Nanoscience News (<front>)

Biomolecular condensates play crucial roles in cellular organisation, regulating diverse biological functions, as well as contributing to disease pathologies when phase separation is dysregulated. However, the physicochemical mechanisms by which they are formed and regulated are still not well understood, especially in the complex environment inside cells consisting of thousands of different components. Computer simulations have emerged as powerful tools to investigate phase transitions in these systems. In this talk, we will discuss how coarse-grained molecular-dynamics simulations at different resolutions can probe the molecular mechanisms governing biomolecular phase separation across different systems, as well as guide the design of proteins that can give rise to condensates with specific properties.

• Speaker: Pin Yu Chew, University of Cambridge
• Wednesday 26 February 2025, 14:30-15:00
• Venue: Unilever Lecture Theatre, Yusuf Hamied Department of Chemistry.
• Series: Theory - Chemistry Research Interest Group; organiser: Lisa Masters.

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Obtaining accurate predictions of thermodynamic properties, especially free energies which define the state of a system, is one of the key goals in atomistic simulations. This can enable a direct understanding of atomic-scale processes and provide a direct link to experiment. Achieving this requires converged statistical sampling from accurate wavefunction based potential energy surfaces, which is a formidable challenge due to the very high computational cost of such methods. Here, we leverage advances in machine learning potentials to efficiently obtain converged thermodynamic properties at increasing levels of theory. To showcase the potential of this approach, I will use the ion pairing of CaCO3 as a benchmark system, since it presents a significant challenge from both electronic structure and sampling perspectives. I will show that a machine learning framework based on second order Møller-Plesset Perturbation Theory delivers excellent agreement with experiment for the ion-pair association free energy—a challenging property for first principles atomistic simulations. Furthermore I will show that classical force fields get the right answer for the wrong reasons. Finally, I will discuss steps towards developing CCSD accuracy machine learning models, the ‘gold-standard’ of quantum chemical methods.

• Speaker: Niamh O'Neill, University of Cambridge
• Wednesday 26 February 2025, 15:00-15:30
• Venue: Unilever Lecture Theatre, Yusuf Hamied Department of Chemistry.
• Series: Theory - Chemistry Research Interest Group; organiser: Lisa Masters.

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Abstract not available

• Speaker: Oscar Westerblad (University of Iceland)
• Wednesday 19 March 2025, 13:00-14:30
• Venue: Seminar Room 2, Department of History and Philosophy of Science.
• Series: CamPoS (Cambridge Philosophy of Science) seminar; organiser: Miguel Ohnesorge.

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We consider the harmonic map heat flow for maps from the plane to the two-sphere. It is known that solutions to the initial value problem exhibit bubbling along a well-chosen sequence of times – the solution decomposes into a superposition of harmonic maps. We prove that every sequence of times admits a subsequence along which bubbling occurs. This is deduced as a corollary of our main theorem, which shows that the solution approaches the family of multi-bubble configurations in continuous time. This is a joint work with Andrew Lawrie (University of Maryland) and Wilhelm Schlag (Yale University).

• Speaker: Jacek Jendrej (Sorbonne)
• Monday 24 February 2025, 14:00-15:00
• Venue: MR13.
• Series: Partial Differential Equations seminar; organiser: Giacomo Ageno.

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Employing near-infrared II (NIR-II) imaging with indocyanine green (ICG)-conjugated recombinant human chorionic gonadotropin (hCG) protein allows for precise visualization of early follicles. This technique aids in the tracking of follicular development, ovarian vasculature, and ovarian tumors, exceeding the spatial capabilities of ultrasound and MRI. The approach provides new perspectives into infertility conditions and tumor monitoring.

Follicular tracking is typically conducted using ultrasound technology, but its effectiveness is constrained by limited resolution. High-resolution imaging of deep tissues can be accomplished using luminescence imaging in the near-infrared II window (NIR-II, 1000–1700 nm); however, the contrast agents that are used lack specificity. Here, it is reported that the FDA-approved indocyanine green (ICG)-conjugated recombinant human chorionic gonadotropin (hCG) protein can target early follicles with long-term effectiveness. A novel high-resolution NIR-II imaging approach is developed for monitoring follicular development as well as ovulation using multi-color imaging of ovarian vessels with a combination of non-overlapping downconversion nanoparticles (DCNPs). The results showed that the ability to monitor early follicles of around 50 µm in diameter exceeded the spatial and temporal resolution of ultrasound or MRI without the reproductive damage associated with computed tomography radiation, and this enabled the clinical identification of the follicular reserve in patients with infertility diseases such as polycystic ovary syndrome (PCOS). In addition, NIR-II imaging clearly targeted ovarian tumors and showed micro-metastatic lesions, thus providing a new tool for monitoring tumors in vivo and guiding surgical resection.

Multitemporal Programmable THz Metadevices

Based on the pixelated design with multi-materials of different photocarrier responses and triggering switches, the photon-induced multitemporal programming is achieved in a THz metadevice with the broadband and multiple polarization states. The time- and frequency-switchable logic gates are demonstrated at a picosecond scale. The article number 2410671 by Jing Lou, Chao Chang, Guangwei Hu, and co-workers promises the compact, flexible and temporally reprogrammable THz multifunctional devices.

Fast Liquid Absorption

A type of delicious fungus, wood ear, displays exceptional water absorption capability on one of its surfaces due to the dense micro-sized hairs on its porous sublayer. This unique structure facilitates simultaneous lateral spreading and vertical imbibition, resulting in rapid, unidirectional water absorption. More details can be found in article number 2413364 by Yu-Qiong Luo, Jie Ju, and co-workers.

Force-Electric Hydrogel Microspheres

The integration of barium titanate (BaTiO3) piezoelectric nanoparticles with microfluidic HAMA hydrogel microspheres enables sustained and stable electrical signal output under wireless ultrasound modulation, precisely regulating cellular fate at the micron scale. By incorporating peptides that specifically recruit target cell populations, this novel piezoelectric hydrogel microsphere system effectively addresses the heterogeneity issues of traditional electrical stimulation therapies, providing a promising and translatable approach for promoting cartilage repair. Further details can be found in article number 2414555 by Mingzhu Zhang and co-workers.

Gas Sensing

In article number 2413023, Lei Miao, Peng Song, Yibei Xue, Shu Yin, and co-workers reveal a strategy for gas selection with anomalous sensing behavior. Novel selectivity is defined as the unique sensing behavior. The formation mechanism of the anomalous sensing behavior is also revealed by the formation conditions of the Schottky barrier.

Silk Fibroin-Based Biomaterials

In article number 2414878, Feng Wang and co-workers present a novel biosynthetic system for developing functional silk fibroin-based biomaterials. The system can efficiently synthesize exogenous recombinant proteins with activity in silk glands of transgenic silkworms and secrete them into silk fibers, providing high-quality raw materials for the subsequent development of functional silk fibroin biomaterials and promoting the application of silk fibroin biomaterials in the field of medical tissue engineering.

Molecular Imaging

Monitoring follicular development is crucial for evaluating female fertility and diagnosing infertility. This work introduces a novel NIR-II imaging strategy using FDA-approved ICG-conjugated hCG protein, enabling high-resolution, long-term tracking of early follicles. Beyond infertility diagnosis, this method also identifies ovarian tumors and micro-metastases, offering a groundbreaking tool for reproductive and oncological applications. More details can be found in article number 2414129 by Hao Chen, Yi Feng, and co-workers.

Mechanical Metamaterials

The development of vehicles and aircraft has created an urgent need for excellent plasticity of mechanical metamaterials. This work proposed mechanical metamaterials with extraordinary plastic properties, namely triangular corrugation-based plate lattice (TCPL) and enhanced TCPL (ETCPL), based on multidimensional performance expansion strategy and deformation constraint strategy. More details can be found in article number 2412064 by Haoyuan Guo and Jianxun Zhang.

Field-Programmable Topographic-Morphing Arrays

Lab-on-a-chip systems seek to leverage microfluidic chips to enable small-scale fluid manipulation, holding significant potential to revolutionize science and industry. Inspired by design strategy of field programmable gate array whose hardware can be reconfigured via software, Jiu-an Lv and co-workers have devised a conceptual-new microfluidic chip-field programmable topographic morphing array with exceptional structural reconfiguration, field programmability, and function scalability for general-purpose lab-on-a-chip systems. More details can be found in article number 2410604.

Numerous nanomedicines are developed to revolutionize disease management. Due to the diverse materials and methods used in fabricating nanomedicines, their mechanical properties can vary significantly, which have increasingly been recognized as a critical factor influencing therapeutic efficacy. This review systematically addresses the impact of nanomedicines’ mechanical properties on their biomedical performance, offering valuable insights for future developments in the field.

Nanomaterials have become essential in the daily lives, finding applications in food, skincare, drugs, and vaccines. Traditionally, the surface chemistry of nanoparticles (NPs) is considered the key factor in determining their interactions with biological systems. However, recent studies have shown that the mechanical properties of nanomaterials are equally important in regulating nano-bio interactions, though they have often been overlooked. Tuning the mechanical properties of nanomaterials and designing them for biomedical applications is thus crucial. This review begins by discussing the various mechanical cues in biological processes, including how viruses and cells adjust their mechanical properties throughout their life cycles. Basic concepts and terminology related to NP mechanical properties are introduced. Next, five different groups of nanomaterials with tunable mechanical properties are explored. The review then examines the impact of NP mechanical properties on their interactions in vitro and in vivo, covering tumor-targeted drug delivery, nanovaccines, and emerging applications such as oral and intranasal drug delivery. Current challenges in the field and perspectives on future developments are also provided.

This review discusses defect engineering strategies for metal-based atomically thin materials (M-ATMs) to enhance their catalytic performance in electrochemical reactions, addressing challenges like insufficient active sites and slow kinetics, while exploring their potential in promoting a circular economy.

Recently, metal-based atomically thin materials (M-ATMs) have experienced rapid development due to their large specific surface areas, abundant electrochemically accessible sites, attractive surface chemistry, and strong in-plane chemical bonds. These characteristics make them highly desirable for energy-related conversion reactions. However, the insufficient active sites and slow reaction kinetics leading to unsatisfactory electrocatalytic performance limited their commercial application. To address these issues, defect engineering of M-ATMs has emerged to increase the active sites, modify the electronic structure, and enhance the catalytic reactivity and stability. This review provides a comprehensive summary of defect engineering strategies for M-ATM nanostructures, including vacancy creation, heteroatom doping, amorphous phase/grain boundary generation, and heterointerface construction. Introducing recent advancements in the application of M-ATMs in electrochemical small molecule conversion reactions (e.g., hydrogen, oxygen, carbon dioxide, nitrogen, and sulfur), which can contribute to a circular economy by recycling molecules like H2, O2, CO2, N2, and S. Furthermore, a crucial link between the reconstruction of atomic-level structure and catalytic activity via analyzing the dynamic evolution of M-ATMs during the reaction process is established. The review also outlines the challenges and prospects associated with M-ATM-based catalysts to inspire further research efforts in developing high-performance M-ATMs.

Single-atom cocatalysts (SACs) in photocatalysis are comprehensively discussed, with a focus on often-overlooked aspects of general concepts and understanding. Key principles, challenges, and recent advancements are covered, highlighting the self-homing effect as a promising avenue for designing SACs with maximized efficiency and unexpected features.

Single-atom (SA) cocatalysts (SACs) have garnered significant attention in photocatalysis due to their unique electronic properties and high atom utilization efficiency. This review provides an overview of the concept and principles of SA cocatalyst in photocatalysis, emphasizing the intrinsic differences to SAs used in classic chemical catalysis. Key factors that influence the efficiency of SAs in photocatalytic reactions, particularly in photocatalytic hydrogen (H2) production, are highlighted. This review further covers synthesis methods, stabilization strategies, and characterization techniques for common SAs used in photocatalysis. Notably, “reactive deposition” method, which often shows a self-homing effect and thus achieves a maximum utilization efficiency of SA cocatalysts, is emphasized. Furthermore, the applications of SA cocatalysts in various photocatalytic processes, including H2 evolution, carbon dioxide reduction, nitrogen fixation, and organic synthesis, are comprehensively reviewed, along with insights into common artifacts in these applications. This review concludes by addressing the challenges faced by SACs in photocatalysis and offering perspectives on future developments, with the aim of informing and advancing research on SAs for photocatalytic energy conversion.

In this review, the authors comprehensively examine the design strategies, fabrication technologies, and diverse applications of P-CHs. By summarizing design strategies, such as molecular, network, phase, and structural engineering, and exploring both 2D and 3D fabrication techniques, it offers a comprehensive overview of P-CHs applications in diverse fields including bioelectronics, soft actuators, energy devices, and solar evaporators.

Conductive hydrogels combine the benefits of soft hydrogels with electrical conductivity and have gained significant attention over the past decade. These innovative materials, including poly(3,4-ethylenedioxythiophene) (PEDOTs)-based conductive hydrogels (P-CHs), are promising for flexible electronics and biological applications due to their tunable flexibility, biocompatibility, and hydrophilicity. Despite the recent advances, the intrinsic correlation between the design, fabrications, and applications of P-CHs has been mostly based on trial-and-error-based Edisonian approaches, significantly limiting their further development. This review comprehensively examines the design strategies, fabrication technologies, and diverse applications of P-CHs. By summarizing design strategies, such as molecular, network, phase, and structural engineering, and exploring both 2D and 3D fabrication techniques, this review offers a comprehensive overview of P-CHs applications in diverse fields including bioelectronics, soft actuators, energy devices, and solar evaporators. Establishing this critical internal connection between design, fabrication, and application aims to guide future research and stimulate innovation in the field of functional P-CHs, offering broad benefits to multidisciplinary researchers.

The declined regeneration potential of aging NPPCs fails to antagonize IVDD. The in-house-customized lipid nanoparticles efficiently introduce Klotho circRNA into NPPCs to engender a renascent phenotypic and attune the balance of ECM synthesis/catabolism. Moreover, chemokine-scavenging hydrogel reservoir in tandem with NPPCs rejuvenated NT-LNPs enlists the regenerative capacity of resident NPPCs and restoration of youthful structure and functional features to the IVD.

The decreased regeneration potential of aging nucleus pulposus resident progenitor cells (NPPCs) fails to resist intervertebral disc degeneration (IVDD), and strategies to remodel the regeneration capacity of senescent NPPC are urgently needed. A decrease in Klotho gene expression in NPPCs of both old mice and humans exacerbates the impaired regenerative functionality of NPPC. Here, an NPPC-targeted lipid thymine nanoparticle (NT-LNP) is reported for the in situ manipulation of the regenerative repair potential of NPPCs, restoration of degenerated nucleus pulposus tissue, and mitigation of IVDD. Specifically, the results showed that the in-house customized lipid nanoparticles efficiently introduced Klotho circular ribonucleic acid (circRNA) into NPPCs to engender a renascent phenotype and tuned the balance of extracellular matrix synthesis/catabolism in vitro and in vivo. Moreover, an intradiscal injectable hydrogel system that scavenges chemokines (MCP1 and IL8) in tandem with NPPCs rejuvenated NT-LNPs in the IVD, modulating the inflammatory environment and synergistically promoting the regeneration of degenerated intervertebral discs. In summary, the findings establish that NPPCs can be re-engineered to be youthful and pluripotent to maintain homeostasis and rejuvenation, thereby providing a reversible treatment strategy for IVDD with broad application in other senescence-related diseases.

A highly transparent photochromic hydrogel electrolyte is developed, which not only serves as an electrolyte for zinc anode-based electrochromic devices but also provides a photochromic effect to reduce tinted transmittance. These dual-responsive dimmers address concerns about low transmittance contrast in electrochromic devices, representing a significant step forward for high-contrast dimming in dynamic windows and AR glasses.

Electrochromism stands out as a highly promising technology for applications including variable optical attenuators, optical switches, transparent displays, and dynamic windows. The pursuit of high-contrast tunability in electrochromic devices remains a challenging goal. Here, the first photochromic hydrogel electrolyte is reported for electro- and photo-dual responsive chromatic devices that yield a high transmittance contrast at 633 nm (ΔT = 83.1%), along with a tinted transmittance below 1.5%. Such high-contrast devices not only hold great promise for dynamic windows but also enable seamless transitions between transparent augmented reality (AR) glass and opaque virtual reality (VR) glass. These findings introduce an innovative strategy for the design of high-contrast dimmers, opening new avenues for the development of chromatic devices.