Human norovirus (HuNoV) is an enteric infectious pathogen belonging to the Caliciviridae family that causes occasional epidemics. Circulating alcohol-tolerant viral particles that are readily transmitted via food-borne routes significantly contribute to the global burden of HuNoV-induced gastroenteritis. Moreover, contact with enzymes secreted by other microorganisms in the environment can impact the infectivity of viruses. Hence, understanding the circulation dynamics of Caliciviridae is critical to mitigating epidemics. Accordingly, in this study, we screened whether environmentally abundant secretase components, particularly proteases, affect Caliciviridae infectivity. Results showed that combining Bacillaceae serine proteases with epsilon-poly-L-lysine (EPL) produced by Streptomyces-a natural antimicrobial-elicited anti-Caliciviridae properties, including against the epidemic HuNoV GII.4_Sydney_2012 strain. In vitro and in vivo biochemical and virological analyses revealed that EPL has two unique synergistic viral inactivation functions. First, it maintains an optimal pH to promote viral surface conformational changes to the protease-sensitive structure. Subsequently, it inhibits viral RNA genome release via partial protease digestion at the P2 and S domains in the VP1 capsid. This study provides new insights regarding the high-dimensional environmental interactions between bacteria and Caliciviridae, while promoting the development of protease-based anti-viral disinfectants.

The phase separation of protein and RNA mixtures underpins the assembly and regulation of numerous membraneless organelles in cells. The ubiquity of protein-RNA condensates in cellular regulatory processes is in part due to their sensitivity to RNA concentration, which affects their physical properties and stability. Recent experiments with poly-cationic peptide-RNA mixtures have revealed closed-loop phase diagrams featuring lower and upper critical solution temperatures. These diagrams indicate reentrant phase transitions shaped by biomolecular interactions and entropic forces such as solvent and ion reorganization. We employed atomistic simulations to study mixtures with various RNA-polylysine stoichiometries and temperatures to elucidate the microscopic driving forces behind reentrant phase transitions in protein-RNA mixtures. Our findings reveal an intricate interplay between hydration, ion condensation, and specific RNA-polylysine hydrogen bonding, resulting in distinct stoichiometry-dependent phase equilibria governing stabilities and structures of the condensate phase. Our simulations show that reentrant transitions are accompanied by desolvation around the phosphate groups of RNA, with increased contacts between phosphate and lysine side chains. In RNA-rich systems at lower temperatures, RNA molecules can form an extensive pi-stacking and hydrogen bond network, leading to percolation. In protein-rich systems, no such percolation-induced transitions are observed. Furthermore, we assessed the performance of three prominent water force fields-Optimal Point Charge (OPC), TIP4P-2005, and TIP4P-D-in capturing reentrant phase transitions. OPC provided a superior balance of interactions, enabling effective capture of reentrant transitions and accurate characterization of changes in solvent reorganization. This study offers atomistic insights into the nature of reentrant phase transitions using simple model peptide and nucleotide mixtures. We believe that our results are broadly applicable to larger classes of peptide-RNA mixtures exhibiting reentrant phase transitions.

UNASSIGNED: Persistent endodontic infections (PEIs) mediated by bacterial biofilm mainly cause persistent periapical inflammation, resulting in recurrent periapical abscesses and progressive bone destruction. However, conventional root canal disinfectants are highly damaging to the tooth and periodontal tissue and ineffective in treating persistent root canal infections. Antimicrobial materials that are biocompatible with apical tissues and can eliminate PEIs-associated bacteria are urgently needed.
UNASSIGNED: Here, ε-poly (L-lysine) derived carbon quantum dots (PL-CQDs) are fabricated using pyrolysis to remove PEIs-associated bacterial biofilms.
UNASSIGNED: Due to their ultra-small size, high positive charge, and active reactive oxygen species (ROS) generation capacity, PL-CQDs exhibit highly effective antibacterial activity against Enterococcus faecalis (E. faecalis), which is greatly dependent on PL-CQDs concentrations. 100 µg/mL PL-CQDs could kill E. faecalis in 5 min. Importantly, PL-CQDs effectively achieved a reduction of biofilms in the isolated teeth model, disrupting the dense structure of biofilms. PL-CQDs have acceptable cytocompatibility and hemocompatibility in vitro and good biosafety in vivo.
UNASSIGNED: Thus, PL-CQDs provide a new strategy for treating E. faecalis-associated PEIs.

ε-Poly-l-lysine (ε-PL) is an effective antimicrobial peptide for controlling fungal plant diseases, exhibiting significant antifungal activity and safety. Despite its known efficacy, the potential of ε-PL in combating plant bacterial diseases remains underexplored. This study evaluated the effectiveness of ε-PL and its nanomaterial derivative in managing tomato bacterial spot disease caused by Pseudomonas syringae pv. tomato. Results indicated that ε-PL substantially inhibited the growth of Pseudomonas syringae pv. tomato. Additionally, when ε-PL was loaded onto attapulgite (encoded as ATT@PL), its antibacterial effect was significantly enhanced. Notably, the antibacterial efficiency of ATT@PL containing 18.80 μg/mL ε-PL was even close to that of 100 μg/mL pure ε-PL. Further molecular study results showed that, ATT@PL stimulated the antioxidant system and the salicylic acid signaling pathway in tomatoes, bolstering the plants disease resistance. Importantly, the nanocomposite demonstrated no negative effects on both seed germination and plant growth, indicating its safety and aligning with sustainable agricultural practices. This study not only confirmed the effectiveness of ε-PL in controlling tomato bacterial spot disease, but also introduced an innovative high antibacterial efficiency ε-PL composite with good bio-safety. This strategy we believe can also be used in improving other bio-pesticides, and has high applicability in agriculture practice.

Poly-l-lysine (PLL) and Matrigel, both classical coating materials for culture substrates in neural stem cell (NSC) research, present distinct interfaces whose effect on NSC behavior at cellular and molecular levels remains ambiguous. Our investigation reveals intriguing disparities: although both PLL and Matrigel interfaces are hydrophilic and feature amine functional groups, Matrigel stands out with lower stiffness and higher roughness. Based on this diversity, Matrigel surpasses PLL, driving NSC adhesion, migration, and proliferation. Intriguingly, PLL promotes NSC differentiation into astrocytes, whereas Matrigel favors neural differentiation and the physiological maturation of neurons. At the molecular level, Matrigel showcases a wider upregulation of genes linked to NSC behavior. Specifically, it enhances ECM-receptor interaction, activates the YAP transcription factor, and heightens glycerophospholipid metabolism, steering NSC proliferation and neural differentiation. Conversely, PLL upregulates genes associated with glial cell differentiation and amino acid metabolism and elevates various amino acid levels, potentially linked to its support for astrocyte differentiation. These distinct transcriptional and metabolic activities jointly shape the divergent NSC behavior on these substrates. This study significantly advances our understanding of substrate regulation on NSC behavior, offering novel insights into optimizing and targeting the application of these surface coating materials in NSC research.

UNASSIGNED: The emergence and rapid spread of multidrug-resistant bacteria (MRB) caused by the excessive use of antibiotics and the development of biofilms have been a growing threat to global public health. Nanoparticles as substitutes for antibiotics were proven to possess substantial abilities for tackling MRB infections via new antimicrobial mechanisms. Particularly, carbon dots (CDs) with unique (bio)physicochemical characteristics have been receiving considerable attention in combating MRB by damaging the bacterial wall, binding to DNA or enzymes, inducing hyperthermia locally, or forming reactive oxygen species.
UNASSIGNED: Herein, how the physicochemical features of various CDs affect their antimicrobial capacity is investigated with the assistance of machine learning (ML) tools.
UNASSIGNED: The synthetic conditions and intrinsic properties of CDs from 121 samples are initially gathered to form the raw dataset, with Minimum inhibitory concentration (MIC) being the output. Four classification algorithms (KNN, SVM, RF, and XGBoost) are trained and validated with the input data. It is found that the ensemble learning methods turn out to be the best on our data. Also, ε-poly(L-lysine) CDs (PL-CDs) were developed to validate the practical application ability of the well-trained ML models in a laboratory with two ensemble models managing the prediction.
UNASSIGNED: Thus, our results demonstrate that ML-based high-throughput theoretical calculation could be used to predict and decode the relationship between CD properties and the anti-bacterial effect, accelerating the development of high-performance nanoparticles and potential clinical translation.

To overcome the biological barriers in the journey of systemic gene delivery, a multifaceted genomic synthetic nanomedicine was elaborated and strategically equipped with a multiple of intriguing responsiveness. Particularly, core-shell plasmid DNA condensates were created based on polyionic complexation with block copolymer of polyethylene glycol (PEG)-polylysine (PLys), namely, the nanoscaled PLys&pDNA nanoparticle tethered with the biocompatible PEG surroundings. Furthermore, redox-reversible disulfide crosslinking was introduced into PLys&pDNA nanoparticle to accomplish adequate structural stabilities, and thermal-responsive polypropylacrylamide (PNIPAM) was introduced as the secondary intermediate surroundings onto the pre-formulated PLys&pDNA nanoparticle with the aim of preventing the potential enzymatic degradation from the environmental nucleases. Hence, hundreds of times prolonged survival and retention was determined in pertinent to the blood circulation properties. Additionally, the installation of a guide ligand at the distal end of PEG segments was proposed to encourage selective tumor uptake. A linear peptide of GPLGVRG, which is selectively susceptible to digestion by the tumor-enriched matrix metalloproteinase 2 (MMP-2), was used as the linkage between the shell and core. This peptide has been shown to detach the bio-inert PEGylation, resulting in further facilitated cell endocytosis and intracellular trafficking activities. Hence, the precisely defined synthetic nanomedicine, which exhibits desirable characteristics, efficient expression of the therapeutic gene in the affected cells, and contributed to potent therapeutic efficacy in systemic treatment of intractable tumors by encapsulating the anti-angiogenic gene.

The mass proliferation of seed cells and imitation of meat structures remain challenging for cell-cultured meat production. With excellent biocompatibility, high water content and porosity, hydrogels are frequently-studied materials for anchorage-dependent cell scaffolds in biotechnology applications. Herein, a scaffold based on gelatin/alginate/ε-Poly-l-lysine (GAL) hydrogel is developed for skeletal muscle cells, which has a great prospect in cell-cultured meat production. In this work, the hydrogel GAL-4:1, composed of gelatin (5 %, w/v), alginate (5 %, w/v) and ε-Poly-l-lysine (molar ratio vs. alginate: 4:1) is selected as cell scaffold based on Young\'s modulus of 11.29 ± 1.94 kPa, satisfactory shear-thinning property and suitable porous organized structure. The commercially available C2C12 mouse skeletal myoblasts and porcine muscle stem cells (PMuSCs), are cultured in the 3D-printed scaffold. The cells show strong ability of attachment, proliferation and differentiation after induction, showing high biocompatibility. Furthermore, the cellular bioprinting is performed with GAL-4:1 hydrogel and freshly extracted PMuSCs. The extracted PMuSCs exhibit high viability and display early myogenesis (desmin) on the 3D scaffold, suggesting the great potential of GAL hydrogel as 3D cellular constructs scaffolds. Overall, we develop a novel GAL hydrogel as a 3D-printed bioactive platform for cultured meat research.

Widespread outbreaks of threatening infections caused by unknown pathogens and water transmission have spawned the development of adsorption methods for pathogen elimination. We proposed a biochar functionalization strategy involving ε-polylysine (PLL), a bio-macromolecular poly(amino acid)s with variable folding conformations, as a \"pathogen gripper\" on biochar. PLL was successfully bridged onto biochar via polydopamine (PDA) crosslinking. The extension of electropositive side chains within PLL enables the capture of both nanoscale viruses and micrometer-scale bacteria in water, achieving excellent removal performances. This functionalized biochar was tentatively incorporated into ultrafiltration (UF) system, to achieve effective and controllable adsorption and retention of pathogens, and to realize the transfer of pathogens from membrane surface/pore to biochar surface as well as flushing water. The biochar-amended UF systems presents complete retention (∼7 LRV) and hydraulic elution of pathogens into membrane flushing water. Improvements in removal of organics and anti-fouling capability were observed, indicating the broken trade-off in UF pathogen removal dependent on irreversible fouling. Chemical characterizations revealed adsorption mechanisms encompassing electrostatic/hydrophobic interactions, pore filling, electron transfer, chemical bonding and secondary structure transitions. Microscopic and mechanical analyses validated the mechanisms for rapid adsorption and pathogen lysis. Low-concentration alkaline solution for used biochar regeneration, facilitated the deprotonation and transformation of PLL side chain to folded structures (α-helix/β-sheet). Biochar regeneration process also promoted the effective detachment/inactivation of pathogens and protection of functional groups on biochar, corroborated by physicochemical inspection and molecular dynamics simulation. The foldability of poly(amino acid)s acting like dynamic arms, significantly contributed to pathogen capture/desorption/inactivation and biochar regeneration. This study also inspires future investigation for performances of UF systems amended by poly(amino acid)s-functionalized biochar under diverse pressure, temperature, reactive oxygen species of feeds and chemical cleaning solutions, with far-reaching implications for public health, environmental applications of biochar, and UF process improvement.

Ion mobility mass spectrometry (IM-MS) measures the mass, size, and shape of ions in the same experiment, and structural information is provided via collision cross-section (CCS) values. The majority of commercially available IM-MS instrumentation relies on the use of CCS calibrants, and here, we present data from a family of poly(l-lysine) dendrimers and explore their suitability for this purpose. In order to test these compounds, we employed three different IM-MS platforms (Agilent 6560 IM-QToF, Waters Synapt G2, and a home-built variable temperature drift tube IM-MS) and used them to investigate six different generations of dendrimers in two buffer gases (helium and nitrogen). Each molecule gives a highly discrete CCS distribution suggestive of single conformers for each m/z value. The DTCCSN2 values of this series of molecules (molecular weight: 330-16,214 Da) range from 182 to 2941 Å2, which spans the CCS range that would be found by many synthetic molecules including supramolecular compounds and many biopolymers. The CCS values for each charge state were highly reproducible in day-to-day analysis on each instrument, although we found small variations in the absolute CCS values between instruments. The rigidity of each dendrimer was probed using collisionally activated and high-temperature IM-MS experiments, where no evidence for a significant CCS change ensued. Taken together, this data indicates that these polymers are candidates for CCS calibration and could also help to reconcile differences found in CCS measurements on different instrument geometries.