Respiratory mucosal vaccination of peptide-poloxamine-DNA nanoparticles provides complete protection against lethal SARS-CoV-2 challenge.

The ongoing SARS-CoV-2 pandemic represents a brutal reminder of the continual threat of mucosal infectious diseases. Mucosal immunity may provide robust protection at the predominant sites of SARS-CoV-2 infection. However, it remains unclear whether respiratory mucosal administration of DNA vaccines could confer protective immune responses against SARS-CoV-2 challenge due to insurmountable barriers posed by the airway. Here, we applied self-assembled peptide-poloxamine nanoparticles with mucus-penetrating properties for pulmonary inoculation of a COVID-19 DNA vaccine (pSpike/PP-sNp). The pSpike/PP-sNp not only displays superior gene transfection and favorable biocompatibility in the mouse airway, but also promotes a tripartite immunity consisting of systemic, cellular, and mucosal immune responses that are characterized by mucosal IgA secretion, high levels of neutralizing antibodies, and resident memory phenotype T-cell responses in the lungs of mice. Most importantly, immunization with pSpike/PP-sNp completely eliminates SARS-CoV-2 infection in both upper and lower respiratory tracts and enables 100% survival rate of mice following lethal SARS-CoV-2 challenge. Our findings indicate PP-sNp is a promising platform in mediating DNA vaccines to elicit all-around mucosal immunity against SARS-CoV-2.

Efficient Transfection of In vitro Transcribed mRNA in Cultured Cells Using Peptide-Poloxamine Nanoparticles.

In vitro transcribed messenger RNA (mRNA) vaccines have displayed enormous potential in fighting against the coronavirus disease 2019 (COVID-19) pandemic. Efficient and safe delivery systems must be included in the mRNA vaccines due to the fragile properties of mRNA. A self-assembled peptide-poloxamine nanoparticle (PP-sNp) gene delivery system is specifically designed for the pulmonary delivery of nucleic acids and displays promising capabilities in mediating successful mRNA transfection. Here, an improved method for preparing PP-sNp is described to elaborate on how the PP-sNp encapsulates Metridia luciferase (MetLuc) mRNA and successfully transfects cultured cells. MetLuc-mRNA is obtained by an in vitro transcription process from a linear DNA template. A PP-sNp is produced by mixing synthetic peptide/poloxamine with mRNA solution using a microfluidic mixer, allowing for the self-assembly of PP-sNp. The charge of PP-sNp is subsequently evaluated by measuring the zeta potential. Meanwhile, the polydispersity and hydrodynamic size of PP-sNp nanoparticles are measured using dynamic light scattering. The mRNA/PP-sNp nanoparticles are transfected into cultured cells, and supernatants from the cell culture are assayed for luciferase activity. The representative results demonstrate their capacity for in vitro transfection. This protocol may shed light on developing next-generation mRNA vaccine delivery systems.

Mechanistic insights into the generation and control of Cl-DBPs during wastewater sludge chlorination disinfection process.

Chlorination disinfection has been widely used to kill the pathogenic microorganisms in wastewater sludge during the special Covid-19 period, but sludge chlorination might cause the generation of harmful disinfection byproducts (DBPs). In this work, the transformation of extracellular polymeric substance (EPS) and mechanisms of Cl-DBPs generation during sludge disinfection by sodium hypochlorite (NaClO) were investigated using multispectral analysis in combination with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The microorganism Escherichia coli (E. coli) was effectively inactivated by active chlorine generated from NaClO. However, a high diversity of Cl-DBPs were produced with the addition of NaClO into sludge, causing the increase of acute toxicity on Q67 luminous bacteria of chlorinated EPS. A variety of N-containing molecular formulas were produced after chlorination, but N-containing DBPs were not detected, which might be the indicative of the dissociation of -NH2 groups after Cl-DBPs generated. Additionally, the release of N-containing compounds was increased in alkaline environment caused by NaClO addition, resulted in more Cl-DBPs generation via nucleophilic substitutions. Whereas, less N-compounds and Cl-DBPs were detected after EPS chlorination under acidic environment, leading to lower cell cytotoxicity. Therefore, N-containing compounds of lignin derivatives in sludge were the major Cl-DBPs precursors, and acidic environment could control the release of N-compounds by eliminating the dissociation of functional groups in lignin derivatives, consequently reducing the generation and cytotoxicity of Cl-DBPs. This study highlights the importance to control the alkalinity of sludge to reduce Cl-DBPs generation prior to chlorination disinfection process, and ensure the safety of subsequential disposal for wastewater sludge.

Coronary heart disease and COVID-19: A meta-analysis.

OBJECTIVE: Since the World Health Organization (WHO) announced coronavirus disease 2019 (COVID-19) had become a global pandemic on March 11, 2020, the number of infections has been increasing. The purpose of this meta-analysis was to investigate the prognosis of COVID-19 in patients with coronary heart disease. METHOD: Pubmed, Embase, and Cochrane Library databases were searched to collect the literature concerning coronary heart disease and COVID-19. The retrieval time was from inception to Nov 20, 2020, using Stata version 14.0 for meta-analysis. RESULTS: A total of 22,148 patients from 40 studies were included. The meta-analysis revealed that coronary heart disease was associated with poor prognosis of COVID-19 (OR=3.42, 95%CI [2.83, 4.13], P < 0.001). After subgroup analysis, coronary heart disease was found to be related to mortality (OR = 3.75, 95%CI [2.91, 4.82], P < 0.001), severe/critical COVID-19 (OR = 3.23, 95%CI [2.19, 4.77], P < 0.001), ICU admission (OR = 2.25, 95%CI [1.34, 3.79], P = 0.002), disease progression (OR = 3.01, 95%CI [1.46, 6.22], P = 0.003); Meta-regression showed that the association between coronary heart disease and poor prognosis of COVID-19 was affected by hypertension (P = 0.004), and subgroup analysis showed that compared with the proportion of hypertension >30% (OR = 2.85, 95%CI [2.33, 3.49]), the proportion of hypertension <30% (OR = 4.78, 95%CI [3.50, 6.51]) had a higher risk of poor prognosis. CONCLUSION: Coronary heart disease is a risk factor for poor prognosis in patients with COVID-19.

OBJETIVO: Desde que la Organización Mundial de la Salud (OMS) anunció que la enfermedad por coronavirus de 2019 (COVID-19) se había convertido en una pandemia global el 11 de marzo de 2020, se ha incrementado el número de infecciones. El objetivo de este metaanálisis fue investigar el pronóstico de la COVID-19 en pacientes con cardiopatía coronaria. MÉTODO: Se realizó una búsqueda en las bases de datos de Pubmed, Embase y Cochrane Library para reunir la literatura relativa a cardiopatía coronaria y COVID-19. El tiempo de recuperación de datos fue desde el inicio hasta el 20 de noviembre de 2020, utilizando la versión 14.0 de Stata® para el metaanálisis. RESULTADOS: Se incluyó un total de 22.148 pacientes de 40 estudios. El metaanálisis reveló que la cardiopatía coronaria estaba asociada a un mal pronóstico de COVID-19 (OR: 3,42; IC 95%: 2,83-4,13; p < 0,001). Tras el análisis de subgrupo, se encontró que la cardiopatía coronaria tenía relación con la mortalidad (OR: 3,75; IC 95%: 2,91-4,82; p < 0,001), COVID-19 grave/crítica (OR: 3,23; IC 95%: 2,19-4,77; p < 0,001), ingreso en la UCI (OR: 2,25; IC 95%: 1,34-3,79; p = 0,002), progresión de la enfermedad (OR: 3,01; IC 95%: 1,46-6,22; p = 0,003). La metarregresión reflejó que la asociación entre cardiopatía coronaria y mal pronóstico de la COVID-19 estaba influida por la hipertensión (p = 0,004), y el análisis de subgrupo mostró que comparada con la proporción de hipertensión > 30% (OR: 2,85; IC 95%: 2,33-3,49), la proporción de hipertensión < 30% (OR: 4,78; IC 95%: 3,50-6,51) tenía mayor riesgo de mal pronóstico. CONCLUSIÓN: La cardiopatía coronaria es un factor de riesgo de mal pronóstico en pacientes con COVID-19.

Coronary heart disease and COVID-19: A meta-analysis.

OBJECTIVE: Since the World Health Organization (WHO) announced coronavirus disease 2019 (COVID-19) had become a global pandemic on March 11, 2020, the number of infections has been increasing. The purpose of this meta-analysis was to investigate the prognosis of COVID-19 in patients with coronary heart disease. METHOD: Pubmed, Embase, and Cochrane Library databases were searched to collect the literature concerning coronary heart disease and COVID-19. The retrieval time was from inception to Nov 20, 2020, using Stata version 14.0 for meta-analysis. RESULTS: A total of 22,148 patients from 40 studies were included. The meta-analysis revealed that coronary heart disease was associated with poor prognosis of COVID-19 (OR=3.42, 95%CI [2.83, 4.13], P<0.001). After subgroup analysis, coronary heart disease was found to be related to mortality (OR=3.75, 95%CI [2.91, 4.82], P<0.001), severe/critical COVID-19 (OR=3.23, 95%CI [2.19, 4.77], P<0.001), ICU admission (OR=2.25, 95%CI [1.34, 3.79], P=0.002), disease progression (OR=3.01, 95%CI [1.46, 6.22], P=0.003); Meta-regression showed that the association between coronary heart disease and poor prognosis of COVID-19 was affected by hypertension (P=0.004), and subgroup analysis showed that compared with the proportion of hypertension >30% (OR=2.85, 95%CI [2.33, 3.49]), the proportion of hypertension <30% (OR=4.78, 95%CI [3.50, 6.51]) had a higher risk of poor prognosis. CONCLUSION: Coronary heart disease is a risk factor for poor prognosis in patients with COVID-19.