• Bisgaard Bonner posted an update 1 day, 6 hours ago

    Oral biofilms, formed by multiple microorganisms and their extracellular polymeric substances, seriously affect people’s life. The emergence of the resistance of biofilms to conventional antibiotics and their side effects on the oral cavity have posed a great challenge in the treatment of dental diseases. Recently, antimicrobial peptides have been recognized as promising alternatives to conventional antibiotics due to their broad antibacterial spectrum, high antibacterial activity, and specific mechanism. However, the research of their anti-biofilm behaviors is still in its infancy, and the underlying mechanism remains unclear. In this study, we investigated the anti-biofilm activities of a designed helical peptide (G3) against Streptococcus mutans (S. mutans), one of the primary causative pathogens of caries. The results indicated that G3 inhibited S. mutans biofilm formation by interfering with different stages of biofilm development. At the initial stage, G3 inhibited the bacterial adhesion by decreasing the bacterial surface charges, hydrophobicity, membrane integrity, and adhesion-related gene transcription. At the later stage, G3 interacted with extracellular DNA to destabilize the 3D architecture of mature biofilms and thus dispersed them. The high activity of G3 against S. mutans biofilms, along with its specific modes of action, endows it great application potential in preventing and treating dental plaque diseases.Intercalation is a unique degree of freedom for tuning the physical and chemical properties of two-dimensional (2D) materials, providing an ideal system to study various electronic states (such as superconductivity, ferromagnetism, and charge density waves). Here, we demonstrate the inversion symmetry breaking in lithium (Li)-intercalated ultrathin graphite (about 20-100 graphene layers) by optical second-harmonic generation (SHG). This inversion symmetry breaking is attributed to nanoscale inhomogeneities (i.e., lattice distortion and dislocations) in lithiated graphite. In addition, the efficiency of the SHG signal in an ultrathin graphite flake is widely tunable by the electrochemical lithiation process, and the efficiency of fully lithiated graphite (LiC6) is comparable to that of other noncentrosymmetric 2D crystals. Our results reveal a novel intercalation-induced inversion symmetry breaking effect and open up possibilities for building 2D intercalated-compounds-based nonlinear optical devices.We demonstrate sequential optical activation of two types of mRNAs in the same mammalian cell through the sequential photocleavage of small molecule caging groups (“photocages”) tethered to the 5′-untranslated region (5′-UTR) of mRNAs. Synthetic photocages were conjugated onto target mRNA using RNA-TAG, an enzymatic site-specific RNA modification technique. Translation of mRNA was severely reduced upon conjugation of the photocages onto the 5′-UTR. However, subsequent photorelease of the cages from the mRNA transcript triggered activation of translation with single-cell spatiotemporal resolution. To achieve sequential photoactivation of two mRNAs in the same cell, we synthesized a pair of photocages that can be selectively cleaved from mRNA upon photoirradiation with different wavelengths of light. Sequential photoactivation of two mRNAs enabled precise optical control of translation of two unique transcripts. We believe that this modular approach to precisely and rapidly control gene expression will serve as a powerful tool in future biological studies that require controlling translation of multiple transcripts with high spatiotemporal resolution.Active sites of proteins are generally encapsulated within three-dimensional peptide scaffolds that provide the molecular-scale confinement microenvironment. Nevertheless, the ability to tune thermodynamic stability in biomimetic molecular confinement relies on the macromolecular crowding effect of lack of stoichiometry and reconfigurability. Here, we report a framework nucleic acid (FNA)-based strategy to increase thermodynamic stability of aptamers. We demonstrate that the molecular-scale confinement increases the thermodynamic stability of aptamers via facilitated folding kinetics, which is confirmed by the single-molecule FRET (smFRET). Unfavorable conformations of aptamers are restricted as revealed by the Monte Carlo simulation. The binding affinity of the DNA framework-confined aptamer is improved by ∼3-fold. With a similar strategy we improve the catalytic activity of hemin-binding aptamer. learn more Our approach thus shows high potential for designing protein-mimicking DNA nanostructures with enhanced binding affinity and catalytic activity for biosensing and biomedical engineering.Treating persistent neuropathic pain remains a major clinical challenge. Current conventional treatment approaches carry a substantial risk of toxicity and provide only transient pain relief. In this work, we show that the activity and expression of the inflammatory mediator secretory phospholipase-A2 (sPLA2) enzyme increases in the spinal cord after painful nerve root compression. We then develop phospholipid micelle-based nanoparticles that release their payload in response to sPLA2 activity. Using a rodent model of neuropathic pain, phospholipid micelles loaded with the sPLA2 inhibitor, thioetheramide-PC (TEA-PC), are administered either locally or intravenously at the time of painful injury or 1-2 days afterward. Local micelle administration immediately after compression prevents pain for up to 7 days. Delayed intravenous administration of the micelles attenuates existing pain. These findings suggest that sPLA2 inhibitor-loaded micelles can be a promising anti-inflammatory nanotherapeutic for neuropathic pain treatment.Subwavelength particles supporting Mie resonances underpin a strategy in nanophotonics for efficient control and manipulation of light by employing both an electric and a magnetic optically induced multipolar resonant response. Here, we demonstrate that monolithic dielectric nanoparticles made of CsPbBr3 halide perovskites can exhibit both efficient Mie-resonant lasing and structural coloring in the visible and near-IR frequency ranges. We employ a simple chemical synthesis with nearly epitaxial quality for fabricating subwavelength cubes with high optical gain and demonstrate single-mode lasing governed by the Mie resonances from nanocubes as small as 310 nm by the side length. These active nanoantennas represent the most compact room-temperature nonplasmonic nanolasers demonstrated until now.