本文選題：聚碳酸亞丙酯 + 硫酸軟骨素酶ABC�。� 參考：《山東大學(xué)》2016年博士論文

【摘要】：研究背景：脊髓損傷(SCI)后的再生修復(fù)和功能重建一直是醫(yī)學(xué)界難以解決的問題。SCI在大多數(shù)國(guó)家的年發(fā)病率為20-40/100萬,在我國(guó)隨著經(jīng)濟(jì)的快速發(fā)展和交通運(yùn)輸效率的不斷提高而呈逐年上升趨勢(shì)。SCI后致殘率高,常常導(dǎo)致截癱等嚴(yán)重功能障礙,給患者及其家庭和社會(huì)帶來極其沉重的經(jīng)濟(jì)和社會(huì)負(fù)擔(dān)。一直以來,人們認(rèn)為中樞神經(jīng)系統(tǒng)(CNS)沒有再生能力,自從Richardson在《Nature》上發(fā)表論文,中樞神經(jīng)系統(tǒng)的再生能力才被人們逐漸認(rèn)知。近年來的實(shí)驗(yàn)結(jié)果表明,CNS的再生修復(fù)能力與細(xì)胞的類型、發(fā)育程度以及細(xì)胞與損傷位置的距離有關(guān),也與損傷后髓磷脂降解產(chǎn)生廢物,離子穩(wěn)態(tài)破壞,神經(jīng)遞質(zhì)釋放改變,遞質(zhì)受體功能障礙以及免疫炎性反應(yīng)有關(guān)。同時(shí),脊髓損傷往往會(huì)改變脊髓復(fù)雜的解剖結(jié)構(gòu),損害脊髓正常生理功能,所以損傷后恢復(fù)相應(yīng)的解剖結(jié)構(gòu)是功能恢復(fù)的必要前提。組織工程材料以其良好的力學(xué)性能及可塑性等優(yōu)點(diǎn)逐漸成為脊髓損傷后再生修復(fù)的一個(gè)可能方向。眾多研究表明,生物材料作為神經(jīng)干細(xì)胞的載體,既可以承載神經(jīng)營(yíng)養(yǎng)因子等細(xì)胞因子,又可以為損傷后的脊髓提供力學(xué)支撐,減少創(chuàng)傷區(qū)域的瘢痕形成。理想的生物材料應(yīng)具有良好的組織相容性,并且較少或完全不會(huì)引起其他不良反應(yīng)；具有優(yōu)秀的可塑造性及力學(xué)特性,以便于加工成為各種目標(biāo)形態(tài)；若想承載細(xì)胞,需有良好的界面使細(xì)胞便于粘附生長(zhǎng)；還應(yīng)有穩(wěn)定的或可調(diào)節(jié)的降解速率,以便適應(yīng)不同細(xì)胞、營(yíng)養(yǎng)因子發(fā)揮作用的時(shí)間；并且降解產(chǎn)物應(yīng)無毒副作用。常見的組織工程材料主要有：(1)天然可降解聚合物；(2)人工合成可降解聚合物；(3)人工合成非可降解聚合物；(4)復(fù)合材料。這些材料的應(yīng)用形式有支架、微球、電紡絲膜片、套管等。脊髓損傷后可應(yīng)用的藥物除了甲基強(qiáng)的松龍得到普遍的認(rèn)可和使用外,其他藥物尚未獲得廣泛認(rèn)可或者由于其他的限制因素?zé)o法實(shí)際應(yīng)用。目前有多種藥物在實(shí)驗(yàn)中顯示出了良好的效果,包括類固醇、阿片受體拮抗劑、抗脂質(zhì)過氧化反應(yīng)劑、神經(jīng)生長(zhǎng)因子、環(huán)磷酸腺苷(cAMP)和硫酸軟骨素酶ABC (ChABC)等。本文研究探討了可降解高分子生物材料聚碳酸亞丙酯(PPC)電紡絲和殼聚糖微球復(fù)合材料緩釋載體的制作方法,以及其在脊髓損傷修復(fù)中應(yīng)用的可行性,并研究了以該緩釋材料為載體局部緩釋不同藥物對(duì)脊髓損傷后軸突再生及功能重建的作用。制作生物可降解載藥高分子材料由于載藥緩釋材料良好的生物相容性,可降解性與持續(xù)釋放藥物等特點(diǎn),其在脊髓損傷中的應(yīng)用研究日漸增多。多數(shù)高分子可降解材料均在體內(nèi)降解為酸性物質(zhì),有可能為脊髓損傷部位帶來二次損傷,所以本研究選用了PPC,其可在體內(nèi)最終降解為二氧化碳和水,且擁有很好的生物相容性；殼聚糖具有優(yōu)異的生物相容性及可降解性,可以溶于水,為荷載蛋白類藥物并保持其活性提供可靠保障。各緩釋材料制作簡(jiǎn)述如下：制備單獨(dú)載db-cAMP的PPC電紡絲:稱量過的PPC原料和db-cAMP粉末放入30mm×50mm的小燒杯中,加入乙腈,攪拌6小時(shí),得到乳白色均勻溶液。溶液中db-cAMP與PPC的質(zhì)量比為1：9。利用靜電紡絲機(jī)進(jìn)行紡絲,使用接地的錫紙作為接收裝置,得到單獨(dú)載db-cAMP的電紡絲膜片。制備含ChABC的殼聚糖微球：稱量過的殼聚糖(CS)粉末放入30mm×50mm的小燒杯中,加入1%乙酸水溶液,攪拌6小時(shí),得到溶液A。準(zhǔn)確稱量聚乙烯毗咯烷酮(PVP)粉末,配制1%的PVP水溶液,微熱攪拌3小時(shí),放入4℃冰箱中,得到溶液B。取ChABC,加入上述PVP水溶液中,攪拌得到溶液C。將溶液C與溶液A混合,攪拌均勻后,得到溶液D。配置1%的多聚磷酸鈉水溶液,將溶液D緩慢滴加到多聚磷酸鈉水溶液中,滴完攪拌3小時(shí),得到乳狀渾濁液,將此渾濁液離心分離,離心力2000g,并用水洗兩次,沉淀凍干,獲得含有ChABC的CS微球。制備含有ChABC的電紡絲-微球和含有ChABC與db-cAMP的電紡絲-微球膜片：將得到的含有ChABC的CS微球定量加入二氯甲烷中,進(jìn)行超聲分散10分鐘,然后加入PPC原料和db-cAMP粉末,攪拌至固體全部溶解,得到乳白色溶液。利用靜電紡絲設(shè)備進(jìn)行紡絲,使用接地的平整錫箔紙作為接收裝置。噴頭至錫箔紙距離為15cm,紡絲電壓為10kV。收集到載藥纖維,得到電紡絲-微球載藥纖維復(fù)合膜；前法中不加db-cAMP粉末即得到只含ChABC的電紡絲-微球膜片。建立大鼠脊髓損傷模型本實(shí)驗(yàn)希望通過研究載藥緩釋材料在脊髓損傷中的應(yīng)用,了解高分子緩釋材料在脊髓損傷治療中的應(yīng)用可能性,并觀察損傷后軸突的再生情況,觀察再生軸突是否可以穿透膠質(zhì)瘢痕。有鑒于此,我們選擇了便于觀察軸突再生的損傷模型-大鼠脊髓半橫斷模型。造模過程簡(jiǎn)述如下：雌性Wister大鼠(200-230g)腹腔注射麻醉后固定于手術(shù)臺(tái)上,剃毛消毒后,充分暴露T7-T9脊椎棘突,咬除T8棘突,打開椎弓板,辨認(rèn)后正中動(dòng)脈,用11號(hào)刀垂直切入脊髓,半橫斷右側(cè)脊髓,確認(rèn)止血后,根據(jù)分組不同,分別植入相應(yīng)的載藥緩釋材料,逐層縫合。術(shù)后給予20萬U/天青霉素,2ml腹腔注射,每日一次,連續(xù)三天,術(shù)后對(duì)大鼠進(jìn)行腹部按摩,幫助其排尿,每日三次,直至其恢復(fù)自主排尿。單獨(dú)載db-cAMP電紡絲在大鼠脊髓半切模型中應(yīng)用的可行性及其效果的研究損傷模型造好之后,載藥材料植入橫斷損傷部位,縫合傷口,給予術(shù)后護(hù)理。在第1,2,3,4周各時(shí)間點(diǎn)采用BBB評(píng)分觀察評(píng)價(jià)大鼠后肢運(yùn)動(dòng)功能恢復(fù)情況,并取材。免疫熒光以及免疫組化染色觀察軸突再生、瘢痕形成、空洞形成等指標(biāo),用于評(píng)價(jià)各載藥材料對(duì)大鼠脊髓半切損傷后軸突再生以及功能恢復(fù)的作用。單獨(dú)載db-cAMP的生物可降解材料PPC電紡絲在大鼠脊髓半切損傷治療的應(yīng)用中,PPC和db-cAMP的混合溶液,做成電紡絲膜片。然后在體外模擬體內(nèi)環(huán)境檢測(cè)db-cAMP的釋放數(shù)據(jù),得到其釋放曲線。結(jié)果顯示,我們的電紡絲材料可以把db-cAMP的釋放時(shí)間延長(zhǎng)至8天,并且釋放速度穩(wěn)定。在SCI后第1,2,3,4周各時(shí)間點(diǎn)應(yīng)用BBB評(píng)分量表對(duì)大鼠運(yùn)動(dòng)功能進(jìn)行評(píng)價(jià),而后借助免疫熒光和免疫組化技術(shù)對(duì)損傷區(qū)域的軸突再生和瘢痕形成進(jìn)行研究。BBB結(jié)果顯示植入載藥電紡絲膜片組(實(shí)驗(yàn)組)大鼠功能恢復(fù)比對(duì)照組以及空白PPC組好,免疫組化和免疫熒光結(jié)果顯示實(shí)驗(yàn)組大鼠有更多的軸突長(zhǎng)入膠質(zhì)瘢痕,軸突再生更活躍,并且損傷部位瘢痕更薄。實(shí)驗(yàn)結(jié)果證明PPC載藥電紡絲膜片可以在大鼠脊髓損傷的治療中應(yīng)用,為脊髓損傷的治療提供了一個(gè)新的給藥選擇。聯(lián)合db-cAMP和ChABC材料與單獨(dú)用藥的效果比較研究我們?cè)赑PC電紡絲載藥材料的基礎(chǔ)上,引入了CS微球,把蛋白類藥物ChABC和靜電紡絲聯(lián)合起來,拓寬了蛋白類藥物在脊髓損傷治療中的應(yīng)用渠道,也增加了脊髓損傷的治療手段。再次驗(yàn)證了生物可降解高分子材料PPC電紡絲和殼聚糖微球載藥體系在脊髓損傷局部緩釋藥物的可行性。同時(shí)驗(yàn)證了小分子化學(xué)藥物db-cAMP和大分子蛋白類藥物ChABC在脊髓損傷局部緩釋的作用。實(shí)驗(yàn)證明,上述兩種單藥應(yīng)用都各自具有一定效果,但促進(jìn)軸突再生和功能恢復(fù)的作用并非十分顯著。考慮到脊髓損傷修復(fù)障礙由不同因素構(gòu)成,因此本實(shí)驗(yàn)進(jìn)行藥物聯(lián)合應(yīng)用,研究電紡絲-微球載藥系統(tǒng)同時(shí)荷載兩種藥物的可行性,驗(yàn)證其聯(lián)合應(yīng)用時(shí)在脊髓損傷的再生修復(fù)方面有無協(xié)同作用,在緩釋方面有無相互影響,并分別和單獨(dú)給藥相比較。檢測(cè)單獨(dú)載藥和聯(lián)合載藥材料中藥物的體外釋放曲線,結(jié)果顯示,與單獨(dú)載藥時(shí)相比較,聯(lián)合載藥時(shí)的藥物釋放曲線并無明顯差別。在損傷后1,2,3,4周各時(shí)間點(diǎn)用BBB評(píng)分法對(duì)大鼠運(yùn)動(dòng)功能進(jìn)行評(píng)分,并應(yīng)用免疫熒光和免疫組化觀察軸突再生和瘢痕形成。結(jié)果證實(shí),各實(shí)驗(yàn)組中軸突再生以及運(yùn)動(dòng)功能恢復(fù)均優(yōu)于對(duì)照組；載有ChABC的材料組,瘢痕壁不連續(xù),瘢痕疏松；單獨(dú)緩釋db-cAMP組和單獨(dú)ChABC組在功能恢復(fù)方面無顯著性差異；聯(lián)合用藥組的軸突再生以及運(yùn)動(dòng)功能恢復(fù)情況均好于單獨(dú)給藥組,組間BBB評(píng)分有顯著性差異(p≤0.05)本研究的主要結(jié)論：1.可降解PPC電紡絲以及殼聚糖微球擁有很好的生物組織相容性以及局部緩釋藥物能力,并且可以通過調(diào)節(jié)電紡絲的直徑、拉伸率、斷裂伸長(zhǎng)率和殼聚糖微球直徑等物理特性調(diào)整其降解速度以達(dá)到優(yōu)化藥物緩釋的目的。2.載有雙丁酰環(huán)磷酸腺苷(dibutyryl cyclic adenosine monophosphate, db-cAMP)的PPC電紡絲材料可以促進(jìn)大鼠SCI后軸突再生、運(yùn)動(dòng)功能恢復(fù)、減少膠質(zhì)瘢痕形成。3.載有硫酸軟骨素酶ABC (ChABC)的殼聚糖微球復(fù)合PPC電紡絲材料可以很好地緩釋ChABC,阻止空洞內(nèi)瘢痕壁形成,使軸突更容易通過損傷區(qū)域,促進(jìn)大鼠脊髓損傷后運(yùn)動(dòng)功能恢復(fù)。4.聯(lián)合載ChABC 和 db-cAMP的電紡絲-微球材料與緩釋單一藥物材料相比進(jìn)一步改善了SCI后大鼠的運(yùn)動(dòng)功能,使損傷區(qū)域殘存神經(jīng)纖維增多、膠質(zhì)瘢痕與空洞接觸面變得不規(guī)則,瘢痕減少。實(shí)驗(yàn)結(jié)果表明,PPC電紡絲和殼聚糖微球復(fù)合材料緩釋載體可穩(wěn)定地在脊髓損傷局部釋放治療藥物,并且其降解和緩釋藥物的速度可調(diào)控。該復(fù)合材料可為神經(jīng)系統(tǒng)局部緩釋藥物治療提供良好的載體,并能為CNS損傷修復(fù)、抗腫瘤治療及退行性疾病等領(lǐng)域的研究提供新的研究平臺(tái)。本實(shí)驗(yàn)結(jié)果顯示該復(fù)合材料緩釋載體具有良好的臨床應(yīng)用前景。
[Abstract]:Background: regenerative repair and functional reconstruction after spinal cord injury (SCI) have been a problem that is difficult to solve in the medical field. The annual incidence of.SCI in most countries is 20-40/100 million. In China, with the rapid development of economy and the increasing of transportation efficiency, the rate of disability is high after the year of.SCI, and it often leads to paraplegia and so on. Heavy dysfunction has brought extremely heavy economic and social burdens on patients and their families and society. It has been thought that the central nervous system (CNS) has no regenerative capacity. Since Richardson has published papers on , the regenerative ability of the central nervous system has been gradually recognized. In recent years, the experimental results show that the CNS is reproduced. The ability of biorepair is related to the type of cell, the degree of development and the distance between the cell and the location of the injury. It is also related to the degradation of myelin after injury, the destruction of the ions, the change of neurotransmitter release, the dysfunction of the transmitter receptor and the inflammatory response. Spinal cord normal physiological function, so recovery of the corresponding anatomical structure after injury is a necessary prerequisite for functional recovery. Tissue engineering materials, with its good mechanical properties and plasticity, have gradually become a possible direction for regenerative repair after spinal cord injury. Many studies have shown that biological materials can be used as the carrier of neural stem cells. Cell factors such as neurotrophic factors can also provide mechanical support for the injured spinal cord and reduce scar formation in the trauma area. Ideal biomaterials should have good histocompatibility, and less or completely do not cause other adverse reactions. Target morphology; in order to carry cells, a good interface is needed to make cells easy to adhere to growth; there should also be a stable or adjustable degradation rate to adapt to different cells, the time for the function of nutrient factors to play; and the degradation products should have no side effects. (1) natural biodegradable polymers; 2) synthetic biodegradable polymers; (3) artificial synthesis of non degradable polymers; (4) composite materials. The applications of these materials include scaffolds, microspheres, electrospun diaphragms, cannula and other drugs. Other drugs that can be applied after spinal cord injury are widely recognized and used, except for methyl strong pine. Other restrictive factors are not practical. A variety of drugs have shown good results in the experiment, including steroids, opioid receptor antagonists, anti lipid peroxidation, nerve growth factors, cAMP and ABC (ChABC). This paper studies the polymerization of biodegradable polymer biomaterials. The preparation of propyl carbonate (PPC) electrospun and chitosan microspheres composite materials and the feasibility of its application in the repair of spinal cord injury, and the effect of local sustained release drugs on spinal cord regeneration and functional reconstruction after spinal cord injury by using the sustained release material as carrier. Due to the good biocompatibility, biodegradability and sustained release drug, the drug release material has been applied in the spinal cord injury. Most of the biodegradable materials are degraded into acidic substances in the body and may cause two damage to the spinal cord injury. Therefore, PPC is selected in this study. The final degradation is carbon dioxide and water, and has good biocompatibility; chitosan has excellent biocompatibility and biodegradability, can dissolve in water, provide a reliable guarantee for the load protein drugs and maintain its activity. The preparation of each release material is as follows: the preparation of the single loaded db-cAMP PPC electrospun: the weighing PPC raw material In a small beaker of 30mm x 50mm with db-cAMP powder, adding acetonitrile and stirring for 6 hours, a homogeneous solution of milk white is obtained. The mass ratio of db-cAMP to PPC in the solution is spinning with 1:9. electrospun machine and the earthing tin paper is used as the receiving device to obtain a single db-cAMP containing electrospun film. The preparation of chitosan microspheres containing ChABC is called. The excess chitosan (CS) powder was put into the small beaker of 30mm x 50mm, adding 1% acetic acid water solution, stirring for 6 hours, getting the solution A. to accurately weigh the polyvinylpyrrolidone (PVP) powder, preparing 1% PVP water solution, stirring for 3 hours, and putting the solution B. to ChABC in the 4 centigrade refrigerator, and stirring to get the solution C. to dissolve in the solution. The mixture of liquid C and solution A is mixed, and after mixing, the solution of polyphosphate sodium polyphosphate solution D. configuration 1% is obtained, and the solution D is slowly dripped into the sodium polyphosphate solution. After stirring for 3 hours, the turbidity liquid is obtained. The turbidity liquid is centrifuged and centrifuged for 2000g, and the CS microspheres containing ChABC are obtained by washing two times and precipitating the freeze-drying. The preparation contains C. HABC electrospun microspheres and electrospun microsphere diaphragm containing ChABC and db-cAMP: the CS microspheres containing ChABC were added into dichloromethane for 10 minutes, then PPC raw materials and db-cAMP powders were added to the solid solution to get a milk white solution. The leveling tin foil is used as the receiving device. The distance of the spray head to the foil paper is 15cm, the spinning voltage is 10kV., and the electrospun microsphere carrier fiber composite membrane is obtained. The electrospun microsphere film containing only ChABC is obtained without db-cAMP powder in the former method. The application of sustained-release materials in spinal cord injury is used to understand the possibility of the application of macromolecule sustained-release materials in the treatment of spinal cord injury, and to observe the regeneration of the axons after injury and to observe whether the regeneration axons can penetrate glial scar. The model process is briefly described as follows: female Wister rat (200-230g) is fixed on the operating table after intraperitoneal injection of anesthesia. After shaving is sterilized, the spinal spinous process is fully exposed, T8 spinous process is bitten, the vertebral arch plate is opened, the posterior median artery is identified, the spinal cord is cut through the spinal cord with No. 11 knife and the right side of the spinal cord is semi transected. After the hemostasis is confirmed, the corresponding groups are implanted the corresponding according to the different grouping and implantation, respectively. The drug sustained-release material was sutured by layer by layer. 200 thousand U/ days postoperatively, penicillin and 2ml were injected intraperitoneally, once a day for three days. After the operation, the rats were massaged in the abdomen to help their urination, three times a day, until their spontaneous urination was restored. The feasibility and effect of the application of db-cAMP electrospun in the rat spinal cord semi cut model were studied. After the injury model was built, the drug loaded materials were implanted into the damaged parts of the transection, suturing the wound and giving the postoperative nursing. The recovery of the motor function of the hind limbs of the rats was evaluated by BBB score at the time point of the 1,2,3,4 week, and the materials were obtained. Immunofluorescence and immunohistochemical staining were used to observe the axon regeneration, scar formation, cavity formation and so on. Effect of drug loading materials on axonal regeneration and functional recovery after spinal cord hemimaxulic injury in rats. A single db-cAMP biodegradable material PPC electrospun was used in the treatment of spinal cord hemi cut injury in rats. A mixed solution of PPC and db-cAMP was made into an electrospun film. Then the release data of db-cAMP were detected in an in vitro model in vivo. The release curves show that our electrospun materials can prolong the release time of db-cAMP to 8 days, and the release rate is stable. The motor function of rats is evaluated by BBB scale at every time point of SCI after 1,2,3,4 week, and then the axon regeneration and scar formation in the damaged area by immunofluorescence and immunohistochemical technique. The results of the study of.BBB showed that the functional recovery of the electrospun film group (experimental group) was better than the control group and the blank PPC group. The results of immunohistochemistry and immunofluorescence showed that the experimental group had more axon growth into the glial scar, the axon regeneration was more active, and the scar was thinner. The experimental results proved that PPC was loaded with medicine. The spun film can be used in the treatment of spinal cord injury in rats, providing a new choice for the treatment of spinal cord injury. Comparison of the effects of db-cAMP and ChABC and the effect of the single drug use. On the basis of the PPC electrospun drug loading materials, we introduced CS microspheres, combined the egg white drugs ChABC and electrostatic spinning. The application channels of protein drugs in the treatment of spinal cord injury also increase the treatment of spinal cord injury. The feasibility of the biodegradable polymer PPC electrospun and chitosan microsphere drug delivery system in the local release of spinal cord injury is verified again. Small molecular chemical drugs, db-cAMP and macromolecule proteins, are verified. The effect of drug ChABC on local sustained release of spinal cord injury. Experiments have shown that these two single drug applications have their own effect, but the role of promoting axonal regeneration and functional recovery is not very significant. Considering that the repair of spinal cord injury is made up of different factors, the combined application of drugs in this experiment is to study electrospun microsphere loading. The feasibility of the simultaneous loading of two drugs to verify the synergistic effect of the combined application of the drug on the regeneration and repair of spinal cord injury. There was no significant difference in the drug release curve of the combined drug loading. The motor function of rats was scored by BBB scoring at 1,2,3,4 weeks after injury, and the axon regeneration and scar formation were observed by immunofluorescence and immunohistochemistry. The results showed that the regeneration of axon and the recovery of motor function in the experimental groups were all better than those of the control group. In the material group carrying ChABC, the scar wall was discontinuous and the scar was loose; there was no significant difference in functional recovery between the single release db-cAMP group and the single ChABC group. The axon regeneration and the motor function recovery of the combined drug group were better than the individual administration group, and the BBB score between the groups was significantly different (P < 0.05). The main conclusions of this study were: 1. Biodegradable PPC electrospun and chitosan microspheres have good biocompatibility and local sustained release drug ability, and can adjust the degradation rate by adjusting the diameter, tensile rate, elongation at break and diameter of chitosan microspheres to achieve the goal of.2. containing dibutylopp. The PPC electrospun material of dibutyryl cyclic adenosine monophosphate (db-cAMP) can promote the regeneration of axon, recovery of motor function after SCI, and reduce the formation of.3. containing chondroitinase ABC (ChABC) containing ABC (ChABC) and PPC electrospun material, which can prevent the formation of cicatricial walls in the cavity. It makes the axon easier to pass through the damaged area, promoting the motor function after the spinal cord injury in rats to restore the motor function of.4. combined with ChABC and db-cAMP, and further improve the motor function of the rats after SCI compared with the sustained release single drug material, and increase the residual nerve fiber in the damaged area, and the glial scar and the cavity contact surface becomes irregular. The results show that the PPC electrospun and Chitosan Microsphere Composite sustained-release carrier can release the drugs locally in the spinal cord injury, and the rate of its degradation and sustained release drugs can be regulated. The composite can provide a good carrier for the local sustained release drug treatment of the nervous system, and can repair the CNS damage and resist the damage. The study of tumor treatment and degenerative diseases provides a new research platform. The results of this experiment show that the composite sustained-release carrier has good prospects for clinical application.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：R651.2

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相關(guān)期刊論文 前1條

1 曹曉建 ,湯長(zhǎng)華 ,羅永湘;Effect of nerve growth factor on neuronal apoptosis after spinal cord injury in rats[J];Chinese Journal of Traumatology;2002年03期

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本文編號(hào)：2007782

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