A single dose of VEGF-A circular RNA sustains in situ long-term expression of protein to accelerate diabetic wound healing.

Diabetic foot ulcer (DFU), which is characterised by damage to minute blood vessels or capillaries around wounds, is one of the most serious and dreaded complications of diabetes. It is challenging to repair chronic non-healing DFU wounds. Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis and promotes wound healing in DFU. However, it is difficult to sustainably deliver VEGF to the wound site owing to its poor stability and easy degradation. To overcome this challenge, lipid nanoparticles (LNP) encapsulating circular RNA (circRNA) encoding VEGF-A have been developed to continuously generate and release VEGF-A and accelerate diabetic wound healing. First, VEGF-A circRNA was synthesized using group I intron autocatalysis strategy and confirmed by enzyme digestion, polymerase chain reaction, and sequencing assay. VEGF-A circRNA was encapsulated in ionizable lipid U-105-derived LNP (U-LNP) using microfluidic technology to fabricate U-LNP/VEGF-A circRNA. For comparison, a commercially ionizable lipid ALC-0315-derived LNP (A-LNP) encapsulating circRNA (A-LNP/circRNA) was used. Dynamic light scattering and transmission electron microscopy characterization indicated that U-LNP/circRNA had spherical structure with an average diameter of 108.5 nm, a polydispersity index of 0.22, and a zeta potential of -3.31 mV. The messenger RNA (mRNA) encapsulation efficiency (EE%) of U-LNP was 87.12%. In vitro transfection data confirmed better stability and long-term VEGF-A expression of circRNA compared with linear mRNA. Assessment of cytotoxicity and innate immunity further revealed that U-LNP/circRNA was biocompatible and induced a weak congenital immune response. Cell scratch and angiogenesis tests demonstrated the bioactivity of U-LNP/VEGF-A circRNA owing to its VEGF-A expression. In situ bioluminescence imaging of firefly luciferase (F-Luc) probe and ELISA demonstrated that circRNA had long-term and strong expression of VEGF-A in the first week, and a gradual decrease in the next week at the wound site and surrounding areas. Finally, a diabetic mouse model was used to validate the healing effect of U-LNP/VEGF-A circRNA formulation. The results showed that a single dose of U-LNP/VEGF-A circRNA administered by dripping resulted in almost complete wound recovery on day 12, which was significantly superior to that of U-LNP/VEGF-A linear mRNA, and it also outperformed recombinant human vascular endothelial growth factor (rhVEGF) injection and A-LNP/circRNA dripping. Histological analysis confirmed the healing efficiency and low toxicity of U-LNP/VEGF-A circRNA formulation. Together, VEGF-A circRNA delivered by U-105-derived LNP showed good performance in wound healing, which was ascribed to the long-term expression and continuous release of VEGF-A, and has potential applications for the treatment of diabetic foot ulcer wounds.

Dietary dicarbonyl compounds exacerbated immune dysfunction and hepatic oxidative stress under high-fat diets in vivo.

High-fat diets (HFDs) predispose to obesity and liver dysfunctions, and α-dicarbonyl compounds (α-DCs) present in highly processed foods are also implicated in relevant pathological processes. However, the synergistic harmful effects of α-DCs co-administered with HFDs remain to be elucidated. In this study, 6-week-old C57BL/6 mice were fed with a HFD co-administered with 0.5% methylglyoxal (MGO)/glyoxal (GO) in water for 8 weeks, and multi-omics approaches were employed to investigate the underlying toxicity mechanisms. The results demonstrated that the MGO intervention with a HFD led to an increased body weight and blood glucose level, accompanied by the biological accumulation of α-DCs and carboxymethyl-lysine, as well as elevated serum levels of inflammatory markers including IL-1ß, IL-6, and MIP-1α. Notably, hepatic lesions were observed in the MGO group under HFD conditions, concomitant with elevated levels of malondialdehyde. Transcriptomic analysis revealed enrichment of pathways and differentially expressed genes (DEGs) associated with inflammation and oxidative stress in the liver. Furthermore, α-DC intervention exacerbated gut microbial dysbiosis in the context of a HFD, and through Spearman correlation analysis, the dominant genera such as Fusobacterium and Bacteroides in the MGO group and Colidextribacter and Parabacteroides in the GO group were significantly correlated with a set of DEGs involved in inflammatory and oxidative stress pathways in the liver. This study provides novel insights into the healthy implications of dietary ultra-processed food products in the context of obesity-associated disorders.

Brain Targeting Nanomedicines: Pitfalls and Promise.

Brain diseases are the most devastating problem among the world's increasingly aging population, and the number of patients with neurological diseases is expected to increase in the future. Although methods for delivering drugs to the brain have advanced significantly, none of these approaches provide satisfactory results for the treatment of brain diseases. This remains a challenge due to the unique anatomy and physiology of the brain, including tight regulation and limited access of substances across the blood-brain barrier. Nanoparticles are considered an ideal drug delivery system to hard-to-reach organs such as the brain. The development of new drugs and new nanomaterial-based brain treatments has opened various opportunities for scientists to develop brain-specific delivery systems that could improve treatment outcomes for patients with brain disorders such as Alzheimer's disease, Parkinson's disease, stroke and brain tumors. In this review, we discuss noteworthy literature that examines recent developments in brain-targeted nanomedicines used in the treatment of neurological diseases.

Preparation and Evaluation of a Novel 99mTc-Labeled Niraparib Isonitrile Complex as a Potential PARP-1 Imaging Agent.

Poly ADP-ribose polymerase (PARP) plays an important role in the DNA repair process and has become an attractive target for cancer therapy in recent years. Given that niraparib has good clinical efficacy as a PARP inhibitor, this study aimed to develop radiolabeled niraparib derivatives for tumor imaging to detect PARP expression and improve the accuracy of stratified patient therapy. The niraparib isonitrile derivative (CNPN) was designed, synthesized, and radiolabeled to obtain the [99mTc]Tc-CNPN complex with high radiochemical purity (>95%). It was lipophilic and stable in vitro. In HeLa cell experiments, the uptake of [99mTc]Tc-CNPN was effectively inhibited by the ligand CNPN, indicating the binding affinity for PARP. According to the biodistribution studies of HeLa tumor-bearing mice, [99mTc]Tc-CNPN has moderate tumor uptake and can be effectively inhibited, demonstrating its specificity for targeting PARP. The SPECT imaging results showed that [99mTc]Tc-CNPN had tumor uptake at 2 h postinjection. All of the results of this study indicated that [99mTc]Tc-CNPN is a promising tumor imaging agent that targets PARP.

Detection of ion cyclotron emission by using an ion cyclotron range of frequency antennas-based diagnostic system in experimental advanced superconducting tokamak.

In the experimental advanced superconducting tokamak (EAST), a novel ion cyclotron range of frequency (ICRF) antenna-based diagnostic system is designed to measure ion cyclotron emission (ICE) driven by high-energy ions. The diagnostic system includes ICRF antenna straps, a three-tune impedance matching system, a coaxial switching system, a direct current block, and a data acquisition and storage system. Using the coaxial switching system, the ICRF antenna can be switched from the heating mode to the coupling mode between two discharges. In the 2023 EAST experiment campaign, core ICE was observed using the ICRF antenna-based diagnostic system during neutron beam injection heating, and the obtained results agreed well with the signal detected by the previous high-frequency B-dot probe-based diagnostic system.

Universal scaling law for chiral antiferromagnetism.

The chiral antiferromagnetic (AFM) materials, which have been widely investigated due to their rich physics, such as non-zero Berry phase and topology, provide a platform for the development of antiferromagnetic spintronics. Here, we find two distinctive anomalous Hall effect (AHE) contributions in the chiral AFM Mn3Pt, originating from a time-reversal symmetry breaking induced intrinsic mechanism and a skew scattering induced topological AHE due to an out-of-plane spin canting with respect to the Kagome plane. We propose a universal AHE scaling law to explain the AHE resistivity ( ρ A H ) in this chiral magnet, with both a scalar spin chirality (SSC)-induced skew scattering topological AHE term, a s k and non-collinear spin-texture induced intrinsic anomalous Hall term, b i n . We found that a s k and b i n can be effectively modulated by the interfacial electron scattering, exhibiting a linear relation with the inverse film thickness. Moreover, the scaling law can explain the anomalous Hall effect in various chiral magnets and has far-reaching implications for chiral-based spintronics devices.

Preparation, Biological Evaluation, and First-in-Human Single-Photon Emission Computed Tomography (SPECT) Study of 99mTc-Labeled Prostate-Specific Membrane Antigen (PSMA)-Targeted Radiotracers Containing Triazole with Reduced Kidneys Accumulation.

Prostate-specific membrane antigen (PSMA), a well-established biological marker for prostate cancer (PCa) imaging and therapy, is overexpressed on the surface of prostate cancer lesions. In this study, a triazole ring was introduced into the linker by click chemistry to generate a HYNIC-derived ligand (T), which exhibited good PSMA affinity (Ki = 2.23 nM). Eight stable 99mTc-labeled complexes, [99mTc]Tc-T-Mn (n = 1-8), with hydrophilic properties were synthesized by incorporating different coligands at high radiochemical yields and purities without purification. The radioligands were concentrated in the kidneys of healthy Kunming male mice and were significantly blocked by the PSMA inhibitor ZJ-43. The uptake of the optimized complex [99mTc]Tc-T-M2 was correlated with PSMA, and it had good PSMA affinity (Kd = 5.42 nM). [99mTc]Tc-T-M2 accumulated on LNCaP (PSMA++) tumors and was significantly blocked by ZJ-43 at 2 h p.i., indicating high PSMA specificity. Relatively suitable kidney uptake was beneficial for reducing kidneys exposure in patients. SPECT/CT imaging of [99mTc]Tc-T-M2 in LNCaP (PSMA++) or 22Rv1 (PSMA+) tumor-bearing mice revealed high tumor uptake, low background uptake (especially low kidney uptake (49.06 ± 9.20 %ID/g) at 2 h p.i.), and obvious inhibition by ZJ-43, whereas PC-3 (PSMA-) tumors were undetectable. A freeze-dried [99mTc]Tc-T-M2 kit was successfully developed (T-M2 kit). Preliminary clinical trials showed that [99mTc]Tc-T-M2 clearly identified small prostate cancer lesions and has potential for clinical application.

Synthesis of (Furyl)Methyl Disulfides via Tandem Reaction of Conjugated Ene-Yne-Ketones with Acetyl-Masked Disulfide Nucleophiles.

In this study, we outline a general method for the construction of various (furyl)methyl disulfides from acetyl-masked disulfide nucleophiles and ene-yne-ketones. This protocol is feathered by metal-free, simple experimental conditions, high efficiency, and scalable potential, which make it attractive and practical.

In situ formation of solidified supramolecular solvent based dispersive liquid-liquid microextraction for the enrichment of phenylurea herbicides in water, fruit juice, and milk.

A convenient, efficient, and green dispersive liquid-liquid microextraction based on the in situ formation of solidified supramolecular solvents combined with high performance liquid chromatography was developed for the determination of four phenylurea herbicides in liquid samples, including monuron, monolinuron, isoproturon, and chlortoluron. Herein, a novel supramolecular solvent was prepared by the in situ reaction of [P4448]Br and NH4PF6, which had the advantages of low melting point, high density, and good dispersibility. In addition, the microscopic morphology and physical properties of supramolecular solvent were characterized, and the extraction conditions were optimized. The results showed that the analytes had good linearity (R2 > 0.9998) within the linear range. The limits of detection and quantification for the four phenylurea herbicides were in the range of 0.13-0.19 µg L-1 and 0.45-0.65 µg L-1, respectively. The prepared supramolecular solvent is suitable for the efficient extraction of phenylurea herbicides in water, fruit juice, and milk.

Enhancing vegetation formation classification: Integrating coarse-scale traditional mapping knowledge and advanced machine learning.

Mapping vegetation formation types in large areas is crucial for ecological and environmental studies. However, this is still challenging to distinguish similar vegetation formation types using existing predictive vegetation mapping methods, based on commonly used environmental variables and remote sensing spectral data, especially when there are not enough training samples. To solve this issue, we proposed a predictive vegetation mapping method by integrating an advanced machine learning algorithm and knowledge in an early coarse-scale vegetation map (VMK). First, we implemented classification using the random forest algorithm by integrating the early vegetation map as an auxiliary feature (VMF). Then, we determined the rationality of classified vegetation types and distinguished the confusing types, respectively, based on the knowledge of the spatial distributions and hierarchies of vegetation. Finally, we replaced each recognized unreasonable vegetation type with its corresponding reasonable vegetation type. We implemented the new method in upstream of the Yellow River based on GaoFen-1 satellite images and other environmental variables (i.e., topographical and climate variables). Results showed that the overall accuracy using the VMK method ranged from 67.7 % to 76.8 %, which was 10.9 % to 13.4 % and 3.2 % to 6.6 %, respectively, higher than that of the method without the early vegetation map (NVM) and the VMF method, based on cross-validation with 20 % to 60 % random training samples. The spatial details of the vegetation map using the VMK method were also more reasonable compared to the NVM and VMF methods. These results indicated that the VMK method can distinctly improve the mapping accuracy at the vegetation formation level by integrating knowledge of existing vegetation maps. The proposed method can largely reduce the requirements on the number of field samples, which is especially important for alpine mountains and arctic region, where collecting training samples is more difficult due to the harsh natural environment.

Orbitronics: light-induced orbital currents in Ni studied by terahertz emission experiments.

Orbitronics is based on the use of orbital currents as information carriers. Orbital currents can be generated from the conversion of charge or spin currents, and inversely, they could be converted back to charge or spin currents. Here we demonstrate that orbital currents can also be generated by femtosecond light pulses on Ni. In multilayers associating Ni with oxides and nonmagnetic metals such as Cu, we detect the orbital currents by their conversion into charge currents and the resulting terahertz emission. We show that the orbital currents extraordinarily predominate the light-induced spin currents in Ni-based systems, whereas only spin currents can be detected with CoFeB-based systems. In addition, the analysis of the time delays of the terahertz pulses leads to relevant information on the velocity and propagation length of orbital carriers. Our finding of light-induced orbital currents and our observation of their conversion into charge currents opens new avenues in orbitronics, including the development of orbitronic terahertz devices.

M2 Microglia-Derived Exosomes Protect Against Glutamate-Induced HT22 Cell Injury via Exosomal miR-124-3p.

As one of the most serious complications of sepsis, sepsis-associated encephalopathy has not been effectively treated or prevented. Exosomes, as a new therapeutic method, play a protective role in neurodegenerative diseases, stroke and traumatic brain injury in recent years. The purpose of this study was to investigate the role of exosomes in glutamate (Glu)-induced neuronal injury, and to explore its mechanism, providing new ideas for the treatment of sepsis-associated encephalopathy. The neuron damage model induced by Glu was established, and its metabolomics was analyzed and identified. BV2 cells were induced to differentiate into M1 and M2 subtypes. After the exosomes from both M1-BV2 cells and M2-BV2 cells were collected, exosome morphological identification was performed by transmission electron microscopy and exosome-specific markers were also detected. These exosomes were then cocultured with HT22 cells. CCK-8 method and LDH kit were used to detect cell viability and toxicity. Cell apoptosis, mitochondrial membrane potential and ROS content were respectively detected by flow cytometry, JC-1 assay and DCFH-DA assay. MiR-124-3p expression level was detected by qRT-PCR and Western blot. Bioinformatics analysis and luciferase reporter assay predicted and verified the relationship between miR-124-3p and ROCK1 or ROCK2. Through metabolomics, 81 different metabolites were found, including fructose, GABA, 2, 4-diaminobutyric acid, etc. The enrichment analysis of differential metabolites showed that they were mainly enriched in glutathione metabolism, glycine and serine metabolism, and urea cycle. M2 microglia-derived exosomes could reduce the apoptosis, decrease the accumulation of ROS, restore the mitochondrial membrane potential and the anti-oxidative stress ability in HT22 cells induced by Glu. It was also found that the protective effect of miR-124-3p mimic on neurons was comparable to that of M2-EXOs. Additionally, M2-EXOs might carry miR-124-3p to target ROCK1 and ROCK2 in neurons, affecting ROCK/PTEN/AKT/mTOR signaling pathway, and then reducing Glu-induced neuronal apoptosis. M2 microglia-derived exosomes may protect HT22 cells against Glu-induced injury by transferring miR-124-3p into HT22 cells, with ROCK being a target gene for miR-124-3p.

Tumor-activated IL-2 mRNA delivered by lipid nanoparticles for cancer immunotherapy.

Interleukin-2 (IL-2) exhibits the unique capacity to modulate immune functions, potentially exerting antitumor effects by stimulating immune responses, making it highly promising for immunotherapy. However, the clinical use of recombinant IL-2 protein faces significant limitations due to its short half-life and systemic toxicity. To overcome these challenges and fully exploit IL-2's potential in tumor immunotherapy, this study reports the development of a tumor-activated IL-2 mRNA, delivered via lipid nanoparticles (LNPs). Initially, ionizable lipid U-101 derived nanoparticles (U-101-LNP) were prepared using microfluidic technology. Subsequent in vitro and in vivo delivery tests demonstrated that U-101-LNP achieved more effective transfection than the approved ALC-0315-LNP. Following this, IL-2F mRNAs, encoding fusion proteins comprising IL-2, a linker, and CD25 (IL-2Rα), were designed and synthesized through in vitro transcription. A cleavable linker, consisting of the peptide sequence SGRSEN↓IRTA, was selected for cleavage by matrix metalloproteinase-14 (MMP-14). IL-2F mRNA was then encapsulated in U-101-LNP to create U-101-LNP/IL-2F mRNA complexes. After optimization, assessments of expression efficiency, masking, and release characteristics revealed that IL-2F with linker C4 demonstrated superior performance. Finally, the antitumor activity of IL-2F mRNA was evaluated. The results indicated that U-101-LNP/IL-2F mRNA achieved the strongest antitumor effect, with an inhibition rate of 70.3%. Immunohistochemistry observations revealed significant expressions of IL-2, IFN-γ, and CD8, suggesting an up-regulation of immunomodulation in tumor tissues. This effect could be ascribed to the expression of IL-2F, followed by the cleavage of the linker under the action of MMP-14 in tumor tissue, which sustainably releases IL-2. H&E staining of tissues treated with U-101-LNP/IL-2F mRNA showed no abnormalities. Further evaluations indicated that the U-101-LNP/IL-2F mRNA group maintained proper levels of inflammatory factors without obvious alterations in liver and renal functions. Taken together, the U-101-LNP/IL-2F mRNA formulation demonstrated effective antitumor activity and safety, which suggests potential applicability in clinical immunotherapy.

Transition-Metal-Free Disulfuration of Amides with Trisulfide Dioxides via Formation of Unaccessible S-S-N Bonds.

Under transition-metal-free conditions, trisulfide dioxides were used as disulfurating reagents to react with a wide range of amides, affording various substituted N-disulfanyl amides in good yields. Furthermore, the gram-scale experiment has confirmed the practicability of this approach.

Synthesis and Preclinical Evaluation of Novel 99mTc-Labeled FAPI-46 Derivatives with Significant Tumor Uptake and Improved Tumor-to-Nontarget Ratios.

Fibroblast activation protein (FAP), which is expressed on the cell membranes of fibroblasts in most solid tumors, has become an important target for tumor diagnosis and treatment. However, previously reported 99mTc-labeled FAPI-04 complexes have high blood uptake, limiting their use in the clinic. In this work, six 99mTc-labeled FAPI-46 derivatives with different linkers (different amino acids, peptides, or polyethylene glycol) were prepared and evaluated. They had good in vitro stability, hydrophilicity, and good specificity for FAP. The biodistribution and MicroSPECT images revealed that they all had high specific tumor uptake for FAP, and their blood uptake was significantly decreased. Among them, [99mTc]Tc-6-1 exhibited the highest target-to-nontarget ratios (tumor/blood: 6.06 ± 1.19; tumor/muscle: 10.26 ± 0.44) and good tumor uptake (16.15 ± 0.83%ID/g), which also had significantly high affinity for FAP, good in vivo stability, and safety. Therefore, [99mTc]Tc-6-1 holds great potential as a promising molecular tracer for FAP tumor imaging.

Radiosynthesis and Bioevaluation of 99mTc-Labeled Isocyanide Ubiquicidin 29-41 Derivatives as Potential Agents for Bacterial Infection Imaging.

To develop a novel 99mTc-labeled ubiquicidin 29-41 derivative for bacterial infection single-photon emission computed tomography (SPECT) imaging with improved target-to-nontarget ratio and lower nontarget organ uptake, a series of isocyanide ubiquicidin 29-41 derivatives (CNnUBI 29-41, n = 5-9) with different carbon linkers were designed, synthesized and radiolabeled with the [99mTc]Tc(I)+ core, [99mTc][Tc(I)(CO)3(H2O)3]+ core and [99mTc][Tc(V)N]2+ core. All the complexes are hydrophilic, maintain good stability and specifically bind Staphylococcus aureus in vitro. The biodistribution in mice with bacterial infection and sterile inflammation demonstrated that [99mTc]Tc-CN5UBI 29-41 was able to distinguish bacterial infection from sterile inflammation, which had an improved abscess uptake and a greater target-to-nontarget ratio. SPECT imaging study of [99mTc]Tc-CN5UBI 29-41 in bacterial infection mice showed that there was a clear accumulation in the infection site, suggesting that this radiotracer could be a potential radiotracer for bacterial infection imaging.

Construction of ß-Acetoxy or ß-Hydroxyl Disulfides via Highly Regioselective Ring-Opening of Epoxides with Acetyl Masked Disulfide Nucleophiles.

In the organic or water phase, acetyl masked disulfide nucleophiles were used as the disulfide source to react with a wide range of epoxides, affording various ß-acetoxy or ß-hydroxyl disulfides in good yields with high regioselectivity. This method features transition-metal-free, simple experimental conditions, high atom economy, and scalable potential, which make it attractive and practical.

The Preparation and Execution of Exploratory Human Studies on Novel 99mTc-Labeled Glucosamine Derivatives Containing Different Phenyl Isonitriles as Promising Tumor Imaging Agents.

As the "molecule of the century", 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) is a radioactive 18F-labeled glucose derivative with a wide range of applications for positron emission tomography (PET) imaging. Single photon emission computed tomography (SPECT) imaging is widely used, but there is no clinical probe comparable to [18F]FDG. In our previous work, [99mTc]Tc-CN5DG and [99mTc]Tc-CN7DG were successfully developed and achieved high-quality SPECT images. However, they still have the disadvantage of low tumor uptake and/or high uptake by nontarget organs. To develop novel tumor imaging agents with high tumor uptake and excellent tumor/nontarget ratios, in this study, starting from d-glucosamine hydrochloride, four phenyl group-containing isonitrile ligands were designed, synthesized, and radiolabeled with 99mTc. All the complexes had high radiochemical purity and good hydrophilicity and stability. Biodistribution experiments showed that [99mTc]Tc-L4 (i.e., [99mTc]Tc-CNMBDG) had the highest tumor uptake and tumor/background ratios among the four probes. In SPECT imaging studies, the tumor detected by [99mTc]Tc-L4 was more clearly visible than that of [99mTc]Tc-CN7DG because of the inappreciable interference from abdominal uptake. Preliminary clinical studies of [99mTc]Tc-L4 have been conducted and successfully showed the lesion location in a patient with non-small-cell lung cancer. In summary, [99mTc]Tc-L4 is expected to be a promising tumor SPECT imaging agent.

[Research progress of exosomes in the diagnosis and treatment of sepsis].

Sepsis is a life-threatening organ dysfunction caused by infection that lead to dysregulation of the host response. Sepsis and septic shock with a high mortality threaten human health at present, which are important medical and health problems. Early diagnosis and treatment decision-making for sepsis and septic shock still need to be improved. Exosomes are extracellular vesicles with a diameter of 30-150 nm formed by the fusion of multi-vesicle bodies and cell membranes. Exosomes can effectively transport a variety of bioactive substances such as proteins, lipids, RNA, DNA, and participate in the regulation of inflammatory response, immune response, infection and other pathophysiological processes. In recent years, exosomes have become one of the important methods for the diagnosis and treatment of systemic inflammatory diseases. This article will focus on the basic and clinical research of sepsis, and focus on the research progress of exosomes in the diagnosis and targeted therapy of sepsis.

Trivalent mRNA Vaccine against SARS-CoV-2 and Variants with Effective Immunization.

mRNA vaccines encoding a single spike protein effectively prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the emergence of SARS-CoV-2 variants leads to a wide range of immune evasion. Herein, a unique trivalent mRNA vaccine based on ancestral SARS-CoV-2, Delta, and Omicron variant spike receptor-binding domain (RBD) mRNAs was developed to tackle the immune evasion of the variants. First, three RBD mRNAs of SARS-CoV-2, Delta, and Omicron were coencapsulated into lipid nanoparticles (LNPs) by using microfluidic technology. After that, the physicochemical properties and time-dependent storage stability of the trivalent mRNA vaccine nanoformulation were tested by using dynamic light scattering (DLS). In vitro, the trivalent mRNA vaccine exhibited better lysosomal escape ability, transfection efficiency, and biocompatibility than did the commercial transfection reagent Lipo3000. In addition, Western blot analyses confirmed that the three RBD proteins can be detected in cells transfected with the trivalent mRNA vaccine. Furthermore, ex vivo imaging analysis indicated that the livers of BALB/c mice had the strongest protein expression levels after intramuscular (IM) injection. Using a prime-boost strategy, this trivalent vaccine elicited robust humoral and T-cell immune responses in both the high-dose and low-dose groups and showed no toxicity in BALB/c mice. Three specific IgG antibodies in the high-dose group against SARS-CoV-2, Delta, and Omicron variants approached ∼1/1,833,333, ∼1/1,866,667, and ∼1/925,000, respectively. Taken together, two doses of inoculation with the trivalent mRNA vaccine may provide broad and effective immunization responses against SARS-CoV-2 and variants.