Construction of an exogenously and endogenously Co-activated DNA logic amplifier for highly reliable intracellular MicroRNA imaging.

DNA-based molecular amplifiers offer significant promise for molecular-level disease diagnosis and treatment, yet tailoring their activation for precise timing and localization remains a challenge. Herein, we've pioneered a dual activation strategy harnessing external light and internal ATP to create a highly controlled DNA logic amplifier (FDLA) for accurate miRNA monitoring in cancer cells. The FDLA was constructed by tethered the two functionalized catalytic hairpin assembly (CHA) hairpin modules (ATP aptamer sealed hairpin aH1 and photocleavable (PC-linker) sites modified hairpin pH2) to DNA tetrahedron (DTN). The FDLA system incorporates ATP aptamers and PC-linkers as logic control units, allowing them to respond to both exogenous UV light and endogenous ATP present within cancer cells. This response triggers the release of CHA hairpin modules, enabling amplified FRET miRNA imaging through an AND-AND gate. The DTN structure could improve the stability of FDLA and accelerate the kinetics of the strand displacement reaction. It is noteworthy that the UV and ATP co-gated DNA circuit can control the DNA bio-computing at specific time and location, offering spatial and temporal capabilities that can be harnessed for miRNA imaging. Furthermore, the miRNA-sensing FDLA amplifier demonstrates reliable imaging of intracellular miRNA with minimal background noise and false-positive signals. This highlights the feasibility of utilizing both exogenous and endogenous regulatory strategies to achieve spatial and temporal control of DNA molecular circuits within living cancer cells. Such advancements hold immense potential for unraveling the correlation between miRNA and associated diseases.

Carrier-Free Nanovaccine: An Innovative Strategy for Ultrahigh Melanoma Neoantigen Loading.

In personalized cancer immunotherapy, developing an effective neoantigen nanovaccine with high immunogenicity is a significant challenge. Traditional nanovaccine delivery systems often require nanocarriers, which can hinder the delivery of the neoantigen and cause significant toxicity. In this study, we present an innovative strategy of carrier-free nanovaccine achieved through direct self-assembly of 2'-fluorinated CpG (2'F-CpG) with melanoma neoantigen peptide (Obsl1). Molecular dynamics simulations demonstrated that the introduction of a fluorine atom into CpG increases the noncovalent interaction between 2'F-CpG and Obsl1, which enhanced the loading of Obsl1 on 2'F-CpG, resulting in the spontaneous formation of a hybrid 2'F-CpG/Obsl1 nanovaccine. This nanovaccine without extra nanocarriers showed ultrahigh Obsl1 loading up to 83.19 wt %, increasing the neoantigen peptide uptake by antigen-presenting cells (APCs). In C57BL/6 mice models, we demonstrated the long-term preventive and therapeutic effects of the prepared 2'F-CpG/Obsl1 nanovaccine against B16F10 melanoma. Immunocellular analysis revealed that the nanovaccine activated innate and adaptive immune responses to cancer cells. Hence, this study established a simple, safe, and effective preparation strategy for a carrier-free neoantigen nanovaccine, which could be adapted for the future design of personalized cancer vaccines in clinical settings.

Heavy Metals in Grains from Jilin Province, China, and Human Health Risk.

ABSTRACT: Heavy metals are an indispensable part of industrial and agricultural development. As the cradle of China's industry and an important province for agricultural production, Jilin Province has been an area of concern about heavy metal pollution in the local environment and grains. In this study, we focused on four heavy metals that are harmful to humans: arsenic (As), cadmium (Cd), methylmercury (MeHg), and inorganic arsenic (iAs). We determined the contents of these metals in 341 grain samples by using graphite furnace atomic absorption spectrometry and liquid chromatography-atomic fluorescence spectrometry and compared our results with the limit value of national standards. To evaluate the potential risk to human health, we determined the target hazard quotient and hazard index. Heavy metals were detected at these rates, from high to low: Cd (48%) > iAs (20.8%) > MeHg (4.6%) > Pb (3%). Most of these values are far below the limit of national standards. The target hazard quotient and hazard index were both smaller than 1; thus, we conclude that heavy metal pollution in grains in Jilin Province is not serious and that people are not at high risk from heavy metals in grains.