Anisotropic hydrogel degradation enhances 3D collective mesenchymal stromal cell alignment, mechanotransduction and osteogenic differentiation.

Tissue engineering involves assembling cells and mimicking the complex anisotropic architecture of biological tissues to perform specific functions. This study uses 3D alginate-based hydrogels with RGD binding motifs to explore the impact of anisotropic degradation of patterned hydrogels (two components: degradable (Deg) and non-degradable (noDeg)) compared to single-phase materials (one component: Deg or noDeg), on the potential of enhancing cell spreading, collective alignment, mechanotransduction and osteogenic differentiation of encapsulated human mesenchymal stromal cells (hMSCs). Spatial patterns of Deg and noDeg subregions are formed by photolithography: UV-triggered thiol-ene crosslinking with matrix metalloprotease (MMP) sensitive peptides form Deg phases, while non-UV exposed regions result in Diels-Alder spontaneous click crosslinking and noDeg phases.

Activity-Based Tracking of Glycan Turnover in Microbiomes.

Glycans shape microbiomes in the ocean and the gut, driving key steps in the global carbon cycle and human health. Yet, our ability to track microbial glycan turnover across microbiomes is limited, as identifying active degraders without prior genomic knowledge remains a key challenge. Here, we introduce an activity-based fluorescence resonance energy transfer (FRET) probe that enables direct visualization and quantification of glycan metabolism in complex microbial communities.

Glycan Annotation of Mass Spectrometry Data.

Carbohydrates are fundamental molecules of life that are involved in virtually all biological processes. The chemical diversity of glycans─carbohydrate chains─enables diverse functions but also challenges analytics. Annotation of glycans in mass spectrometry (MS) data relies heavily on experimental databases or manual calculations, hindering the discovery of novel glycan compositions and structures.

Exploring marine glycans: structure, function, and the frontier of chemical synthesis.

Marine glycans are structurally diverse biomolecules that play pivotal roles in oceanic carbon cycling by regulating microbial metabolism, accelerating organic matter turnover, and contribute to carbon sequestration. Glycans originating from marine organisms exhibit a wide range of bioactivities and applications in medicine, biotechnology, cosmetics, food and agriculture. The structural complexity of glycans poses significant challenges in understanding their functions, as traditional purification and characterization methods are often hindered by their inherent heterogeneity.

Photolabile Linkers for Solid-Phase Synthesis of Oligosaccharides.

Photolabile linkers are chemically very stable and can be cleaved under mild conditions without destructive reactions on target molecules. o-Nitrobenzyl-based linkers are widely used in solid phase synthesis. Recently, our group developed several o-nitrobenzylic-based photolabile resins retaining different modifications at reducing-end of glycans after photocleavage.

Confined Flash Printing and Synthesis of Stable Perovskite Nanofilms under Ambient Conditions.

The fabrication of stable perovskite nanofilm patterns is important for the development of functional optical devices. However, current production approaches are limited by the requirement for strict inert gas protection and long processing times. Here, a confined flash printing synthesis method is presented to generate perovskite nanofilms under ambient conditions, combining precursor transfer, perovskite synthesis, crystallization, and polymer protection in a single step within milliseconds.

Bio-electrocatalytic Alkene Reduction Using Ene-Reductases with Methyl Viologen as Electron Mediator.

Asymmetric hydrogenation of alkene moieties is important for the synthesis of chiral molecules, but achieving high stereoselectivity remains a challenge. Biocatalysis using ene-reductases (EReds) offers a viable solution. However, the need for NAD(P)H cofactors limits large-scale applications.

A Fluorinated Sialic Acid Vaccine Lead Against Meningitis B and C.

Inspired by the specificity of α-(2,9)-sialyl epitopes in bacterial capsular polysaccharides (CPS), a doubly fluorinated disaccharide has been validated as a vaccine lead against serogroups C and/or B. Emulating the importance of fluorine in drug discovery, this molecular editing approach serves a multitude of purposes, which range from controlling α-selective chemical sialylation to mitigating competing elimination. Conjugation of the disialoside with two carrier proteins (CRM197 and PorA) enabled a semisynthetic vaccine to be generated; this was then investigated in six groups of six mice.

Recyclable and Robust Optical Nanoprobes with Engineered Enzymes for Sustainable Serodiagnostics.

Recyclable fluorescence assays that can be stored at room temperature would greatly benefit biomedical diagnostics by bringing sustainability and cost-efficiency, especially for point-of-care serodiagnostics in developing regions. Here, a general strategy is proposed to generate recyclable fluorescent probes by using engineered enzymes with enhanced thermo-/chemo-stability, which maintains an outstanding serodiagnostic performance (accuracy >95%) after 10 times of recycling as well as after storage at elevated temperatures (37 °C for 10 days). With these three outstanding properties, recyclable fluorescent probes can be designed to detect various biomarkers of clinical importance by using different enzymes.

Relevance of Host Cell Surface Glycan Structure for Cell Specificity of Influenza A Viruses.

Influenza A viruses (IAVs) initiate infection via binding of the viral hemagglutinin (HA) to sialylated glycans on host cells. HA's receptor specificity towards individual glycans is well studied and clearly critical for virus infection, but the contribution of the highly heterogeneous and complex glycocalyx to virus-cell adhesion remains elusive. Here, we use two complementary methods, glycan arrays and single-virus force spectroscopy (SVFS), to compare influenza virus receptor specificity with virus binding to live cells.

Hydrogels with stiffness-degradation spatial patterns control anisotropic 3D cell response.

In nature, tissues are patterned, but most biomaterials used in human applications are not. Patterned biomaterials offer the opportunity to mimic spatially segregating biophysical and biochemical properties found in nature. Engineering such properties allows to study cell-matrix interactions in anisotropic matrices in great detail.

Rational Design of a Triple Tumor Microenvironment-Responsive Nanoplatform for Enhanced Tumor Theranostics.

The development of responsive nanoplatforms based on the tumor microenvironment (TME) is critical for tumor diagnosis and treatment. Concentrating on a single TME-responsive nanoplatform, however, may result in insufficient diagnostic accuracy and treatment efficacy. Herein, layered double-hydroxides (LDHs) and rare earth nanomaterials (Er@Lu) were combined to create a triple TME-responsive nanoplatform that was then modified with cypate (a fluorescent dye with strong absorbance) by a peptide chain and loaded with epigallocatechin gallate (EGCG), a chemotherapeutic drug.

Self-repairing interphase reconstructed in each cycle for highly reversible aqueous zinc batteries.

Aqueous zinc (Zn) chemistry features intrinsic safety, but suffers from severe irreversibility, as exemplified by low Coulombic efficiency, sustained water consumption and dendrite growth, which hampers practical applications of rechargeable Zn batteries. Herein, we report a highly reversible aqueous Zn battery in which the graphitic carbon nitride quantum dots additive serves as fast colloid ion carriers and assists the construction of a dynamic & self-repairing protective interphase. This real-time assembled interphase enables an ion-sieving effect and is found actively regenerate in each battery cycle, in effect endowing the system with single Zn conduction and constant conformal integrality, executing timely adaption of Zn deposition, thus retaining sustainable long-term protective effect.

Imaging Keratan Sulfate in Ocular Tissue Sections by Immunofluorescence Microscopy and LA-ICP-MS.

Carbohydrate-specific antibodies can serve as valuable tools to monitor alterations in the extracellular matrix resulting from pathologies. Here, the keratan sulfate-specific monoclonal antibody MZ15 was characterized in more detail by immunofluorescence microscopy as well as laser ablation ICP-MS using tissue cryosections and paraffin-embedded samples. Pretreatment with keratanase II prevented staining of samples and therefore demonstrated efficient enzymatic keratan sulfate degradation.

Influence of Methylene Fluorination and Chain Length on the Hydration Shell Structure and Thermodynamics of Linear Diols.

The interplay between the local hydration shell structure, the length of hydrophobic solutes, and their identity (perfluorinated or not) remains poorly understood. We address this issue by combining Raman-multivariate curve resolution (Raman-MCR) spectroscopy, simulation, and quantum-mechanical calculations to quantify the thermodynamics and the first principle interactions behind the formation of defects in the hydration shell of alkyl-diol and perfluoroalkyl-diol chains. The hydration shell of the fluorinated diols contains substantially more defects than that of the nonfluorinated diols; these defects are water hydroxy groups that do not donate hydrogen bonds and which either point to the solute (radial-dangling OH) or not (nonradial-dangling OH).

Ionic surfactants as assembly crosslinkers triggered supramolecular membrane with 2D↔3D conversion under multiple stimulus.

Hypothesis: General strategies leading to 2D assemblies promise a significant step forward in the development of supramolecular materials with diversity and superiority. Considering molecular packing parameter indicates a connection between molecular geometry and aggregate morphology, we predict the introduction of ionic surfactants as assembly crosslinker would be endowed to develop a methodology of 2D supramolecular assembles.

Experiments: In this work, by introducing ionic surfactants such as sodium dodecylsulfate (SDS), the molecular packing parameter P in bolaamphiphile (A2G) system was increased, which successfully manipulated the transformation of the 3D vesicles into 2D membranes.

In vitro efficacy of Artemisia extracts against SARS-CoV-2.

Background: Traditional medicines based on herbal extracts have been proposed as affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Teas and drinks containing extracts of Artemisia annua and Artemisia afra have been widely used in Africa in efforts to prevent SARS-CoV-2 infection and fight COVID-19.

Methods: The plant extracts and Covid-Organics drink produced in Madagascar were tested for plaque reduction using both feline coronavirus and SARS-CoV-2 in vitro.

Evaluation of Multivalent Sialylated Polyglycerols for Resistance Induction in and Broad Antiviral Activity against Influenza A Viruses.

The development of multivalent sialic acid-based inhibitors active against a variety of influenza A virus (IAV) strains has been hampered by high genetic and structural variability of the targeted viral hemagglutinin (HA). Here, we addressed this challenge by employing sialylated polyglycerols (PGs). Efficacy of prototypic PGs was restricted to a narrow spectrum of IAV strains.

Artemisinin inhibits NRas palmitoylation by targeting the protein acyltransferase ZDHHC6.

Protein S-palmitoylation is a post-translational modification that plays a crucial role in cancer cells by regulating the function and localization of oncoproteins and tumor suppressor proteins. Here, we identify artemisinin (ART), a clinically approved antimalarial endoperoxide natural product with promising anticancer activities, as an inhibitor of the ER-residing palmitoyl transferase ZDHHC6 in cancer cells using a chemoproteomic approach. We show that ART covalently binds and inhibits ZDHHC6 to reduce palmitoylation of the oncogenic protein NRas, disrupt NRas subcellular localization, and attenuate the downstream pro-proliferative signaling cascades.

In vitro efficacy of artemisinin-based treatments against SARS-CoV-2.

Effective and affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are needed. We report in vitro efficacy of Artemisia annua extracts as well as artemisinin, artesunate, and artemether against SARS-CoV-2. The latter two are approved active pharmaceutical ingredients of anti-malarial drugs.

Multi-Channel Optical Device for Solar-Driven Bacterial Inactivation under Real-Time Temperature Feedback.

Solar-driven photothermal antibacterial devices have attracted a lot of interest due to the fact that solar energy is one of the cleanest sources of energy in the world. However, conventional materials have a narrow absorbance band, resulting in deficient solar harvesting. In addition, lack of knowledge on temperature change in these devices during the photothermal process has also led to a waste of energy.

Customized Photothermal Therapy of Subcutaneous Orthotopic Cancer by Multichannel Luminescent Nanocomposites.

Photothermal therapy (PTT) is a potentially advanced strategy for highly precise cancer treatment. Tumor-microenvironment-activatable agents provide useful tools for PTT, but their photothermal conversion capacities vary and cannot be evaluated in vivo; thus, a general PTT prescription does not work with individual activatable agents. Here, glutathione (GSH)-activatable nanocomposites, silicomolybdate-functionalized NaLuF :Yb,Er@NaLuF @NaLuF :Nd are prepared, for customized PTT of subcutaneous orthotopic cancer.

Automated Assembly of Starch and Glycogen Polysaccharides.

Polysaccharides are Nature's most abundant biomaterials essential for plant cell wall construction and energy storage. Seemingly minor structural differences result in entirely different functions: cellulose, a β (1-4) linked glucose polymer, forms fibrils that can support large trees, while amylose, an α (1-4) linked glucose polymer forms soft hollow fibers used for energy storage. A detailed understanding of polysaccharide structures requires pure materials that cannot be isolated from natural sources.