測量儀,材料體外降解等手段進行表征。結(jié)果表明：PLA/MWCNTs導電復合纖維直徑均勻、形貌良好；MWCNTs在復合纖維內(nèi)部分散均勻；復合纖維力學性能得到大幅提高,且定向纖維支架比無規(guī)取向纖維支架力學性能強；在MWCNTs含量為3%時,有電滲閾值現(xiàn)象；PLA/MWCNTs導電復合電紡纖維體外降解速度受MWCNTs含量的影響顯著。其次,我們使用自制裝置對成骨細胞在導電PLA/MWCNTs纖維支架上的生長進行了不同大小的微直流電刺激(50,100,200A),以研究導電復合纖維的形貌特征和電刺激對成骨細胞體外生長的協(xié)同影響。我們分別使用Alamar blue法,普通光學顯

3、微鏡,熒光顯微鏡和掃描電子顯微鏡對細胞的生長進行了表征。結(jié)果表明：沒有電刺激時,成骨細胞在無規(guī)取向纖維支架上向四周均勻生長,在定向纖維支架上沿纖維取向生長,且細胞在定向纖維支架上增殖數(shù)量要好于無規(guī)取向纖維支架,且MWCNTs含量為3%時,細胞生長情況最好；50,100A電刺激都能促進成骨細胞的生長,100A電刺激最有利于細胞生長,200A電刺激導致成骨細胞大量死亡；成骨細胞在電刺激作用下,沿電流方向生長(100A電刺激效果最好),無規(guī)取向?qū)щ娎w維支架上的細胞在電刺激作用下形貌變得狹長,定向纖維支架上細胞長寬比也有所提高。最后,對于載藥(茶多酚)PCL/MWCNTs復合電紡纖維支架,首先采用傅里

4、葉轉(zhuǎn)換紅外分析儀(FTIR)對MWCNTs/GTP進行表征,然后采用掃描電子顯微鏡(SEM),透射電子顯微鏡(TEM),激光共聚焦顯微鏡,萬能力學測試儀,體外降解,體外藥物控制釋放,細胞實驗(OB, A549, Hep G2)等手段進行了表征。結(jié)果表明：茶多酚(GTP)成功粘附在了MWCNTs表面;PCL/MWCNTs復合電紡纖維直徑分別較寬,形貌良好,MWCNTs在纖維內(nèi)部分散均勻；復合纖維支架力學性能由于MWCNTs而增強,由于小分子藥物GTP而下降；載藥PCL/MWCNTs復合纖維支架體外降解速度受MWCNTs和GTP含量的影響較大；載藥PCL/MWCNTs復合纖維支架相對于純PCL載藥

5、支架來說,能有效降低GTP的突釋現(xiàn)象,且對正常細胞毒性較小,對腫瘤細胞生長有一定的抑制作用。【英文摘要】In this paper, the conductive poly(d,l-lactide)/multi-walled carbon nanotubes (PLA/MWCNTs) composite fibrous scaffolds with two morphologies (random oriented and aligned fiber) and polycaprolactone/multi-walled carbon nanotubes (PCL/MWCNTs) composi

6、te fibrous scaffold containing green tea polyphenols (GTP) were successfully fabricated by electrospinning. The biodegradable materials we selected PLA and PCL are non-toxic and have excellent biocompatibility; MWCNTs has excellent mechanical properties, electrical conductivity and good biocompatibi

7、lity. Therefore, it is foreseeable that the fibrous scaffolds we prepared have broad application in tissue engineering and drug controlled release.Firstly, the characterization of scanning electron microscopy (SEM), transmission electron microscopy (TEM), universal mechanical testing machine, surfac

8、e resistivity testing, materials degradation in vitro were given to conductive PLA/MWCNTs composite fibrous scaffold. Results showed that:the conductive PLA/MWCNTs composite fiber had uniform diameter and good morphology; MWCNTs dispersed well within the composite fiber; mechanical properties of com

9、posite PLA/MWCNTs fibers increased significantly compared with pure PLA fibers, and the mechanical properties of aligned composite fibrous scaffold were better than random oriented fibrous scaffold when content of MWCNTs was the same; electrical percolation threshold was existed when content of MWCN

10、Ts was 3%; in vitro degradation of PLA/MWCNTs composite fibrous scaffold was affected significantly by MWCNTs.Secondly, in order to study the coordinate effect of micro-current stimulation and morphology of scaffold on the growth of obsteoblast, three different sizes of direct current stimulation (5

11、0,100,200A) was applied to the obsteoblast through conductive PLA/MWCNTs fibrous scaffold by a home-made device. The characterization of alamar blue, optical microscope, fluorescence microscope and scanning electron microscopy were executed. Results showed that: without electrical stimulation, obste

12、oblast on random oriented fibrous scaffold grew surroundly, while obsteoblast on aligned fibrous scaffold grew along the orientation of aligned fibers and the cell proliferation was better especially when content of MWCNTs was 3%; additionally, electrical stimulation of 50 and 100A can promote the g

13、rowth of osteoblasts, especially for 100A, while electrical stimulation of 200A led to massive death for osteoblasts; at last, the electrical stimulation caused obsteoblast grown along the direction of the direct current (the effect of 100A was best of all) no matter for random oriented or aligned f

14、ibrous scaffold.Finally, the characterization of fourier transform infrared analyzer (FTIR), scanning electron microscopy (SEM), laser scanning confocal microscope, universal mechanical testing machine, materials degradationin vitro, drug controlled release in vitro and cell experiment (OB, A549, He

15、p G2) were applied to PCL/MWCNTs composite electrospun fibrous scaffold containing GTP. Results showed that:GTP successful adhere to the surface of MWCNTs by noncovalent interactions; PCL/MWCNTs composite electrospun fibrous scaffold had wide distribution of diameter and good morphology, MWCNTs disp

16、ersed well within the fiber; PCL/MWCNTs composite fibrous scaffold possessed enhanced mechanical properties due to MWCNTs although it was weaken by GTP; in vitro degradation of PCL/MWCNTs composite fibrous scaffold was affected by MWCNTs and the content of GTP; the PCL/MWCNTs composite fibrous scaff

17、old containing GTP could effectively control the burst release of GTP compared to pure PCL scaffold with GTP, and they had minor cytotoxic to normal obsteoblast and inhibition to tumor cells (A549 and Hep G2).【關鍵詞】多壁碳納米管 聚乳酸 聚己內(nèi)酯 靜電紡絲 組織工程支架 藥物控制釋放【英文關鍵詞】MWCNTs PLA PCL electrospinning tissue enginee

18、ring scaffold drug controlled release【目錄】可降解高分子/碳納米管復合電紡纖維的制備及其性能研究摘要7-9Abstract9-10第1章 緒論15-261.1 前言151.2 靜電紡絲體系15-171.2.1 靜電紡絲體系的歷史15-161.2.2 靜電紡絲原理及影響因素16-171.3 電紡纖維的材料及結(jié)構17-221.3.1 電紡纖維的材料17-191.3.2 電紡纖維的結(jié)構19-221.4 電紡纖維與組織工程支架22-231.5 電紡纖維與藥物控制釋放231.6 電紡纖維的其他應用23-241.7 本文研究目的、主要內(nèi)容與創(chuàng)新點24-261.7.1

19、本文研究目的24-251.7.2 本文研究主要內(nèi)容251.7.3 本文研究主要創(chuàng)新點25-26第2章 導電PLA/MWCNTs復合纖維的制備與表征26-382.1 前言262.2 實驗材料及設備26-272.2.1 實驗材料26-272.2.2 實驗設備272.3 導電PLA/MWCNTs復合纖維膜制備27-282.3.1 MWCNTs酸化與紡絲液27-282.3.2 靜電紡絲282.4 導電PLA/MWCNTs復合纖維膜表征28-292.4.1 SEM282.4.2 TEM282.4.3 拉伸力學測試28-292.4.4 表面電阻率測試292.4.5 體外降解表征292.5 數(shù)據(jù)統(tǒng)計學處理2

20、9-302.6 結(jié)果與分析30-372.6.1 表面形貌分析30-322.6.2 內(nèi)部結(jié)構分析32-332.6.3 力學特征分析33-342.6.4 表面電阻率分析34-352.6.5 體外降解分析35-372.7 本章小結(jié)37-38第3章 微電流刺激對導電PLA/MWCNTs纖維上成骨細胞生長影響38-473.1 前言383.2 實驗材料及設備38-393.2.1 實驗材料383.2.2 實驗設備38-393.3 成骨細胞體外培養(yǎng)39-403.3.1 器材及細胞專用液體393.3.2 材料滅菌和預處理39-403.3.3 細胞接種與微電流刺激實驗403.4 成骨細胞體外表征40-413.4.1 Alamar blue40-413.4.2 光學顯微鏡413.4.3 熒光顯微鏡413.4.4 掃描電子顯微鏡(SEM)413.5 結(jié)果與分析41-463.5.1 細胞增殖結(jié)果分析41