聚乳酸/壳聚糖复合支架材料的生物相容性研究

为改善聚乳酸作为骨组织工程支架材料降解速率过快、亲水性差和降解产物呈酸性等缺点，本研究制备了一系列高孔隙率的聚乳酸／壳聚糖三维多孔复合支架材料，通过软骨细胞培养、动物皮下和肌肉植入试验对其进行了生物相容性研究。软骨细胞培养试验表明软骨细胞能在复合支架材料贴附增殖，材料无明显毒性；植入试验结果显示纯聚乳酸在体内2个月左右已经降解吸收，失去力学强度，复合材料三个月后仍能保持一定的力学强度和形状，而且组织切片也同时表明复合材料的炎症反应远远低于纯聚乳酸材料。     

壳聚糖液晶膜生物相容性的研究

壳聚糖因具有良好的生物相容性、生物可降解性、无口服毒性等而广泛应用于组织工程领域。近年来一些研究表明,液晶态普遍存在于生命体中。本研究从仿生角度出发,制备出壳聚糖液晶薄膜。采用偏光显微镜和动态接触角测定仪分别研究其织构和亲水性能,并通过体外细胞培养法研究了生物相容性。实验结果表明,壳聚糖液晶薄膜呈现典型的胆甾相液晶织构,与非液晶薄膜相比,它不仅具有更好的亲水性能,而且能更好地促进L929细胞黏附、生长、增殖及分化,表现出良好的生物相容性。本研究为开发新型生物材料和更好地模拟体内微环境提供了新的思路。     

壳聚糖膜的降解与生物相容性研究

用小鼠作实验动物，研究了壳聚膜的生物降解与生物相容性，结果表明，壳聚糖膜易于生物降解，在植入初期有轻度炎症反应，至１６周后炎症反应基本消失。作为一种新型天然可吸收性生物材料，壳聚糖具有很好的发展应用前景。     

羟丁基壳聚糖的生物相容性研究

目的研究新型温敏性生物材料羟丁基壳聚糖的生物安全性,初步探讨该材料植入体内有无毒副作用。方法将壳聚糖进行羟丁基化制备出温敏性水凝胶,选用小鼠成纤维细胞L929细胞,通过MTS法、倒置显微镜观察等方法进行体外细胞毒性试验。通过SD大鼠尾缘静脉浸提液注射,进行急性毒性试验,通过新西兰兔耳缘静脉浸提液注射及皮内浸提液注射,进行致热原反应试验及皮内刺激试验。结果羟丁基壳聚糖无细胞毒性,不引起试验动物体温升高,无皮肤刺激反应,急性毒性试验不引起试验动物死亡或者其它不适。结论羟丁基壳聚糖材料生物相容性好,是一种安全的生物材料,有望作为新型药物载体应用于临床。     

壳聚糖-羧甲基壳聚糖复合膜的研制及其生物相容性评价

壳聚糖膜降解较慢^[1]，为了加快其降解速度，研制了壳聚糖-羧甲基壳聚糖复合膜(以下简称复合膜)并进行了生物学评价。结果表明，该复合膜具有很好的生物相容性，可以满足体内植入膜的基本要求。     

壳聚糖-镁膜体外生物相容性的初步研究

目的： 研究壳聚糖镁膜的制备及其与PC12细胞的体外生物相容性,初步探讨壳聚糖-镁络合后形成的复合物作为组织工程材料的可行性。方法: 合成壳聚糖-镁膜,应用扫描电镜观察复合材料的表面形态,并用X射线能谱仪分析壳聚糖-镁复合膜中镁的含量;测定复合膜的膨胀率;在体外将复合膜与PC12细胞共培养,用MTT方法检测细胞活力。扫描电镜观察PC12细胞在材料上的形态学变化。结果: 单纯壳聚糖与壳聚糖-镁膜各组相比,表面较为光滑,而复合膜表面含有大量的细小孔隙;复合膜中的镁元素的的含量与投入的硫酸镁量呈一定的剂量依赖。形态学观察表明,PC12细胞在CM上生长良好,至7 d时,可见微绒毛丰富并有较长突起,部分细胞之间形成突触状结构;MTT检测结果表明,培养7 d时实验组细胞活力超过对照组。结论: 壳聚糖可以与镁络合形成复合物,但是两者之间的络合率不成正比关系;壳聚糖镁膜与PC12细胞有良好的体外相容性。     

生物玻璃/壳聚糖三维多孔支架的抗感染性能和生物相容性研究

目的 研发制备生物玻璃/壳聚糖三维多孔支架(BG/CS),对其生物相容性及抗感染性能进行研究,阐明其抗感染作用的关键因素。方法 通过模板法制备多孔生物玻璃(BG)支架,注入壳聚糖乙酸,合成生物玻璃/壳聚糖多孔支架,此后以BG作为对照组,通过场发射扫描电镜(FESEM)观察各组材料的表面形貌和孔结构;接种Balb/c小鼠胚胎成纤维细胞(Balb/c 3T3 cells)于不同材料表面培养,分析其对细胞黏附及增殖的影响;各组支架材料分别与标准菌株ATCC 35984(表皮葡萄球菌)和ATCC 25923(金黄色葡萄球菌)共培养,以复合染料染色,在激光共聚焦显微镜(CLSM)下观察各组支架材料表面活菌和死菌的荧光强度;采用结晶紫染色法,定量分析材料表面细菌生物膜形成情况;进行细菌涂板并计数菌落(CFUs/cm2),测算抑菌效率。结果 BG/CS支架材料表面被覆一层壳聚糖,支架呈多孔结构,孔径较均一(200～400 m);材料细胞共培养4 h,BG/CS和BG表面的黏附细胞数量比较差异无统计学意义;共培养1 d,两组材料表面细胞均可正常黏附和铺展;第1～7 d的增殖过程中,各组材料表面细胞的增殖趋势接近,组间细胞增殖率比较差异无统计学意义;经过8 h细菌与材料共培养,CLSM下观测BG支架表面存在大量的细菌黏附(绿色荧光),BG/CS表面则显示出代表死亡细菌的红色荧光;生物膜定量实验显示在2～5 h,5～8 h,与BG组相比,BG/CS支架则明显抑制了生物膜的形成(P0.01);共培养12 h,与BG组相比,BG/CS组胰酶大豆琼脂平板(TSA)培养板表面细菌的单克隆菌落数明显较少,表现出较高的抑菌效率(P0.01)。结论 生物玻璃/壳聚糖三维多孔支架(BG/CS)具有较好的体外生物相容性和抗感染性能,有望作为一种应用于骨关节感染预防及治疗的骨修复填充材料。     

壳聚糖的生物相容性*

背景：壳聚糖是惟一一种被广泛应用于生物医学工程领域的碱性、带有正电荷的天然多糖,其生物相容性是决定这些应用价值的关键。 目的：综述了壳聚糖的生物相容性,包括组织相容性、血液相容性和力学相容性。 方法：由第一作者检索1990/2011 PubMed数据库、中国知网数据库及万方数据库有关壳聚糖及其衍生物在生物医学上的应用和生物相容性等方面的文献。 结果与结论：壳聚糖作为可生物降解高分子材料具有良好的组织相容性及与人体组织相匹配所需要的力学相容性,被逐渐应用于人工皮肤、手术缝合线、眼科修复、人工骨骼、牙齿修复、肿瘤治疗等方面。但壳聚糖的促凝血作用使其血液相容性很差,目前很多研究关注于寻找解决这一问题的方法,改善其血液相容性,扩展其在生物医学工程上的应用领域,使其更加安全有效地与人体心血管系统直接接触。 关键词：壳聚糖;组织相容性;血液相容性;力学相容性;生物材料 doi:10.3969/j.issn.1673-8225.2012.12.034     

壳聚糖/纳米羟基磷灰石分层复合支架的生物相容性研究

制备壳聚糖/纳米羟基磷灰石(CS/nHA)分层复合支架,对其进行细胞毒性评价.分离培养大鼠软骨细胞接种于支架,相差显微镜和扫描电镜观察细胞的黏附及生长情况.动物皮下埋植试验观察其组织相容性.实验结果证实壳聚糖/纳米羟基磷灰石分层复合支架具有良好的生物相容性,有望成为较好的骨软骨组织工程支架.     

脐带间质干细胞与壳聚糖支架的生物相容性研究

探讨脐带间质干细胞与壳聚糖支架的生物相容性。分离培养脐带间质干细胞,将其种植到壳聚糖支架上,观察细胞在支架上的形态特征,并检测细胞黏附性和细胞增殖活性。脐带间质干细胞能够在壳聚糖支架上黏附生长,并保持良好的细胞形态,与对照组相比,其黏附率和细胞增殖活性均无显著性差异。脐带间质干细胞与壳聚糖支架之间具有良好的生物相容性,可应用于复合材料的制备。     

可注射壳聚糖/纳米羟基磷灰石/胶原复合材料的生物相容性实验研究

目的　评价可注射壳聚糖/纳米羟基磷灰石/胶原复合材料的组织相容性,以及探讨材料负载骨髓基质干细胞进行骨修复的可行性。 方法　壳聚糖/纳米羟基磷灰石/胶原材料与BrdU标记的rBMSc混合,注射入大鼠皮下,于皮下植入后24 h,14 d和28 d分别断颈处死大鼠,进行大体观察、HE、MASSON染色、免疫组化染色。 结果　壳聚糖/纳米羟基磷灰石/胶原材料在室温呈液态,经1 ml注射器26号针头注射入大鼠皮下后,材料在体内可以迅速原位成形成凝胶状态,并在原位保持形状,BrdU标记的rBMSc弥散于材料中,28 d的免疫组化结果显示细胞存活良好。 结论　壳聚糖/纳米羟基磷灰石/胶原复合材料具有良好的组织相容性,是一种良好的负载干细胞的骨组织工程支架。     

Influence of seeding density and dynamic deformational loading on the developing structure/function relationships of chondrocyte-seeded agarose hydrogels

Chondrocytes cultured in agarose hydrogels develop a functional extracellular matrix. Application of dynamic strain at physiologic levels to these constructs over time can increase their mechanical properties. In this study, the effect of seeding density (20 and 60×10⁶ cells/ml) on tissue elaboration was investigated. Higher seeding densities increased tissue properties in free-swelling culture, with constructs seeded at 20 and 60×10⁶ cells/ml reaching maximum values over the 63 day culture period of aggregate modulus H _A: 43±15 kPa, Youngs modulus E _Y: 39±3 kPa, and glycosaminglycan content [GAG]: 0.96%±0.13% wet weight; and H _A: 58±12 kPa, E _Y: 60±5 kPa, and [GAG]: 1.49% ± 0.26% wet weight, respectively. It was further observed that the application of daily dynamic deformational loading to constructs seeded at 20×10⁶ cells/ml enhanced biochemical content (150%) and mechanical properties (threefold) compared to free-swelling controls by day 28. However, at a concentration of 60×10⁶ cells/ml, no difference in mechanical properties was found in loaded samples versus their free-swelling controls. Multiple regression analysis showed that the mechanical properties of the tissue constructs depend more strongly on collagen content than GAG content; a finding that is more pronounced with the application of daily dynamic deformational loading. Our findings provide evidence for initial cell seeding density and nutrient accessibility as important parameters in modulating tissue development of engineered constructs, and their ability to respond to a defined mechanical stimulus. © 2002 Biomedical Engineering Society. PAC2002: 8717-d, 8719Rr     

生物降解性防术后粘连膜的实验研究

本文首次采用新型医用天然高分子材料壳聚糖作膜材料，制备了可降解吸收防术后粘连膜，并通过动物实验研究其生物降解性和生物相容性．初步研究结果表明，壳聚糖具有很好的成膜性。壳聚糖膜在小鼠体内可以缓慢降解，并具有较好的生物相容性，是一种很有发展前景的天然防术后粘连膜材料。     

人体硬组织替代材料表面对血浆蛋白的吸附研究

本文研究了四种人体硬组织替代材料对三种血浆蛋白的吸附情况，发现材料吸附蛋白的多少是由材料的性质的蛋白质的种类决定的，并有一定规律性。其中生物玻璃陶瓷的吸附最强。钛合金最弱，球蛋白最易被吸附。     

不同配比壳聚糖/聚磷酸钙复合支架应用于半月板的生物相容性研究

目的评价对比不同配比壳聚糖/聚磷酸钙复合支架的体外生物相容性,观察半月板纤维软骨细胞在不同配比支架材料上的生长情况,选出最佳配比CS/CPP生物材料用于半月板的治疗。方法利用ADA将CS与CPP混合液交联,制备不同配比的CS/CPP复合支架材料。采用扫描电镜检测半月板细胞在支架材料上的生长情况。采用MTT法检测不同配比CS/CPP支架材料浸提液的毒性,通过细胞接种的方法评价支架材料的生物相容性。结果扫描电镜下,CS/CPP复合支架材料均呈三维多孔结构;细胞在支架材料上粘性良好,分布均匀,生长良好,其中配比为3∶7CS/CPP复合支架材料上细胞粘性最好,黏附细胞数量最多。不同配比CS/CPP复合支架材料不同浓度浸提液的毒性均不高于1级,全部合格,配比为3∶7CS/CPP复合支架材料浸提液细胞相对增殖高、毒性小,细胞相容性最好,与其它配比相比,差异有统计学意义(0.05)。结论不同配比壳聚糖/聚磷酸钙均具有良好的细胞相容性,其中配比为3∶7CS/CPP复合支架材料生物相容性最好,有望成为组织工程半月板的支架载体。     

In vivo biocompatibility of porous silicon biomaterials for drug delivery to the heart

Myocardial infarction (MI), commonly known as a heart attack, is the irreversible necrosis of heart muscle secondary to prolonged ischemia, which is an increasing problem in terms of morbidity, mortality and healthcare costs worldwide. Along with the idea to develop nanocarriers that efficiently deliver therapeutic agents to target the heart, in this study, we aimed to test the in vivo biocompatibility of different sizes of thermally hydrocarbonized porous silicon (THCPSi) microparticles and thermally oxidized porous silicon (TOPSi) micro and nanoparticles in the heart tissue. Despite the absence or low cytotoxicity, both particle types showed good in vivo biocompatibility, with no influence on hematological parameters and no considerable changes in cardiac function before and after MI. The local injection of THCPSi microparticles into the myocardium led to significant higher activation of inflammatory cytokine and fibrosis promoting genes compared to TOPSi micro and nanoparticles; however, both particles showed no significant effect on myocardial fibrosis at one week post-injection. Our results suggest that THCPSi and TOPSi micro and nanoparticles could be applied for cardiac delivery of therapeutic agents in the future, and the PSi biomaterials might serve as a promising platform for the specific treatment of heart diseases.     

壳聚糖/二氧化硅/羟基磷灰石杂化材料的体内反应性研究

目的　分析壳聚糖/二氧化硅(CS-SiO2)及壳聚糖/二氧化硅/羟基磷灰石（CS-SiO2-HA）杂化材料的体内反应性。 方法　分别将CS-SiO2和CS-SiO2-HA杂化材料植入C57BL/6小鼠腓肠肌内,设置对照组（腓肠肌钝性分离后直接缝合）,分别于植入术后14、28、42、56 d摘取包含植入物的腓肠肌,冰冻切片,HE染色及免疫荧光观察材料诱发的局部炎症、肌纤维性坏死与再生。 结果　组织学观察可见,肌内植入初期（14 d）,CS-SiO2及CS-SiO2-HA杂化物均诱发炎症细胞渗出,以CS-SiO2-HA组的炎性渗出更为显著。28 d后渗出细胞数量开始下降;56 d时,CS-SiO2组的肌内炎症反应几乎消失,但CS-SiO2-HA仍可见少量渗出。免疫荧光的检测进一步证实,CS-SiO2-HA杂化物较CS-SiO2导致更为严重的肌纤维坏死,所触发的单核/巨噬细胞等炎性渗出范围更广、持续时间久。CS-SiO2及CS-SiO2-HA杂化物移植2月后,肌内炎症基本消失,肌纤维修复完成。 结论　CS-SiO22-HA和CS-SiO2杂化材料在体内均可诱发短期、局部的炎症反应,CS-SiO2的体内相容性优于CS-SiO2-HA杂化物。     

玻璃酸钠壳聚糖纳米粒对烧伤角膜新生血管生长的影响

BACKGROUND:Chitosan nanoparticles-encapsuled sodium hyaluronate is an effective drug for the burned cornea. OBJECTIVE:To verify the effect of sodium hyaluronate/chitosan nanoparticles on the neovascularization in burned cornea. METHODS:Thirty Sprague-Dawley rats were randomly divided into three groups, and the model of burned cornea caused by base was established in the rats of model and experimental groups, followed by respectively treated with 10 μL sodium hyaluronate/chitosan nanoparticle suspension and normal saline, once daily, for consecutive 4 weeks. Rats only given normal saline were used as controls. Four weeks later, the dynamic growth of newly formed blood vessels in the cornea was observed using silt lamp. The levels of tumor necrosis factor-α and interleukin-6 were detected by ELISA, histological changes of the cornea were observed by hematoxylin-eosin staining, and the mRNA expression levels of vascular endothelial growth factor and cyclooxygenase 2 were detected by real-time PCR. RESULTS AND CONCLUSION:Compared with the control group, the area of the newly formed blood vessel and the levels of tumor necrosis factor-α, vascular endothelial growth factor and cyclooxygenase 2 were significantly increased in the model group (P < 0.05, P < 0.01). In the experimental group, all above indicators were significantly lower than those in the model group (P < 0.05). There were a large number of inflammatory cells and neovascularization in the model group, but only few inflammatory cells in the experimental group. These results show that sodium hyaluronate/chitosan nanoparticles can inhibit the neovascularization in the burned cornea.     

The promotion of osteointegration under diabetic conditions using chitosan/hydroxyapatite composite coating on porous titanium surfaces

Composited Chitosan/Hydroxyapatite (CS/HA) material coated on titanium surface (cTi) is a promising approach to produce biomaterials with better osseointegration capacity, but its bio-performance under diabetic conditions and the mechanisms involved remain elusive. We propose that the alterations in the Wnt/β-catenin pathway may play a role in mediating the improvement effect of cTi on diabetes-induced impaired implant osteointegration. To confirm the hypothesis, primary rat osteoblasts incubated on Ti and cTi were subjected to normal serum (NS), diabetic serum (DS), DS + Wnt3a (a specific Wnt agonist) and DS + Dkk1 (a specific Wnt antagonist) treatment. In vivo study was performed on diabetic sheep implanted with Ti or cTi into the bone defect on crista iliaca. Results showed that diabetes depressed osteoblast function evidenced by impaired cell adhesion and morphology, decreased cell proliferation and ALP activity, and higher apoptotic rate on Ti. Importantly, both cTi and Wnt3a treatment ameliorated osteoblastic dysfunction and apoptosis under diabetic condition. Implantation with cTi significantly improved osteointegration evidenced by Micro-CT and histological examinations compared with Ti. Moreover, the aforementioned promotive effects afforded by cTi were abolished by blocking Wnt pathway with Dkk1. Our study explicitly demonstrates that CS/HA composite material improves diabetes-induced impaired osteointegration of Ti via the reactivation of Wnt/β-catenin pathway and provides a target point for biomaterial modification to attain better clinical performance in diabetic patients.