bims-drudre Biomed News
on Targeted drug delivery and programmed release mechanisms
Issue of 2021‒06‒27
twelve papers selected by
Ceren Kimna
Technical University of Munich

  1. Adv Nanobiomed Res. 2021 Jun;1(6): 2000061
      MicroRNAs (miRNAs) are small noncoding RNAs that play key roles in post- transcriptional gene regulation. Being involved in regulating virtually all cellular processes, from proliferation and differentiation to migration and apoptosis, they have emerged as important epigenetic players. While most interest has gone into which miRNAs are involved in specific cellular processes or pathologies, the dosage-dependent effects of miRNAs remain vastly unexplored. Different doses of miRNAs can cause selective downregulation of target genes, in turn determining what signaling pathways and cellular responses are triggered. To explore this behavior, the effects of incremental miRNA dosage need to be studied; however, current delivery methods for miRNAs are unable to control how much miRNA enters a cell. Herein, an approach is presented based on a nanostrawelectroporation delivery platform that decouples the delivery from biological mechanisms (e.g., endocytosis) to enable precise control over the amount of miRNA delivered, along with demonstrating ratiometric intracellular delivery into primary dermal fibroblasts for miR-181a and miR-27a. In addition, it is shown that the nanostraw delivery platform allows efficient delivery of miRNAs into primary keratinocytes, opening new opportunities for successful miRNA delivery into this hard-to-transfect cell type.
    Keywords:  controlled delivery; epigenetics; microRNA; nanobiotechnology; nanostraw
  2. Nat Chem Biol. 2021 Jul;17(7): 828-836
      The ability to tune RNA and gene expression dynamics is greatly needed for biotechnological applications. Native RNA stabilizers or engineered 5' stability hairpins have been used to regulate transcript half-life to control recombinant protein expression. However, these methods have been mostly ad hoc and hence lack predictability and modularity. Here, we report a library of RNA modules called degradation-tuning RNAs (dtRNAs) that can increase or decrease transcript stability in vivo and in vitro. dtRNAs enable modulation of transcript stability over a 40-fold dynamic range in Escherichia coli with minimal influence on translation initiation. We harness dtRNAs in messenger RNAs and noncoding RNAs to tune gene circuit dynamics and enhance CRISPR interference in vivo. Use of stabilizing dtRNAs in cell-free transcription-translation reactions also tunes gene and RNA aptamer production. Finally, we combine dtRNAs with toehold switch sensors to enhance the performance of paper-based norovirus diagnostics, illustrating the potential of dtRNAs for biotechnological applications.
  3. Nat Biomed Eng. 2021 Jun 24.
      The performance of immune-checkpoint inhibitors, which benefit only a subset of patients and can cause serious immune-related adverse events, underscores the need for strategies that induce T-cell immunity with minimal toxicity. The gut microbiota has been implicated in the outcomes of patients following cancer immunotherapy, yet manipulating the gut microbiome to achieve systemic antitumour immunity is challenging. Here we show in multiple murine tumour models that inulin-a widely consumed dietary fibre-formulated as a 'colon-retentive' orally administered gel can effectively modulate the gut microbiome in situ, induce systemic memory-T-cell responses and amplify the antitumour activity of the checkpoint inhibitor anti-programmed cell death protein-1 (α-PD-1). Orally delivered inulin-gel treatments increased the relative abundances of key commensal microorganisms and their short-chain-fatty-acid metabolites, and led to enhanced recall responses for interferon-γ+CD8+ T cells as well as to the establishment of stem-like T-cell factor-1+PD-1+CD8+ T cells within the tumour microenvironment. Gels for the in situ modulation of the gut microbiome may be applicable more broadly to treat pathologies associated with a dysregulated gut microbiome.
  4. Sci Adv. 2021 Jun;pii: eabh3693. [Epub ahead of print]7(26):
      Chronic inflammation contributes to the pathogenesis of all muscular dystrophies. Inflammatory T cells damage muscle, while regulatory T cells (Tregs) promote regeneration. We hypothesized that providing anti-inflammatory cytokines in dystrophic muscle would promote proregenerative immune phenotypes and improve function. Primary T cells from dystrophic (mdx) mice responded appropriately to inflammatory or suppressive cytokines. Subsequently, interleukin-4 (IL-4)- or IL-10-conjugated gold nanoparticles (PA4, PA10) were injected into chronically injured, aged, mdx muscle. PA4 and PA10 increased T cell recruitment, with PA4 doubling CD4+/CD8- T cells versus controls. Further, 50% of CD4+/CD8- T cells were immunosuppressive Tregs following PA4, versus 20% in controls. Concomitant with Treg recruitment, muscles exhibited increased fiber area and fourfold increases in contraction force and velocity versus controls. The ability of PA4 to shift immune responses, and improve dystrophic muscle function, suggests that immunomodulatory treatment may benefit many genetically diverse muscular dystrophies, all of which share inflammatory pathology.
  5. ACS Nano. 2021 Jun 25.
      Molecular traffic across lipid membranes is a vital process in cell biology that involves specialized biological pores with a great variety of pore diameters, from fractions of a nanometer to >30 nm. Creating artificial membrane pores covering similar size and complexity will aid the understanding of transmembrane molecular transport in cells, while artificial pores are also a necessary ingredient for synthetic cells. Here, we report the construction of DNA origami nanopores that have an inner diameter as large as 30 nm. We developed methods to successfully insert these ultrawide pores into the lipid membrane of giant unilamellar vesicles (GUVs) by administering the pores concomitantly with vesicle formation in an inverted-emulsion cDICE technique. The reconstituted pores permit the transmembrane diffusion of large macromolecules, such as folded proteins, which demonstrates the formation of large membrane-spanning open pores. The pores are size selective, as dextran molecules with a diameter up to 28 nm can traverse the pores, whereas larger dextran molecules are blocked. By FRAP measurements and modeling of the GFP influx rate, we find that up to hundreds of pores can be functionally reconstituted into a single GUV. Our technique bears great potential for applications across different fields from biomimetics, to synthetic biology, to drug delivery.
    Keywords:  DNA origami; cDICE; liposomes; nanopores; transmembrane transport
  6. ACS Nano. 2021 Jun 24.
      Immune checkpoint blockade is a promising approach for cancer immunotherapy, but many patients do not respond due to the immunosuppressive tumor microenvironment (ITM). Herein, we propose visible-light-triggered prodrug nanoparticles (LT-NPs) for reversing ITM into high immunogenic tumors to potentiate checkpoint blockade immunotherapy. The photosensitizer (verteporfin; VPF), cathepin B-specific cleavable peptide (FRRG), and doxorubicin (DOX) conjugates are self-assembled into LT-NPs without any additional carrier material. The LT-NPs are specifically cleaved to VPF and DOX in cathepsin B-overexpressing cancer cells, thereby inducing cancer-specific cytotoxicity and immunogenic cell death (ICD) upon visible light irradiation. In tumor models, LT-NPs highly accumulate within tumors via the enhanced permeability and retention effect, and photochemotherapy of VPF and DOX induces effective ICD and maturation of dendritic cells to stimulate cross-presentation of cancer-antigens to T cells. Furthermore, LT-NPs with PD-L1 blockade greatly inhibit tumor growth, tumor recurrence, and lung metastasis by initiating a strong antitumor immune response. The photochemotherapy by LT-NPs provides a promising strategy for effective checkpoint blockade immunotherapy.
    Keywords:  antitumor immune response; cancer immunotherapy; immune checkpoint blockade; light-triggered prodrug; photochemotherapy
  7. Small. 2021 Jun 25. e2100479
      Local minimally invasive injection of anticancer therapies is a compelling approach to maximize the utilization of drugs and reduce the systemic adverse drug effects. However, the clinical translation is still hampered by many challenges such as short residence time of therapeutic agents and the difficulty in achieving multi-modulation combination therapy. Herein, mesoporous silica-coated gold nanorods (AuNR@SiO2 ) core-shell nanoparticles are fabricated to facilitate drug loading while rendering them photothermally responsive. Subsequently, AuNR@SiO2 is anchored into a monodisperse photocrosslinkable gelatin (GelMA) microgel through one-step microfluidic technology. Chemotherapeutic drug doxorubicin (DOX) is loaded into AuNR@SiO2 and 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is loaded in the microgel layer. The osteosarcoma targeting ligand alendronate is conjugated to AuNR@SiO2 to improve the tumor targeting. The microgel greatly improves the injectability since they can be dispersed in buffer and the injectability and degradability are adjustable by microfluidics during the fabrication. The drug release can, in turn, be modulated by multi-round light-trigger. Importantly, a single super low drug dose (1 mg kg-1 DOX with 5 mg kg-1 DMXAA) with peritumoral injection generates long-term therapeutic effect and significantly inhibited tumor growth in osteosarcoma bearing mice. Therefore, this nanocomposite@microgel system can act as a peritumoral reservoir for long-term effective osteosarcoma treatment.
    Keywords:  modulatable biodegradability; nanocomposite microgel; osteosarcoma targeting; triple-synergetic therapy; ultra-low dosage
  8. Nat Commun. 2021 Jun 25. 12(1): 3953
      The systemic therapeutic utilisation of RNA interference (RNAi) is limited by the non-specific off-target effects, which can have severe adverse impacts in clinical applications. The accurate use of RNAi requires tumour-specific on-demand conditional activation to eliminate the off-target effects of RNAi, for which conventional RNAi systems cannot be used. Herein, a tumourous biomarker-activated RNAi platform is achieved through the careful design of RNAi prodrugs in extracellular vesicles (EVs) with cancer-specific recognition/activation features. These RNAi prodrugs are assembled by splitting and reconstituting the principal siRNAs into a hybridisation chain reaction (HCR) amplification machine. EVs facilitate the specific and efficient internalisation of RNAi prodrugs into target tumour cells, where endogenous microRNAs (miRNAs) promote immediate and autonomous HCR-amplified RNAi activation to simultaneously silence multiantenna hypoxia-related genes. With multiple guaranteed cancer recognition and synergistic therapy features, the miRNA-initiated HCR-promoted RNAi cascade holds great promise for personalised theranostics that enable reliable diagnosis and programmable on-demand therapy.
  9. J Control Release. 2021 Jun 22. pii: S0168-3659(21)00314-X. [Epub ahead of print]
      Immune checkpoint blockade (ICB) treatment is promising for the clinical therapy of numerous malignancies. However, most cancer patients rarely benefit from such single-agent immunotherapies because of the complexity of both the tumor and tumor microenvironment. A tumor-specific liposomal vehicle (DOX-SAL) modified with a sialic acid-cholesterol conjugate (SA-CH) and remotely loaded with doxorubicin (DOX) is herein reported for improving chemoimmunotherapy. The intravenous administration of DOX-SAL dramatically downregulates tumor-associated macrophage (TAM)-mediated immunosuppression, inhibits immunoregulatory functions, and promotes intratumoral infiltration of CD8+ T cells. Compared to conventional liposomes, DOX-SAL-mediated combination therapy with a PD-1-blocking monoclonal antibody (aPD-1 mAb) almost completely eliminates B16F10 tumors and efficiently inhibits 4 T1 tumors. Moreover, cancer stem cells exhibit efficient tumor-initiating, tumor-propagating, and immunosuppressive tumor microenvironment-shaping capabilities. To further improve the treatment efficacy of an immunologically "cold" tumor, metformin (MET), which selectively eradicates breast cancer tumor stem cells, is co-encapsulated with DOX into liposomes to develop DOX/MET-SAL. The combination therapy with DOX/MET-SAL and aPD-1 mAb in a 4 T1 orthotopic mouse model indicates their synergetic benefit on primary tumor inhibition, metastasis suppression, and survival rate improvement. Thus, the multifunctional liposomal platform has potential value for ICB combination immunotherapy.
    Keywords:  Cancer stem cell; Immune checkpoint blockade therapy; Liposome; Sialic acid conjugate; Tumor-associated macrophage
  10. Adv Mater. 2021 Jun 25. e2101155
      Immunotherapy shows promising therapeutic potential for long-term tumor regression. However, current cancer immunotherapy displays a low response rate due to insufficient immunogenicity of the tumor cells. To address these challenges, herein, intracellular-acidity-activatable dynamic nanoparticles for eliciting immunogenicity by inducing ferroptosis of the tumor cells are engineered. The nanoparticles are engineered by integrating an ionizable block copolymer and acid-liable phenylboronate ester (PBE) dynamic covalent bonds for tumor-specific delivery of the ferroptosis inducer, a glutathione peroxidase 4 inhibitor RSL-3. The nanoparticles can stably encapsulate RSL-3 inside the hydrophobic core via π-π stacking interaction with the PBE groups at neutral pH (pH = 7.4), while releasing the payload in the endocytic vesicles (pH = 5.8-6.2) by acidity-triggered cleavage of the PBE dynamic covalent bonds. Furthermore, the nanoparticles can perform acid-activatable photodynamic therapy by protonation of the ionizable core, and significantly recruit tumor-infiltrating T lymphocytes for interferon gamma secretion, and thus sensitize the tumor cells to RSL-3-inducible ferroptosis. The combination of nanoparticle-induced ferroptosis and blockade of programmed death ligand 1 efficiently inhibits growth of B16-F10 melanoma tumor and lung metastasis of 4T1 breast tumors, suggesting the promising potential of ferroptosis induction for promoting cancer immunotherapy.
    Keywords:  T lymphocytes; cancer immunotherapy; ferroptosis; immune resistance; immunogenic cell death
  11. Adv Sci (Weinh). 2021 Jun 20. e2100968
      Brush polymers have emerged as components of novel materials that show huge potential in multiple disciplines and applications, including self-assembling photonic crystals, drug delivery vectors, biomimetic lubricants, and ultrasoft elastomers. However, an understanding of how this unique topology can affect the properties of highly solvated materials like hydrogels remain under investigated. Here, it is investigated how the high functionality and large overall size of brush polymers enhances the gelation kinetics of low polymer weight percent gels, enabling 100-fold faster gelation rates and 15-fold higher stiffness values than gels crosslinked by traditional star polymers of the same composition and polymer chain length. This work demonstrates that brush polymer topology provides a useful means to control gelation kinetics without the need to manipulate polymer composition or crosslinking chemistry. The unique architecture of brush polymers also results in restrained or even nonswelling behavior at different temperatures, regardless of the polymer concentration. Brush polymers therefore are an interesting tool for examining how high-functionality polymer building blocks can affect structure-property relationships and chemical kinetics in hydrogel materials, and also provide a useful rapidly-setting hydrogel platform with tunable properties and great potential for multiple material applications.
    Keywords:  brush polymers; fast-forming hydrogels; multifunctional crosslinkers; polymer NPs; polymer hydrogels
  12. Biomaterials. 2021 Jun 10. pii: S0142-9612(21)00323-9. [Epub ahead of print]275 120967
      Although osteoarthritis (OA) is the most prevalent degenerative joint disease, there is no effective disease-modifying therapy. We report an empty self-assembled hyaluronic acid nanoparticle (HA-NP) as a potential therapeutic agent for OA treatment. In mouse primary articular chondrocytes, HA-NPs blocked the receptor-mediated cellular uptake of free low-molecular-weight HA, and the cellular uptake of HA-NPs increased by ectopic expression of CD44, using an adenoviral delivery system (Ad-Cd44). HA-NP showed in vitro resistance to digestion with hyaluronidase and in vivo long-term retention ability in knee joint, compared with free high-molecular-weight (HMW) HA. CD44 expression increased in the damaged articular cartilage of patients and mice with OA. Ad-Cd44 infection and IL-1β treatment induced in vitro phenotypes of OA by enhancing catabolic gene expression in primary articular chondrocytes, and these effects were attenuated by HA-NP, but not HMW HA. Both Cd44 deficiency and intra-articular injection of HA-NP protected joint cartilage against OA development in the OA mouse model. NF-κB was found to mediate CD44-induced catabolic factor expression and HA-NP inhibited CD44-induced NF-κB activation in chondrocytes. Our results identify an empty HA-NP as a potential therapeutic agent targeting CD44 for OA treatment, and the CD44-NF-κB-catabolic gene axis as an underlying mechanism of destructive cartilage disorders.
    Keywords:  CD44; Catabolic factor; Hyaluronic acid; Osteoarthritis; Self-assembled nanoparticle