Most of the current methods for programmable RNA drug therapies are unsuitable for the clinic due to low uptake efficiency and high cytotoxicity. Extracellular vesicles (EVs) could solve these problems because they represent a natural mode of intercellular communication. However, current cellular sources for EV production are limited in availability and safety in terms of horizontal gene transfer. One potentially ideal source could be human red blood cells (RBCs). Group O-RBCs can be used as universal donors for large-scale EV production since they are readily available in blood banks and they are devoid of DNA. Here, we describe and validate a new strategy to generate large-scale amounts of RBC-derived EVs for the delivery of RNA drugs, including antisense oligonucleotides, Cas9 mRNA, and guide RNAs. RNA drug delivery with RBCEVs shows highly robust microRNA inhibition and CRISPR–Cas9 genome editing in both human cells and xenograft mouse models, with no observable cytotoxicity.

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As one type of voluntary environmental regulations, environmental disclosure plays an important role in promoting sustainable development of enterprises by enhancing their environmental awareness. Based on the social responsibility and annual reports published by heavily polluting listed companies in China between 2007 and 2016, this article investigates their environmental disclosure and assesses the impact on their green innovation activities as well as its influence mechanisms. Text analysis is used to measure the environmental disclosure by way of three dimensions including environmental investment and management, environmental supervision and agency certification, and environmental performance and governance. The results of the Poisson regression model for panel data show that environmental disclosure has significantly encouraged green innovations carried out by heavily polluting listed companies in China during the past decade and this result is consistent with a variety of robustness checks. Besides, the mediation effect test demonstrates that environmental disclosure stimulated green innovations of heavily polluting listed companies by expanding their financing channels, promoting their product sales, and raising media attention.

Direct measurement of thermodynamic and kinetic parameters of oligonucleotide-directed DNA triple helix formation has been achieved by fluorescence spectroscopic methods. Fluorescence resonance energy transfer (FRET) was used to study the binding of an acceptor-labeled single-stranded oligonucleotide to a donor-labeled DNA duplex. Equilibrium binding constants and association rate constants for triplex formation between 5'-tetramethylrhodamine-labeled 11-mer, 13-mer, and 15-mer homopyrimidine oligonucleotides and a 5'-fluorescein-labeled, 25-bp DNA duplex containing a 15-bp homopurine site were determined by FRET measurements, and the values were in close agreement with those determined by established methods. The thermal dissociation profile of the triplex-to-duplex transition was also directly observed by FRET and was consistent with the triplex melting curves obtained by UV absorbance measurements. In addition, a homogeneous fluorescence anisotropy assay is described which enables determination of the binding constants between 5'-tetramethylrhodamine-labeled 11-mer and 13-mer homopyrimidine oligonucleotides and unlabeled 25-, 30-, and 50-bp double-stranded DNA containing a homopurine target site. These results demonstrate the utility of nonradioactive fluorescence measurements as an efficient method for studying triple helix formation under homogeneous solution conditions and highlight the uniqueness of the FRET method for obtaining equilibrium, kinetic, and thermal dissociation data in a straightforward manner.