The combined application of stem cells and three-dimensional bioprinting scaffolds for the repair of spinal cord injury

Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

中、美、澳STEM教师专业标准 及其实施效益:比较与启示

中、美、澳STEM教师专业标准,因国情不同而各有特点:美国制定了四大领域的教师专业标准,澳大利亚则是在多元主体参与下制定普适性STEM教师专业标准架构,而中国出台了专门的STEM教师能力等级标准,强调培养复合型的跨学科教师,尚处于摸索阶段。美、澳作为STEM教育的先发国家,其STEM教师专业标准的实施效益总体良好,值得借鉴。我国需要博采国际经验,加快STEM教师专业标准的完善,尽快培养出一支数量足够、素质优良的STEM师资队伍。

家社联动:美国社会机构参与家庭STEM教育——基于STEM未来希望基金会的个案研究

自20世纪60年代起,美国政府开始关注家庭参与教育及相关政策的制定。但目前,美国不同家庭获取教育资源的差距依旧明显。在此背景下,一些社会机构做出了积极响应,多方参与家庭教育,实现教育的家社联动,美国STEM未来希望基金会便是其中之一。它支持并与众多机构合作,搭建多方参与的家庭STEM教育支持网络;赋能家庭参与STEM教育,包括提供丰富的STEM学习资源,为家长参与STEM教育提供指导,提高家庭STEM教育信心;为家庭引进多样化学习模块,多方互动提升家庭STEM教育能力,亲子共学提振家庭STEM学习氛围。这些都为家社联动开展STEM教育进行了积极探索,也为我国推进家校社合作提供了借鉴。

The advantages of multi-level omics research on stem cell-based therapies for ischemic stroke

Stem cell transplantation is a potential therapeutic strategy for ischemic stroke. However, despite many years of preclinical research, the application of stem cells is still limited to the clinical trial stage. Although stem cell therapy can be highly beneficial in promoting functional recovery, the precise mechanisms of action that are responsible for this effect have yet to be fully elucidated. Omics analysis provides us with a new perspective to investigate the physiological mechanisms and multiple functions of stem cells in ischemic stroke. Transcriptomic, proteomic, and metabolomic analyses have become important tools for discovering biomarkers and analyzing molecular changes under pathological conditions. Omics analysis could help us to identify new pathways mediated by stem cells for the treatment of ischemic stroke via stem cell therapy, thereby facilitating the translation of stem cell therapies into clinical use. In this review, we summarize the pathophysiology of ischemic stroke and discuss recent progress in the development of stem cell therapies for the treatment of ischemic stroke by applying multi-level omics. We also discuss changes in RNAs, proteins, and metabolites in the cerebral tissues and body fluids under stroke conditions and following stem cell treatment, and summarize the regulatory factors that play a key role in stem cell therapy. The exploration of stem cell therapy at the molecular level will facilitate the clinical application of stem cells and provide new treatment possibilities for the complete recovery of neurological function in patients with ischemic stroke.

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis

Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.

论STEM教育的本土化建构:内涵、价值及实践探索

STEM教育很早就被引入国内并成为我国科技与工程教育的重要教育理念和方式。但是作为一个“舶来品”,在我国面向未来的教育改革中,STEM教育必须进行本土化建构,才能更好地服务于我国科技创新人才培养的需求。内涵上,在我国中小学教育领域,“STEM教育”这个术语有着多种既相互关联又兼具不同指向的多元内涵:它既是一个研究领域、一种育人理念,又是一种课程形态、一种教学方式。价值上,我国STEM教育有着自己的教育实践土壤,必须通过本土化改造,突出育人方式变革,聚焦核心素养发展,培植现代化的教育生态,才能发挥其育人价值,真正成为我国学校教育的重要表征。虽然STEM教育自21世纪初被引入后日趋与我国教育改革实践相融合,但当前仍然面临教学方式固化、教育目标不清、教师能力不足等现实问题。在推动教育现代化发展和教育数字化战略行动的大背景下,唯有将STEM教育研究及其本土化改造与创新融入我国教育改革的内在构成之中,才能使其在我国发挥持久的生命力。

Metabolic and proteostatic differences in quiescent and active neural stem cells

Adult neural stem cells are neurogenesis progenitor cells that play an important role in neurogenesis.Therefore,neural regeneration may be a promising target for treatment of many neurological illnesses.The regenerative capacity of adult neural stem cells can be chara cterized by two states:quiescent and active.Quiescent adult neural stem cells are more stable and guarantee the quantity and quality of the adult neural stem cell pool.Active adult neural stem cells are chara cterized by rapid proliferation and differentiation into neurons which allow for integration into neural circuits.This review focuses on diffe rences between quiescent and active adult neural stem cells in nutrition metabolism and protein homeostasis.Furthermore,we discuss the physiological significance and underlying advantages of these diffe rences.Due to the limited number of adult neural stem cells studies,we refe rred to studies of embryonic adult neural stem cells or non-mammalian adult neural stem cells to evaluate specific mechanisms.

Emerging strategies for nerve repair and regeneration in ischemic stroke:neural stem cell therapy

Ischemic stroke is a major cause of mortality and disability worldwide,with limited treatment options available in clinical practice.The emergence of stem cell therapy has provided new hope to the field of stroke treatment via the restoration of brain neuron function.Exogenous neural stem cells are beneficial not only in cell replacement but also through the bystander effect.Neural stem cells regulate multiple physiological responses,including nerve repair,endogenous regeneration,immune function,and blood-brain barrier permeability,through the secretion of bioactive substances,including extracellular vesicles/exosomes.However,due to the complex microenvironment of ischemic cerebrovascular events and the low survival rate of neural stem cells following transplantation,limitations in the treatment effect remain unresolved.In this paper,we provide a detailed summary of the potential mechanisms of neural stem cell therapy for the treatment of ischemic stroke,review current neural stem cell therapeutic strategies and clinical trial results,and summarize the latest advancements in neural stem cell engineering to improve the survival rate of neural stem cells.We hope that this review could help provide insight into the therapeutic potential of neural stem cells and guide future scientific endeavors on neural stem cells.

Unlocking the versatile potential:Adipose-derived mesenchymal stem cells in ocular surface reconstruction and oculoplastics

This review comprehensively explores the versatile potential of mesenchymal stem cells(MSCs)with a specific focus on adipose-derived MSCs.Ophthalmic and oculoplastic surgery,encompassing diverse procedures for ocular and periocular enhancement,demands advanced solutions for tissue restoration,functional and aesthetic refinement,and aging.Investigating immunomodulatory,regenerative,and healing capacities of MSCs,this review underscores the potential use of adipose-derived MSCs as a cost-effective alternative from bench to bedside,addressing common unmet needs in the field of reconstructive and regenerative surgery.

High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

Deer antler stem cell niche: An interesting perspective

In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant interest for their potential to serve as natural scaffolds for cells.In this editorial,we provide commentary on the study by Wang et al,in a recently published issue of World J Stem Cells,which investigates the use of a decellularized xenogeneic extracellular matrix(ECM)derived from antler stem cells for repairing osteochondral defects in rat knee joints.Our focus lies specifically on the crucial role of biological scaffolds as a strategy for augmenting stem cell potential and regenerative capabilities,thanks to the establishment of a favorable microenvironment(niche).Stem cell differen-tiation heavily depends on exposure to intrinsic properties of the ECM,including its chemical and protein composition,as well as the mechanical forces it can generate.Collectively,these physicochemical cues contribute to a bio-instructive signaling environment that offers tissue-specific guidance for achieving effective repair and regeneration.The interest in mechanobiology,often conceptualized as a form of“structural memory”,is steadily gaining more validation and momen-tum,especially in light of findings such as these.

STEM视域下初中化学跨学科项目式学习实践研究——以“探寻火箭发射的奥秘”为例

基于STEM教育理念,以“探寻火箭发射的奥秘”为载体,引导学生进行跨学科项目式学习,以“探究火箭原理”“再探火箭燃料”“模拟火箭设计和制作”“成果展示与评价”四个子任务驱动,引导学生运用多学科知识设计和制作三种模拟火箭,有效提升学生的综合素养,实现跨学科协同育人。

融合STEM理念促进认识方式发展的主题式学习——以“乙烷脱氢制乙烯工艺发展研究”为例

以“乙烷脱氢制乙烯工艺发展研究”为主题,融合STEM理念,开展高中化学主题式学习。通过完成“乙烷热裂解制乙烯”“乙烷蒸气裂解制乙烯”“乙烷催化氧化脱氢制乙烯”等3个子任务,巩固化学反应与能量、化学反应速率、化学平衡等核心知识,发展化学学科能力和工程思维,形成化工生产三维认知模型。

澳大利亚STEM教育政策分析与启示

近年来,澳大利亚政府部门、学术组织推出促进STEM教育发展的系列政策。这些政策主要受澳大利亚政治体制、技术发展、社会性别因素的影响,政策行动者呈现出多元化特点。政策内容在制度领域、资源配置和教与学方面都有涉及,但以资源配置为主。在政策实施上以项目为主并注重继承与创新。借鉴澳大利亚的做法,我国STEM教育政策的制定应成为多部门的责任,在内容上可综合考虑制度领域、资源配置和教与学等方面,同时在实施中加强推广成熟做法。

将工程设计融入科学课堂的美国STEM课程--以StLE项目为例

近年来,基于工程设计的STEM整合教育逐渐成为国际科学教育改革与发展的大趋势。美国塔夫茨工程教育与推广中心建立了融入工程设计的科学研究项目,旨在通过将工程设计作为科学探究情境,实现科学与工程两种实践的有意义融合,探索STEM整合教育的有效方式。该项目的经验可为我国科学教育领域实施大科学教育提供两方面启示:“整合”需要系统思考和精心安排,研究界和实践界的沟通与合作是实现有效STEM整合教育的重要前提。

以色列STEM教育体系与特征探微

以色列的社会和经济发展与科技创新紧密相关,而其STEM教育体系是科技创新的支撑。以色列构建起由多元主体参与的STEM教育体系,包括政府部门统筹协调STEM教育发展、国防部在以色列STEM教育体系中扮演关键角色、中小学开设丰富多彩的STEM课程、高等教育机构为国家培养大批工程师和科学技术人才、企业和社会组织积极投身STEM教育,并以多样化的项目为载体助推STEM教育发展。以色列国家安全和经济产业发展需要决定其高度重视STEM教育,特殊国情为其STEM教育发展带来阻碍和助推两方面作用。为STEM教育营造有利的政策环境,多元主体协同参与对以色列STEM教育发展具有重要推动作用。

初中STEM课程中元认知能力培养的策略研究

STEM教育具有多学科整合、基于项目的协作学习和真实的问题解决情境等学科特征。然而,对于习惯于传统教学方法的学生来说,由于缺乏系统的认知能力和调节能力,容易导致STEM教育的教学效果不佳。元认知能力是建立在一定的元认知知识和情感的基础上,对自身认知活动进行调节和控制的高级能力。有研究表明,培养学生的元认知能力可以提高其在STEM教育中的学习能力、学习成绩和学习效果。然而,现有研究大多将某个策略应用到STEM教育中培养元认知能力,或者聚焦于元认知能力某一维度的培养,缺乏系统全面的元认知能力培养策略。因此,本研究根据元认知的结构和STEM教育的特点,提出了在STEM教育中全面系统地培养元认知能力的策略模型。而后,本研究通过准实验研究法验证以上策略的应用效果,在STEM课程中,实验组采用元认知培养策略,对照组采用传统方法进行教学。根据问卷数据的ANCOVA分析结果,得出以下结论:①元认知培养策略可以有效提高学生的元认知能力,包括元认知知识、元认知经验和元认知监控;②元认知培养策略可以促进学生的学习成绩和知识获取。

非正式学习环境中的STEM教育:美国博物馆学习服务案例研究

非正式学习环境为STEM教育提供了独特的机会和资源。作为非正式学习环境的典型代表,美国博物馆以知识共享为使命,通过策划丰富多样的教育活动,为各年龄段学生提供有针对性的STEM教育资源。研究聚焦于美国国家自然历史博物馆、旧金山探索博物馆和西雅图飞行博物馆在STEM教育领域的实践探索,归纳总结了美国博物馆在提供STEM学习资源,与学校STEM教育有效衔接,支持STEM教师专业发展,吸引家庭参与STEM教育,促进STEM教育公平等方面的经验,这些经验为我国发展非正式学习环境中的STEM教育,丰富STEM教育资源提供了良好的借鉴。

Three-dimensional crystal defect imaging by STEM depth sectioning

One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic resolution.Despite the success of aberration correction to deep sub-angstrom lateral resolution,spatial resolution in depth is still far from atomic resolution.In scanning transmission electron microscopy(STEM),this poor depth resolution is due to the limitation of the illumination angle.To overcome this physical limitation,it is essential to implement a next-generation aberration corrector in STEM that can significantly improve the depth resolution.This review discusses the capability of depth sectioning for three-dimensional imaging combined with large-angle illumination STEM.Furthermore,the statistical analysis approach remarkably improves the depth resolution,making it possible to achieve three-dimensional atomic resolution imaging at oxide surfaces.We will also discuss the future prospects of three-dimensional imaging at atomic resolution by STEM depth sectioning.