角蛋白/海藻酸钠/聚丙烯酰胺水凝胶皮肤敷料的制备及创口修复研究

为了获得更为理想的皮肤创口修复敷料,在海藻酸钠(SA)和聚丙烯酰胺(PAM)水凝胶的基础上复合人发角蛋白(KTN),制得KTN/SA/PAM水凝胶皮肤敷料。用电子万能测试机、扫描电子显微镜等对其进行表征,结果显示,KTN/SA/PAM水凝胶皮肤敷料拉伸强度为42.41 kPa,弹性模量11.19 kPa,接近人体皮肤组织;与带血猪皮的黏附性可高达为5.1 kPa,2 h吸水率为144.3%,较好地满足了皮肤创口修复敷料的基本要求。进一步的大鼠皮肤创面修复实验显示,KTN/SA/PAM水凝胶皮肤敷料相对于市售创口贴和SA/PAM水凝胶具有更好的修复能力,创口皮肤组织切片组织学分析表明,经KTN/SA/PAM皮肤敷料处理后的创口处未成熟组织区域最小,胶原纤维排列最为整齐,14 d后,伤口愈合程度与正常皮肤几乎接近。预示KTN/SA/PAM皮肤敷料可能是一种较有前景的皮肤伤口修复敷料。     

壳聚糖基创伤敷料在伤口处理过程中的作用机制与应用

创伤处理过程中,出血、伤口感染及愈合缓慢都给伤口快速愈合带来不良影响,因此,开发具有抗菌、止血及愈合等功效的创伤敷料具有重要意义。壳聚糖是天然存在的多糖材料,壳聚糖基敷料在创伤愈合过程中表现出良好的生物相容性和生物可降解性,同时还具有黏附性、抗菌性、止血及伤口愈合等优良特性。本文中,笔者主要基于壳聚糖的创伤敷料在伤口愈合过程中的作用机理,分析壳聚糖在应用过程中的缺陷,同时结合目前创伤处理敷料的优势,提出对壳聚糖基创伤敷料的改进方法,从而扩大壳聚糖的应用。     

静电纺丝用作难愈合伤口敷料的研究进展

静电纺丝伤口敷料作为一种新型功能性敷料,具有较大的比表面积、可调控的孔隙率和良好的生物性能,既有益于细胞呼吸,又 可抑制细菌感染伤口,并能促进细胞增殖和加速创面愈合,是未来伤口敷料研发领域发展的新方向。介绍静电纺丝纳米纤维的原理、特点, 重点阐述各类聚合物、生物活性物质在静电纺丝伤口敷料制备中的应用进展。     

功能核酸DNA水凝胶的理化特性及应用进展

自DNA被开发为纳米级的自组装材料以来,凭借其可调节的多功能性、便利的可编程性、精确的分子识别能力、高通用性以及优越的生物相容性和生物降解性连接了生命科学和材料科学两大领域。受益于DNA纳米材料的结构特性,以功能核酸作为构建单元,经交联、自组装形成的功能核酸DNA水凝胶已成为新型材料领域的研究热点。基于此,对功能核酸DNA水凝胶所具有的主要理化特性进行了总结,并进一步综述了近年来功能核酸DNA水凝胶在药物递送与靶向治疗、生物传感、三维组织构建等生物医学、分子检测及环境工程等领域中的应用进展。最后,从生命科学和材料科学的角度总结了在设计与搭建功能核酸DNA水凝胶时应考虑的关键点和方向,以期助力DNA水凝胶在多学科领域的研究与应用。     

水凝胶医用敷料的研究进展

水凝胶由于具有含水量高、生物相容性好、可保持创面湿润,持续吸收创面渗出物、被及时降解,以及能通过结构设计和功能整合赋予水凝胶敷料多种优异性能而被视为一种理想的创面敷料.本文系统总结了功能化水凝胶敷料在创面形成到创面愈合的一系列复杂动态过程中可发挥的重要作用(止血、抗菌、抗炎和促组织再生等),并简单总结了部分先进功能敷料...     

丝素蛋白材料在皮肤创伤愈合中的研究进展

摘要：丝素蛋白是一种天然的高分子纤维蛋白,其结构的特殊性决定了较好的机械性能,再因其优良的生物相容性、降解产物无毒等特点,被广泛用于各种材料的研究。通过各种化学修饰和负载生长因子等,使丝素蛋白在体内外具有促进成纤维细胞增殖分化的作用,拥有诱导创面愈合的功能,同时其可部分降解,具有缓释性能好,柔韧性强,透气以及透水等较好的理化性质不但在皮肤组织工程学中的广泛的应用,并且在敷料领域的研究也显示了其治疗烧烫伤、创伤达到抑制疤痕、促进伤口快速愈合的治疗效果。总之,通过改良丝素蛋白材料的加工方法,通过化学修饰、其他物质复合等手段得到适合于皮肤修复的具有优良性能的各种材料,是具有很大潜力的极具临床价值的皮肤修复材料。本文旨在综述国内及国外学者的各种关于丝素蛋白生物材料治疗皮肤损伤的研究最新进展。     

细菌纤维素在医学方面的应用

细菌纤维素是由木葡糖酸醋杆菌等细菌合成的纤维素,在化学组成、分子结构上与植物纤维素相近,但具有传统的纤维素所无法比拟的优势,如高亲水性、持水性、生物适应性、可调控性以及高纯度、高透明度等,因而在医学上显示出了巨大的应用潜力。细菌纤维素可用作人造皮肤、外科敷料、人造血管、软骨组织、震动膜、缓释载体等,是最有前途的生物聚合材料之一。     

精卫水胶体伤口敷料在压疮护理中的应用与效果观察

目的探讨精卫水胶体伤口敷料在压疮护理中的应用效果。方法对59例Ⅰ~Ⅲ期压疮患者应用精卫水胶体伤口敷料治疗护理,观察压疮的治疗效果、治愈时间。结果治疗总有效率为94.9%,好转5.1%。其中Ⅰ期压疮治愈时间为(2±2)天,Ⅱ期压疮治愈时间为(14±3)天,Ⅲ期压疮治愈时间为(34±5)天。结论精卫水胶体伤口敷料在压疮护理中的治疗效果明显,能促进压疮的愈合,减轻了患者的痛苦。     

自组装短肽水凝胶支架三维培养环境对骨髓间充质干细胞生物学特性及心肌方向分化的影响

目的:探究短肽GFS-4自组装形成的水凝胶作为支架材料构建三维微环境对BMSCs生物学特性及向心肌细胞方向诱导分化过程的影响。方法:刚果红染色、红细胞膜裂解实验检测短肽GFS-4自组装效果及对细胞膜是否具有裂解作用;CCK8和AO/EB染色分别检测对BMSCs活性和凋亡的影响;Real-time PCR分析BMSCs诱导分化后MLC-2v、GATA-4基因表达情况。结果:GFS-4自组装后形成致密凝胶,自组装前后对细胞膜无损伤;三维培养环境细胞呈球形生长,细胞活力和凋亡速度均低于二维培养环境。三维培养组在诱导分化过程中的第5天和第7天MLC-2v、GATA-4基因表达均显著高于二维组(P0.05)。结论:短肽GFS-4自组装水凝胶构建的三维微环境延缓了BMSCs的增殖速度和凋亡速度,并促进向心肌方向诱导分化过程中MLC-2v、GATA-4基因的表达。     

自愈合水凝胶在组织工程中的研究进展

作为新型生物医用智能材料,自愈合水凝胶在解决柔性生物材料损伤修复问题及实现生物材料智能化和高效化中具有重要意义.本文综述了目前新型自愈合水凝胶的最新设计思路、性能以及在神经修复、骨缺损修复、心脏组织修复、肝脏止血等组织工程中的应用.这些研究进展为设计制备智能多功能水凝胶材料提供了创新思路,为增加柔性自愈合材料的多样性提供了新途径,为智能水凝胶材料在组织工程中的发展及生物医学中的应用奠定了良好的基础.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.