Nano Today最新文献_第2页

Biomechanically matched and multistage hybrid porous scaffolds for stem cell-based osteochondral regeneration 用于干细胞骨软骨再生的生物力学匹配多级混合多孔支架

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-11-04 DOI: 10.1016/j.nantod.2024.102539

Shao-Jie Wang , Rong-Hui Deng , Chang-Hui Song , Fu-Zhen Yuan , Peng-Qiang Li , Xiao-Yan Cao , Xing Wang , Lin Lin , Ji-Ying Zhang , Yu-Fang Zhu , Jia-Kuo Yu

Osteochondral tissue has limited self-repair ability owing to its ischemic microenvironment and mechanically challenging conditions. Cell-based tissue engineering, a promising strategy for osteochondral regeneration, is influenced by the osteochondral-inducing scaffolds, such as bioactive agents and bionic microstructures, and mechanical properties. The current platforms are unsatisfactory because they fail to match the mechanical strength of natural osteochondral tissue while retaining high porosity and bioactivity. Hence, we developed growth factor-free multistage porous hybrid scaffolds composed of poly(lactic-co-glycolic acid) (PLGA) backbones with milli-micrometer two-stage pores and bioactive poly(γ-ethyl-l-glutamate) (PELG) thermo-responsive hydrogel. Highly porous pure PLGA backbones with controllable pore structures and tunable mechanical strength were prepared using low-temperature deposition modeling 3D printing and salt-leaching method with sodium chloride (NaCl) as a porogen. The arginine-glycine-aspartic acid (RGD) peptide and the chondrogenic molecule kartogenin (KGN) were conjugated to the terminals of poly(ethylene glycol) and PELG to enhance cell proliferation and induce cartilage differentiation, respectively. Moreover, the multistage PLGA/^RGDPELG_KGN porous hybrid scaffolds provided conducive environments for the proliferation and chondrogenesis of peripheral blood-derived mesenchymal stem cells (PBMSCs) and successfully repaired critical-sized osteochondral defects in the rabbit femoral trochlea, indicating its clinical potential for osteochondral repair.

骨软骨组织由于其缺血微环境和具有机械挑战性的条件，自我修复能力有限。基于细胞的组织工程是一种很有前景的骨软骨再生策略，它受到骨软骨诱导支架（如生物活性剂和仿生微结构）和机械性能的影响。目前的平台不能令人满意，因为它们无法在保持高孔隙率和生物活性的同时，达到天然骨软骨组织的机械强度。因此，我们开发了不含生长因子的多级多孔混合支架，由具有毫微米级两级孔隙的聚乳酸-共聚乙醇酸（PLGA）骨架和生物活性聚γ-乙基-谷氨酸（PELG）热响应水凝胶组成。以氯化钠（NaCl）为成孔剂，采用低温沉积建模三维打印和盐浸法制备了具有可控孔隙结构和可调机械强度的高多孔纯聚乳酸乙二胺（PLGA）骨架。精氨酸-甘氨酸-天冬氨酸（RGD）肽和软骨生成分子卡托原蛋白（KGN）分别被连接到聚乙二醇和PELG的末端，以增强细胞增殖和诱导软骨分化。此外，多级PLGA/RGDPELGKGN多孔杂化支架为外周血间充质干细胞（PBMSCs）的增殖和软骨生成提供了有利的环境，并成功修复了家兔股骨蹄部临界大小的骨软骨缺损，显示了其在骨软骨修复方面的临床潜力。

{"title":"Biomechanically matched and multistage hybrid porous scaffolds for stem cell-based osteochondral regeneration","authors":"Shao-Jie Wang , Rong-Hui Deng , Chang-Hui Song , Fu-Zhen Yuan , Peng-Qiang Li , Xiao-Yan Cao , Xing Wang , Lin Lin , Ji-Ying Zhang , Yu-Fang Zhu , Jia-Kuo Yu","doi":"10.1016/j.nantod.2024.102539","DOIUrl":"10.1016/j.nantod.2024.102539","url":null,"abstract":"<div><div>Osteochondral tissue has limited self-repair ability owing to its ischemic microenvironment and mechanically challenging conditions. Cell-based tissue engineering, a promising strategy for osteochondral regeneration, is influenced by the osteochondral-inducing scaffolds, such as bioactive agents and bionic microstructures, and mechanical properties. The current platforms are unsatisfactory because they fail to match the mechanical strength of natural osteochondral tissue while retaining high porosity and bioactivity. Hence, we developed growth factor-free multistage porous hybrid scaffolds composed of poly(lactic-<em>co</em>-glycolic acid) (PLGA) backbones with milli-micrometer two-stage pores and bioactive poly(γ-ethyl-<span>l</span>-glutamate) (PELG) thermo-responsive hydrogel. Highly porous pure PLGA backbones with controllable pore structures and tunable mechanical strength were prepared using low-temperature deposition modeling 3D printing and salt-leaching method with sodium chloride (NaCl) as a porogen. The arginine-glycine-aspartic acid (RGD) peptide and the chondrogenic molecule kartogenin (KGN) were conjugated to the terminals of poly(ethylene glycol) and PELG to enhance cell proliferation and induce cartilage differentiation, respectively. Moreover, the multistage PLGA/<sup>RGD</sup>PELG<sub>KGN</sub> porous hybrid scaffolds provided conducive environments for the proliferation and chondrogenesis of peripheral blood-derived mesenchymal stem cells (PBMSCs) and successfully repaired critical-sized osteochondral defects in the rabbit femoral trochlea, indicating its clinical potential for osteochondral repair.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102539"},"PeriodicalIF":13.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced glomerular transfection by BMP7 gene nanocarriers inhibits CKD and promotes SOX9-dependent tubule regeneration 通过 BMP7 基因纳米载体增强肾小球转染可抑制 CKD 并促进 SOX9 依赖性肾小管再生

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-11-04 DOI: 10.1016/j.nantod.2024.102545

Yifan Tai , Zhen Liu , Yanrong Wang , Xinyan Zhang , Ruifang Li , Jiangyue Yu , Yao Chen , Lili Zhao , Jia Li , Xueyuan Bai , Deling Kong , Adam C. Midgley

Renal fibrosis and loss of kidney function are key characteristics of chronic kidney disease (CKD). To address the lack of effective treatments, multifunctional layer-by-layer (LbL) assembled polymeric gene-carrier nanoparticles (PCHS-NP) are prepared to realize preferential accumulation and retention within renal glomerular cells, thereby effectively leveraging cortically localized structures for the synthesis and paracrine secretion of the antifibrotic growth factor, bone morphogenetic protein-7 (BMP7). PCHS-NP had stable homogenous morphologies, kidney-targeting functionality, antioxidative effects, and high transfection efficiency. In unilateral ureteral obstruction (UUO)-induced renal fibrosis, a single systemic injection of PCHS-NP prevents tubular atrophy and interstitial fibrosis, and the resultant tissue microenvironment is more conducive to tubular regeneration driven by the upregulation of proliferative SOX9-expressing tubular cells. In longer-term folic acid (FA)-induced renal fibrosis, we show that early, late, and repeat systemic injections restore kidney health and function. This study indicates that PCHS-NP accomplish a promising therapeutic option for the treatment of CKD.

肾脏纤维化和肾功能丧失是慢性肾脏病（CKD）的主要特征。为了解决缺乏有效治疗方法的问题，研究人员制备了多功能逐层（LbL）组装聚合物基因载体纳米颗粒（PCHS-NP），以实现在肾小球细胞内的优先积聚和保留，从而有效利用皮质局部结构合成和旁分泌抗纤维化生长因子骨形态发生蛋白-7（BMP7）。PCHS-NP 具有稳定的均质形态、肾脏靶向功能、抗氧化作用和高转染效率。在单侧输尿管梗阻（UUO）诱导的肾脏纤维化中，单次全身注射PCHS-NP可防止肾小管萎缩和间质纤维化，由此产生的组织微环境更有利于表达SOX9的增殖性肾小管细胞上调所驱动的肾小管再生。在长期叶酸（FA）诱导的肾脏纤维化中，我们发现早期、晚期和重复全身注射叶酸都能恢复肾脏的健康和功能。这项研究表明，PCHS-NP是治疗慢性肾功能衰竭的一种很有前景的治疗方案。

{"title":"Enhanced glomerular transfection by BMP7 gene nanocarriers inhibits CKD and promotes SOX9-dependent tubule regeneration","authors":"Yifan Tai , Zhen Liu , Yanrong Wang , Xinyan Zhang , Ruifang Li , Jiangyue Yu , Yao Chen , Lili Zhao , Jia Li , Xueyuan Bai , Deling Kong , Adam C. Midgley","doi":"10.1016/j.nantod.2024.102545","DOIUrl":"10.1016/j.nantod.2024.102545","url":null,"abstract":"<div><div>Renal fibrosis and loss of kidney function are key characteristics of chronic kidney disease (CKD). To address the lack of effective treatments, multifunctional layer-by-layer (LbL) assembled polymeric gene-carrier nanoparticles (PCHS-NP) are prepared to realize preferential accumulation and retention within renal glomerular cells, thereby effectively leveraging cortically localized structures for the synthesis and paracrine secretion of the antifibrotic growth factor, bone morphogenetic protein-7 (BMP7). PCHS-NP had stable homogenous morphologies, kidney-targeting functionality, antioxidative effects, and high transfection efficiency. In unilateral ureteral obstruction (UUO)-induced renal fibrosis, a single systemic injection of PCHS-NP prevents tubular atrophy and interstitial fibrosis, and the resultant tissue microenvironment is more conducive to tubular regeneration driven by the upregulation of proliferative SOX9-expressing tubular cells. In longer-term folic acid (FA)-induced renal fibrosis, we show that early, late, and repeat systemic injections restore kidney health and function. This study indicates that PCHS-NP accomplish a promising therapeutic option for the treatment of CKD.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102545"},"PeriodicalIF":13.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamics of strong metal-support interactions: Investigating Pt and Pt-based alloys on CdS nanorods through experimental and simulated approaches 强金属-支撑相互作用的动力学：通过实验和模拟方法研究 CdS 纳米棒上的铂和铂基合金

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-11-02 DOI: 10.1016/j.nantod.2024.102543

Jiuyi Hu , Jiayu Xu , Ri Feng , Shaohui Zheng , Jiajia Li , Zhicheng Zhang , Wenjing Liu , Faisal Saleem

The catalytic performance of supported metal nanoparticles (NPs) is greatly affected by metal-support interaction (MSI). Understanding the mechanisms and dynamics of MSI in heterogeneous catalysis remains challenging. Traditionally, MSI studies have focused on metal oxide supports and rarely compared MSI between Pt and Pt-based alloys, despite the importance of Pt in catalysis. In this study, we introduce CdS nanorods as a novel support material and investigate the MSI behavior of both Pt and Pt-based alloy NPs using in situ TEM electron beam irradiation. Our findings show that Pt NPs have strong MSI with CdS and that encapsulation layers form over Pt NPs because Pt has the high surface energy. On the other hand, Pt-based alloys have weaker MSI. These experiments were validated by direct thermal annealing for four hours. Molecular dynamics simulations were used to explain the observed behavior, providing insights into how the surface energy differences between Pt and Pt-based alloys influence their interactions with CdS nanorods. These findings offer valuable insights into catalyst design, highlighting the potential for controlling MSI strength to optimize catalytic performance in heterogeneous systems.

金属-支撑物相互作用（MSI）对支撑金属纳米粒子（NPs）的催化性能有很大影响。了解异相催化中 MSI 的机理和动态仍具有挑战性。尽管铂在催化过程中具有重要作用，但传统的 MSI 研究主要集中在金属氧化物支撑上，很少对铂和铂基合金之间的 MSI 进行比较。在本研究中，我们引入了 CdS 纳米棒作为新型支撑材料，并利用原位 TEM 电子束辐照研究了铂和铂基合金 NPs 的 MSI 行为。我们的研究结果表明，铂氮氧化物与 CdS 具有很强的 MSI，并且由于铂具有很高的表面能，在铂氮氧化物上形成了封装层。另一方面，铂基合金的 MSI 较弱。这些实验通过直接热退火四小时进行了验证。分子动力学模拟用于解释观察到的行为，为了解铂和铂基合金之间的表面能差异如何影响它们与 CdS 纳米棒的相互作用提供了见解。这些发现为催化剂设计提供了宝贵的见解，突出了控制 MSI 强度以优化异质体系催化性能的潜力。

{"title":"Dynamics of strong metal-support interactions: Investigating Pt and Pt-based alloys on CdS nanorods through experimental and simulated approaches","authors":"Jiuyi Hu , Jiayu Xu , Ri Feng , Shaohui Zheng , Jiajia Li , Zhicheng Zhang , Wenjing Liu , Faisal Saleem","doi":"10.1016/j.nantod.2024.102543","DOIUrl":"10.1016/j.nantod.2024.102543","url":null,"abstract":"<div><div>The catalytic performance of supported metal nanoparticles (NPs) is greatly affected by metal-support interaction (MSI). Understanding the mechanisms and dynamics of MSI in heterogeneous catalysis remains challenging. Traditionally, MSI studies have focused on metal oxide supports and rarely compared MSI between Pt and Pt-based alloys, despite the importance of Pt in catalysis. In this study, we introduce CdS nanorods as a novel support material and investigate the MSI behavior of both Pt and Pt-based alloy NPs using in situ TEM electron beam irradiation. Our findings show that Pt NPs have strong MSI with CdS and that encapsulation layers form over Pt NPs because Pt has the high surface energy. On the other hand, Pt-based alloys have weaker MSI. These experiments were validated by direct thermal annealing for four hours. Molecular dynamics simulations were used to explain the observed behavior, providing insights into how the surface energy differences between Pt and Pt-based alloys influence their interactions with CdS nanorods. These findings offer valuable insights into catalyst design, highlighting the potential for controlling MSI strength to optimize catalytic performance in heterogeneous systems.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102543"},"PeriodicalIF":13.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Glucose-gated nanocoating endowing polyetheretherketone implants for enzymatic gas therapy to boost infectious diabetic osseointegration 葡萄糖门控纳米涂层赋予聚醚醚酮植入物以酶气疗法，促进感染性糖尿病骨整合

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-31 DOI: 10.1016/j.nantod.2024.102541

Jiahe Li , Menglin Fan , Zheng Jiao , Yau Kei Chan , Lei Cheng , Jiyao Li , Yi Deng , Kunneng Liang

The hyperglycemic micromilieu surrounding implants in diabetic patients leads to high failure rate of implantation and implant-associated infection. Carbon monoxide (CO) has been reported to combat infections; however, its on-demand liberation and the elucidation of the underlying antibacterial mechanism remain challenging. To address this issue, we develop a multipurpose orthopedic implant comprising polyetheretherketone, glucose oxidase (GOx), and manganese carbonyl nanocrystals (MnCO), serving as a glucose-gated nanocoating for enzymatic gas therapy to improve infectious diabetic osseointegration. The GOx acts as a glucose-actuated gate responsive to hyperglycemia, thereby delivering CO in situ triggered by the GOx-driven Fenton-like reaction of MnCO nanocrystals. The released CO considerably prevents bacterial multiplication by penetrating the membrane, binding to cytochrome bo₃, and interfering with the respiratory chain in vitro. Furthermore, the engineered implant displays desired antibacterial properties and enhances osseointegration in vivo. Collectively, the orthopedic nanocoating implant is capable of delivering glucose-gated enzymatic gas therapy, promising for treating infectious diabetic bone defects.

糖尿病患者植入物周围的高血糖微环境导致植入失败率和植入物相关感染率居高不下。据报道，一氧化碳（CO）具有抗感染作用；然而，按需释放一氧化碳以及阐明其潜在的抗菌机制仍是一项挑战。为了解决这个问题，我们开发了一种由聚醚醚酮、葡萄糖氧化酶（GOx）和羰基锰纳米晶体（MnCO）组成的多用途骨科植入物，作为一种葡萄糖门控纳米涂层，用于酶促气体疗法，以改善糖尿病感染性骨结合。GOx 可作为葡萄糖触发门对高血糖做出反应，从而在 GOx 驱动的 MnCO 纳米晶体的芬顿反应触发下原位释放二氧化碳。释放出的 CO 可穿透薄膜，与细胞色素 bo3 结合，并在体外干扰呼吸链，从而大大阻止了细菌的繁殖。此外，这种工程植入物还具有理想的抗菌特性，并能增强体内的骨结合。总之，骨科纳米涂层植入物能够提供葡萄糖门控酶气体疗法，有望用于治疗感染性糖尿病骨缺损。

{"title":"Glucose-gated nanocoating endowing polyetheretherketone implants for enzymatic gas therapy to boost infectious diabetic osseointegration","authors":"Jiahe Li , Menglin Fan , Zheng Jiao , Yau Kei Chan , Lei Cheng , Jiyao Li , Yi Deng , Kunneng Liang","doi":"10.1016/j.nantod.2024.102541","DOIUrl":"10.1016/j.nantod.2024.102541","url":null,"abstract":"<div><div>The hyperglycemic micromilieu surrounding implants in diabetic patients leads to high failure rate of implantation and implant-associated infection. Carbon monoxide (CO) has been reported to combat infections; however, its on-demand liberation and the elucidation of the underlying antibacterial mechanism remain challenging. To address this issue, we develop a multipurpose orthopedic implant comprising polyetheretherketone, glucose oxidase (GOx), and manganese carbonyl nanocrystals (MnCO), serving as a glucose-gated nanocoating for enzymatic gas therapy to improve infectious diabetic osseointegration. The GOx acts as a glucose-actuated gate responsive to hyperglycemia, thereby delivering CO <em>in situ</em> triggered by the GOx-driven Fenton-like reaction of MnCO nanocrystals. The released CO considerably prevents bacterial multiplication by penetrating the membrane, binding to cytochrome <em>bo</em><sub><em>3</em></sub>, and interfering with the respiratory chain <em>in vitro</em>. Furthermore, the engineered implant displays desired antibacterial properties and enhances osseointegration <em>in vivo</em>. Collectively, the orthopedic nanocoating implant is capable of delivering glucose-gated enzymatic gas therapy, promising for treating infectious diabetic bone defects.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102541"},"PeriodicalIF":13.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic scale in-situ observation of gas-solid interaction regulating the pre-nucleation process of Pd atomic clusters 原子尺度原位观测调节钯原子团簇预成核过程的气固相互作用

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-30 DOI: 10.1016/j.nantod.2024.102533

Yuchen Zhu, Yinghui Sun, Zhitao Zhao, Yingying Xu, Hao Li, Rongming Wang

Advancements in nanotechnology have propelled the understanding of atomic-scale nucleation processes, essential for the evolution of atomic manufacturing. The process of amorphous precursors nucleation showcases a complex transition influenced by various factors. Utilizing aberration-corrected ETEM and theoretical calculation, we explore the nucleation of amorphous Pd atomic clusters. This study examines the nucleation dynamics and gas-solid interaction regulating of Pd clusters on ultrathin carbon films, prepared via electron beam evaporation. HRTEM observation and FFT analysis reveal that, in the early stage of nucleation, Pd cluster growth predominantly follows an Ostwald ripening-like mechanism. Atoms from smaller clusters migrate and attach to larger ones, facilitating their progression to critical nucleation size. Environmental conditions significantly influence this process; hydrogen atmospheres lower the surface energy of Pd clusters, reducing the critical nucleation size, while argon atmospheres impede growth of Pd clusters by occupying migration sites on the carbon surface. These insights into atomic cluster behavior and environmental interactions are crucial for understanding the early stages of nucleation from amorphous to crystalline and can help opens new avenues for the controlled fabrication of materials with optimized functionalities.

纳米技术的进步推动了对原子尺度成核过程的了解，这对原子制造业的发展至关重要。非晶前驱体的成核过程展示了受各种因素影响的复杂转变。利用像差校正 ETEM 和理论计算，我们探索了非晶钯原子簇的成核过程。本研究探讨了电子束蒸发法制备的超薄碳膜上钯原子簇的成核动力学和气固相互作用调控。HRTEM 观察和 FFT 分析表明，在成核的早期阶段，钯簇的生长主要遵循类似奥斯特瓦尔德熟化的机制。较小簇团中的原子迁移并附着到较大的簇团上，促进它们向临界成核尺寸发展。环境条件会对这一过程产生重大影响；氢气环境会降低钯簇的表面能，从而减小临界成核尺寸，而氩气环境则会占据碳表面的迁移位点，从而阻碍钯簇的生长。这些关于原子团簇行为和环境相互作用的见解对于理解从无定形到晶体成核的早期阶段至关重要，有助于为控制制造具有优化功能的材料开辟新的途径。

{"title":"Atomic scale in-situ observation of gas-solid interaction regulating the pre-nucleation process of Pd atomic clusters","authors":"Yuchen Zhu, Yinghui Sun, Zhitao Zhao, Yingying Xu, Hao Li, Rongming Wang","doi":"10.1016/j.nantod.2024.102533","DOIUrl":"10.1016/j.nantod.2024.102533","url":null,"abstract":"<div><div>Advancements in nanotechnology have propelled the understanding of atomic-scale nucleation processes, essential for the evolution of atomic manufacturing. The process of amorphous precursors nucleation showcases a complex transition influenced by various factors. Utilizing aberration-corrected ETEM and theoretical calculation, we explore the nucleation of amorphous Pd atomic clusters. This study examines the nucleation dynamics and gas-solid interaction regulating of Pd clusters on ultrathin carbon films, prepared via electron beam evaporation. HRTEM observation and FFT analysis reveal that, in the early stage of nucleation, Pd cluster growth predominantly follows an Ostwald ripening-like mechanism. Atoms from smaller clusters migrate and attach to larger ones, facilitating their progression to critical nucleation size. Environmental conditions significantly influence this process; hydrogen atmospheres lower the surface energy of Pd clusters, reducing the critical nucleation size, while argon atmospheres impede growth of Pd clusters by occupying migration sites on the carbon surface. These insights into atomic cluster behavior and environmental interactions are crucial for understanding the early stages of nucleation from amorphous to crystalline and can help opens new avenues for the controlled fabrication of materials with optimized functionalities.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102533"},"PeriodicalIF":13.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Atomic-scale imaging of structural evolution from anatase TiO2 to cubic TiO under electron beam irradiation 电子束辐照下锐钛矿二氧化钛到立方氧化钛结构演变的原子尺度成像

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-30 DOI: 10.1016/j.nantod.2024.102532

Yuye Li , Jing Xia , Xuanze Li , Lifeng Tian , Peiyu Qiao , Jianyu Cao , Zhongshi Zhang , Qing Meng , Jiangtao Li , Chang Liu , Xiangmin Meng

The introduction of oxygen vacancies into transition metal oxides can change their phases and electronic structures, subsequently impacting the physical and chemical properties. However, comprehensively understanding the phase transition process at the atomic scale remains challenging. Here, we directly image the atomic structural evolution from anatase TiO₂ to cubic TiO under electron beam irradiation via in-situ scanning transmission electron microscope and electron energy loss spectroscopy, with a detailed analysis of the TiO/TiO₂ interfacial structure. During this process, electron beam irradiation induces the formation of oxygen vacancies on the TiO₂ surface, which drives the migration and rearrangement of Ti atoms. Theoretical and experimental methods are employed to provide insight into possible migration paths. Moreover, the formation of TiO is detected from other directions, but less distinct than that observed on the (010)_TiO2 facet. This demonstrates an interesting facet dependence attributed to variations in the formation energies of surface oxygen vacancies. In addition, subsequent irradiation on TiO does not induce new structural change, but only surface roughening. Our findings offer valuable atomic-scale insights to the complex structural evolution as well as a new method to precisely manipulate phases of the transition metal oxides.

在过渡金属氧化物中引入氧空位可改变其相位和电子结构，进而影响其物理和化学特性。然而，在原子尺度上全面了解相变过程仍具有挑战性。在这里，我们通过原位扫描透射电子显微镜和电子能量损失光谱，对电子束辐照下从锐钛矿型二氧化钛到立方氧化钛的原子结构演变过程进行了直接成像，并对二氧化钛/二氧化钛界面结构进行了详细分析。在此过程中，电子束辐照诱导了 TiO2 表面氧空位的形成，从而推动了 Ti 原子的迁移和重排。我们采用理论和实验方法深入研究了可能的迁移路径。此外，还从其他方向检测到氧化钛的形成，但不如在 (010)TiO2 面上观察到的那么明显。这表明了一种有趣的面依赖性，归因于表面氧空位形成能量的变化。此外，对二氧化钛的后续辐照不会引起新的结构变化，而只是表面粗糙化。我们的研究结果为复杂的结构演变提供了宝贵的原子尺度见解，也为精确操纵过渡金属氧化物的相提供了一种新方法。

{"title":"Atomic-scale imaging of structural evolution from anatase TiO2 to cubic TiO under electron beam irradiation","authors":"Yuye Li , Jing Xia , Xuanze Li , Lifeng Tian , Peiyu Qiao , Jianyu Cao , Zhongshi Zhang , Qing Meng , Jiangtao Li , Chang Liu , Xiangmin Meng","doi":"10.1016/j.nantod.2024.102532","DOIUrl":"10.1016/j.nantod.2024.102532","url":null,"abstract":"<div><div>The introduction of oxygen vacancies into transition metal oxides can change their phases and electronic structures, subsequently impacting the physical and chemical properties. However, comprehensively understanding the phase transition process at the atomic scale remains challenging. Here, we directly image the atomic structural evolution from anatase TiO<sub>2</sub> to cubic TiO under electron beam irradiation via in-situ scanning transmission electron microscope and electron energy loss spectroscopy, with a detailed analysis of the TiO/TiO<sub>2</sub> interfacial structure. During this process, electron beam irradiation induces the formation of oxygen vacancies on the TiO<sub>2</sub> surface, which drives the migration and rearrangement of Ti atoms. Theoretical and experimental methods are employed to provide insight into possible migration paths. Moreover, the formation of TiO is detected from other directions, but less distinct than that observed on the (010)<sub>TiO2</sub> facet. This demonstrates an interesting facet dependence attributed to variations in the formation energies of surface oxygen vacancies. In addition, subsequent irradiation on TiO does not induce new structural change, but only surface roughening. Our findings offer valuable atomic-scale insights to the complex structural evolution as well as a new method to precisely manipulate phases of the transition metal oxides.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102532"},"PeriodicalIF":13.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tunable multi-responsive N-heterocyclic carbene-gold nanoenzyme for tumor-specific pyroptosis and immune activation in cancer therapy 可调多反应 N-杂环碳金纳米酶，用于肿瘤特异性热休克和癌症治疗中的免疫激活

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-30 DOI: 10.1016/j.nantod.2024.102537

Shanshan Liang , Bing Wang , Wei Chen , Tingfeng Zhang , Hao Fang , Minglu Zhang , Si Xu , Zongyi Su , Lingna Zheng , Meng Wang , Xiao He , Weiyue Feng

Heterogeneity of the tumor microenvironment (TME) poses significant obstacles to effective tumor treatment. Pyroptosis-based immunogenic cell death (ICD) therapy is an ideal strategy to overcome TME heterogeneity and achieve a satisfactory antitumor effect. However, specific activation of pyroptosis in tumors while sparing normal tissue still remains a great challenge. Here, we have developed novel, biocompatible N-heterocyclic carbenes-gold nanoparticles (NHC@AuNPs) as TME-responsive nanoenzyme and potential pyroptosis inducers through an azide-alkyne cycloaddition “click” reaction and direct aurophilic interaction (Au^I∙∙∙Au^I). The NHC@AuNPs demonstrated tunable multi-responsive abilities within the TME, including superior peroxidase (POD) activity, GSH depletion through on-site cleavage Au-Au bond, inhibition of thioredoxin reductase and enhancement of ROS. This ROS buildup damages mitochondria, further enhancing H₂O₂ release and amplifying the catalytic cycle of ROS production. NHC ligation also exhibited enhanced fusion of NPs with the lipid bilayer, promoting high intracellular uptake in cancer cells. In vitro and in vivo experiments demonstrated that NHC@AuNPs effectively trigger pyroptosis in tumor cells through the ROS-modulated NLRP3/caspase-1/GSDMD pathway and activate antitumor immunity, such as the increased infiltration of CD4⁺ and CD8⁺ T cells, as well as the significant release of proinflammatory cytokines. These findings provide valuable insights for designing pyroptosis-inducer in cancer therapies.

肿瘤微环境（TME）的异质性是有效治疗肿瘤的重大障碍。基于热蛋白沉积的免疫性细胞死亡疗法（ICD）是克服肿瘤微环境异质性并取得满意抗肿瘤效果的理想策略。然而，如何特异性地激活肿瘤中的热蛋白沉积同时保护正常组织仍然是一个巨大的挑战。在此，我们通过叠氮-炔烃环加成 "点击 "反应和直接亲氨基作用（AuI∙∙∙AuI），开发了新型、生物相容性N-杂环碳烯-金纳米颗粒（NHC@AuNPs），作为TME响应型纳米酶和潜在的热诱变诱导剂。NHC@AuNPs在TME中表现出了可调的多反应能力，包括卓越的过氧化物酶（POD）活性、通过现场裂解Au-Au键消耗GSH、抑制硫代氧化还原酶和增强ROS。这种 ROS 的积累会破坏线粒体，进一步加强 H2O2 的释放并扩大 ROS 生成的催化循环。NHC 连接还能增强 NPs 与脂质双分子层的融合，促进癌细胞的高胞内吸收。体外和体内实验表明，NHC@AuNPs 可通过 ROS 调节的 NLRP3/aspcase-1/GSDMD 通路有效触发肿瘤细胞的热凋亡，并激活抗肿瘤免疫，如增加 CD4+ 和 CD8+ T 细胞的浸润，以及显著释放促炎细胞因子。这些发现为在癌症疗法中设计热诱变诱导剂提供了宝贵的启示。

{"title":"Tunable multi-responsive N-heterocyclic carbene-gold nanoenzyme for tumor-specific pyroptosis and immune activation in cancer therapy","authors":"Shanshan Liang , Bing Wang , Wei Chen , Tingfeng Zhang , Hao Fang , Minglu Zhang , Si Xu , Zongyi Su , Lingna Zheng , Meng Wang , Xiao He , Weiyue Feng","doi":"10.1016/j.nantod.2024.102537","DOIUrl":"10.1016/j.nantod.2024.102537","url":null,"abstract":"<div><div>Heterogeneity of the tumor microenvironment (TME) poses significant obstacles to effective tumor treatment. Pyroptosis-based immunogenic cell death (ICD) therapy is an ideal strategy to overcome TME heterogeneity and achieve a satisfactory antitumor effect. However, specific activation of pyroptosis in tumors while sparing normal tissue still remains a great challenge. Here, we have developed novel, biocompatible N-heterocyclic carbenes-gold nanoparticles (NHC@AuNPs) as TME-responsive nanoenzyme and potential pyroptosis inducers through an azide-alkyne cycloaddition “click” reaction and direct aurophilic interaction (Au<sup>I</sup>∙∙∙Au<sup>I</sup>). The NHC@AuNPs demonstrated tunable multi-responsive abilities within the TME, including superior peroxidase (POD) activity, GSH depletion through on-site cleavage Au-Au bond, inhibition of thioredoxin reductase and enhancement of ROS. This ROS buildup damages mitochondria, further enhancing H<sub>2</sub>O<sub>2</sub> release and amplifying the catalytic cycle of ROS production. NHC ligation also exhibited enhanced fusion of NPs with the lipid bilayer, promoting high intracellular uptake in cancer cells. <em>In vitro</em> and <em>in vivo</em> experiments demonstrated that NHC@AuNPs effectively trigger pyroptosis in tumor cells through the ROS-modulated NLRP3/caspase-1/GSDMD pathway and activate antitumor immunity, such as the increased infiltration of CD4<sup>+</sup> and CD8<sup>+</sup> T cells, as well as the significant release of proinflammatory cytokines. These findings provide valuable insights for designing pyroptosis-inducer in cancer therapies.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102537"},"PeriodicalIF":13.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deriving 2D in-plane heterostructures in TMDC nanosheets via electron beam irradiation 通过电子束辐照在 TMDC 纳米片中生成二维平面异质结构

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-30 DOI: 10.1016/j.nantod.2024.102540

Yatong Zhu , Wen Ai , Mao Ye , Chen Li , Mingrui Zhou , Fuqiang Chu , Guocai Dong , Yilong Zhou , Xiaohui Hu , Tao Xu , Litao Sun

2D in-plane heterostructures can enhance the electronic performance of hybrid systems, allowing for a variety of electronic device applications. However, precisely achieving uniform in-plane heterostructures with seamless interfaces at the same atomic planes remains a challenge. In this work, 2D in-plane heterostructures were successfully fabricated through electron beam irradiation-induced phase transformation in transition metal dichalcogenides (TMDCs). The transformed phases were seamlessly connected to the pristine TMDCs, forming ultraclean and atomically sharp interfaces of heterostructures. The phases were stable and determined to be novel tetragonal-like atomic structures by experimental and theoretical analyses. In situ transmission electron microscopy revealed that the phase transition involved atomic loss, lattice contraction, and then significant structural reconstruction in the pristine TMDCs. These results demonstrate that electron irradiation can efficiently achieve precise manufacturing of 2D in-plane heterostructures, offering new opportunities for the development of high-quality 2D in-plane heterostructures and novel 2D devices with high performance.

二维面内异质结构可以提高混合系统的电子性能，从而实现各种电子器件应用。然而，在同一原子面上精确地实现具有无缝界面的均匀面内异质结构仍然是一项挑战。在这项工作中，通过电子束辐照诱导过渡金属二卤化物（TMDCs）相变，成功制备了二维面内异质结构。转化后的相与原始 TMDC 无缝连接，形成了超清晰、原子锐利的异质结构界面。这些相非常稳定，并通过实验和理论分析被确定为新型四方类原子结构。原位透射电子显微镜显示，相变涉及原始 TMDC 的原子丢失、晶格收缩，然后是显著的结构重建。这些结果表明，电子辐照可以有效地实现二维面内异质结构的精确制造，为开发高质量的二维面内异质结构和具有高性能的新型二维器件提供了新的机遇。

{"title":"Deriving 2D in-plane heterostructures in TMDC nanosheets via electron beam irradiation","authors":"Yatong Zhu , Wen Ai , Mao Ye , Chen Li , Mingrui Zhou , Fuqiang Chu , Guocai Dong , Yilong Zhou , Xiaohui Hu , Tao Xu , Litao Sun","doi":"10.1016/j.nantod.2024.102540","DOIUrl":"10.1016/j.nantod.2024.102540","url":null,"abstract":"<div><div>2D in-plane heterostructures can enhance the electronic performance of hybrid systems, allowing for a variety of electronic device applications. However, precisely achieving uniform in-plane heterostructures with seamless interfaces at the same atomic planes remains a challenge. In this work, 2D in-plane heterostructures were successfully fabricated through electron beam irradiation-induced phase transformation in transition metal dichalcogenides (TMDCs). The transformed phases were seamlessly connected to the pristine TMDCs, forming ultraclean and atomically sharp interfaces of heterostructures. The phases were stable and determined to be novel tetragonal-like atomic structures by experimental and theoretical analyses. <em>In situ</em> transmission electron microscopy revealed that the phase transition involved atomic loss, lattice contraction, and then significant structural reconstruction in the pristine TMDCs. These results demonstrate that electron irradiation can efficiently achieve precise manufacturing of 2D in-plane heterostructures, offering new opportunities for the development of high-quality 2D in-plane heterostructures and novel 2D devices with high performance.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102540"},"PeriodicalIF":13.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatiotemporal orchestration of a ferroptosis-immunotherapy “cycle” via a sequential drug delivery system for antitumor immunity 通过抗肿瘤免疫连续给药系统实现铁蛋白沉积-免疫疗法 "循环 "的时空协调

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-29 DOI: 10.1016/j.nantod.2024.102535

Yongjuan Li , Xinyan Li , Mengzhe Zhang , Xiao Weng , Jinmeng Yi , Yongjian Cao , Ningjing Lei , Zhihai Qin , Xiaoyuan Chen , Weijing Yang

Interferon-gamma (IFN-γ) and iron can induce ferroptosis; however, distinct target sites restrict their synergistic therapeutic efficacy in simple combination therapy. Herein, two nanoplatforms are constructed with the same polymeric skeleton but different payloads to separately target antigen-presenting cells (APCs) and tumor cells for amplified ferroptosis in immunotherapy. Negatively charged 2′,3′-cyclic GMP-AMP is electronically loaded in pH-responsive nanoparticles (PNPs@cGAMP), which activates the stimulator of interferon gene (STING) pathway in APCs, accompanied by an immune response activation cascade with IFN-γ secretion for tumor ferroptosis. Gossypol is conjugated to the polymer chain by forming a pH-sensitive Schiff base that further coordinates with ferric iron (Fe³⁺) to self-assemble into another size-switchable nanoprodrug (PGNPs@Fe). In the acidic tumor microenvironment, PGNPs@Fe shrinks into Gos@Fe for deeper tumor penetration, which disassembles into Fe³⁺ and gossypol for lipid peroxide generation, resulting in ferroptosis and immunogenic cell death. Compared to multiple administrations of a single nanoformulation, this ferroptosis-immunotherapy "cycle" exhibits notably improved antitumor activity in subcutaneous xenograft and distal metastatic B16F10 tumor models. The mouse survival rate is significantly prolonged after combination with immune checkpoint blockade. This design emphasizes the spatiotemporal orchestration of payloads and provides novel perspectives on intelligent nanotherapeutics combinations for future clinical applications.

γ干扰素（IFN-γ）和铁能诱导铁凋亡；然而，不同的靶点限制了它们在简单联合治疗中的协同疗效。在此，我们构建了两种具有相同聚合物骨架但不同有效载荷的纳米平台，分别靶向抗原递呈细胞（APC）和肿瘤细胞，在免疫疗法中放大铁凋亡作用。带负电荷的 2′,3′-环 GMP-AMP 以电子方式载入 pH 值响应型纳米粒子（PNPs@cGAMP）中，从而激活 APCs 中的干扰素基因刺激器（STING）通路，并伴随着 IFN-γ 分泌的免疫反应激活级联，以促进肿瘤的铁凋亡。戈西泊通过形成对 pH 值敏感的希夫碱与聚合物链共轭，进一步与铁 (Fe3+) 配位，自组装成另一种尺寸可调的纳米药物（PGNPs@Fe）。在酸性肿瘤微环境中，PGNPs@Fe 会收缩成 Gos@Fe，以便更深入地穿透肿瘤，而 Gos@Fe 则会分解成 Fe3+ 和棉酚，生成过氧化脂质，导致铁细胞凋亡和免疫性细胞死亡。与多次施用单一纳米制剂相比，这种嗜铁-免疫疗法 "循环 "在皮下异种移植和远端转移的 B16F10 肿瘤模型中显示出明显提高的抗肿瘤活性。与免疫检查点阻断相结合后，小鼠存活率明显延长。这种设计强调了有效载荷的时空协调，为未来临床应用中的智能纳米治疗组合提供了新的视角。

{"title":"Spatiotemporal orchestration of a ferroptosis-immunotherapy “cycle” via a sequential drug delivery system for antitumor immunity","authors":"Yongjuan Li , Xinyan Li , Mengzhe Zhang , Xiao Weng , Jinmeng Yi , Yongjian Cao , Ningjing Lei , Zhihai Qin , Xiaoyuan Chen , Weijing Yang","doi":"10.1016/j.nantod.2024.102535","DOIUrl":"10.1016/j.nantod.2024.102535","url":null,"abstract":"<div><div>Interferon-gamma (IFN-γ) and iron can induce ferroptosis; however, distinct target sites restrict their synergistic therapeutic efficacy in simple combination therapy. Herein, two nanoplatforms are constructed with the same polymeric skeleton but different payloads to separately target antigen-presenting cells (APCs) and tumor cells for amplified ferroptosis in immunotherapy. Negatively charged 2′,3′-cyclic GMP-AMP is electronically loaded in pH-responsive nanoparticles (PNPs@cGAMP), which activates the stimulator of interferon gene (STING) pathway in APCs, accompanied by an immune response activation cascade with IFN-γ secretion for tumor ferroptosis. Gossypol is conjugated to the polymer chain by forming a pH-sensitive Schiff base that further coordinates with ferric iron (Fe<sup>3+</sup>) to self-assemble into another size-switchable nanoprodrug (PGNPs@Fe). In the acidic tumor microenvironment, PGNPs@Fe shrinks into Gos@Fe for deeper tumor penetration, which disassembles into Fe<sup>3+</sup> and gossypol for lipid peroxide generation, resulting in ferroptosis and immunogenic cell death. Compared to multiple administrations of a single nanoformulation, this ferroptosis-immunotherapy \"cycle\" exhibits notably improved antitumor activity in subcutaneous xenograft and distal metastatic B16F10 tumor models. The mouse survival rate is significantly prolonged after combination with immune checkpoint blockade. This design emphasizes the spatiotemporal orchestration of payloads and provides novel perspectives on intelligent nanotherapeutics combinations for future clinical applications.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102535"},"PeriodicalIF":13.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Opposite synaptic plasticity in oxidation-layer-controlled 2D materials-based memristors for mimicking heterosynaptic plasticity 氧化层控制二维材料忆阻器中的相反突触可塑性，用于模拟异突触可塑性

IF 13.2 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Today

Pub Date : 2024-10-28 DOI: 10.1016/j.nantod.2024.102534

Tien Dat Ngo , Je-Jun Lee , Hyung-Seok Bae , Tuyen Huynh , Kwangro Lee , Myeongjin Lee , Yasir Hassan , Ji-In Park , Hee-Suk Chung , Jin-Hong Park , Won Jong Yoo , Min Sup Choi

Memristors with nonstoichiometric tungsten oxide (WO_x) as an active layer, derived from the oxidation of atomically thin two-dimensional tungsten diselenide (WSe₂), enable the creation of the monolithic layered structure of WO_x/WSe₂. These devices are promising candidates for emulating various biological synaptic functions in the human brain. In this study, we fabricate monolithic few-layer WO_x/WSe₂ memristors with precisely controlled WO_x thickness by UV-ozone treatment from 1 L to 9 L, depending on chuck temperature. The postsynaptic responses of the topmost single-layer (1 L) oxidized WSe₂ and fully (9 L) oxidized WSe₂ memristors exhibit sharply contrasting behaviors, which can be applied to mimic the heterosynaptic plasticity in the CA1 region of the hippocampus. Beyond the significance of emulating the biological synaptic characteristics, we explore the feasibility of using each oxidation-layer-controlled memristor as a hardware accelerator. Their performances are assessed through application in a CIFAR-10 pattern recognition task using a convolutional neural network. Pattern recognition rates of 84 % and 71 % are obtained for the 1 L and 9 L WO_x-based devices, respectively. We also examine the applicability of a synaptic cell composed of devices with oppositely switched characteristics. Consequently, the synaptic weight—defined as the difference in conductance between two synaptic devices—can be either increased (potentiated) or decreased (depressed) by simultaneously updating both devices with the same voltage signal. This weight update concept achieves a moderate recognition rate of 85.94 % when using an MNIST pattern-based recognition task, simplifying the complex weight-adjustment process.

由原子薄二维二硒化钨（WSe2）氧化而成的非化学计量的氧化钨（WOx）作为活性层的晶闸管，能够形成 WOx/WSe2 的单片分层结构。这些器件有望模拟人脑中的各种生物突触功能。在本研究中，我们通过紫外线-臭氧处理，根据夹头温度的不同，制造出了单片几层 WOx/WSe2 记忆晶闸管，其 WOx 厚度可精确控制在 1 L 到 9 L 之间。最上层单层（1 L）氧化 WSe2 和完全（9 L）氧化 WSe2 记忆晶体的突触后反应表现出截然不同的行为，可用于模拟海马 CA1 区的异突触可塑性。除了模拟生物突触特性的意义之外，我们还探索了将每个氧化层控制的忆阻器用作硬件加速器的可行性。通过使用卷积神经网络在 CIFAR-10 模式识别任务中的应用，对它们的性能进行了评估。基于 1 L 和 9 L WOx 的器件的模式识别率分别为 84% 和 71%。我们还研究了由具有相反开关特性的器件组成的突触单元的适用性。因此，通过同时用相同的电压信号更新两个器件，可以增加（增强）或减少（抑制）突触权重，突触权重定义为两个突触器件之间的电导差。这种权重更新概念简化了复杂的权重调整过程，在使用基于 MNIST 模式的识别任务时，达到了 85.94% 的中等识别率。

{"title":"Opposite synaptic plasticity in oxidation-layer-controlled 2D materials-based memristors for mimicking heterosynaptic plasticity","authors":"Tien Dat Ngo , Je-Jun Lee , Hyung-Seok Bae , Tuyen Huynh , Kwangro Lee , Myeongjin Lee , Yasir Hassan , Ji-In Park , Hee-Suk Chung , Jin-Hong Park , Won Jong Yoo , Min Sup Choi","doi":"10.1016/j.nantod.2024.102534","DOIUrl":"10.1016/j.nantod.2024.102534","url":null,"abstract":"<div><div>Memristors with nonstoichiometric tungsten oxide (WO<sub>x</sub>) as an active layer, derived from the oxidation of atomically thin two-dimensional tungsten diselenide (WSe<sub>2</sub>), enable the creation of the monolithic layered structure of WO<sub>x</sub>/WSe<sub>2</sub>. These devices are promising candidates for emulating various biological synaptic functions in the human brain. In this study, we fabricate monolithic few-layer WO<sub>x</sub>/WSe<sub>2</sub> memristors with precisely controlled WO<sub>x</sub> thickness by UV-ozone treatment from 1 L to 9 L, depending on chuck temperature. The postsynaptic responses of the topmost single-layer (1 L) oxidized WSe<sub>2</sub> and fully (9 L) oxidized WSe<sub>2</sub> memristors exhibit sharply contrasting behaviors, which can be applied to mimic the heterosynaptic plasticity in the CA1 region of the hippocampus. Beyond the significance of emulating the biological synaptic characteristics, we explore the feasibility of using each oxidation-layer-controlled memristor as a hardware accelerator. Their performances are assessed through application in a CIFAR-10 pattern recognition task using a convolutional neural network. Pattern recognition rates of 84 % and 71 % are obtained for the 1 L and 9 L WO<sub>x</sub>-based devices, respectively. We also examine the applicability of a synaptic cell composed of devices with oppositely switched characteristics. Consequently, the synaptic weight—defined as the difference in conductance between two synaptic devices—can be either increased (potentiated) or decreased (depressed) by simultaneously updating both devices with the same voltage signal. This weight update concept achieves a moderate recognition rate of 85.94 % when using an MNIST pattern-based recognition task, simplifying the complex weight-adjustment process.</div></div>","PeriodicalId":395,"journal":{"name":"Nano Today","volume":"59 ","pages":"Article 102534"},"PeriodicalIF":13.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142540160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0