静电纺丝聚乳酸复合物纳米纤维材料与小鼠神经干细胞的生物相容性

背景:聚乳酸聚乙醇酸支架材料广泛应用于组织工程学领域,但其细胞黏附性较差、缺乏活性功能基团以及疏水性较强等缺点限制了其进一步的发展和应用。目的:观察小鼠神经干细胞与静电纺丝聚乳酸聚乙醇酸/聚乙二醇共聚物纳米纤维支架材料的体外相容性。方法:自孕15 d CD-1小鼠胚胎大脑皮质分离培养小鼠神经干细胞。静电纺丝法制备聚乳酸聚乙醇酸和聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架材料,扫描电镜观察材料结构;取第5代神经干细胞分别接种于聚乳酸聚乙醇酸和静电纺丝聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架材料上,进行体外培养。结果与结论:扫描电镜检测显示,两种支架材料呈现相互交联的多孔网状结构。聚乳酸聚乙醇酸组和静电纺丝聚乳酸聚乙醇酸/聚乙二醇组纤维直径和孔隙率差异无显著性意义(P0.05)。CCK-8检测显示,两种材料无明显细胞毒性。神经干细胞在支架材料中生长良好,两组吸光度值均随培养时间延长而增大,两组在培养1,3,5,7,9,11 d吸光度值差异均有显著性意义(P0.05)。两组材料培养3,6,9 h,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组的细胞黏附率明显高于聚乳酸聚乙醇酸组(P0.05)。Hoechst染色显示两组细胞核质均染,形态正常,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组细胞数量明显多于聚乳酸聚乙醇酸组(P0.05)。扫描电镜观察显示,与聚乳酸聚乙醇酸组相比,静电纺丝聚乳酸聚乙醇酸/聚乙二醇组神经干细胞在支架上的生长情况和基质分泌更好。结果说明,静电纺丝法制备的静电纺丝聚乳酸聚乙醇酸/聚乙二醇纳米纤维支架细胞生物相容性良好,安全无毒,具备合适的孔径和孔隙率,适宜神经干细胞生长,是一种适用于组织工程优质的支架载体。     

三维支架材料与脂肪干细胞的生物相容性

背景：构建组织工程化气管需要适合的三维支架。 目的：观察脂肪干细胞与聚乳酸-乙醇酸共聚物及聚三亚甲基碳酸酯共聚物支架的生物相容性。 方法：采用组织块法原代分离培养SD大鼠脂肪干细胞,行流式细胞术及多向分化能力鉴定。将脂肪干细胞分别种植于聚乳酸-乙醇酸共聚物和聚乳酸-乙醇酸-三亚甲基碳酸酯共聚物支架中,扫描电镜观察细胞与支架的生物相容性。 结果与结论：脂肪干细胞种植于两种支架材料后生长速度快,扫描电镜观察可见脂肪干细胞呈球型,并伸展形成伪足,贴附于支架材料,细胞间相互连接成团。说明聚乳酸-乙醇酸共聚物与聚三亚甲基碳酸酯共聚物支架均具有良好的生物相容性,无细胞毒性,其多孔的三维立体状结构适合脂肪干细胞黏附生长。     

低温快速成型亲水改性复合人工骨支架的性能测定

背景：低温快速成型技术具有支架成型可控性、保持材料生物学活性和易于实现支架材料的三维多孔立体结构等优势,被迅速用于骨组织工程支架的制备。 目的：采用低温快速成型制备聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石复合支架,并检测其性能。 方法：采用低温快速成型设备分别制备聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石与聚乳酸-乙醇酸/纳米羟基磷灰石复合支架,通过电镜观察支架超微结构,以介质(乙醇)浸泡法测定支架孔隙率,采用电子试验机检测支架力学性能;将两种支架材料分别与大鼠成骨细胞共培养,培养12 h采用沉淀法检测细胞黏附率,培养1,3,5,7,9,12 d采用CCK-8法检测细胞增殖。 结果与结论：两组支架孔径均在理想范围内并具有较高孔隙率,但聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石支架的孔径波动范围大,孔径均值较聚乳酸-乙醇酸/纳米羟基磷灰石支架小且部分有闭塞现象。聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石支架的细胞黏附率及表面细胞增殖活性高于聚乳酸-乙醇酸/纳米羟基磷灰石支架(P < 0.05),力学性能低于聚乳酸-乙醇酸/纳米羟基磷灰石支架(P < 0.05)。表明聚乙二醇改性聚乳酸-乙醇酸/纳米羟基磷灰石复合支架具有良好的细胞相容性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

定制型聚羟基乙酸/聚乳酸支架与犬骨髓基质细胞的体外复合培养

背景：聚羟基乙酸、聚乳酸均属于脂肪族聚酯,是一种具有一定机械强度和良好成型性能的生物可降解材料,在体内无毒,不聚积,且有良好的生物相容性。 目的：应用CAD、CAM、快速成型和激光扫描技术等组成的数字医学系统制作聚羟基乙酸/聚乳酸三维仿真的下颌支髁突形态模型,并检测其细胞生物相容性。 方法：通过CT扫描获得犬头颅骨影像信息,以CAD和CAM实现下颌骨髁突形态的三维重建影像,快速成型技术获得下颌骨髁突的树脂阳模。阴阳模转换获得相应石膏阴模,聚羟基乙酸/聚乳酸在阴模内成型。抽取犬髂骨骨髓获得骨髓基质细胞,与定制型聚羟基乙酸/聚乳酸支架在体外复合培养,检测支架材料的生物相容性。 结果与结论：定制型聚羟基乙酸/聚乳酸支架和影像原型比较,当测试点误差小于1.0 mm时,复合率大于95%。通过CAD、CAM、快速成型技术、预压成型技术和激光扫描技术等组成的数字医学系统可实现颅颌面下颌骨髁突形态结构聚羟基乙酸/聚乳酸生物材料的三维仿真。体外复合培养结果表明,定制型聚羟基乙酸/聚乳酸支架和骨髓基质细胞具有良好的生物相容性。     

聚乳酸-乙醇酸复合中药自然铜活性骨修复支架生物学评价

目的评价新型骨修复材料聚乳酸-乙醇酸复合中药自然铜活性骨修复支架的生物安全性。方法根据医疗器械生物学评价标准的要求,选取了溶血试验、细胞毒性试验、遗传毒性试验、刺激与致敏试验、全身毒性试验、植入试验等,全方位评价该新型材料的生物安全性。结果聚乳酸-乙醇酸复合中药自然铜活性骨修复支架的血液相容性良好,无全身毒性和细胞毒性,未发现短期遗传毒性,无皮肤刺激和致敏作用,材料植入骨后周围组织反应正常,骨修复情况良好。结论聚乳酸-乙醇酸复合中药自然铜活性骨修复支架是一种生物相容性好的骨修复材料,可安全应用于临床。     

可注射藻酸盐支架与人骨髓基质干细胞的体外复合培养*☆

背景：目前可注射组织工程骨的研究主要限于动物实验,若人骨髓基质干细胞与藻酸盐生物相容性良好,可注射组织工程骨将是极具前途的临床治疗手段。 目的：体外观察人骨髓基质干细胞与可注射支架藻酸钙凝胶的生物相容性。 方法：实验组将第2代人骨髓基质干细胞与藻酸钙凝胶复合培养,对照组单纯接种骨髓基质干细胞。倒置相差显微镜、扫描电镜观察各组细胞形态及增殖情况,MTT法半定量检测细胞增殖情况。 结果与结论：倒置显微镜下见实验组细胞生长良好,与对照组无明显差异。扫描电镜见骨髓基质干细胞在藻酸钙表面贴附、增殖良好,第6天时细胞已跨越微孔表面或向孔内生长。MTT法显示与对照组相比,实验组细胞增殖能力不受影响。结果初步表明藻酸钙与人骨髓基质干细胞体外生物相容性较好。      

Ⅰ型胶原修饰聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞的黏附和成骨分化

背景：组织工程骨成骨功能终末细胞需要骨髓间充质干细胞在体外加以诱导或在体内以基因转染等技术加以诱导。 目的：研究Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞黏附和成骨分化的能力。 方法：制备聚乳酸聚乙醇酸微球支架,分离纯化雌性SD大鼠骨髓间充质干细胞。将培养至第3代骨髓间充质干细胞与未经处理的聚乳酸聚乙醇酸微球及Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球共同培养14 d,观察细胞在不同支架表面的黏附生长。 结果：扫描电镜及FDA-PI染色发现,骨髓间充质干细胞可在聚乳酸聚乙醇酸微球支架上生长,而与未修饰的聚乳酸聚乙醇酸微球相比骨髓间充质干细胞更容易在Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球上黏附增殖。Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球有利于骨髓间充质干细胞的黏附、增殖,并且有一定诱导干细胞成骨分化的能力。     

天然及合成尿道重建支架材料的生物相容性及力学性能

背景：目前应用何种尿道组织工程修复重建支架材料更为合适的争论仍不断出现,其生物相容性及力学特性的评估也鲜见报道。 目的：评估应用于尿道修复重建多种生物材料的力学特性及生物相容性。 方法：脱细胞法制备小肠黏膜下层组织、膀胱脱细胞基质以及脱细胞尿道海绵体基质,同时编织法制备聚乙醇酸支架。单轴拉伸测试测定各类支架生物力学特性,光镜及扫描电镜测定支架表面孔径大小。线粒体代谢活性MTT法检测各种生物材料的细胞毒性。所有支架表面接种海绵体平滑肌细胞,体外培养14 d后进一步评估细胞渗透情况。 结果与结论：生物力学评估显示脱细胞尿道海绵体基质在弹性模量以及断裂强度方面的检测结果明显优于其余材料(P < 0.05)。MTT结果显示所有支架材料均支持正常的细胞生长代谢,并未发现存在明显的细胞毒性。聚乙醇酸在扫描电镜中显示出最大的孔径(> 200 μm),同时脱细胞尿道海绵体基质的尿道面(< 5 μm)和海绵体面(>10 μm)观察到明显不同的孔径大小。细胞接种14 d后聚乙醇酸材料的内部可见种子细胞的广泛分布,在膀胱脱细胞基质以及脱细胞尿道海绵体基质的尿道面未发现有明显的细胞渗透迹象,而小肠黏膜下层组织和脱细胞尿道海绵体基质的海绵体面观察到明显的细胞渗透生长表现。提示所有支架材料显示出良好的生物相容性,同时在力学特性方面也与正常尿道组织相仿,但脱细胞尿道海绵体基质在力学和组织学的诸多参数上具有一定的优越性。     

静电纺丝制备聚乳酸乙醇酸共聚物-胶原皮肤组织工程支架的实验研究

制备具有良好生物相容性的组织工程皮肤支架。以聚乳酸乙醇酸共聚物和胶原为原料,利用静电纺丝的方法,制备组织工程皮肤支架,并观察支架的形貌、降解等物理性能,利用CCK-8、伊红染色等方法观察支架的生物相容性。支架具有良好的纤维形貌,直径均匀。支架在磷酸盐缓冲液中降解8周,质量损失为35%,表明支架具有良好的生物可降解性。人成纤维细胞种植在支架上后,生长情况良好。种植3 d后,细胞存活率为75%;种植14 d后,细胞存活率为90%,表明细胞支架没有明显的细胞毒性,具有良好的生物相容性。用静电纺丝制备的聚乳酸乙醇酸共聚物-胶原支架是一种良好的皮肤组织工程支架,可以构建具有生物学功能的组织工程皮肤。     

聚羟基丁酸/戊酸酯共聚物膜与人骨髓间充质干细胞的体外生物相容性

背景：聚羟基丁酸/戊酸酯共聚物是近年来受到重视的聚羟基脂肪酸族组织工程支架材料,具有免疫排斥反应低、生物相容性好和降解产物无毒副作用的优点。 目的：观察聚羟基丁酸/戊酸酯共聚物膜材料与人骨髓间充质干细胞的体外生物相容性。 方法：将第3代人骨髓间充质干细胞种植于聚羟基丁酸/戊酸酯共聚物膜上作为实验组,培养板单纯培养细胞作为对照组,计算1,2,4 h两组贴壁细胞的数量,得出细胞贴壁率。MTT比色法观察2,4,6,8 d两组细胞的增殖情况。采用Hoechst33258荧光法,检测3,6,9,12 d两组细胞内的DNA含量。将人骨髓间充质干细胞接种聚羟基丁酸/戊酸酯共聚物膜材料上5 d后,电镜扫描观察细胞在材料上的生长情况。 结果与结论：共培养1 h时,实验组的细胞贴壁率低于对照组;其他时间段两组之间细胞贴壁率差异无显著意义。两组各时点间的细胞增殖差异无显著意义。两组各时间点细胞内DNA含量差异无显著意义。扫描电镜观察人骨髓间充质干细胞在聚羟基丁酸/戊酸酯共聚物膜上生长良好,形态呈梭形,细胞间连接紧密,分泌较多细胞基质。证明聚羟基丁酸/戊酸酯共聚物膜材料与人骨髓间充质干细胞有良好的生物相容性。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

改性纳米羟基磷灰石/PLGA材料同骨髓基质干细胞复合后相关生物学评价

背景：改性纳米羟基磷灰石/聚乙交酯-丙交酯复合材料(L-lactic acid oligomer/Poly(lactide-co-glycolde),PLGA/g-HA)因具有良好的稳定性及机械性能,目前备受关注。 目的：观察骨髓基质干细胞和改性PLGA/g-HA体外复合后的细胞活性及生物相容性。 方法：原代培养兔骨髓基质干细胞,传代培养至第3代,MTT比色法检测在不同浓度PLGA/g-HA浸提液(10%、30%、50%、80%)中骨髓基质干细胞的增殖情况,以及骨髓基质干细胞在PLGA/g-HA表面的黏附性及其细胞形态。 结果与结论：于培养后1,3 d测得在不同浓度浸提液下骨髓基质干细胞的A值,10%浸提液组和对照组相比无显著性差异,4种浓度浸提液的细胞毒性均为1级;扫描电镜观察到骨髓基质干细胞在PLGA/g-HA表面逐渐伸展,形成伪足,最终牢固锚定在材料表面。提示在PLGA/g-HA的浸提液中骨髓基质干细胞能够发生增殖,对细胞无毒性。骨髓基质干细胞可以黏附在PLGA/g-HA表面且形态正常,生长状态良好,证明PLGA/g-HA具有良好的相容性和黏附性,可作为修复骨缺损的复合组织工程骨。     

同种异体和异种来源骨髓间充质干细胞诱导成软骨修复喉软骨缺损

BACKGROUND: Because chondrocytes have no regeneration ability, to select suitable seed cells is the primary problem to repair cartilage defects. OBJECTIVE: To investigate the effect of allogeneic versus heterologous bone marrow mesenchymal stem cells (BMSCs) in repairing laryngeal cartilage defects after chondrogenic induction. METHODS: BMSCs from human and rabbits were isolated and cultured. Passage 3 cells were cultured in chondrogenic induction medium containing transforming transforming growth factor beta 1 and bone morphogenetic protein, and then were dropped onto a poly(lactic-co-glycolic acid) (PLGA) scaffold. Thirty New Zealand rabbits were randomly assigned into three groups: blank control group, human BMSCs group, rabbit BMSCs group. Animal models of laryngeal cartilage defects were made in the three groups. After modeling, saline-soaked PLGA scaffold, PLAG scaffold with human BMSCs or with rabbit BMSCs were implanted respectively into the rabbits in the normal blank, human BMSCs and rabbit BMSCs groups. The expression of type II collagen in the larynx and its surrounding tissues was detected by immunohistochemistry at 4 and 8 weeks postoperatively. RESULTS AND CONCLUSION: The animals in each group breathed normally with no presence of wheezing, and their eating and activity were good. Moreover, there was no purulency or infection in the three groups. At 4 and 8 weeks after operation, the positive rates of type II collagen in the two BMSCs groups were significantly higher than that in the blank control group (P < 0.05). There was no significant difference between two BMSCs groups (P > 0.05). These results show that both allogeneic and heterologous BMSCs have good therapeutic effects on the repair of laryngeal cartilage defects in rabbits.      

犬骨髓基质细胞和蚕丝丝素的体外生物相容性

目的 探讨体外培养的犬骨髓基质细胞(BMSCs)与蚕丝丝素材料的生物相容性,寻找BMSCs组织工程化神经的支架材料.方法 通过差速贴壁法体外分离、培养犬骨髓基质细胞,与丝素共培养后,通过光镜(经免疫荧光染色)、扫描电镜观察细胞在丝素上黏附和生长情况.利用丝素浸出液培养BMSCs后,通过透射电镜观察细胞内部超微结构,用四甲基偶氮唑盐(MTT)法检测丝素、羟基磷灰石、有机锡浸出液和普通IMDM完全培养基培养细胞12、24、48、72h和7d的细胞活力,每组重复12次.流式细胞术检测丝素浸出液培养BMSCs的细胞周期及表型,实验重复3次.结果 通过光镜、扫描电镜观察,发现BMSCs 紧紧黏附于丝素材料,并沿着丝素纤维延伸,黏附于丝素纤维的细胞呈圆形、椭圆形及呈梭形.与普通IMDM完全培养基培养的细胞相比,透射电镜下可见丝素浸出液培养后的BMSCs内部结构未见异常;MTT检测丝素和羟基磷灰石浸出液对骨髓基质细胞的活力无显著性影响(P＞0.05);流式细胞术检测丝素浸出液对骨髓基质细胞周期和表型无明显影响.结论 蚕丝丝素材料与犬BMSCs生物相容性好,且未见丝素对BMSCs有毒性作用,可作为BMSCs组织工程化神经的支架材料.     

丝素蛋白/壳聚糖复合支架材料的细胞相容性**

背景：大量研究表明丝素蛋白、壳聚糖为天然高分子材料,具有良好的细胞生物相容性。 目的：探讨丝素蛋白/壳聚糖复合支架材料与诱导的兔骨髓间充质干细胞的生物相容性。 方法：将兔骨髓间充质干细胞分离培养、诱导后,与丝素蛋白/壳聚糖三维支架材料体外共培养,以材料的细胞毒性、细胞增殖活力、材料细胞黏附率及扫描电镜等检测评价材料的细胞相容性。 结果与结论：经诱导后的骨髓间充质干细胞在支架材料上黏附、生长良好,保持正常的分裂增殖速度;随时间的增加,细胞黏附率增加,材料组较对照组黏附率强,差异有显著性意义(P < 0.05)。扫描电镜观察发现细胞接种48 h后细胞生长良好,与支架黏附紧密,增殖分裂活跃。说明丝素蛋白/壳聚糖三维支架材料具有良好的细胞相容性。     

The influence of osteoblast differentiation stage on bone formation in autogenously implanted cell-based poly(lactide-co-glycolide) and calcium phosphate constructs

We tested the hypothesis that the osteoblast differentiation status of bone marrow stem cells (BMSCs) combined with a three-dimensional (3D) structure modulates bone formation when autogenously implanted. Rat BMSCs were aspirated, expanded, and seeded into a 3D composite of poly(lactide-co-glycolide) and calcium phosphate (PLGA/CaP) to produce a hybrid biomaterial. Calvarial defects were implanted with (1) scaffold without cells (SC/NC), (2) scaffold and BMSCs (SC+BMSC), (3) scaffold and osteoblasts differentiated for 7 days (SC+OB7), and (4) for 14 days (SC+OB14). After 4 weeks, there was more bone formation in groups combining scaffold and cells, SC+BMSC and SC+OB7. A nonsignificant higher amount of bone formation was observed on SC+OB14 compared with SC/NC. Additionally, more blood vessels were counted within all hybrid biomaterials, without differences among them, than into SC/NC. These findings provide evidences that the cell differentiation status affects in vivo bone formation in autogenously implanted cell-based constructs. Undifferentiated BMSCs or osteoblasts in early stage of differentiation combined with PLGA/CaP scaffold favored bone formation compared with plain scaffold and that one associated with more mature osteoblasts.     

聚乳酸-聚乙醇酸可降解支架构建组织工程食管

目的:观察人食管上皮细胞在聚乳酸-聚乙醇酸(PLGA)支架上的贴附和生长情况,利用组织工程技术培养工程化人工食管.方法:制作PLGA三维细胞支架;分离培养成人食管上皮细胞,体外扩增后种植到PLGA支架上.在体外和裸鼠体内分别培养食管上皮细胞-支架复合物,分期终止培养,进行组织学染色、扫描电镜、细胞角蛋白免疫组织化学检测.结果:体外培养显示,人食管上皮细胞在支架材料上贴附生长良好,长期培养仍保持食管上皮细胞特性,裸鼠体内培养4周后可形成食管黏膜样组织.结论:PLGA支架适合食管上皮细胞黏附生长,可作为食管组织工程的细胞载体.     

The effect of timing of mechanical stimulation on proliferation and differentiation of goat bone marrow stem cells cultured on braided PLGA scaffolds

Bone marrow stromal cells (BMSCs) have been shown to proliferate and produce matrix when seeded onto braided poly(L-lactide/glycolide) acid (PLGA) scaffolds. Mechanical stimulation may be applied to stimulate tissue formation during ligament tissue engineering. This study describes for the first time the effect of constant load on BMSCs seeded onto a braided PLGA scaffold. The seeded scaffolds were subjected to four different loading regimes: Scaffolds were unloaded, loaded during seeding, immediately after seeding, or 2 days after seeding. During the first 5 days, changing the mechanical environment seemed to inhibit proliferation, because cells on scaffolds loaded immediately after seeding or after a 2-day delay, contained fewer cells than on unloaded scaffolds or scaffolds loaded during seeding (p<0.01 for scaffolds loaded after 2 days). During this period, differentiation increased with the period of load applied. After day 5, differences in cell content and collagen production leveled off. After day 11, cell number decreased, whereas collagen production continued to increase. Cell number and differentiation at day 23 were independent of the timing of the mechanical stimulation applied. In conclusion, static load applied to BMSCs cultured on PLGA scaffolds allows for proliferation and differentiation, with loading during seeding yielding the most rapid response. Future research should be aimed at elucidating the biomechanical and biochemical characteristics of tissue formed by BMSCs on PLGA under mechanical stimulation.     

Enhancement of osteogenesis by poly(lactide-co-glycolide) sponges loaded with surface-embedded hydroxyapatite particles and rhBMP-2

The bone mesenchymal stem cells (BMSCs) were seeded on [poly(lactide-co-glycolide) scaffolds with hydroxyapatite (HA) coating, and "s" stands for surface] (PLGA/HA-S), PLGA/HA-M (containing the same HA amount in the matrix as that of the PLGA/HA-S and "m" stands for matrix), and PLGA scaffolds, which were then cultured in a medium-containing Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2). In vitro culture of rat BMSCs found no different cell morphology in all the scaffolds, but the alkaline phosphatase activity and osteogenic gene expression of type I collagen (COL I) and osteocalcin (OCN) in the PLGA/HA-S scaffolds were always highest and were significantly improved in comparison with those in the PLGA scaffolds. In a rat calvarial defect model, new bone formation was enhanced in the PLGA/HA-S/ErhBMP-2 implants at 4 and 8 weeks after implantation too. Therefore, the PLGA/HA-S scaffold can better enhance the ErhBMP-2-induced osteogenic differentiation of BMSCs in vitro and osteogenesis in vivo.     

改性纳米羟基磷灰石/聚乳酸-聚羟乙酸复合骨髓基质干细胞修复兔桡骨缺损*

背景：前期试验证实骨髓基质干细胞能够在改性纳米羟基磷灰石/聚乳酸-聚羟乙酸材料表面黏附、增殖,该材料具有良好的生物安全性。 目的：观察骨髓基质干细胞与改性纳米羟基磷灰石/聚乳酸-聚羟乙酸材料复合修复兔桡骨缺损的效果。 方法：建立兔15 mm桡骨缺损模型,随机分为3组：空白对照组不进行任何处理,实验组植入改性纳米羟基磷灰石/聚乳酸-聚羟乙酸+骨髓基质干细胞组织工程化骨,对照组植入单纯改性纳米羟基磷灰石/聚乳酸-聚羟乙酸支架材料。 结果与结论：①X射线评价：术后1~12周,实验组骨缺损修复程度及速度明显优于空白对照组与对照组(P < 0.05)。②组织学检测：实验组术后4周即可观察到新生骨和纤维组织长入材料空隙,局部形成陷窝结构;8周时新生骨组织增多,部分可观察到成熟的骨小梁结构;12周时可见大量成熟骨细胞,骨小梁排列紧密,移植材料逐步被新生骨取代,与正常骨组织形态基本一致,且骨小梁出现时间早于空白对照组与对照组。说明骨髓基质干细胞复合改性纳米羟基磷灰石/聚乳酸-聚羟乙酸构建的组织工程化骨能够促进骨缺损处新骨的生成,较单纯支架材料具有明显优势。     

Growth and metabolism of human hepatocytes on biomodified collagen poly(lactic-co-glycolic acid) three-dimensional scaffold

Hepatic tissue engineering offers a promising approach toward alleviating the need for donor liver, yet many challenges must be overcome including choice of scaffold, cell source, and immunologic barriers. Poly(lactic-co-glycolic acid) (PLGA) polymers are innovative biodegradable materials that have been shown to be useful as scaffolds for seeding and culturing various types of cells. In this study, a porous sponge scaffold of modified PLGA polymer with collagen was investigated for its ability to improve the growth and metabolism of human hepatocytes. We evaluated the biocompatibility of collagen-modified PLGA (C-PLGA) scaffolds with hepatocytes isolated from human liver. Cell adhesion and function (cell density, culture lifespan, albumin synthesis, urea synthesis, and ammonia elimination and diazepam clearance) were assessed during different culture periods. The number of hepatocytes cultured in C-PLGA scaffolds was higher compared with those cultured in PLGA scaffolds without collagen modification, and the lifespan of hepatocytes cultured in C-PLGA scaffolds was longer than that of cells cultured in PLGA scaffolds. Albumin and urea synthesis and ammonia elimination from attached hepatocytes were greater in C-PLGA than in PLGA scaffolds, with the exception of diazepam clearance. Collagen-modified PLGA scaffold is a promising biomaterial for hepatic tissue engineering.