bims-novged Biomed News
on Non-viral vectors for gene delivery
Issue of 2023‒05‒14
ten papers selected by
the Merkel lab
Ludwig-Maximilians University

  1. Adv Drug Deliv Rev. 2023 May 05. pii: S0169-409X(23)00176-X. [Epub ahead of print] 114861
      Lipid nanoparticles (LNPs) have revolutionized the field of drug delivery through their applications in siRNA delivery to the liver (Onpattro) and their use in the Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines. While LNPs have been extensively studied for the delivery of RNA drugs to muscle and liver targets, their potential to deliver drugs to challenging tissue targets such as the brain remains underexplored. Multiple brain disorders currently lack safe and effective therapies and therefore repurposing LNPs could potentially be a game changer for improving drug delivery to cellular targets both at and across the blood-brain barrier (BBB). In this review, we will discuss (1) the rationale and factors involved in optimizing LNPs for brain delivery, (2) ionic liquid-coated LNPs as a potential approach for increasing LNP accumulation in the brain tissue and (3) considerations, open questions and potential opportunities in the development of LNPs for delivery to the brain.
    Keywords:  Lipid nanoparticles; blood-brain barrier; ionic liquids; ionizable cationic lipid; red blood cell hitchhiking
  2. Mol Pharm. 2023 May 07.
      Intracellular delivery of therapeutic biomacromolecules, including nucleic acids and proteins, attracts extensive attention in biotherapeutics for various diseases. Herein, a strategy is proposed for the construction of poly(disulfide)s for the efficient delivery of both nucleic acids and proteins into cells. A convenient photo-cross-linking polymerization was adopted between disulfide bonds in two modified lipoic acid monomers (Zn coordinated with dipicolylamine analogue (ZnDPA) and guanidine (GUA)). The disulfide-containing main chain of the resulting poly(disulfide)s was responsive to reducing circumstance, facilitating the release of cargos. By screening the feeding ratio of ZnDPA and GUA, the resulting poly(disulfide)s exhibited better performance in the delivery of nucleic acids including plasmid DNA and siRNA than commercially available transfection reagents. Cellular uptake results revealed that the polymer/cargo complexes entered the cells mainly following a thiol-mediated uptake pathway. Meanwhile, the polymer could also efficiently deliver proteins into cells without an obvious loss of protein activity, showing the versatility of the poly(disulfide)s for the delivery of various biomacromolecules. Moreover, the in vivo therapeutic effect of the materials was verified in the E.G7-OVA tumor-bearing mice. Ovalbumin-based nanovaccine induced a strong cellular immune response, especially cytotoxic T lymphocyte cellular immune response, and inhibited tumor growth. These results revealed the promise of the poly(disulfide)s in the application of both gene therapy and immunotherapy.
    Keywords:  Gene transfection; Lipoic acid; Protein delivery; Reduction responsiveness; Tumor immunotherapy
  3. Adv Healthc Mater. 2023 May 08. e2203252
      Gene therapy holds great promise as an effective treatment for many diseases of genetic origin. Gene therapy works by employing cationic polymers, liposomes, and nanoparticles to condense DNA into polyplexes via electronic interactions.Then, a therapeutic gene is introduced into target cells, thereby restoring or changing cellular function. However, gene transfection efficiency remains low in vivo due to high protein binding, poor targeting ability, and substantial endosomal entrapment. Artificial sheaths containing PEG, anions, or zwitterions can be introduced onto the surface of gene carriers to prevent interaction with proteins; however, they reduce the cellular uptake efficacy, endosomal escape, targeting ability, thereby, lowering gene transfection. Here, we report that linking dipicolylamine-zinc (DPA-Zn) ions onto polyplex nanoparticles can produce a strong hydration water layer around the polyplex, mimicking the function of PEGylation to reduce protein binding while targeting cancer cells, augmenting cellular uptake and endosomal escape. The polyplexes with a strong hydration water layer on the surface could achieve high gene transfection even in a 50% serum environment. This strategy provides a new solution for preventing protein adsorption while improving cellular uptake and endosomal escape. This article is protected by copyright. All rights reserved.
    Keywords:  dipicolylamine-zinc; gene delivery; hydration water layer; targeting cancer cells
  4. J Mater Chem B. 2023 May 10.
      Polyethyleneimine (PEI) derivatives substituted by lactose, succinic acid or alkyl domains were evaluated as nonviral gene delivery vectors towards balancing gene transfection and cytotoxicity. The investigations were focused on pDNA transfection into arising retinal pigment epithelia (ARPE-19) and human hepatocellular carcinoma (HepG2) cell lines. The first mentioned cell line was chosen as motivated by the non-negligible number of ocular disorders linked to gene aberrations, whereas the second one is a cell line overexpressing the asialoglycoprotein receptor (ASGP-R), which can bind to galactose residues. The presence of short alkyl domains (C4 and C6), and particularly the succinylation of the PEI chains, improved the biological outputs of the gene vectors. The presence of hydrophobic units possibly enhances lytic activity, whereas the incorporation of succinic acid slightly reduces polymer-DNA interaction strength, thereby enabling more efficient intracellular unpacking and cargo release. Succinylation is also supposed to decrease cytotoxicity and avoid protein adsorption to the polyplexes. The presence of long carbon chains (for instance, C12) nevertheless, results in higher levels of cytotoxicity and respective lower transfection rates. The sugar-decorated polyplexes are overall less cytotoxic, but the presence of lactose moieties also leads to larger polyplexes and notably weak polymer-DNA binding, which compromise the transfection efficiency. Yet, along with the presence of short lytic alkyl domains, the double-substitution of PEI synergistically boosts gene transfection probably due to the uptake of higher DNA and polymer amounts without cell damage. Overall, the experimental data suggest that ocular and hepatic gene therapies may be potentialized by fine-tuning the hydrophobic-to-hydrophilic balance, and succinic acid is a favorable motif for the modification of PEI.
  5. Drug Deliv Transl Res. 2023 May 08.
      Nanocarrier-assisted pulmonary drug delivery system has been widely employed for lung local disease treatment due to its enhanced drug lesion accumulation and reduced systematical side effects. However, the mucus barriers covered on the epithelia of trachea and bronchial tree construct a dense barrier for inhaled nanocarrier transport, which compromises the therapeutical effects. In this study, a lipid liquid crystalline nanoparticle NLP@Z with surface zwitterion material hexadecyl betaine (HB) modification and N-acetylcysteine (NAC) encapsulation was presented to exert the combination strategy of mucus-inert surface and mucus degradation. The HB modification endowed NLP@Z mucus-inert surface to inhibit the interaction between NLP@Z and mucins, and the encapsulated NAC could effectively degrade the mucins and further decrease the mucus viscosity. This combination strategy was proved to significantly promote the mucus penetration performance and enhance epithelial cell uptake. In addition, the proposed NLP@Z was equipped with desired nebulization property, which could be served as a potential pulmonary delivery nanoplatform. In summary, the proposed NLP@Z highlights the employment of the combination strategy for mucus penetration enhancement in pulmonary delivery, which may become a versatile platform for lung disease therapy.
    Keywords:  Mucus penetration; N-acetylcysteine; Nebulization; Pulmonary delivery; Zwitterion material
  6. J Control Release. 2023 May 08. pii: S0168-3659(23)00307-3. [Epub ahead of print]
      Design of experiment (DoE) is a powerful statistical technique used for variable screening and optimization. It is based on the simultaneous variation of multiple factors with the objective of finding the configuration of parameters that optimizes one or more outputs of interest, while using the minimal number of experimental runs required for testing, resulting very cost and time-efficient. Despite the high potential offered by this approach for innovation and process optimization, DoE is still only marginally applied in the field of nanomedicine and often its rationale application and analysis result is difficult to grasp by many. In this review, we discuss some of the latest applications of DoE in the formulation of nanovectors used for drug delivery across many different applications. First, we introduce general principles of DoE to the reader, which are indispensable to understand the works we report. Then, we give particular attention to the process variables, the specific designs, and the readouts used for process analysis and optimization for different classes of nanovectors. Finally, we try to delve into the current shortcomings of DoE application and possible future directions that could be employed to further improve the information that can be derived from this approach.
    Keywords:  Design of Experiment; Drug delivery; Nanomedicine; Nanoparticles; Optimization; Screening
  7. Mol Ther Nucleic Acids. 2023 Jun 13. 32 468-477
      Small interfering RNA (siRNA) and short hairpin RNA (shRNA) are widely used as RNA interference (RNAi) reagents. Recently, truncated shRNAs that trigger RNAi in a Dicer-independent manner have been developed. We generated a novel class of RNAi reagent, designated enforced strand bias (ESB) RNA, in which an siRNA duplex was chemically bridged between the 3' terminal overhang region of the guide strand and the 5' terminal nucleotide of the passenger strand. ESB RNA, which is chemically bridged at the 2' positions of ribose (2'-2' ESB RNA), functions in a Dicer-independent manner and was highly effective at triggering RNAi without the passenger strand-derived off-target effect. In addition, the 2'-2' ESB RNA exhibited a unique target sequence preference that differs from siRNA and silenced target sequences that could not be effectively suppressed by siRNA. Our results indicate that ESB RNA has the potential to be an effective RNAi reagent even when the target sequence is not suitable for siRNA.
    Keywords:  Dicer independent; ESB RNA; MT: Oligonucleotides: Therapies and Applications; RNA interference; chemically bridged siRNA; off-target effect; strand bias; target sequence preference
  8. J Phys Chem Lett. 2023 May 09. 4532-4540
      Intrinsically disordered peptides can form biomolecular condensates through liquid-liquid phase separation. These condensates play diverse roles in cells, including inducing large-scale changes in membrane morphology. Here we employ coarse-grained molecular dynamics simulations to identify the most salient physical principles that govern membrane remodeling by condensates. By systematically varying the interaction strengths among the polymers and lipids in our coarse-grained model, we are able to recapitulate various membrane transformations observed in different experiments. Endocytosis and exocytosis of the condensate are observed when the interpolymeric attraction is stronger than polymer-lipid interaction. We find a critical size of the condensate required to exhibit successful endocytosis. Multilamellarity and local gelation are observed when the polymer-lipid attraction is significantly stronger than the interpolymeric attraction. Our insights provide essential guidance to the design of (bio)polymers for the manipulation of membrane morphology in various applications such as drug delivery and synthetic biology.
  9. Adv Healthc Mater. 2023 May 08. e2202921
      The delivery of nucleic acid vaccine to stimulate host immune responses against COVID-19 shows promise. However, nucleic acid vaccines have drawbacks, including rapid clearance and poor cellular uptake, that limit their therapeutic potential. Microrobots can be engineered to sustain vaccine release and further control the interactions with immune cells that are vital for robust vaccination. Here, we report the three-dimensional (3D) fabrication of biocompatible and biodegradable microrobots via the two-photon polymerization of gelatin methacryloyl (GelMA) and their proof-of-concept application for DNA vaccine delivery. We demonstrated programmed degradation and drug release by varying the local exposure dose in 3D laser lithography and further functionalized the GelMA microspheres with polyethyleneimine for DNA vaccine delivery to dendritic cell and primary cells. In mice, the DNA vaccine delivered by functionalized microspheres elicited fast, enhanced, and durable antigen expression, which may lead to prolonged protection. Furthermore, we demonstrated the maneuverability of microrobots by fabricating GelMA microspheres on magnetic skeletons. In conclusion, GelMA microrobots may provide an efficient vaccination strategy by controlling the expression duration of DNA vaccines. This article is protected by copyright. All rights reserved.
    Keywords:  DNA; biodegradable hydrogels; microrobots; nanoparticles; vaccine delivery
  10. Mol Ther Nucleic Acids. 2023 Jun 13. 32 415-431
      Pulmonary fibrosis (PF) is an interstitial lung disease with complex pathological mechanism, and there is currently a lack of therapeutics that can heal it completely. Using gene therapy with drugs provides promising therapeutic strategies for synergistically reversing PF. However, improving the intracellular accumulation and transfection efficiency of therapeutic nucleic acids is still a critical issue that urgently needs to be addressed. Herein, we developed lipid nanoparticles (PEDPs) with high transfection efficiency coloaded with pDNA of nuclear factor erythroid 2-related factor 2 (pNrf2) and pirfenidone (PFD) for PF therapy. PEDPs can penetrate biological barriers, accumulate at the target, and exert therapeutic effects, eventually alleviating the oxidative stress imbalance in type II alveolar epithelial cells (AECs II) and inhibiting myofibroblast overactivation through the synergistic effects of Nrf2 combined with PFD, thus reversing PF. In addition, we systematically engineered various liposomes (LNPs), demonstrated that reducing the polyethylene glycol (PEG) proportion could significantly improve the uptake and transfection efficiency of the LNPs, and proposed a possible mechanism for this influence. This study clearly reveals that controlling the composition ratio of PEG in PEDPs can efficiently deliver therapeutics into AECs II, improve pNrf2 transfection, and synergize with PFD in a prospective strategy to reverse PF.
    Keywords:  Gene delivery; MT: Delivery Strategies; Oxidative stress; Pulmonary fibrosis; Synergistic regulation; transfected liposomes; transfection efficiency