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Recently, lipid nanoparticles (LNPs)‐based mRNA delivery has been approved by the FDA for SARS‐CoV‐2 vaccines. However, there are still considerable points for improvement in LNPs. Especially, local administration of LNPs‐formulated mRNA can cause off‐target translation of mRNA in distal organs which can induce unintended adverse effects. With the hypothesis that large and rigid nanoparticles can be applied to enhance retention of nanoparticles at the injection site, a polyethyleneimine (PEI)‐coated porous silica nanoparticles (PPSNs)‐based mRNA delivery platform is designed. PPSNs not only facilitate localized translation of mRNA at the site of injection but also prolonged protein expression. It is further demonstrated that the development of a highly efficacious Zika virus (ZIKV) vaccine using mRNA encoding full‐length ZIKV pre‐membrane (prM) and envelope (E) protein delivered by PPSNs. The ZIKV prME mRNA‐loaded PPSNs vaccine elicits robust immune responses, including high levels of neutralizing antibodies and ZIKV E‐specific T cell responses in C57BL/6 mice. Moreover, a single injection of prME‐PPSNs vaccine provided complete protection against the ZIKV challenge in mice. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) continue to be applied to agricultural and medical applications because of their antibacterial and antifungal effects. However, AgNPs are vulnerable to poisoning by oxidation or sulfidation, and unintentional toxicity can occur via leaching. Therefore, ensuring the stability of AgNPs for practical applications is considered an important requirement. In this study, we propose the solvothermal galvanic replacement of a Te nanorod (TeNR) template with a Ag precursor to manufacture highly stable and biocompatible Ag–Te nanoparticles (AgTeNPs). In addition to their high stability, AgTeNPs composed of Ag2Te–Ag4.53Te3 were evaluated as a nanotherapeutic agent enabled by their selective toxicity through metabolic degradation in breast cancer cells. It has been demonstrated that combinatorial treatment with hyperthermic cancer-cell ablation through photothermal conversion provides an effective cancer treatment in vitro and in vivo. The discovered new biocompatible Ag nanomaterials with innate anticancer effects are expected to be applied to various application fields. [ABSTRACT FROM AUTHOR]

This paper reports an enzyme activity assay that combines the assets of both homogeneous and solid-phase formats. In this method, enzyme reactions are carded out in solution using substrates that are tagged with an immobilization reagent that allows the substrates to be selectively immobilized to self-assembled monolayers (SAMs), for direct analysis by matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). As a model enzyme reaction, this work examined the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to an arginine side chain of a peptide substrate by the enzyme protein arginine methyltransferase 1 (RMT1). A cysteine-terminated peptide substrate was methylated by RMT1 in solution and then applied to a maleimide-presenting SAM to give selective immobilizaton of the peptide. Time-dependent analysis of methylation using MALDI-TOFMS clearly showed that both the presence and relative amount of the two reaction products-the mono- and dimethylated peptides-can be conveniently evaluated. This assay strategy is rapid, takes advantage of solution-phase assay conditions, avoids the use of labels and complicated purification steps, and is applicable to multianalyte analyses.