Efficient Transfection of <em>In vitro</em> 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. ...

Ludwig-Maximilians University of Munich

Cystic fibrosis (CF) is an autosomal recessive genetic disease affecting > 70,000 individuals worldwide. Despite improvements in current therapies, most patients do not survive beyond their early 30s. After cloning of the cystic fibrosis transmembrane regulator (CFTR) gene, there was considerable clinical interest in the possible therapeutic delivery of CFTR genes directly to the lung. Several clinical studies have since demonstrated proof-of-principle for correction of the underlying chloride defect in CF patients using viral and non-viral vectors. Inefficient gene transfer and host-antigen-specific immune responses caused by replication-deficient viral vectors have elevated non-viral approaches to becoming the field's most promising therapeutic contenders. Among these non-viral gene therapy vectors are cationic liposome/plasmid DNA complexes and compacted DNA nanoparticles carrying the CFTR gene, which have shown promise for the treatment of CF in phase I clinical trials. However, the levels of CFTR expression achieved in the respiratory epithelium were too low and only of limited duration. Improved strategies for efficient and prolonged expression of the transgene are therefore necessary. This review outlines the current repertoire of available gene vectors and discusses novel strategies to enhance the efficiency and selectivity of gene transfer for gene delivery into the lung.

Gene therapy for cystic fibrosis lung disease: current status and future perspectives.

The removal of highly viscous mucus from the airways is an important task in the treatment of chronic lung disease like in cystic fibrosis. The inhalation of recombinant human DNase- I (rhDNase-I) is used to facilitate the removal of tenacious airway secretions in different lung diseases and especially in CF. Little is known about endogenous DNase activity in the airway surface liquid. Therefore, we analysed bronchoalveolar lavage fluid (BAL) and exhaled breath condensate (EBC) for the presence of endogenous DNase activity.

Airway surface liquid contains endogenous DNase activity which can be activated by exogenous magnesium.

Cationic polymers have been intensively investigated for plasmid-DNA (pDNA), but few studies addressed their use for messenger-RNA (mRNA) delivery. We analyzed two types of polymers, linear polyethylenimine (l-PEI) and poly-N,N-dimethylaminoethylmethacrylate P(DMAEMA), to highlight specific requirements for the design of mRNA delivery reagents. The effect of PEGylation was investigated using P(DMAEMA-co-OEGMA) copolymer.

PEGylation improves nanoparticle formation and transfection efficiency of messenger RNA.

Developing safe and efficient non-viral delivery systems remains a major challenge for in vivo applications of gene therapy, especially in cystic fibrosis. Unlike conventional cationic polymers or lipids, the emerging poloxamine-based copolymers display promising in vivo gene delivery capabilities. However, poloxamines are invalid for in vitro applications and their in vivo transfection efficiency is still low compared with viral vectors. Here, we show that peptides developed by modular design approaches can spontaneously form compact and monodisperse nanoparticles with poloxamines and nucleic acids via self-assembly. Both messenger RNA and plasmid DNA expression mediated by peptide-poloxamine nanoparticles are greatly boosted in vitro and in the lungs of cystic fibrosis mice with negligible toxicity. Peptide-poloxamine nanoparticles containing integrating vectors enable successful in vitro and in vivo long-term restoration of cystic fibrosis transmembrane conductance regulator deficiency with a safe integration profile. Our dataset provides a new framework for designing non-viral gene delivery systems qualified for in vivo genetic modifications.

Self-assembled peptide-poloxamine nanoparticles enable in vitro and in vivo genome restoration for cystic fibrosis.

In vitro-transcribed (IVT) mRNA has come into focus in recent years as a potential therapeutic approach for the treatment of genetic diseases. The nebulized formulations of IVT-mRNA-encoding alpha-1-antitrypsin (A1AT-mRNA) would be a highly acceptable and tolerable remedy for the protein replacement therapy for alpha-1-antitrypsin deficiency in the future. Here we show that lipoplexes containing A1AT-mRNA prepared in optimum conditions could successfully transfect human bronchial epithelial cells without significant toxicity. A reduction in transfection efficiency was observed for aerosolized lipoplexes that can be partially overcome by increasing the initial number of components. A1AT produced from cells transfected by nebulized A1AT-mRNA lipoplexes is functional and could successfully inhibit the enzyme activity of trypsin as well as elastase. Our data indicate that aerosolization of A1AT-mRNA therapy constitutes a potentially powerful means to transfect airway epithelial cells with the purpose of producing functional A1AT, while bringing along the unique advantages of IVT-mRNA.

In Vitro Investigations on Optimizing and Nebulization of IVT-mRNA Formulations for Potential Pulmonary-Based Alpha-1-Antitrypsin Deficiency Treatment.

Recent advancements in the field of in vitro transcribed mRNA (IVT-mRNA) vaccination have attracted considerable attention to such vaccination as a cutting-edge technique against infectious diseases including COVID-19 caused by SARS-CoV-2. While numerous pathogens infect the host through the respiratory mucosa, conventional parenterally administered vaccines are unable to induce protective immunity at mucosal surfaces. Mucosal immunization enables the induction of both mucosal and systemic immunity, efficiently removing pathogens from the mucosa before an infection occurs. Although respiratory mucosal vaccination is highly appealing, successful nasal or pulmonary delivery of nucleic acid-based vaccines is challenging because of several physical and biological barriers at the airway mucosal site, such as a variety of protective enzymes and mucociliary clearance, which remove exogenously inhaled substances. Hence, advanced nanotechnologies enabling delivery of DNA and IVT-mRNA to the nasal and pulmonary mucosa are urgently needed. Ideal nanocarriers for nucleic acid vaccines should be able to efficiently load and protect genetic payloads, overcome physical and biological barriers at the airway mucosal site, facilitate transfection in targeted epithelial or antigen-presenting cells, and incorporate adjuvants. In this review, we discuss recent developments in nucleic acid delivery systems that target airway mucosa for vaccination purposes.

Joseph Rosenecker

Department of Pediatrics

Ludwig-Maximilians University of Munich

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

Joseph Rosenecker

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Pediatrics

Ludwig-Maximilians University of Munich

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

Department of Pediatrics