bims-novged Biomed News
on Non-viral vectors for gene delivery
Issue of 2022–07–17
ten papers selected by
the Merkel lab, Ludwig-Maximilians University



  1. BioTech (Basel). 2022 Mar 07. pii: 6. [Epub ahead of print]11(1):
      The research and development of non-viral gene therapy has been extensive over the past decade and has received a big push thanks to the recent successful approval of non-viral nucleic acid therapy products. Despite these developments, nucleic acid therapy applications in cancer have been limited. One of the main causes of this has been the imbalance in development of delivery vectors as compared with sophisticated nucleic acid payloads, such as siRNA, mRNA, etc. This paper reviews non-viral vectors that can be used to deliver nucleic acids for cancer treatment. It discusses various types of vectors and highlights their current applications. Additionally, it discusses a perspective on the current regulatory landscape to facilitate the commercial translation of gene therapy.
    Keywords:  CMC; cancer; gene therapy; lipid nanoparticles; lipids; mRNA; nanoparticles; non-viral vectors; nucleic acid delivery; polymers; regulatory landscape; siRNA; translation
    DOI:  https://doi.org/10.3390/biotech11010006
  2. Int J Nanomedicine. 2022 ;17 2893-2905
       Introduction: Since the coronavirus disease 2019 (COVID-19) pandemic, the value of mRNA vaccine has been widely recognized worldwide. Messenger RNA (mRNA) therapy platform provides a promising alternative to DNA delivery in non-viral gene therapy. Lipid nanoparticles (LNPs), as effective mRNA delivery carriers, have been highly valued by the pharmaceutical industry, and many LNPs have entered clinical trials.
    Methods: We developed an ideal lipid nanoformulation, named LNP3, composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and cholesterol, and observed its release efficiency, sustained release, organ specific targeting and thermal stability.
    Results: In vitro studies showed that the transfection efficiency of LNP3 was higher than that of LNPs composed of DOTAP-DOPE and DOTAP-cholesterol. The positive to negative charge ratio of LNPs is a determinant of mRNA transfer efficiency in different cell lines. We noted that the buffer affected the packaging of mRNA LNPs and identified sodium potassium magnesium calcium and glucose solution (SPMCG) as a favorable buffer formulation. LNP3 suspension can be lyophilized into a thermally stable formulation to maintain activity after rehydration both in vitro and in vivo. Finally, LNP3 showed sustained release and organ specific targeting.
    Conclusion: We have developed an ideal lipid nanoformulation composed of DOTAP, DOPE and cholesterol for effective mRNA delivery.
    Keywords:  1,2-dioleoyl-3-trimethylammonium-propane; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine; cholesterol; lipid nanoparticles; mRNA delivery
    DOI:  https://doi.org/10.2147/IJN.S363990
  3. Nano Res. 2022 Jul 06. 1-20
      The novel coronavirus disease 2019 (COVID-19) is still rampant all over the world, causing incalculable losses to the world. Major pharmaceutical organizations around the globe are focusing on vaccine research and drug development to prevent further damage caused by the pandemic. The messenger RNA (mRNA) technology has got ample of attention after the success of the two very effective mRNA vaccines during the recent pandemic of COVID-19. mRNA vaccine has been promoted to the core stage of pharmaceutical industry, and the rapid development of mRNA technology has exceeded expectations. Beyond COVID-19, the mRNA vaccine has been tested for various infectious diseases and undergoing clinical trials. Due to the ability of constant mutation, the viral infections demand abrupt responses and immediate production, and therefore mRNA-based technology offers best answers to sudden outbreaks. The need for mRNA-based vaccine became more obvious due to the recent emergence of new Omicron variant. In this review, we summarized the unique properties of mRNA-based vaccines for infectious diseases, delivery technologies, discussed current challenges, and highlighted the prospects of this promising technology in the future. We also discussed various clinical studies as well preclinical studies conducted on mRNA therapeutics for diverse infectious diseases.
    Keywords:  coronavirus disease 2019 (COVID-19); drug delivery; infectious disease; lipid-nanoparticle; messenger RNA (mRNA) vaccine; virus
    DOI:  https://doi.org/10.1007/s12274-022-4627-5
  4. Expert Opin Drug Deliv. 2022 Jul 12.
       INTRODUCTION: Gene therapy is becoming increasingly common in clinical practice, giving hope for the correction of a wide range of human diseases and defects. The CRISPR/Cas9 system, consisting of the Cas9 nuclease and single-guide RNA (sgRNA), has revolutionized the field of gene editing. However, efficiently delivering the CRISPR-Cas9 to the target organ or cell remains a significant challenge. In recent years, with rapid advances in nanoscience, materials science, and medicine, researchers have developed various technologies that can deliver CRISPR-Cas9 in different forms for in vitro and in vivo gene editing. Here, we review the development of the CRISPR-Cas9 and describe the delivery forms and the vectors that have emerged in CRISPR-Cas9 delivery, summarizing the key barriers and the promising strategies that vectors currently face in delivering the CRISPR-Cas9.
    AREAS COVERED: With the rapid development of CRISPR-Cas9, delivery methods are becoming increasingly important in the in vivo delivery of CRISPR-Cas9.
    EXPERT OPINION: CRISPR-Cas9 is becoming increasingly common in clinical trials. However, the complex nuclease and protease environment is a tremendous challenge for in vivo clinical applications. Therefore, the development of delivery methods is highly likely to take the application of CRISPR-Cas9 technology to another level.
    Keywords:  CRISPR; Cas9; drug delivery; gene editing; review
    DOI:  https://doi.org/10.1080/17425247.2022.2100342
  5. Int J Pharm. 2022 Jul 08. pii: S0378-5173(22)00528-2. [Epub ahead of print]624 121973
      Lipid-polymer hybrid nanoparticles are promising platforms in the field of targeted drug delivery, integrating the positive features of polymeric and lipid nanocarriers. However, the use of bulk procedures in lipid-polymer hybrid nanoparticles formulation is hindering their large-scale manufacturing. Therefore, the aim of this study is to explore the suitability of alternative formulation methods, such as microfluidics, to obtain surface-tunable nanoparticles displaying suitable characteristics. Formulations were prepared by single-step nanoprecipitation or using a micromixer chip. The nanocarriers were then surface-modified with an aptamer and an antibody, two common nanoparticle vectorization strategies, developing an optimized functionalization protocol. Both naked and surface-modified nanoparticles were characterized in terms of size, polydispersity, zeta potential and morphology. Moreover, the aptamer/antibody association efficiency was also determined. Nano-sized monodisperse nanoparticles, exhibiting a spherical core-shell structure, were obtained through both procedures. Furthermore, all the nanocarriers were successfully functionalized, showing association efficiency values above 70%. Interestingly, microfluidic-based nanoparticles displayed a smaller size and a more positive zeta potential than those prepared by single-step nanoprecipitation. Outcomes suggest both techniques led to lipid-polymer hybrid nanoparticles displaying a similar functionalization efficiency. Conversely, the microfluidic approach provided an improved control over critical parameters, as particle size or charge, constituting an interesting alternative to traditional formulation procedures.
    Keywords:  Anti-CD 24; Aptamers; Lipid-polymer hybrid nanoparticles; Microfluidics; Targeted therapy
    DOI:  https://doi.org/10.1016/j.ijpharm.2022.121973
  6. J Biomed Mater Res B Appl Biomater. 2022 Jul 11.
      Given their versatility and formability, polymers have proven to be a viable platform facilitating a controlled and tuned release for a variety of therapeutic agents. One growing area of polymer drug delivery is polymeric prodrugs, which covalently link active pharmaceutical ingredients to a polymeric form to enhance stability, delivery, and pharmacology. One such class of polymeric prodrugs, poly(beta amino esters) (PβAEs) can be synthesized into crosslinked, or "thermoset," networks which greatly limits their processability. An antioxidant-PβAE polymer prodrug that is soluble in organic solutions would permit enhanced processability, increasing their utility and manufacturability. Curcumin PβAEs were synthesized to be soluble in organic solvents while retaining the release and activity properties. To demonstrate the polymer processability, curcumin PβAEs were further synthesized into nanoparticles and thin films. Control over nanoparticle size and film thickness was established through variance of dope solution concentration and withdrawal speed, respectively. Layering of polymeric films was demonstrated through inkjet printing of thin films. Polymer function was characterized through curcumin release and antioxidant activity. The processing of the polymer had a drastic impact on the curcumin release profiles indicating the polymer degradation was influenced by surface area and porosity of the final product. Previously, release was controlled primarily through the hydrophobicity of the polymer. Here, we demonstrate a novel method for further tuning the degradation by processing the polymer.
    Keywords:  antioxidant; controlled release; poly(beta amino ester) (PβAE)
    DOI:  https://doi.org/10.1002/jbm.b.35123
  7. Int J Pharm. 2022 Jul 09. pii: S0378-5173(22)00566-X. [Epub ahead of print] 122011
      Poly-L-lysine (PLL) is a promising candidate for the treatment of pulmonary infection with lower occurrence of drug-resistance due to its unique antibacterial mechanisms. Dry powder inhalations (DPIs) are considered as the first choice for formulating PLL to treat pulmonary infection on account of direct delivery and satisfactory stability. However, hygroscopicity of PLL limited its therapeutic effect on pulmonary infection when PLL developed into DPIs. The hygroscopicity caused two obstacles including the low drug deposition in the lower respiratory tract and undesirable aerosolization performance deterioration. In this study, PLL was co-spray-dried with L-leucine (LL) to achieve moisture-resistance and desirable aerosolization performance. The ratio of PLL and LL was optimized to obtain particles with different morphology, hygroscopicity and aerodynamic properties. The obtained PLL DPIs were suitable for inhalation with a corrugated surface formed by hydrophobic LL. The anti-hygroscopicity, aerosolization performance and rheological properties of P2 DPIs were optimal when PLL: LL = 85: 15. The DPIs particles were stable after being stored at high relative humidity (60 ± 5%), and their superiority in treating pulmonary infections was also proved by in vitro and in vivo experiments. The established PLL DPIs were proved to be a feasible and desirable approach to treat pulmonary infections.
    Keywords:  Aerosolization performance; Dry powder inhalations; Moisture-resistance; Poly-L-lysine; Pulmonary infection
    DOI:  https://doi.org/10.1016/j.ijpharm.2022.122011
  8. Soft Matter. 2022 Jul 12.
      A feasible one pot synthesis of hollow spherical nucleic acids (SNAs) using phospholipid liposomes is reported. These constructs are synthesized in a chemically straightforward process involving formation of unilamellar liposomes, coating the liposomes with a thin cross-linked polymeric layer, and grafting the latter with short (about 20 bases) DNA oligonucleotide strands. They consist of vesicular cores, composed of readily available phospholipid (1,2-dipalmitoyl-sn-glycero-phosphocholine), whereas the strands are deliberately arranged on the surface of the vesicular entities. The initial vesicular structure and morphology are preserved during the coating and grafting reactions. The novel hollow/vesicular SNAs are characterized with a hydrodynamic radius and radius of gyration of 78.3 and 88.5 nm, respectively, and moderately negative (-14.2 mV) ζ potential. They carry thousands (5868) of oligonucleotide strands per vesicle, which are not strongly radially oriented and adopt an unextended conformation as anticipated from the smaller value of the grafting density compared to the critical grafting density at the transition to brush conformation. The constructs are practically devoid of toxicity and exhibit high binding affinity to complementary nucleic acids. Unlike any other nucleic acid structural motif, they cross the cell membrane and enter cells without the need of transfection agents.
    DOI:  https://doi.org/10.1039/d2sm00355d
  9. Soft Matter. 2022 Jul 13.
      By employing dissipative particle dynamics (DPD) simulations combined with stochastic polymerization models, we have conducted a detailed simulation study of supramolecular solution polymerization as well as interfacial polymerization employing a coarse-grained model which is closer to the real monomer structure. By adding bending angle potentials to coarse-grained models representing supramolecular reactive monomers, we achieved monomer model simulations for different kinds of multiple hydrogen bonds. Our simulation results indicated that for the interfacial polymerization system, the volume of the monomer caused a strong steric hindrance effect, which in turn led to a low average degree of polymerization of the product. Therefore, by appropriately reducing the volume of the reaction monomer (corresponding to different confinement ascribed to the multiple hydrogen bonds), the average polymerization degree, the degree of reaction and the polymerization rate of the monomer can be effectively improved. For the solution polymerization system and the interfacial polymerization system, a certain proportion of rigid monomers and flexible monomers (60% rigid monomers and 40% flexible monomers) are mixed. High molecular weight products can thus be obtained via the polymerization reaction. The simulation strategy proposed in this study can not only provide theoretical guidance for better design of new supramolecular systems, but also provide ideas for the further synthesis of higher molecular weight supramolecular polymers.
    DOI:  https://doi.org/10.1039/d2sm00508e
  10. Front Med Technol. 2022 ;4 924501
      Nose-to-brain delivery is a promising way to reach the central nervous system with therapeutic drugs. However, the location of the olfactory region at the top of the nasal cavity complexifies this route of administration. In this study, we used a 3D-printed replica of a nasal cavity (a so-called "nasal cast") to reproduce in vitro the deposition of a solid powder. We considered two different delivery devices: a unidirectional device generating a classical spray and a bidirectional device that relies on the user expiration. A new artificial mucus also coated the replica. Five parameters were varied to measure their influence on the powder deposition pattern in the olfactory region of the cast: the administration device, the instillation angle and side, the presence of a septum perforation, and the flow rate of possible concomitant inspiration. We found that the unidirectional powder device is more effective in targeting the olfactory zone than the bi-directional device. Also, aiming the spray nozzle directly at the olfactory area is more effective than targeting the center of the nasal valve. Moreover, the choice of the nostril and the presence of a perforation in the septum also significantly influence the olfactory deposition. On the contrary, the inspiratory flow has only a minor effect on the powder outcome. By selecting the more efficient administration device and parameters, 44% of the powder can reach the olfactory region of the nasal cast.
    Keywords:  artificial mucus; bidirectional device; nasal cast; nasal spray; nose-to-brain; powder
    DOI:  https://doi.org/10.3389/fmedt.2022.924501