Are bone marrow regenerative cells ideal seed cells for the treatment of cerebral ischemia?

Bone marrow cells for the treatment of ischemic brain injury may depend on the secretion of a large number of neurotrophic factors. Bone marrow regenerative cells are capable of increasing the secretion of neurotrophic factors. In this study, after tail vein injection of 5-fluorouracil for 7 days, bone marrow cells and bone marrow regenerative cells were isolated from the tibias and femurs of rats, and then administered intravenously via the tail vein after focal cerebral ischemia. Immunohistological staining and reverse transcription-PCR detection showed that transplanted bone marrow cells and bone marrow regenerative cells could migrate and survive in the ischemic regions, such as the cortical and striatal infarction zone. These cells promote vascular endothelial cell growth factor mRNA expression in the ischemic marginal zone surrounding the ischemic penumbra of the cortical and striatal infarction zone, and have great advantages in promoting the recovery of neurological function, reducing infarct size and promoting angiogenesis. Bone marrow regenerative cells exhibited stronger neuroprotective effects than bone marrow cells. Our experimental findings indicate that bone marrow regenerative cells are preferable over bone marrow cells for cell therapy for neural regeneration after cerebral ischemia. Their neuroprotective effect is largely due to their ability to induce the secretion of factors that promote vascular regeneration, such as vascular endothelial growth factor.

Selected suitable seed cell, scaffold and growth factor could maximize the repair effect using tissue engineering method in spinal cord injury

Spinal cord injury usually leads to permanent disability, which could cause a huge financial problem to the patient. Up to now there is no effective method to treat this disease. The key of the treatment is to enable the damage zone axonal regeneration and luckily it could go through the damage zone; last a connection can be established with the target neurons. This study attempts to combine stem cell, material science and genetic modification technology together, by preparing two genes modified adipose-derived stem cells and inducing them into neuron direction; then by compositing them on the silk fibroin/chitosan scaffold and implanting them into the spinal cord injury model, seed cells can have features of neuron cells. At the same time, it could stably express the brain-derived neurotrophic factor and neurotrophin-3, both of which could produce synergistic effects, which have a positive effect on the recovery of spinal cord. The spinal cord scaffold bridges the broken end of the spinal cord and isolates with the surrounding environment, which could avoid a scar effect on the nerve regeneration and provide three-dimensional space for the seed cell growth, and at last we hope to provide a new treatment for spinal cord injury with the tissue engineering technique.

Current progress of skin tissue engineering:Seed cells, bioscaffolds, and construction strategies

The development of cell biology, molecular biology, and material science, has been propelling biomimic tissue-engineered skins to become more sophisticated in scientificity and more simplified in practicality. In order to improve the safety, durability, elasticity, biocompatibility, and clinical efficacy of tissue-engineered skin, several powerful seed cells have already found their application in wound repair, and a variety of bioactive scaffolds have been discovered to influence cell fate in epidermogenesis. These exuberant interests provide insights into advanced construction strategies for complex skin mimics. Based on these exciting developments, a complete full-thickness tissue-engineered skin is likely to be generated.

Selection of different endothelialization modes and different seed cells for tissue-engineered vascular graft

Tissue-engineered vascular grafts(TEVGs)have enormous potential for vascular replacement therapy.However,thrombosis and intimal hyperplasia are important problems associated with TEVGs especially small diameter TEVGs(<6 mm)after transplantation.Endothelialization of TEVGs is a key point to prevent thrombosis.Here,we discuss different types of endothelialization and different seed cells of tissue-engineered vascular grafts.Meanwhile,endothelial heterogeneity is also discussed.Based on it,we provide a new perspective for selecting suitable types of endothelialization and suitable seed cells to improve the long-term patency rate of tissue-engineered vascular grafts with different diameters and lengths.

Effect of ^(211)At treating pollen and stigma on generative cells and seed setting of rice

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CELLULAR SUBSTANCE EXUDATION AND SEED VIGOUR

In this paper, seeds of pinus koraiensis which has a characteristic of deep dormancy were selected as an experiment material, and the relation of cellular substance exudation to seed vigour is discussed based on the dormant state, the different measuring parts and the imbibed state of seeds before testing, as well as on the respiration of embryo and endosperm. The major measured results arc as follows: (1) After soaking for 24h, the dry embryo conductivity of sccdlot L is greater that than of sccdlot H: (2) The substance exudation of dry embryo of sccdlot H is less than that of sccdlot L; (3) After seeds imbibed, the substance exudation of dormant embryo of sccdlot H is more than that of sccdlot L; (4) After germination hastening treatment, the substance exudation of H embryos is greater than that of L embryos; (5) After artificially accelerated ageing treatment, the embryo conductivity of imbibed seeds has a positive correlation with seed vigour.

A prospective study:intraoperative ^(125)I radioactive seed implant therapy in advanced esophageal squamous cell carcinoma

Objective： To investigated the role of intraoperative iodine-125 （125I） brachytherapy as a treatment option for advanced thoracic esophageal squamous cell carcinoma （ESCC）. Methods： Using preoperative computed tomography （CT）-based staging criteria, between 2000 and 2008, 298 patients with ESCC （stage Ⅱ-Ⅲ） were enrolled in this prospective study. With informed consent, patients were randomized into two groups： intraoperative ^125^I seed implantation and surgery alone （control group）. Twenty to forty 125I seeds （0.5 mCi per seed）, with a total activity in 10-30 mCi, and a matched peripheral dose （MPD） of 60-70 Gy, were implanted under direct visualization. The surgical procedure used in this study was either a radical resection, which involved an esophagectomy through a left thoracotomy with two-field lymphadenectomy, or palliative resection. The postoperative complications were observed and recorded. The location and quality assessment of J25I seeds were assessed using CT scans or X-ray imaging. The short-term efficacy was evaluated according to WHO criteria. The 1, 3, 5 and 7-year survival rates were determined on follow-up. Results： There was no displacement or loss of 125I seeds. The local recurrence rates in the intraoperative 125I seed implantation group and control group were 14.9% and 38.7%, respectively （P 〈 0.05）. An objective response rate of 92% was observed in the seed implant group, which was significantly higher than 0% in the control group （P 〈 0.05）. There was no significant difference between the two groups when comparing of complications （P 〉 0.05）. The 1-year survival rate of the two groups were not significantly different （P 〉 0.05）. However, the 3, 5 and 7-year survival rates in the united 125I group （64%, 55.3% and 8%, respectively） were statistically different from those in the control group （52%, 29.1% and 1.4%,respectively）（P 〈 0.05）. Conclusion： Intraoperative 125I seed implantation is safe and effective for advanced ESCC. Seed implantation may reduce the local recurrence rate and improve survival in patients with ESCC. The MPD of 60-70 Gy, with single 125I seed activity of 0.5 mCi, is reasonable.

颌骨来源骨髓间充质干细胞成骨分化的特点、优势与应用

背景:颌面部骨组织缺损修复是目前研究的热点与难点,而种子细胞的选择是关键。颌骨来源骨髓间充质干细胞是存在于颌骨内的成体间充质干细胞,在颌面部组织再生方面的应用更具优势。目的:综述颌骨来源骨髓间充质干细胞的生物学特性和成骨分化优势以及药物、体内环境、微小RNA对其成骨分化影响的相关研究进展。方法:利用计算机在PubMed和中国知网进行文献检索。中文检索词为“口腔,骨组织工程,干细胞”,英文检索词为“oral,bone tissue engineering,stem cells”。共检索下载文章405篇,根据纳入与排除标准对文章进行筛选,最终纳入70篇文献进行综述。结果与结论:颌骨来源骨髓间充质干细胞是口腔骨组织工程的优良种子细胞,与长骨骨髓间充质干细胞相比,颌骨来源骨髓间充质干细胞具有更强的增殖能力和成骨分化能力。药物、体内环境、微小RNA均可以调控颌骨来源骨髓间充质干细胞的成骨分化,但目前对颌骨来源骨髓间充质干细胞的研究尚处于初始阶段,因此需要更多论证力较强的研究来证实其在颌面部骨组织再生领域的应用更具优势。

Antioxidant,anti-alpha-glucosidase and pancreatic beta-cell protective effects of methanolic extract of Ensete superbum Cheesm seeds

Objective: To investigate the antioxidant, anti-a-glucosidase and pancreatic b-cell protective potential of Ensete superbum(E. superbum) seeds.Methods: A variety of in vitro assays including radical scavenging, reducing power potential, phenolic content determination, a-glucosidase assay and pancreatic b-cell(1.4E7 cells) viability were employed for assessing the effect of methanolic extract of E. superbum seeds.Results: The radical scavenging and reducing power effects comparable with the standard rutin were obtained while the enzyme inhibitory activity of the extract was 68-fold better than the standard antidiabetic drug, acarbose. The seed extract of E. superbum was packed-full of polyphenols with mean percentage gallic acid equivalent value of(38.2 ± 1.8)(n = 3). The protection of pancreatic cells from massive onslaught of hydrogen peroxide was far superior to that obtained for rutin.Conclusions: The reputed antidiabetic therapeutic uses of the seeds extract of E. superbum may be justified on the basis of inhibition of carbohydrate enzymes, antioxidant effects and pancreatic b-cell protection.

Effect of ^(125)I seeds and ^(103)Pd stents on proliferation of vascular smooth muscle cells

This study aims at the theoretical and practical evidence for prevention of restenosis in vitro.Vascular smooth muscle cell(VSMC)model was established using adherent cell culture methods.The proliferation of VSMC was investigated by the cell counting method and 3H-TDR implementation test.The results are as follows.(1) For ^125I-seeds,the inhibition rate was 29.3% at 74B1(P<0.05),35.2% at 148Bq(P<0.05)and 42.4% at 370Bq(P<0.05),For ^103Pd-implanted stents,the inhibition rate was 14.7% at 4.44MBq(P<0.05),24.0% at 5.92MBq(P<0.05) and 38.0%at 7.4MBq(p<0.05),There was no significant difference between the blank tests and non-radioactive tests.(2) 48 hours exposure from ^125I-seeds at 148Bq or ^103Pd-implanted stents at 7.4MBq did not result in VSMC's morphological alteration,but that from ^125I-seeds at 370Bq caused morphological changes,Both ^125I-seeds and ^103Pd0-implanted stents inhibit the VSMC DNA synthesis in vitro.The inhibition effects are significantly related to their exposure duration and doses.

Plant Seeds-Based Dye-Sensitized Solar Cells

In this work, we investigate the performance of dye-sensitized solar cells (DSSCs) based on natural dyes extracted from ten different plant seeds. The extracts were characterized by UV-VIS absorption spectra. The solar cells were assembled using a TiO2 mesoporous film on FTO-coated glass. The photovoltaic properties of the DSSCs were studied under an incident irradiation of 100 mW/cm2. The best performance was for the DSSC sensitized with Eruca sativa with a solar energy conversion efficiency of 0.725%. Moreover, the validity of these extracts was compared using two types of semiconductor layers (TiO2 and ZnO), and finally the photovoltaic properties of one of these dyes were studied using different types of electrolytes.

接种密度对牛颗粒细胞形态及相关基因表达的影响

牛卵巢颗粒细胞是雌激素(Estrogen,E_(2))合成的主要来源,具有E_(2)活性的牛颗粒细胞体外模型的建立是研究E_(2)合成与分泌过程中潜在调控机制的重要工具,该细胞模型的建立可为E_(2)合成分子调控机制及牛卵巢卵泡发育机制的研究提供理论与技术支持。细胞接种密度是颗粒细胞体外培养模型的关键因素,高密度可引起细胞生理及分子的显著变化。研究通过不同接种密度下的形态变化和基因表达筛选牛颗粒细胞体外培养最优接种密度,采用长期无血清法培养牛原代颗粒细胞,培养液中添加FSH及IGF-1以诱导E_(2)的合成。培养7 d后,采集6孔板中高(3.0×10^(6)个细胞/孔)、中(2.0×10^(6)个细胞/孔)、低(1.0×10^(6)个细胞/孔)3种不同接种密度的细胞图像进行观测,并利用qRT-PCR技术检测3种不同接种密度中相关基因的表达情况。结果表明,低密度(1.0×10^(6)个细胞/孔)接种细胞呈现成纤维细胞样外观,细胞无聚集倾向;中密度组(2.0×10^(6)个细胞/孔)可观察到少量聚集的细胞团;高密度(3.0×10^(6)个细胞/孔)培养条件下,大多数细胞聚集成细胞团。低密度组(1.0×10^(6)个细胞/孔)中,CYP19A1及FSHR高表达,RGS2及VNN2低表达;高密度组(3.0×10^(6)个细胞/孔)表达量则相反。综上所述,低密度组(1.0×10^(6)个细胞/孔)细胞可作为具有E_(2)活性的牛颗粒细胞体外模型。

血管化类器官的构建策略

背景:有效促进类器官内部血管发生是目前类器官培养中的焦点问题,作为一种新近发展的生物培养技术,血管化的类器官在研究活体组织的发育、疾病形成的机制、组织替代疗法以及药物筛选等方面,都有很大的研究和应用价值。目的:对近年来类器官血管化的方法或策略进行归纳总结,分析类器官血管化形成机制以及构建策略,以期为更加深入地研究类器官的发生机制和为临床转化提供可靠的思路。方法:检索PubMed及中国知网数据库收录的相关文献。英文检索词为“organoids,Vascularization,Vascular,Vascular development,vessel”,中文检索词为“血管发生,血管生成,类器官,干细胞,血管化,预血管化”,最终纳入77篇文献进行归纳总结。结果与结论:①类器官血管化形成机制涉及3个关键因素,即种子细胞、细胞因子与细胞外基质。种子细胞为血管化类器官提供了关键的细胞来源,细胞因子为类器官内部的血管发生起了重要的信号引导作用,细胞外基质为血管细胞提供了外在的生长环境,促进类器官血管化的发生。②血管化类器官的构建策略包括细胞自我重组、微血管碎片渗入、宿主体内移植以及微流控芯片等。体外诱导多能干细胞向血管内皮祖细胞分化能顺利与邻近组织整合并具有血管生成的潜力,故可利用多能干细胞的自我重组功能构建血管化类器官。微血管碎片保留了其细胞复杂性、天然结构和表型可塑性,更利于模拟天然微血管从而促进类器官的血管化。宿主体内移植是目前类器官实现完整血液灌流的最佳方法,而微流控芯片则为实现类器官体外血液供应提供了解决方案。③类器官的多种构建策略如多类干细胞共分化、信号分子的精准调控、微血管渗入和活体宿主移植等,一定程度上在类器官中引入血管成分,使得类器官在功能和成熟度上更接近相应组织。然而缺乏血流灌注仍然是一个难题,迄今为止,仅宿主体内移植才能在类器官中实现有效的血流灌注,因此类器官在血管化方面仍面临许多挑战。

尿道组织工程中常用的种子细胞

组织工程学是当前治疗尿道损伤的研究热点。基于种子细胞的组织工程修复促进了多种治疗方法的发展,组织工程修复时,将选择的合适的种子细胞与支架材料结合并移植到损伤部位,通过种子细胞的增殖和分化修复组织缺损。近年来,尿道组织工程的发展较明显,如来自阴茎组织、膀胱和口腔的自体细胞,以及来自骨髓、脂肪组织和尿液等的干细胞均在尿道修复和重建过程中发挥了巨大作用。未来,针对尿道组织工程中常用种子细胞的深入研究将进一步促进尿道修复和重建的发展。

骨组织工程中种子细胞的研究进展

骨缺损是临床常见的疾病,但其治疗困难。在体外将种子细胞进行成骨诱导培养是运用组织工程策略解决骨缺损修复问题的关键因素,其中种子细胞是不可或缺的。目前,常用的种子细胞包括骨髓间充质干细胞、胚胎干细胞、脂肪来源干细胞、脐带间充质干细胞等。近年来,对于种子细胞的研究涉及分离培养鉴定、成骨诱导、信号通路、基因修饰以及联合培养等方面,目的在于揭示成骨机制,提高成骨效率,最终使组织工程技术在临床上得到应用。但种子细胞的培养要求较高,其前沿培养技术主要包括细胞的基因修饰和细胞的共培养。因此,未来需继续寻找或制备容易获取、生物相容性好、成骨能力更强且分化更稳定的种子细胞,这对骨组织工程领域具有重要意义。

组织工程技术在阴道重建中的应用及进展

阴道缺损对患者造成的身心压力巨大,传统的阴道重建方法能在一定程度上恢复生理功能,但往往伴随着长治疗周期和多种并发症。随着组织工程技术的进步,其在阴道重建领域的应用展现出了解决女性生殖系统缺损的优势和潜能。本文分析了近年来组织工程在阴道重建领域的研究进展,探究种子细胞、生物材料、信号因子和动物模型的应用前景,以期为临床阴道修复提供启发和参考。

肝脏类器官在肝脏疾病模型与移植治疗中的应用潜力

背景:肝脏类器官对阐明肝脏疾病的确切病理机制及对肝脏疾病的治疗具有重要的意义。目的:总结目前国内外该领域的基础研究,回顾以往肝脏类器官的构建、疾病建模和移植治疗的重要研究进展,探讨肝脏类器官联合组织工程技术的应用前景。方法:检索PubMed数据库及中国知网数据库收录的相关文献,英文检索词为“liver,organoids,liver diseases”,中文检索词为“肝,类器官,肝脏疾病”,主要检索时限为2018年4月至2024年4月,通过人工阅读排除重复文献等,最终纳入94篇文献进行归纳分析。结果与结论:①肝脏类器官构建的种子细胞主要集中于成体细胞和多能干细胞,通过辅助各种细胞因子参与信号引导作用和细胞外基质提供3D微环境,促进类器官的产生,但是整体成熟度不高,有望通过结合组织工程技术改善这一问题;②体外疾病建模方面主要在简单疾病和单基因遗传病领域研究较多,类器官高度保留患者遗传特性,有望通过结合CRISPR-Cas9基因矫正和其他新兴技术模拟更复杂的肝脏疾病并阐明更深层次的病理机制;③体内移植治疗方面,肝脏类器官能够安全有效的植入,表现出惊人的肝功能替代潜力及组织再生能力,并且还可能通过与其他组织工程材料结合达到治疗目的。

Olfactory ensheathing cell transplantation for spinal cord injury An 18-year bibliometric analysis based on the Web of Science

OBJECTIVE： Olfactory ensheathing cell （OEC） transplantation is a promising new approach for the treatment of spinal cord injury （SCI）, and an increasing number of scientific publications are devoted to this treatment strategy. This bibliometric analysis was conducted to assess global research trends in OEC transplantation for SCI. DATA SOURCE： All of the data in this study originate from the Web of Science maintained by the Institute for Scientific Information, USA, and includes SCI-EXPANDED, SSCI, A＆HCI, CPCI-S, CPCI-SSH, BKCI-S, BKCI-SSH, CCR-EXPANDED and IC. The Institute for Scientific Information＇s Web of Science was searched using the keywords ＂olfactory ensheathing cells＂ or ＂OECs＂ or ＂olfactory ensheathing gila＂ or ＂OEG＂ or ＂olfactory ensheathing glial cells＂ or ＂OEGs＂ and ＂spinal cord injury＂ or ＂SCI＂ or ＂spinal injury＂ or ＂spinal transection＂ for literature published from January 1898 to May 2012. DATA SELECTION： Original articles, reviews, proceedings papers and meeting abstracts, book chapters and editorial materials on OEC transplantation for SCI were included. Simultaneously, unpublished literature and literature for which manual information retrieval was required were excluded. MAIN OUTCOME MEASURES： All selected literatures addressing OEC transplantation for SCI were evaluated in the following aspects： publication year, document type, language, author, institution, times cited, Web of Science category, core source title, countries/territories and funding agency.RESULTS： In the Web of Science published by the Institute for Scientific Information, the earliest literature record was in April, 1995. Four hundred and fourteen publications addressing OEC transplantation for SCI were added to the data library in the past 18 years, with an annually increasing trend. Of 415 records, 405 publications were in English. Two hundred and fifty-nine articles ranked first in the distribution of document type, followed by 141 reviews. Thirty articles and 20 reviews, cited more than 55 times by the date the publication data were downloaded by us, can be regarded as the most classical references. The journal Experimental Neurology published the most literature （32 records）, followed by Glia. The United States had the most literature, followed by China. In addition, Yale University was the most productive institution in the world, while The Second Military Medical University contributed the most in China. The journal Experimental Neurology published the most OEC transplantation literature in the United States, while Neural Regeneration Research published the most in China. CONCLUSION： This analysis provides insight into the current state and trends in OEC transplantation for SCI research. Furthermore, we anticipate that this analysis will help encourage international cooperation and teamwork on OEC transplantation for SCI to facilitate the development of more effective treatments for SCI.

食管组织工程:研究、应用与展望

食管作为人体消化系统的重要组成部分,其损伤与疾病严重影响着患者的健康与生活质量。近年来,组织工程技术在食管修复和重建中取得显著进展。本文旨在探讨食管组织工程在食管损伤修复和重建中的应用研究,以应对传统食管替代术带来的高并发症风险。本文综述了支架材料、种子细胞、生长因子等关键要素在组织工程食管构建中的一些最新研究进展,并总结了组织工程技术在内镜黏膜下剥离术后食管修复中的应用情况。最后,本文讨论了食管组织工程面临的挑战与未来研究方向,以期为食管组织工程的发展及转化提供参考。