ACS Publications最新文献

{"title":"Recycling Materials for Sustainable DNA Origami Manufacturing.","authors":"Michael J Neuhoff, Yuchen Wang, Nicholas J Vantangoli, Michael G Poirier, Carlos E Castro, Wolfgang G Pfeifer","doi":"10.1021/acs.nanolett.4c02695","DOIUrl":"https://doi.org/10.1021/acs.nanolett.4c02695","url":null,"abstract":"<p><p>DNA origami nanotechnology has great potential in multiple fields including biomedical, biophysical, and nanofabrication applications. However, current production pipelines lead to single-use devices incorporating a small fraction of initial reactants, resulting in a wasteful manufacturing process. Here, we introduce two complementary approaches to overcome these limitations by recycling the strand components of DNA origami nanostructures (DONs). We demonstrate reprogramming entire DONs into new devices, reusing scaffold strands. We validate this approach by reprogramming DONs with complex geometries into each other, using their distinct geometries to verify successful scaffold recycling. We reprogram one DON into a dynamic structure and show both pristine and recycled structures display similar properties. Second, we demonstrate the recovery of excess staple strands postassembly and fold DONs with these recycled strands, showing these structures exhibit the expected geometry and dynamic properties. Finally, we demonstrate the combination of both approaches, successfully fabricating DONs solely from recycled DNA components.</p>","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":null,"pages":null},"PeriodicalIF":9.6,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306621","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}

{"title":"Boosting Med Chem Education: Integrating Biology for Drug Discovery Talents.","authors":"Qiu Sun, Liang Ouyang","doi":"10.1021/acs.jmedchem.4c02208","DOIUrl":"https://doi.org/10.1021/acs.jmedchem.4c02208","url":null,"abstract":"","PeriodicalId":46,"journal":{"name":"Journal of Medicinal Chemistry","volume":null,"pages":null},"PeriodicalIF":6.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the Origins of the Disorder-to-Order Transition of a Modified Cholesterol in Ternary Lipid Bilayers.","authors":"Ayan Majumder, Yuanqing Gu, Yi-Chen Chen, Xingda An, Björn M Reinhard, John E Straub","doi":"10.1021/jacs.4c09495","DOIUrl":"https://doi.org/10.1021/jacs.4c09495","url":null,"abstract":"<p><p>In a recent study, spectroscopic observations of modified cholesterol in both lipid-coated nanoparticles and liposomes provided evidence for a disorder-to-order orientational transition with increasing temperature. Below a critical temperature, in a membrane composed of modified cholesterol, saturated (DPPC) lipid, and anionic (DOPS) lipid, a roughly equal population of head-out and head-in conformations was observed. Surprisingly, as temperature was increased the modified cholesterol presented an abrupt transition to a population of all head-in orientations. Additionally, when saturated DPPC lipids were replaced by unsaturated DOPC the disorder-to-order transition was eliminated. To gain insight into this curious transition, we use all-atom molecular dynamics simulations to characterize the structure and fluctuations of lipid bilayers composed of saturated and unsaturated lipids, in the presence of normal and modified cholesterol. Free energy differences between head-out and head-in conformations are computed as a function of varying lipid membrane composition for normal and modified cholesterol. In bilayers primarily composed of DPPC, the orientation of modified cholesterol is observed to depend sensitively on the orientation of the surrounding normal or modified cholesterol molecules, suggesting cooperative Ising-like interactions favoring an ordered state. In bilayers primarily composed of DOPC, spontaneous flip-flop of modified cholesterol is observed, consistent with the measured small free energy barrier separating the head-in and head-out orientations. This combined experimental and computational study effectively characterizes the orientational dimorphism and provides novel insight into the fundamental nature of cholesterol interactions in membrane.</p>","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":null,"pages":null},"PeriodicalIF":14.4,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulating Monodispersity by Controlling Droplet Spacing.","authors":"Dheeraj Sapkota, Laura L A Adams","doi":"10.1021/acs.langmuir.4c02058","DOIUrl":"https://doi.org/10.1021/acs.langmuir.4c02058","url":null,"abstract":"<p><p>We report a new method for regulating monodispersity in the generation of single emulsions. The spacing between two consecutive emulsions during their generation is used to identify monodisperse and polydisperse regimes, with monodispersity having a size dispersion of <9% as an upper limit. A theoretical fit to our data is also presented. Moreover, a phase diagram of drop diameter as a function of inner and outer fluid flow rates indicates optimal flow parameters for the production of monodisperse drops. Our findings emphasize the robustness of using droplet spacing as a controlled parameter in regulating monodispersity, despite geometric differences in microfluidic devices.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-Assisted Self-Healable Biovitrimer/rGO Framework for Anticorrosion Applications.","authors":"Poonam Singh, Wolfgang H Binder, Pankaj Kumar, Rajkumar Patel, Gun Jin Yun, Sravendra Rana","doi":"10.1021/acsami.4c13361","DOIUrl":"https://doi.org/10.1021/acsami.4c13361","url":null,"abstract":"<p><p>Microwave-stimulated smart self-healable polymeric coatings with significant protective technology against corrosion have been developed in this work. Herein, a generous approach is strategized to generate linseed oil-derived epoxy composites embedded with reduced graphene oxide (rGO) as a nanofiller in the shielding network. The composite showed excellent self-healing and shape memory properties when irradiated with microwaves due to the dynamic reversible nature of the disulfide covalent bond exchange mechanism. The network also has improved thermomechanical properties and thermal stability, with a storage modulus of 20.8 GPa and a low activation energy of 79 kJ/mol, indicating a fast disulfide dynamic exchange reaction. The amine functionality in the composite contributes to excellent corrosion protection, with 99.9% protection efficiency, as validated via a Tafel plot. The composite also showed excellent hydrophobicity, with a 131° contact angle. This study provides insights into the engineering and application of smart materials as anticorrosive coatings.</p>","PeriodicalId":5,"journal":{"name":"ACS Applied Materials & Interfaces","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Inhalable Nanoshield for Effective Prevention of Influenza Virus Infections.","authors":"Jing Li, Xue-Hui Shi, Dan-Dan Fu, Lei Du, Bo Tang, Jian Ao, Ai-Xin Ma, Yi-Ning Hou, Zhi-Gang Wang, Shu-Lin Liu, Dai-Wen Pang","doi":"10.1021/acsnano.4c04631","DOIUrl":"https://doi.org/10.1021/acsnano.4c04631","url":null,"abstract":"<p><p>Influenza virus (IV) infection currently poses a serious and continuing threat to the global public health. Developing effective prevention strategies is important to defend against infection and spread of IV. Here, we developed a triple-protective nanoshield against IV infection in the lungs, formed by self-assembling DSPE-PEG amphiphilic polymers encapsulating the flu-preventive antiviral drug Arbidol internally. The preventive effect of the nanoshield against virus infection includes increasing the viscosity in the surrounding environment to physically defend against viral entry, forming a hydrated layer to block the interaction between viruses and cells, and inhibiting virus replication. Our finding suggested that a single inhalation of the nanoshield provides effective protection against IV infection for at least 8 h. Thus, this nanoshield may be a potential pandemic protection agent against IV, especially in viral environments, where no prophylactic or therapeutic measures are available.</p>","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":null,"pages":null},"PeriodicalIF":15.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306525","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}

{"title":"Tautomeric Conflicts in Forty Small-Molecule Databases.","authors":"Devendra K Dhaked, Marc C Nicklaus","doi":"10.1021/acs.jcim.4c00700","DOIUrl":"https://doi.org/10.1021/acs.jcim.4c00700","url":null,"abstract":"<p><p>We have analyzed 40 different databases ranging in size from a few thousand to nearly 100 million molecules, comprising a total of over 210 million structures, for their tautomeric conflicts. A tautomeric conflict is defined as an occurrence of two or more structures within a data set identified by the tautomeric rules applied as being tautomers of each other. We tested a total of 119 detailed tautomeric transform rules expressed as SMIRKS, out of which 79 yielded at least one conflict. These transformations include three types of tautomerism: prototropic, ring-chain, and valence tautomerism. The databases analyzed spanned a wide variety of types including large aggregating databases, drug collections, and structure collections based on experimental data. All databases analyzed showed intra-database tautomeric conflicts. The conflict rates as percentage of the database were typically in the few tenths of a percent range, which for the largest databases amounts to >100,000 cases per database.</p>","PeriodicalId":44,"journal":{"name":"Journal of Chemical Information and Modeling ","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Biotransformation on Internal Concentrations and Specificity Classification of Organic Chemicals in the Zebrafish Embryo (<i>Danio rerio</i>).","authors":"Nico Grasse, Riccardo Massei, Bettina Seiwert, Stefan Scholz, Beate I Escher, Thorsten Reemtsma, Qiuguo Fu","doi":"10.1021/acs.est.4c04156","DOIUrl":"https://doi.org/10.1021/acs.est.4c04156","url":null,"abstract":"<p><p>Internal concentrations (ICs) are crucial for linking exposure to effects in the development of New Approach Methodologies. ICs of chemicals in aquatic organisms are primarily driven by hydrophobicity and modulated by biotransformation and efflux. Comparing the predicted baseline to observed toxicity enables the estimation of effect specificity, but biological processes can lead to overestimating ICs and bias the specificity assessment. To evaluate the prediction of a mass balance model (MBM) and the impact of biotransformation on ICs, experimental ICs of 63 chemicals in zebrafish embryos were compared to predictions with physicochemical properties as input parameters. Experimental ICs of 79% (50 of 63) of the chemicals deviated less than 10-fold from predictions, and the remaining 13 deviated up to a factor of 90. Using experimental ICs changed the classification for 19 chemicals, with ICs 5 to 90 times lower than predicted, showing the bias of specificity classification. Uptake kinetics of pirinixic acid, genistein, dexamethasone, ethoprophos, atorvastatin, and niflumic acid were studied over a 96 h exposure period, and transformation products (TPs) were elucidated using suspect- and nontarget screening with UPLC-HRMS. 35 TPs (5 to 8 TPs per compound) were tentatively identified and semiquantified based on peak areas, suggesting that biotransformation may partly account for the overpredictions of ICs.</p>","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical Kinetics of Radical-Radical Reaction NH₂ṄH + ṄH₂ and Its Implications for Monomethylhydrazine Pyrolysis Mechanism.","authors":"Chunyu Wang, Qian Zhao, Hao Zhao, Binxu Pu, Zuohua Huang, Longfei Li, Yingjia Zhang","doi":"10.1021/acs.jpca.4c02034","DOIUrl":"https://doi.org/10.1021/acs.jpca.4c02034","url":null,"abstract":"<p><p>Significant discrepancies were observed between the experiments and the simulations for ṄH₂ time-histories in monomethylhydrazine pyrolysis with the robust mechanism proposed by Pascal and Catoire. The rate of formation analyses for ṄH₂ indicated the significance of the reaction NH₂ṄH + ṄH₂ = H₂NN + NH₃, which has not been well-defined. In <i>this study</i>, <i>ab initio</i> calculations were performed for the theoretical description of the NH₂ṄH + ṄH₂ chemistry. Most stationary points on the potential energy surface were quantified at the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level, and the multireference methods were employed for barrier-less reaction and some transition states. The temperature- and pressure-dependent rate coefficients were determined using classical and microcanonical variational transition state theories. Four primary reaction channels were identified as competitive: 1) The H atom abstraction reaction yielding N₂H₂(T) + NH₃, dominating at 1350-3000 K across the 0.001-100 atm pressure range. 2) The H atom abstraction reaction forming N₂H₂(S) + NH₃, dominating at 800-1350 K and competing with the processes of chemical activation and collisional stabilization below 800 K. 3) The chemical-activated reaction resulting in H₂NN(S) + NH₃, dominating below 800 K at 0.001 atm. 4) The collisional-stabilized recombination reaction leading to N₃H₅, becoming significant as pressure increases and dominating below 600 and 650 K at 1 and 100 atm, respectively. The implications of newly calculated NH₂ṄH + ṄH₂ kinetics for the monomethylhydrazine pyrolysis mechanism were evaluated, and updates were implemented. Sensitivity analyses indicated the necessity of additional research efforts to comprehend the dynamics of CH₃NH₂ unimolecular and N₂H₂ + ṄH₂ reaction systems. The rate coefficients presented in <i>this study</i> can be employed to develop the chemical kinetic model of nitryl-containing systems.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Switchback RNA.","authors":"Bharath Raj Madhanagopal, Hannah Talbot, Arlin Rodriguez, Arun Richard Chandrasekaran","doi":"10.1021/acschembio.4c00518","DOIUrl":"https://doi.org/10.1021/acschembio.4c00518","url":null,"abstract":"<p><p>Intricately designed DNA and RNA motifs guide the assembly of robust and functional nucleic acid nanostructures. In this work, we present a globally left-handed RNA motif with two parallel strands called switchback RNA and report its assembly, biophysical, and biochemical characterization. Switchback RNA can be assembled in buffers without Mg²⁺, with improved thermal stability in buffers containing Mg²⁺, Na⁺, or K⁺. Differences in the binding of small molecules to switchback RNA and conventional RNA indicate design-based approaches for small molecule loading on RNA nanostructures. Further, the differential affinity of the two component strands in switchback or conventional duplex conformations allows for toehold-less strand displacement. Enzyme studies showed that the switchback and conventional RNA structures have similar levels of nuclease resistance. These results provide insights for employing switchback RNA as a structural motif in RNA nanotechnology. Our observation that RNA strands with switchback complementarity can form stable complexes at low magnesium concentrations encourages studies into the potential occurrence of switchback RNA in nature.</p>","PeriodicalId":11,"journal":{"name":"ACS Chemical Biology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}