bims-drudre Biomed News
on Targeted drug delivery and programmed release mechanisms
Issue of 2021‒02‒14
ten papers selected by
Ceren Kimna
Technical University of Munich

  1. Sci Transl Med. 2021 Feb 10. pii: eabe3889. [Epub ahead of print]13(580):
      Percutaneous locoregional therapies (LRTs), such as thermal ablation, are performed to limit the progression of hepatocellular carcinoma (HCC) and offer a bridge for patients waiting for liver transplantation. However, physiological challenges related to tumor location, size, and existence of multiple lesions as well as safety concerns related to potential thermal injury to adjacent tissues may preclude the use of thermal ablation or lead to its failure. Here, we showed a successful injection of an ionic liquid into tissue under image guidance, ablation of tumors in response to the injected ionic liquid, and persistence (28 days) of coinjected chemotherapy with the ionic liquid in the ablation zone. In a rat HCC model, the rabbit VX2 liver tumor model, and 12 human resected tumors, injection of the ionic liquid led to consistent tumor ablation. Combining the ionic liquid with the chemotherapy agent, doxorubicin, resulted in synergistic cytotoxicity when tested with cultured HCC cells and uniform drug distribution throughout the ablation zone when percutaneously injected into liver tumors in the rabbit liver tumor model. Because this ionic liquid preparation is simple to use, is efficacious, and has a low cost, we propose that this new LRT may bridge more patients to liver transplantation.
  2. Nature. 2021 Feb 10.
      Here we report on the antibody and memory B cell responses in a cohort of 20 volunteers who received either the Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccines1-4. Eight weeks after the second vaccine injection volunteers showed high levels of IgM, and IgG anti-SARS-CoV-2 spike protein (S) and receptor binding domain (RBD) binding titers. Moreover, the plasma neutralizing activity, and the relative numbers of RBD-specific memory B cells were equivalent to individuals who recovered from natural infection5,6. However, activity against SARS-CoV-2 variants encoding E484K or N501Y or the K417N:E484K:N501Y combination was reduced by a small but significant margin. Vaccine-elicited monoclonal antibodies (mAbs) potently neutralize SARS-CoV-2, targeting a number of different RBD epitopes in common with mAbs isolated from infected donors5-8. However, neutralization by 14 of the 17 most potent mAbs tested was reduced or abolished by either K417N, or E484K, or N501Y mutations. Notably, the same mutations were selected when recombinant vesicular stomatitis virus (rVSV)/SARS-CoV-2 S was cultured in the presence of the vaccine elicited mAbs. Taken together the results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid potential loss of clinical efficacy.
  3. Sci Adv. 2021 Feb;pii: eaba5515. [Epub ahead of print]7(7):
      Three-dimensional (3D) multicellular organoids recapitulate the native complexities of human tissue better than traditional cellular monolayers. As organoids are insufficiently supported using standard static culture, microphysiological systems (MPSs) provide a key enabling technology to maintain organoid physiology in vitro. Here, a polydimethylsiloxane-free MPS that enables continuous dynamic culture and serial in situ multiparametric assessments was leveraged to culture organoids, specifically human and rodent pancreatic islets, within a 3D alginate hydrogel. Computational modeling predicted reduced hypoxic stress and improved insulin secretion compared to static culture. Experimental validation via serial, high-content, and noninvasive assessments quantitatively confirmed that the MPS platform retained organoid viability and functionality for at least 10 days, in stark contrast to the acute decline observed overnight under static conditions. Our findings demonstrate the importance of a dynamic in vitro microenvironment for the preservation of primary organoid function and the utility of this MPS for in situ multiparametric assessment.
  4. Cell. 2021 Jan 26. pii: S0092-8674(21)00078-7. [Epub ahead of print]
      The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is continuing to disrupt personal lives, global healthcare systems, and economies. Hence, there is an urgent need for a vaccine that prevents viral infection, transmission, and disease. Here, we present a two-component protein-based nanoparticle vaccine that displays multiple copies of the SARS-CoV-2 spike protein. Immunization studies show that this vaccine induces potent neutralizing antibody responses in mice, rabbits, and cynomolgus macaques. The vaccine-induced immunity protects macaques against a high-dose challenge, resulting in strongly reduced viral infection and replication in the upper and lower airways. These nanoparticles are a promising vaccine candidate to curtail the SARS-CoV-2 pandemic.
    Keywords:  B cells; COVID-19; SARS-CoV-2; antibodies; immunity; macaques; nanoparticles; protection; vaccine
  5. ACS Nano. 2021 Feb 12.
      Although certain therapeutic agents with immunogenic properties may enhance antitumor immunity, cancer cells can eliminate harmful cytoplasmic entities and escape immunosurveillance by orchestrating autophagy. Here, an ingenious in situ self-assembled nanomicelle dissolving microneedle (DMN) patch was designed for intralesional delivery of immunogenic cell death-inducer (IR780) and autophagy inhibitor (chloroquine, CQ) coencapsulated micelles (C/I-Mil) for efficient antitumor therapy. Upon insertion into skin, the self-assembled C/I-Mil was generated, followed by electrostatic binding of hyaluronic acid, the matrix material of DMNs, accompanied by the dissolution of DMNs. Subsequently, photothermal-mediated size-tunable C/I-Mil could effectively penetrate into deep tumor tissue and be massively internalized via CD44 receptor-mediated endocytosis, precisely ablate tumors with the help of autophagy inhibition, and promote the release of damage-associated molecular patterns. Moreover, CQ could also act as an immune modulator to remodel tumor-associated macrophages toward the M1 phenotype via activating NF-κB. In vivo results showed that the localized photoimmunotherapy in synergy with autophagy inhibition could effectively eliminate primary and distant tumors, followed by a relapse-free survival of more than 40 days via remodeling the tumor immunosuppressive microenvironment. Our work provides a versatile, generalizable framework for employing self-assembled DMN-mediated autophagy inhibition integrated with photoimmunotherapy to sensitize superficial tumors and initiate optimal antitumor immunity.
    Keywords:  autophagy inhibition; dissolving microneedles; immunogenic cell death; nanomicelles; photoimmunotherapy; self-assembly
  6. Sci Transl Med. 2021 Feb 10. pii: eabd3438. [Epub ahead of print]13(580):
      Nucleic acids are used in many therapeutic modalities, including gene therapy, but their ability to trigger host immune responses in vivo can lead to decreased safety and efficacy. In the case of adeno-associated viral (AAV) vectors, studies have shown that the genome of the vector activates Toll-like receptor 9 (TLR9), a pattern recognition receptor that senses foreign DNA. Here, we engineered AAV vectors to be intrinsically less immunogenic by incorporating short DNA oligonucleotides that antagonize TLR9 activation directly into the vector genome. The engineered vectors elicited markedly reduced innate immune and T cell responses and enhanced gene expression in clinically relevant mouse and pig models across different tissues, including liver, muscle, and retina. Subretinal administration of higher-dose AAV in pigs resulted in photoreceptor pathology with microglia and T cell infiltration. These adverse findings were avoided in the contralateral eyes of the same animals that were injected with the engineered vectors. However, intravitreal injection of higher-dose AAV in macaques, a more immunogenic route of administration, showed that the engineered vector delayed but did not prevent clinical uveitis, suggesting that other immune factors in addition to TLR9 may contribute to intraocular inflammation in this model. Our results demonstrate that linking specific immunomodulatory noncoding sequences to much longer therapeutic nucleic acids can "cloak" the vector from inducing unwanted immune responses in multiple, but not all, models. This "coupled immunomodulation" strategy may widen the therapeutic window for AAV therapies as well as other DNA-based gene transfer methods.
  7. Adv Mater. 2021 Feb 08. e2007738
      Probing endogenous molecular profiles is of fundamental importance to understand cellular function and processes. Despite the promise of programmable nucleic-acid-based aptasensors across the breadth of biomolecular detection, target-responsive aptasensors enabling intracellular detection are as of yet infrequently realized. Several challenges remain, including the difficulties in quantification/normalization of quencher-based intensiometric signals, stability issues of the probe architecture, and complex sensor operations often necessitating extensive structural modeling. Here, the biomimetic crystallization-empowered self-assembly of a tumor-targetable DNA-inorganic hybrid nanocomposite aptasensor is presented, which enables Förster resonance energy transfer (FRET)-based quantitative interpretation of changes in the cellular target abundance. Leveraging the design programmability and high-throughput fabrication of rolling circle amplification-driven DNA nanoarchitecture, this designer platform offers a method to self-assemble a robust nanosensor from a multifunctionality-encoded template that includes a cell-targeting aptamer, a ratiometric aptasensor, and a cholesterol-decorating element. Taking prostate cancer cells and intracellular adenosine triphosphate molecules as a model system, a synergistic effect in the targeted delivery by cholesterol and aptamers, and the feasibility of quantitative intracellular aptasensing are demonstrated. It is envisioned that this approach provides a highly generalizable strategy across wide-ranging target systems toward a biologically deliverable nanosensor that enables quantitative monitoring of the abundance of endogenous biomolecules.
    Keywords:  DNA flowers; Förster resonance energy transfer; aptasensors; ratiometric aptasensing; rolling circle amplification
  8. ACS Nano. 2021 Feb 08.
      Materials that respond to endogenous stimuli are being leveraged to enhance spatiotemporal control in a range of biomedical applications from drug delivery to diagnostic tools. The design of materials that undergo morphological or chemical changes in response to specific biological cues or pathologies will be an important area of research for improving efficacies of existing therapies and imaging agents, while also being promising for developing personalized theranostic systems. Internal stimuli-responsive systems can be engineered across length scales from nanometers to macroscopic and can respond to endogenous signals such as enzymes, pH, glucose, ATP, hypoxia, redox signals, and nucleic acids by incorporating synthetic bio-inspired moieties or natural building blocks. This Review will summarize response mechanisms and fabrication strategies used in internal stimuli-responsive materials with a focus on drug delivery and imaging for a broad range of pathologies, including cancer, diabetes, vascular disorders, inflammation, and microbial infections. We will also discuss observed challenges, future research directions, and clinical translation aspects of these responsive materials.
    Keywords:  biological stimuli; enzymes; formulations; materials; nanomedicine; nanoparticles; pH; responsive polymers
  9. Small. 2021 Feb 12. e2006484
      Nanotechnology has provided great opportunities for managing neoplastic conditions at various levels, from preventive and diagnostic to therapeutic fields. However, when it comes to clinical application, nanoparticles (NPs) have some limitations in terms of biological stability, poor targeting, and rapid clearance from the body. Therefore, biomimetic approaches, utilizing immune cell membranes, are proposed to solve these issues. For example, macrophage or neutrophil cell membrane coated NPs are developed with the ability to interact with tumor tissue to suppress cancer progression and metastasis. The functionality of these particles largely depends on the surface proteins of the immune cells and their preserved function during membrane extraction and coating process on the NPs. Proteins on the outer surface of immune cells can render a wide range of activities to the NPs, including prolonged blood circulation, remarkable competency in recognizing antigens for enhanced targeting, better cellular interactions, gradual drug release, and reduced toxicity in vivo. In this review, nano-based systems coated with immune cells-derived membranous layers, their detailed production process, and the applicability of these biomimetic systems in cancer treatment are discussed. In addition, future perspectives and challenges for their clinical translation are also presented.
    Keywords:  T cells; biomimetics; immune cell membranes; macrophages; nanoparticles; neutrophils
  10. ACS Nano. 2021 Feb 08.
      Programmed Death-1 (PD-1) is a coinhibitory receptor expressed on activated T cells that suppresses T-cell signaling and effector functions. It has been previously shown that binding to its ligand PD-L1 induces a spatial reorganization of PD-1 receptors into microclusters on the cell membrane. However, the roles of the spatial organization of PD-L1 on PD-1 clustering and T-cell signaling have not been elucidated. Here, we used DNA origami flat sheets to display PD-L1 ligands at defined nanoscale distances and investigated their ability to inhibit T-cell activation in vitro. We found that DNA origami flat sheets modified with CD3 and CD28 activating antibodies (FS-α-CD3-CD28) induced robust T-cell activation. Co-treatment with flat sheets presenting PD-L1 ligands separated by ∼200 nm (FS-PD-L1-200), but not 13 nm (FS-PD-L1-13) or 40 nm (FS-PD-L1-40), caused an inhibition of T-cell signaling, which increased with increasing molar ratio of FS-PD-L1-200 to FS-α-CD3-CD28. Furthermore, FS-PD-L1-200 induced the formation of smaller PD-1 nanoclusters and caused a larger reduction in IL-2 expression compared to FS-PD-L1-13. Together, these findings suggest that the spatial organization of PD-L1 determines its ability to regulate T-cell signaling and may guide the development of future nanomedicine-based immunomodulatory therapies.
    Keywords:  DNA nanotechnology; DNA origami; PD-1 receptor; cancer immunotherapy; nanoscale spatial distribution