bims-novged Biomed News
on Non-viral vectors for gene delivery
Issue of 2022–12–11
ten papers selected by
the Merkel lab, Ludwig-Maximilians University



  1. Chemistry. 2022 Dec 05.
      Bioreducible polymeric mRNA carriers are an emerging family of vectors for gene delivery and vaccine development. Several bioreducible systems have been generated through aqueous-phase ring-opening polymerization of lipoic acid derivatives, however this methodology limits the incorporation of hydrophobic functionalities into resulting polymers. Herein we synthesize a poly(active ester)disulfide polymer that can undergo facile aminolysis with amine-containing substrates under stoichiometric control and  mild reaction conditions to yield a library of multifunctional polydisulfide polymers. Functionalized polydisulfide polymer species form stable mRNA-polymer nanoparticles for intracellular delivery of mRNAs in vitro . Alkyl-functionalized polydisulfide-RNA nanoparticles demonstrate rapid cellular uptake and excellent biodegradability when delivering EGFP and OVA mRNAs to cells in vitro . This streamlined polydisulfide synthesis provides a new facile methodology for accessing multifunctional bioreducible polymers as biomaterials for RNA delivery and other applications.
    Keywords:  bioreducible polymer, poly(active esters), postpolymerization modification, multifunctional polymer, mRNA delivery
    DOI:  https://doi.org/10.1002/chem.202203393
  2. Lab Chip. 2022 Dec 08.
      Transfection describes the delivery of exogenous nucleic acids (NAs) to cells utilizing non-viral means. In the last few decades, scientists have been doing their utmost to design ever more effective transfection reagents. These are eventually mixed with NAs to give rise to gene delivery complexes, which must undergo characterization, testing, and further refinement through the sequential reiteration of these steps. Unfortunately, although microfluidics offers distinct advantages over the canonical approaches to preparing particles, the systems available do not address the most frequent and practical quest for the simultaneous generation of multiple polymer-to-NA ratios (N/Ps). Herein, we developed a user-friendly microfluidic cartridge to repeatably prepare non-viral gene delivery particles and screen across a range of seven N/Ps at once or significant volumes of polyplexes at a given N/P. The microchip is equipped with a chaotic serial dilution generator for the automatic linear dilution of the polymer to the downstream area, which encompasses the NA divider to dispense equal amounts of DNA to the mixing area, enabling the formation of particles at seven N/Ps eventually collected in individual built-in tanks. This is the first example of a stand-alone microfluidic cartridge for the fast and repeatable preparation of non-viral gene delivery complexes at different N/Ps and their storage.
    DOI:  https://doi.org/10.1039/d2lc00744d
  3. Mol Biol (Mosk). 2022 Nov-Dec;56(6):56(6): 1023-1038
      Gene editing with programmable nucleases opens new perspectives in important practice areas, such as healthcare and agriculture. The most challenging problem for the safe and effective therapeutic use of gene editing technologies is the proper delivery and expression of gene editors in cells and tissues of different organisms. Virus-based and nonviral systems can be used for the successful delivery of gene editors. Here we have reviewed structural elements of nonviral DNA- and RNA-based expression vectors for gene editing and delivery methods in vitro and in vivo.
    Keywords:  Cas9; IVT RNA; TALEN; ZFN; expression DNA vector; gene therapy; genome editing; mRNA-based delivery; nanoparticles
    DOI:  https://doi.org/10.31857/S002689842206026X
  4. Colloids Surf B Biointerfaces. 2022 Nov 17. pii: S0927-7765(22)00716-0. [Epub ahead of print]222 113032
      Recently, an extensive research effort has been directed toward the improvement of nonviral transfection vectors, such as polymeric materials. The macromolecular structure of polymers has a substantial effect on their transfection efficacy. In this context, the modern advances in polymer production techniques, such as the deactivation-enhanced radical atom transfer polymerization (DE-ATRP), have been fundamental for the synthesis of controlled architecture nanomaterials. In this study, hyperbranched poly(β-pinene)-PDMAEMA-PEGDMA nanometric copolymers were synthesised at high conversion via DE-ATRP using different concentrations of β-pinene for gene delivery applications. The structural characterization and the biological performance of the materials were investigated. The copolymers' molar mass (10,434-16,438 mol l-1), dispersity, and conversion (90-95%) varied significantly with β-pinene proportion on the polymerizations. The polymer-gene complexes generated (280-110 nm) presented excellent solution stability due to the β-pinene segment on the copolymers. Gene delivery and transfection were highly dependent on the copolymer composition. The copolymers containing the highest β-pinene proportions exhibited the best results with high transfection effectivity. In conclusion, the incorporation of β-pinene in DMAEMA-PEGMA copolymer formulations is a renewable option to improve the materials' branching ratio, polyplex stability, and gene delivery performance without causing cytotoxic effects.
    Keywords:  Biocompatibility; DE-ATRP; DMAEMA; Gene transfection; Hyperbranched structure
    DOI:  https://doi.org/10.1016/j.colsurfb.2022.113032
  5. J Colloid Interface Sci. 2022 Nov 15. pii: S0021-9797(22)02017-3. [Epub ahead of print]633 511-525
      Pulmonary delivery of small interfering RNA (siRNA) using nanoparticle-based delivery systems is promising for local treatment of respiratory diseases. We designed dry powder inhaler formulations of siRNA-loaded lipid-polymer hybrid nanoparticles (LPNs) with aerosolization properties optimized for inhalation therapy. Interactions between LPNs and pulmonary surfactant (PS) determine the fate of inhaled LPNs, but interaction mechanisms are unknown. Here we used surface-sensitive techniques to study how physicochemical properties and pathological microenvironments influence interactions between siRNA-loaded LPNs and supported PS layers. PS was deposited on SiO2 surfaces as single bilayer or multilayers and characterized using quartz crystal microbalance with dissipation monitoring and Fourier-transform infrared spectroscopy with attenuated total reflection. Immobilization of PS as multilayers, resembling the structural PS organization in the alveolar subphase, effectively reduced the relative importance of interactions between PS and the underlying surface. However, the binding affinity between PS and LPNs was identical in the two models. The physicochemical LPN properties influenced the translocation pathways and retention time of LPNs. Membrane fluidity and electrostatic interactions were decisive for the interaction strength between LPNs and PS. Experimental conditions reflecting pathological microenvironments promoted LPN deposition. Hence, these results shed new light on design criteria for LPN transport through the air-blood barrier.
    Keywords:  Lipid-polymer hybrid nanoparticles; Pathological microenvironments; Physicochemical properties; Pulmonary drug delivery; Pulmonary surfactant; Surface-sensitive techniques
    DOI:  https://doi.org/10.1016/j.jcis.2022.11.059
  6. Bioact Mater. 2023 May;23 438-470
      The approved worldwide use of two messenger RNA (mRNA) vaccines (BNT162b2 and mRNA-1273) in late 2020 has proven the remarkable success of mRNA therapeutics together with lipid nanoformulation technology in protecting people against coronaviruses during COVID-19 pandemic. This unprecedented and exciting dual strategy with nanoformulations and mRNA therapeutics in play is believed to be a promising paradigm in targeted cancer immunotherapy in future. Recent advances in nanoformulation technologies play a prominent role in adapting mRNA platform in cancer treatment. In this review, we introduce the biologic principles and advancements of mRNA technology, and chemistry fundamentals of intriguing mRNA delivery nanoformulations. We discuss the latest promising nano-mRNA therapeutics for enhanced cancer immunotherapy by modulation of targeted specific subtypes of immune cells, such as dendritic cells (DCs) at peripheral lymphoid organs for initiating mRNA cancer vaccine-mediated antigen specific immunotherapy, and DCs, natural killer (NK) cells, cytotoxic T cells, or multiple immunosuppressive immune cells at tumor microenvironment (TME) for reversing immune evasion. We highlight the clinical progress of advanced nano-mRNA therapeutics in targeted cancer therapy and provide our perspectives on future directions of this transformative integrated technology toward clinical implementation.
    Keywords:  Cancer immunotherapy; Nanoformulations; Targeted cancer therapy; mRNA delivery; mRNA therapeutics
    DOI:  https://doi.org/10.1016/j.bioactmat.2022.11.014
  7. Biomed Pharmacother. 2022 Dec 05. pii: S0753-3322(22)01454-8. [Epub ahead of print]157 114065
      Nanomedicine has emerged as a promising platform for disease treatment and much progress has been achieved in the clinical translation for cancer treatment. Several types of nanomedicines have been approved for therapeutic application. However, many nanoparticles still suffer from challenges in the translation from bench to bedside. Currently, nanoparticle-based delivery systems have been developed to explore their functions in targeted gene silencing and cancer therapy. This review describes the research progress of different nano-carriers in targeted gene editing, and the recent progress in co-delivery of anticancer drugs and small ribonucleic acid. We also summarize the strategies for improving the specificity of carrier systems. Finally, we discuss the functions of targeted nano-carriers in overcoming chemotherapeutic drug resistance in cancer therapy. As research continues to advance, a better understanding of the safety including long-term toxicity, immunogenicity, and body metabolism may impel nanoparticle translation.
    Keywords:  Cancer therapy; Drug resistance; Malignant tumor; Nanoparticle; Small interfering RNA; Targeted gene silencing
    DOI:  https://doi.org/10.1016/j.biopha.2022.114065
  8. J Pharm Sci. 2022 Nov 30. pii: S0022-3549(22)00540-8. [Epub ahead of print]
      The efficacy of mRNA-lipid nanoparticles (mRNA-LNPs) depends on several factors, including their size and morphology. This study presents a new technique to characterize mRNA-LNPs in an aqueous medium using atomic force microscopy (AFM). This method utilizes an anti-polyethylene glycol antibody to immobilize mRNA-LNPs onto a glass substrate without corruption, which cannot be avoided with conventional procedures using solid substrates such as mica and glass. The obtained AFM images showed spherical and bleb-like structures of mRNA-LNPs, consistent with previous observations made using cryo-transmission electron microscopy. The AFM method also revealed the predominant existence of nanoparticles with a diameter < 60 nm, which were not detectable by dynamic light scattering and nanoparticle tracking analysis. As mRNA-LNPs are usually not monodisperse, but rather polydisperse, the AFM method can provide useful complementary information about mRNA-LNPs in their development and quality assessment.
    Keywords:  lipid nanoparticle; nanomedicine; particle size; physicochemical properties; regulatory science; vaccine
    DOI:  https://doi.org/10.1016/j.xphs.2022.11.026
  9. Mater Horiz. 2022 Dec 05.
      COVID-19 mRNA vaccines represent a completely new category of vaccines and play a crucial role in controlling the COVID-19 pandemic. In this study, we have developed a PEG-lipid-free two-component mRNA vaccine (PFTCmvac) by formulating mRNA encoding the receptor binding domain (RBD) of SARS-CoV-2 into lipid-like nanoassemblies. Without using polyethylene glycol (PEG)-lipids, the self-assembled PFTCmvac forms thermostable nanoassemblies and exhibits a dose-dependent cellular uptake and membrane disruption, eventually leading to high-level protein expression in both mammalian cells and mice. Vaccination with PFTCmvac elicits strong humoral and cellular responses in mice, without evidence of significant adverse reactions. In addition, the vaccine platform does not trigger complement activation in human serum, even at a high serum concentration. Collectively, the PEG-lipid-free two-component nanoassemblies provide an alternative delivery technology for COVID-19 mRNA vaccines and opportunities for the rapid production of new mRNA vaccines against emerging infectious diseases.
    DOI:  https://doi.org/10.1039/d2mh01260j
  10. Adv Mater. 2022 Dec 07. e2206636
      Protein corona broadly affects the delivery of nanomedicines in vivo. Although it has been widely studied by multiple strategies like centrifugal sedimentation, the rapidly forming mechanism and the dynamic structure of the protein corona at the seconds level remains challenging. Here, a photocatalytic proximity labeling technology in nanoparticles (nano-PPL) is developed. By fabricating a "core-shell" nanoparticle co-loaded with chlorin e6 catalyst and biotin-phenol probe, nano-PPL technology is validated for the rapid and precise labeling of corona proteins in situ. Nano-PPL significantly improves the temporal resolution of nano-protein interactions to 5 s duration compared with the classical centrifugation method (>30 s duration). Furthermore, nano-PPL achieves the fast and dynamic mapping of the protein corona on anionic and cationic nanoparticles, respectively. Finally, nano-PPL is deployed to verify the effect of the rapidly formed protein corona on the initial interaction of nanoparticles with cells. These findings highlight a significant methodological advance toward nano-protein interactions in the delivery of nanomedicines in vivo. This article is protected by copyright. All rights reserved.
    Keywords:  Nanomedicines; biotinylation; nano-protein interaction; photocatalytic proximity labeling; protein corona
    DOI:  https://doi.org/10.1002/adma.202206636