bims-drudre Biomed News
on Targeted drug delivery and programmed release mechanisms
Issue of 2021‒10‒03
thirteen papers selected by
Ceren Kimna
Technical University of Munich

  1. J Nanobiotechnology. 2021 Sep 26. 19(1): 288
      BACKGROUND: Small interfering RNA (siRNA) has emerged as a kind of promising therapeutic agents for cancer therapy. However, the off-target effect and degradation are the main challenges for siRNAs delivery. Herein, an enzyme-free DNA amplification strategy initiated by a specific endogenous microRNA has been developed for in situ generation of siRNAs with enhanced gene therapy effect on cervical carcinoma.METHODS: This strategy contains three DNA hairpins (H1, H2/PS and H3) which can be triggered by microRNA-21 (miR-21) for self-assembly of DNA nanowheels (DNWs). Notably, this system is consistent with the operation of a DNA logic circuitry containing cascaded "AND" gates with feedback mechanism. Accordingly, a versatile biosensing and bioimaging platform is fabricated for sensitive and specific analysis of miR-21 in HeLa cells via fluorescence resonance energy transfer (FRET). Meanwhile, since the vascular endothelial growth factor (VEGF) antisense and sense sequences are encoded in hairpin reactants, the performance of this DNA circuit leads to in situ assembly of VEGF siRNAs in DNWs, which can be specifically recognized and cleaved by Dicer for gene therapy of cervical carcinoma.
    RESULTS: The proposed isothermal amplification approach exhibits high sensitivity for miR-21 with a detection limit of 0.25 pM and indicates excellent specificity to discriminate target miR-21 from the single-base mismatched sequence. Furthermore, this strategy achieves accurate and sensitive imaging analysis of the expression and distribution of miR-21 in different living cells. To note, compared to naked siRNAs alone, in situ siRNA generation shows a significantly enhanced gene silencing and anti-tumor effect due to the high reaction efficiency of DNA circuit and improved delivery stability of siRNAs.
    CONCLUSIONS: The endogenous miRNA-activated DNA circuit provides an exciting opportunity to construct a general nanoplatform for precise cancer diagnosis and efficient gene therapy, which has an important significance in clinical translation.
    Keywords:  Cervical carcinoma; DNA nanotechnology; Gene therapy; miRNA; siRNA
  2. Nat Commun. 2021 Oct 01. 12(1): 5754
      Small-molecule responsive protein switches are crucial components to control synthetic cellular activities. However, the repertoire of small-molecule protein switches is insufficient for many applications, including those in the translational spaces, where properties such as safety, immunogenicity, drug half-life, and drug side-effects are critical. Here, we present a computational protein design strategy to repurpose drug-inhibited protein-protein interactions as OFF- and ON-switches. The designed binders and drug-receptors form chemically-disruptable heterodimers (CDH) which dissociate in the presence of small molecules. To design ON-switches, we converted the CDHs into a multi-domain architecture which we refer to as activation by inhibitor release switches (AIR) that incorporate a rationally designed drug-insensitive receptor protein. CDHs and AIRs showed excellent performance as drug responsive switches to control combinations of synthetic circuits in mammalian cells. This approach effectively expands the chemical space and logic responses in living cells and provides a blueprint to develop new ON- and OFF-switches.
  3. ACS Nano. 2021 Oct 01.
      Bacterial infectious diseases seriously threaten public health and life. The specific interaction between an antibody and its multivalent antigen is an attractive way to defeat infectious disease. However, due to the high expense and strict storage and applied conditions for antibodies, it is highly desirable but remains an urgent challenge for disease diagnosis and treatment to construct artificial antibodies with strong stability and binding ability and excellent selectivity. Herein, we designed and synthesized antibody-like bio-orthogonal catalysts with the ability to recognize specific bacteria and accomplish in situ drug synthesis in captured bacteria by using improved bacterial imprinting technology. On one hand, the artificial antibody possesses a matching morphology for binding pathogens, and on the other hand, it acts as a bio-orthogonal catalyst for in situ synthesis of antibacterial drugs in live bacteria. Both in vitro and in vivo experiments have demonstrated that our designed antibody can distinguish and selectively bind to specific pathogens and eliminate them on site with the activated drugs. Therefore, our work provides a strategy for designing artificial antibodies with bio-orthogonal catalytic activity and may broaden the application of bio-orthogonal chemistry.
    Keywords:  antibody mimics; antimicrobial; bio-orthogonal catalyst; recognition; shape-selective
  4. Adv Mater. 2021 Oct 01. e2104139
      Targeted oral delivery of a drug via the intestinal lymphatic system (ILS) has the advantages of protecting against hepatic first-pass metabolism of the drug and improving its pharmacokinetic performance. It is also a promising route for the oral delivery of vaccines and therapeutic agents to induce mucosal immune responses and treat lymphatic diseases, respectively. This article describes the anatomical structures and physiological characteristics of the ILS, with an emphasis on enterocytes and microfold (M) cells, which are the main gateways for the transport of particulate delivery vehicles across the intestinal epithelium into the lymphatics. A comprehensive overview of recent advances in the rational engineering of particulate vehicles, along with the challenges and opportunities that they present for improving ILS drug delivery, is provided, and the mechanisms by which such vehicles target and transport through enterocytes or M cells are discussed. The use of naturally sourced materials, such as yeast microcapsules and their derived polymeric β-glucans, as novel ILS-targeting delivery vehicles is also reviewed. Such use is the focus of an emerging field of research. Their potential use in the oral delivery of nucleic acids, such as mRNA vaccines, is proposed.
    Keywords:  M cell; enterocyte; intestinal lymphatic system; oral drug delivery; β-glucans
  5. Nat Nanotechnol. 2021 Sep 27.
      Recent advances in molecular engineering and synthetic biology provide biomolecular and cell-based therapies with a high degree of molecular specificity, but limited spatiotemporal control. Here we show that biomolecules and cells can be engineered to deliver potent mechanical effects at specific locations inside the body through ultrasound-induced inertial cavitation. This capability is enabled by gas vesicles, a unique class of genetically encodable air-filled protein nanostructures. We show that low-frequency ultrasound can convert these biomolecules into micrometre-scale cavitating bubbles, unleashing strong local mechanical effects. This enables engineered gas vesicles to serve as remotely actuated cell-killing and tissue-disrupting agents, and allows genetically engineered cells to lyse, release molecular payloads and produce local mechanical damage on command. We demonstrate the capabilities of biomolecular inertial cavitation in vitro, in cellulo and in vivo, including in a mouse model of tumour-homing probiotic therapy.
  6. Adv Mater. 2021 Oct 02. e2103505
      The combination of immunotherapy with other forms of treatment is an emerging strategy for boosting antitumor responses. By combining multiple modes of action, these combinatorial therapies can improve clinical outcomes through unique synergisms. Here, we show a microrobot-based strategy that integrates tumor tissue disruption with biological stimulation for cancer immunotherapy. The microrobot is fabricated by loading bacterial outer membrane vesicles onto a self-propelling micromotor, which can react with water to generate a propulsion force. When administered intratumorally to a solid tumor, the disruption of the local tumor tissue coupled with the delivery of an immunostimulatory payload led to complete tumor regression. Additionally, treatment of the primary tumor resulted in the simultaneous education of the host immune system, enabling it to control the growth of distant tumors. Overall, this work introduces a distinct application of microrobots in cancer immunotherapy and offers an attractive strategy for amplifying cancer treatment efficacy when combined with conventional therapies. This article is protected by copyright. All rights reserved.
    Keywords:  cancer immunotherapy; immunostimulant; in situ vaccination; micromotor; physical destruction
  7. ACS Nano. 2021 Sep 28.
      Multifunctional antimicrobial strategies are urgently needed to treat methicillin-resistant Staphylococcus aureus (MRSA) caused pneumonia due to its increasing resistance, enhanced virulence, and high pathogenicity. Here, we report that lysostaphin, a bacteriolytic enzyme, encapsulated within poly(lactic-co-glycolic acid) microspheres (LyIR@MS) specially treats planktonic MRSA bacteria, mature biofilms, and related pneumonia. Optimized LyIR@MS with suitable diameters could deliver a sufficient amount of lysostaphin to the lung without a decrease in survival rate after intravenous injection. Furthermore, the degradable properties of the carrier make it safe for targeted release of lysostaphin to eliminate MRSA, repressing the expression of virulence genes and improving the sensitivity of biofilms to host neutrophils. In the MRSA pneumonia mouse model, treatment or prophylaxis with LyIR@MS significantly improved survival rate and relieved inflammatory injury without introducing adverse events. These findings suggest the clinical translational potential of LyIR@MS for the treatment of MRSA-infected lung diseases.
    Keywords:  MRSA; PLGA microspheres; biofilm; lung target; lysostaphin; pneumonia
  8. Proc Natl Acad Sci U S A. 2021 Oct 05. pii: e2106808118. [Epub ahead of print]118(40):
      The structural and functional diversity of materials in nature depends on the controlled assembly of discrete building blocks into complex architectures via specific, multistep, hierarchical assembly pathways. Achieving similar complexity in synthetic materials through hierarchical assembly is challenging due to difficulties with defining multiple recognition areas on synthetic building blocks and controlling the sequence through which those recognition sites direct assembly. Here, we show that we can exploit the chemical anisotropy of proteins and the programmability of DNA ligands to deliberately control the hierarchical assembly of protein-DNA materials. Through DNA sequence design, we introduce orthogonal DNA interactions with disparate interaction strengths ("strong" and "weak") onto specific geometric regions of a model protein, stable protein 1 (Sp1). We show that the spatial encoding of DNA ligands leads to highly directional assembly via strong interactions and that, by design, the first stage of assembly increases the multivalency of weak DNA-DNA interactions that give rise to an emergent second stage of assembly. Furthermore, we demonstrate that judicious DNA design not only directs assembly along a given pathway but can also direct distinct structural outcomes from a single pathway. This combination of protein surface and DNA sequence design allows us to encode the structural and chemical information necessary into building blocks to program their multistep hierarchical assembly. Our findings represent a strategy for controlling the hierarchical assembly of proteins to realize a diverse set of protein-DNA materials by design.
    Keywords:  DNA; hierarchy; nanotechnology; protein assembly; supramolecular chemistry
  9. Nat Commun. 2021 Sep 28. 12(1): 5682
      Controlled self-assembly of colloidal particles into predetermined organization facilitates the bottom-up manufacture of artificial materials with designated hierarchies and synergistically integrated functionalities. However, it remains a major challenge to assemble individual nanoparticles with minimal building instructions in a programmable fashion due to the lack of directional interactions. Here, we develop a general paradigm for controlled co-assembly of soft block copolymer micelles and simple unvarnished hard nanoparticles through variable noncovalent interactions, including hydrogen bonding and coordination interactions. Upon association, the hairy micelle corona binds with the hard nanoparticles with a specific valence depending exactly on their relative size and feeding ratio. This permits the integration of block copolymer micelles with a diverse array of hard nanoparticles with tunable chemistry into multidimensional colloidal molecules and polymers. Secondary co-assembly of the resulting colloidal molecules further leads to the formation of more complex hierarchical colloidal superstructures. Notably, such colloidal assembly is processible on surface either through initiating the alternating co-assembly from a micelle immobilized on a substrate or directly grafting a colloidal oligomer onto the micellar anchor.
  10. Nanoscale. 2021 Oct 01. 13(37): 15552-15559
      Dynamic DNA origami nanostructures that respond to external stimuli are promising platforms for cargo delivery and nanoscale sensing. However, the low stability of such nanostructures under physiological conditions presents a major obstacle for their use in biomedical applications. This article describes a stable tetrahedral DNA nanorobot (TDN) programmed to undergo a controlled conformational change in response to epithelial cell adhesion molecule (EpCAM), a molecular biomarker specifically expressed on the circulating tumor cells. Multiresolution molecular dynamics simulations verified the overall stability of the folded TDN design and characterized local distortions in the folded structure. Atomic force microscopy and gel electrophoresis results showed that tetragonal structures are more stable than unfolded DNA origami sheets. Live cell experiments demonstrated the low cytotoxicity and target specificity of TDN. In summary, the proposed TDN can not only effectively resist nuclease catalysis but also has the potential to monitor EpCAM-positive cells precisely.
  11. J Control Release. 2021 Sep 23. pii: S0168-3659(21)00500-9. [Epub ahead of print]
      Gene therapy has gained popularity in the treatment of incurable diseases. However, cell components, such as surface membrane, cytoskeleton protein, and nuclear envelope, retard the transport of nucleic acids, lowering the transfection efficiency. We developed a physical-chemical hybrid platform (S-RCLs) involving cationic lipid nanoparticles (RCLs) exposed to cyclic stretch. The transfection efficiency and delivery mechanisms of S-RCLs for siRNAs and pDNAs (plasmid DNAs encoding luciferase) were investigated. S-RCLs effectively delivered both siRNAs and pDNAs by overcoming the cell barriers. Mechanistically, S-RCLs promote the cellular uptake mediated by CD44, EH-domain containing 2 (EHD2), and caveolin-1 (CAV-1); intracellular transport via MAP6 Domain Containing 1 (Map6d1) and F-actin; and DNA transcription regulated by LSM3 and Hist1h3e in the nucleus. Thus, S-RCLs are a promising hybrid platform with excellent efficiency and biocompatibility for gene delivery both in vitro and in vivo.
    Keywords:  Biophysical stretch; Cationic lipid nanoparticles; Gene delivery; Hybrid platform; pDNA; siRNA
  12. Proc Natl Acad Sci U S A. 2021 Oct 05. pii: e2114227118. [Epub ahead of print]118(40):
      Human malignant hematopoietic stem and progenitor cells (HSPCs) reside in bone marrow (BM) niches, which remain challenging to explore due to limited in vivo accessibility and constraints with humanized animal models. Several in vitro systems have been established to culture patient-derived HSPCs in specific microenvironments, but they do not fully recapitulate the complex features of native bone marrow. Our group previously reported that human osteoblastic BM niches (O-N), engineered by culturing mesenchymal stromal cells within three-dimensional (3D) porous scaffolds under perfusion flow in a bioreactor system, are capable of maintaining, expanding, and functionally regulating healthy human cord blood-derived HSPCs. Here, we first demonstrate that this 3D O-N can sustain malignant CD34+ cells from acute myeloid leukemia (AML) and myeloproliferative neoplasm patients for up to 3 wk. Human malignant cells distributed in the bioreactor system mimicking the spatial distribution found in native BM tissue, where most HSPCs remain linked to the niches and mature cells are released to the circulation. Using human adipose tissue-derived stromal vascular fraction cells, we then generated a stromal-vascular niche and demonstrated that O-N and stromal-vascular niche differentially regulate leukemic UCSD-AML1 cell expansion, immunophenotype, and response to chemotherapy. The developed system offers a unique platform to investigate human leukemogenesis and response to drugs in customized environments, mimicking defined features of native hematopoietic niches and compatible with the establishment of personalized settings.
    Keywords:  3D perfusion bioreactors; AML/MPN; engineering stem cell niches; osteoblastic niche; stromal-vascular niche
  13. Nano Lett. 2021 Oct 01.
      Despite being promising, the clinical application of magnetic hyperthermia for brain cancer treatment is limited by the requirement of highly invasive intracranial injections. To overcome this limitation, here we report the development of gallic acid-coated magnetic nanoclovers (GA-MNCs), which allow not only for noninvasive delivery of magnetic hyperthermia but also for targeted delivery of systemic chemotherapy to brain tumors. GA-MNCs are composed of clover-shaped MNCs in the core, which can induce magnetic heat in high efficiency, and polymerized GA on the shell, which enables tumor vessel-targeting. We demonstrate that intravenous administration of GA-MNCs following alternating magnetic field exposure effectively inhibited brain cancer development and preferentially disrupted tumor vasculature, making it possible to efficiently deliver systemic chemotherapy for further improved efficacy. Due to the noninvasive nature and high efficiency in killing tumor cells and enhancing systemic drug delivery, GA-MNCs have the potential to be translated for improved treatment of brain cancer.
    Keywords:  VE-cadherin; brain cancer; magnetic hyperthermia; nanoclovers; vascular disrupting