The effect of the fibre orientation of electrospun scaffolds on the matrix production of rabbit annulus fibrosus-derived stem cells

Annulus fibrosus （AF） tissue engineering has recently received increasing attention as a treatment for intervertebral disc 0VD） degeneration; however, such engineering remains challenging because of the remarkable complexity of AF tissue. In order to engineer a functional AF replacement, the fabrication of cell-scaffold constructs that mimic the cellular, biochemical and structural features of native AF tissue is critical. In this study, we fabricated aligned fibroua polyurethane scaffolds using an electrospinning technique and used them for culturing AF-derived-stem/progenitor cells （AFSCs）. Random fibrous scaffolds, also prepared via electrospinningy were used as a control. We compared the morphology, proliferation, gene expression and matrix production of AFSCs on aligned scaffolds and random scaffolds. There was no apparent difference in the attachment or proliferation of cells cultured on aligned scaffolds and random scaffolds. However, compared to cells on random scaffolds, the AFSCs on aligned scaffolds were more elongated and better aligned, and they exhibited higher gene expression and matrix production of coUagen-I and aggrecan. The gene expression and protein production of coUagen-II did not appear to differ between the two groups. Together, these findings indicate that aligned fibrous scaffolds may provide a favourable microenvironment for the differentiation of AFSCs into cells similar to outer AF cells, which predominantly produce collagen-I matrix.

Synthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/chitin nanocrystals composite scaffolds for tissue engineering

Poly（3-hydroxybutyrate-co-3-hydroxyvalerate）（PHBV）/chitin nanocrystals（CNC） composite scaffolds were synthesized by the salt leaching and thermally induced phase separation（TIPS） technique.The scaffolds have porous structures with macro-pores（100-300 μm in diameters） and micro-pores（10μm）.The surface characteristics of the scaffolds were characterized by X-ray photoelectron spectroscopy（XPS） and static water contact angle measurement,and the mechanical properties were investigated by a compression test.Human adipose-derived stem cells（hADSCs） were seeded onto the PHBV/CNC scaffolds and in vitro cell culture results showed that the composite scaffolds enhanced the hADSCs adhesion,which implies that the material may have potential application in tissue engineering.

Hydrophilicity Evaluation of Collagen Based Scaffold Optimized by Chitin Fibres for Bone Tissue Engineering

Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we evaluated hydrophilicity of a new nano-hydroxyapatite/collagen/PLLA (nHACP) scaffold optimized by chitin fibres for bone tissue engineering. The results show that with the CF content increase, hydrophilicity of nHACP/CF increases, which reflects from the side that the addition of the chitin fibres can improve the cytocompatibility of the nHACP. Moreover, crosslink does not take significant influences on the material hydrophilicity. The results suggest that nHACP/CF with the crosslink should be a kind of potential appropriate scaffold for tissue engineering.

Chitin nanocrystal-assisted 3D bioprinting of gelatin methacrylate scaffolds

In recent years,there has been an increasing focus on the application of hydrogels in tissue engineering.The integration of 3D bioprinting technology has expanded the potential applications of hydrogels.However,few commercially available hydrogels used for 3D biological printing exhibit both excellent biocompatibility and mechanical properties.Gelatin methacrylate(GelMA)has good biocompatibility and is widely used in 3D bioprinting.However,its low mechanical properties limit its use as a standalone bioink for 3D bioprinting.In this work,we designed a biomaterial ink composed of GelMA and chitin nanocrystal(ChiNC).We explored fundamental printing properties of composite bioinks,including rheological properties,porosity,equilibrium swelling rate,mechanical properties,biocompatibility,effects on the secretion of angiogenic factors and fidelity of 3D bioprinting.The results showed that adding 1%(w/v)ChiNC to 10%(w/v)GelMA improved the mechanical properties and printability of the GelMA hydrogels,promoted cell adhesion,proliferation and vascularization and enabled the printing of complex 3D scaffolds.This strategy of incorporating ChiNC to enhance the performance of GelMA biomaterials could potentially be applied to other biomaterials,thereby expanding the range of materials available for use.Furthermore,in combination with 3D bioprinting technology,this approach could be leveraged to bioprint scaffolds with complex structures,further broadening the potential applications in tissue engineering.

Chitin scaffold combined with autologous small nerve repairs sciatic nerve defects

Although autologous nerve transplantation is the gold standard for treating peripheral nerve defects,it has many clinical limitations.As an alternative,various tissue-engineered nerve grafts have been developed to substitute for autologous nerves.In this study,a novel nerve graft composed of chitin scaffolds and a small autologous nerve was used to repair sciatic nerve defects in rats.The novel nerve graft greatly facilitated regeneration of the sciatic nerve and myelin sheath,reduced atrophy of the target muscle,and effectively restored neurological function.When the epineurium of the small autogenous nerve was removed,the degree of nerve regeneration was similar to that which occurs after autogenous nerve transplantation.These findings suggest that our novel nerve graft might eventually be a new option for the construction of tissue-engineered nerve scaffolds.The study was approved by the Research Ethics Committee of Peking University People's Hospital(approval No.2019 PHE27)on October 18,2019.

纳米羟基磷灰石-氧化锌复合支架生物性能及对MC3T3-E1成骨细胞行为的影响

背景:有研究发现,在纳米羟基磷灰石中掺杂金属离子锌可改善纳米羟基磷灰石的力学性能。目的:探讨含不同质量分数氧化锌的纳米羟基磷灰石陶瓷支架的生物性能,以及对MC3T3-E1成骨细胞的生物学行为的影响。方法:应用甲壳素凝胶体系制备含有不同质量分数(0%,0.5%,1.5%,2.5%,3.5%)氧化锌的纳米羟基磷灰石陶瓷支架,表征支架的物理性能。将5组纳米羟基磷灰石-氧化锌复合支架分别与MC3T3-E1成骨细胞共培养,分别进行Calcein-AM/PI活死细胞染色、CCK-8细胞增殖实验、CellTiter-LumiTM发光实验、碱性磷酸酶活性检测、茜素红染色及钙离子定量分析。结果与结论:(1)扫描电镜下可见纳米羟基磷灰石-氧化锌复合支架表面具有三维贯通的孔隙,复合支架的孔径大小均匀,孔径范围在300-400μm,孔隙率均在70%以上;随着氧化锌质量分数的增加,复合支架的抗压强度逐渐升高。(2)Calcein-AM/PI活死细胞染色显示,5组支架均无明显的细胞毒性,其中2.5%组细胞存活率高于0%组(P<0.05)。CCK-8细胞增殖与CellTiter-LumiTM发光实验实验显示,各组细胞增殖及活性由强到弱的顺序为:2.5%组>1.5%组>0.5%组>0%组>3.5%组。各组细胞碱性磷酸酶活性由高到低的顺序为:2.5%组>1.5%组>3.5%组>0.5%组>0%组。茜素红染色与钙离子定量分析显示,各组细胞矿化结节形成能力由强到弱的顺序为:2.5%组>1.5%组>0.5%组>3.5%组>0%组。(3)结果表明,氧化锌的掺杂提高了纳米羟基磷灰石支架的力学性能,可促进成骨细胞的增殖与分化,其中掺杂质量分数2.5%氧化锌的复合支架促成骨细胞增殖和分化能力最佳。

甲壳素纤维的性能及应用

甲壳素是地球上存量极为丰富的一种自然资源,甲壳素纤维是近几年人们开发的一种新的纤维品种。其具有极好的生物特性,被广泛应用于食品、医学、纺织、化妆品、农业、化工、环保等领域。本文对它的制备方法和工艺路线,它的吸湿透气性、抗菌性、染色性、生物降解性等性能以及它的一些用途等方面进行了阐述。

甲壳素和壳聚糖作为天然生物高分子材料的研究进展

甲壳素是自然界中含量仅次于纤维素的天然高分子,壳聚糖是甲壳素脱乙酰化后带有阳离子的多糖。壳聚糖中的自由氨基以及它的高结晶性,使得它能溶于酸,而不溶于碱和绝大数的有机溶剂。同时壳聚糖具有无毒性、无刺激性、良好的生物相容性、生物可溶解性,以及高的电荷密度,因而被作为一种新型的天然生物材料得到广泛应用。文章介绍了甲壳素和壳聚糖的结构和性质,综述分析了甲壳素和壳聚糖在制备微球和作为支架材料中的应用,并总结了甲壳素和壳聚糖在这两个方面存在的问题和发展前景。

SC-CO_2纤维粘接法制备PLA/TCP/Collagen组织工程支架材料

在超临界CO_2(SC-CO_2)循环萃取条件下制备PLA/TCP/Collagen(PTC)多孔组织工程支架材料,研究了胶原含量对支架材料的总孔隙率、开孔率、孔洞形态和力学性能的影响,以及胶原纤维在支架材料中的分布.结果表明:用SC-CO_2反复循环萃取法制备的PTC支架材料开孔率可达到82.81%,比不加胶原的PLA/TCP支架高约25%;孔径为200-500μm,孔洞之间出现重要的'隧道'结构;胶原纤维在SC-CO_2反复循环萃取法处理后保持着网络形态,在支架中分布均匀;胶原纤维加入使支架材料的压缩模量和压缩强度明显下降.

染整加工对甲壳素纤维抗菌性能的影响

讨论了染整加工对甲壳素纤维抗菌效果和纤维强力的影响,以及含量不同的甲壳素纤维与棉、毛纤维混纺的抗菌效果。

多糖类生物降解医用纤维

本文介绍了几种多糖纤维(藻酸纤维、甲壳质纤维、脱乙酰甲壳质纤维及改性 Lyoell纤维)的生产、结构与性能及其在治疗伤口中的应用。这些多糖纤维具有良好的生物相容性、生物降解性和生物活性,且无毒,有利于伤口的愈合,因而是制作高性能伤口包扎用品的理想材料。

甲壳素壳聚糖成纤性研究

分析了甲壳素和壳聚糖成纤的可能性与技术方法 ,并通过一系列的实验发现制备纤维过程中存在的问题和形成的机理 ,提出了影响其成纤的关键因素 。

甲壳素纤维制造工艺初探

介绍了甲壳素基本性质。阐明了甲壳素纤维开发的意义 ,探讨了甲壳素纤维制造的可能性和基本方法。重点论述了在制造过程中凝固浴的选择及对纤维诸方面的影响 。

甲壳素纤维制备工艺研究进展

甲壳素是地球上存量极为丰富的一种自然资源,甲壳素纤维是近几年人们开发的一种新的纤维品种。本文论述了甲壳素的基本性能,介绍了甲壳素及壳聚糖纤维的制备方法及几个国内外甲壳素纤维品种,分析了甲壳素纤维的应用领域。

皮芯型甲壳素粘胶纤维的基本性能研究

研究皮芯型甲壳素粘胶纤维的基本性能。测试了其拉伸性、卷曲弹性、形态结构及摩擦性能,并与纯甲壳素纤维、普通粘胶纤维和Modal纤维进行了对比。结果表明:在常温干态下,皮芯型甲壳素粘胶纤维的断裂强度大于纯甲壳素纤维,小于普通粘胶纤维和Modal纤维;断裂伸长率大于纯甲壳素纤维、普通粘胶纤维和Modal纤维。湿态下皮芯型甲壳素粘胶纤维的力学性能变化较普通粘胶纤维的小,其卷曲弹性比普通粘胶纤维差;动摩擦因数和静摩擦因数均大于普通粘胶纤维。

婴儿脐带结扎保护带的研制

以棉、超吸水纤维和甲壳素纤维为原料,利用PHB良好的热塑性能,开发一种完全可降解的医用热粘合非织造布。主要探讨了热轧工艺中的热轧温度、轧辊转速、轧辊隔距等工艺参数对产品性能的影响。

甲壳质及其非织造布的应用

甲壳质在自然界资源十分丰富 ,其本身具有诸多的优点 ,是很优良的天然高分子材料。本文介绍了甲壳质的提取。

新型的绿色环保纤维

文章着重介绍了再生纤维素纤维、再生蛋白质纤维、聚乳酸纤维、甲壳素(壳聚糖)纤维、转基因纤维的生产、性能及应用,并讨论了绿色纤维产品开发的重要意义。

医用纺品及其新技术

对医用纺织品的类别、材料和性能要求作了简要说明。以几种新功能纤维为例对医用纺织品的新技术作了介绍。由此可预测医用纺织品的发展前景。

角蛋白生物材料在创伤愈合中的应用研究进展

伤口愈合是一种复杂、动态和多步骤的过程,其愈合速率受创伤类型、病理学条件、敷料类型等因素影响。理想的创伤敷料应具备加速伤口愈合、防止感染、恢复皮肤结构和性能以及良好的生物相容性和降解性等特点。因此伤口辅料的研究热点是天然源的生物材料及其衍生材料,如壳聚糖、明胶、胶原蛋白、丝素蛋白、角蛋白等。角蛋白是一种具有良好生物相容性、可降解性且原材料易得的蛋白质,其含有的肽链主体是具有细胞粘附位点的氨基酸链段,如亮氨酸-天冬氨酸-缬氨酸(LDV)、谷氨酸-天冬氨酸-丝氨酸(EDS)和精氨酸-甘氨酸-天冬氨酸(RGD),可模拟细胞外基质,促进成纤维细胞的粘附、增殖、转移等,此外,角蛋白还具有快速凝血和聚集红细胞的作用。然而,角蛋白存在脆性以及力学性能和加工性能差的缺点,通常添加合成或天然的高分子材料作为增塑剂、交联剂形成复合材料(如聚乙烯醇、聚乳酸、壳聚糖、明胶等)以改善这些缺陷。这些复合材料已应用于促进伤口的愈合。本文综述了角蛋白及其复合水凝胶、海绵状多孔支架和膜材料的制备以及在伤口愈合方面的研究成果,特别是将皮肤转化生长因子、抗菌药(如莫匹罗星)、抑菌生物材料(如天然植物中的酚酸)以及抗菌金属纳米物(如纳米银和氧化锌)等加载到角蛋白复合材料中,可得到为伤口愈合创造理想环境的多功能角蛋白伤口敷料,用于急性或慢性伤口的愈合,如在糖尿病足部溃疡等伤口愈合中,可增强抑菌效果和缩短伤口的炎症时间等。同时也讨论了角蛋白作为生物材料在医药领域的发展前景。