1,720,995 research outputs found
A plant derived multifunctional tool for nanobiotechnology based on Tomato bushy stunt virus
No full textStructure, size, physicochemical properties and production strategies make many plant viruses ideal protein based nanoscaffolds, nanocontainers and nano-building blocks expected to deliver a multitude of applications in different fields such as biomedicine, pharmaceutical chemistry, separation science, catalytic chemistry, crop pest control and biomaterials science. Functionalization of viral nanoparticles through modification by design of their external and internal surfaces is essential to fully exploit the potentiality of these objects. In the present paper we describe the development of a plant derived multifunctional tool for nanobiotechnology based on Tomato bushy stunt virus. We demonstrate the ability of this system to remarkably sustain genetic modifications and in vitro chemical derivatizations of its outer surface, which resulted in the successful display of large chimeric peptides fusions and small chemical molecules, respectively. Moreover, we have defined physicochemical conditions for viral swelling and reversible viral pore gating that we have successfully employed for foreign molecules loading and retention in the inner cavity of this plant virus nanoparticles system. Finally, a production and purification strategy from Nicotiana benthamiana plants has been addressed and optimized. © 2012 Springer Science+Business Media Dordrecht
Plant-derived chimeric virus particles for the diagnosis of primary sjögren syndrome
No full textPlants are ideal for the production of protein-based nanomaterials because they synthesize and assemble complex multimeric proteins that cannot be expressed efficiently using other platforms. Plant viruses can be thought of as self-replicating proteinaceous nanomaterials generally stable and easily produced in high titers. We used Potato virus X (PVX), chimeric virus particles, and Cowpea mosaic virus, empty virus-like particles to display a linear peptide (lipo) derived from human lipocalin, which is immunodominant in Sjögren’s syndrome (SjS) and is thus recognized by autoantibodies in SjS patient serum. These virus-derived nanoparticles were thus used to develop a diagnostic assay for SjS based on a direct enzyme linked immunosorbent assay format. We found that PVX-lipo formulations were more sensitive than the chemically synthesized immunodominant peptide and equally specific when used to distinguish between healthy individuals and SjS patients. Our novel assay therefore allows the diagnosis of SjS using a simple, low-invasive serum test, contrasting with the invasive labial biopsy required for current tests. Our results demonstrate that nanomaterials based on plant viruses can be used as diagnostic reagents for SjS, and could also be developed for the diagnosis of other diseases. © 2015 Tinazzi, Merlin, Bason, Beri, Zampieri, Lico, Bartoloni, Puccetti, Lunardi, Pezzotti and Avesani
In vitro and in vivo toxicity evaluation of plant virus nanocarriers
No full textThe use of biological self-assembling materials, plant virus nanoparticles in particular, appears very intriguing as it allows a great choice of symmetries and dimensions, easy chemical and biological engineering of both surface and/or internal cavity as well as safe and rapid production in plants. In this perspective, we present an initial evaluation of the safety profile of two structurally different plant viruses produced in Nicotiana benthamiana L. plants: the filamentous Potato virus X and the icosahedral Tomato bushy stunt virus. In vitro haemolysis assay was used to test the cytotoxic effects, which could arise by pVNPs interaction with cellular membranes, while early embryo assay was used to evaluate toxicity and teratogenicity in vivo. Data indicates that these structurally robust particles, still able to infect plants after incubation in serum up to 24. h, have neither toxic nor teratogenic effects in vitro and in vivo. This work represents the first safety-focused characterization of pVNPs in view of their possible use as drug delivery carriers. © 2015 Elsevier B.V
Nanoparticles in biomedicine: New insights from plant viruses
No full textIn recent years there has been an outburst of interest regarding the employment of nanoparticles for biomedical applications. Among the different types, such as metallic, organic, biological and hybrid systems, virus based nanoparticles have become a popular field of research. Viruses are able to form organized structures by molecular self assembly of repetitive building blocks, which implies non covalent interactions of protein monomers to form the quaternary structure of viral capsids. Plant virus based systems, in particular, are among the most advanced and exploited for their potential use as bioinspired structured nanomaterials and nanovectors. Plant viruses have a size particularly suitable for nanoscale applications and can offer several advantages. In fact, they are structurally uniform, robust, biodegradable and easy to produce. Moreover, many are the examples regarding functionalization of plant virus based nanoparticles by means of modification of their external surface and by loading cargo molecules into their internal cavity. This plasticity in terms of nanoparticles engineering is the ground on which multivalency, payload containment and targeted delivery can be fully exploited. This review aims primarily to summarize the most important plant virus based nanoparticles systems through their recent applications in biomedicine, such as epitope display for vaccine development and targeted delivery for diagnosis or therapy. In addition, their production in the most commonly used plant propagation and expression systems will be also reviewed. © 2013 Bentham Science Publishers
Viral vectors for production of recombinant proteins in plants
No full textGlobal demand for recombinant proteins has steadily accelerated for the last 20 years. These recombinant proteins have a wide range of important applications, including vaccines and therapeutics for human and animal health, industrial enzymes, new materials and components of novel nano-particles for various applications. The majority of recombinant proteins are produced by traditional biological “factories,” that is, predominantly mammalian and microbial cell cultures along with yeast and insect cells. However, these traditional technologies cannot satisfy the increasing market demand due to prohibitive capital investment requirements. During the last two decades, plants have been under intensive investigation to provide an alternative system for cost-effective, highly scalable, and safe production of recombinant proteins. Although the genetic engineering of plant viral vectors for heterologous gene expression can be dated back to the early 1980s, recent understanding of plant virology and technical progress in molecular biology have allowed for significant improvements and fine tuning of these vectors. These breakthroughs enable the flourishing of a variety of new viral-based expression systems and their wide application by academic and industry groups. In this review, we describe the principal plant viral-based production strategies and the latest plant viral expression systems, with a particular focus on the variety of proteins produced and their applications. We will summarize the recent progress in the downstream processing of plant materials for efficient extraction and purification of recombinant proteins. J. Cell. Physiol. 216: 366–377, 2008. © 2008 Wiley-Liss, Inc
Nanoparticles in biomedicine: New insights from plant viruses
No full textIn recent years there has been an outburst of interest regarding the employment of nanoparticles for biomedical applications. Among the different types, such as metallic, organic, biological and hybrid systems, virus based nanoparticles have become a popular field of research. Viruses are able to form organized structures by molecular self assembly of repetitive building blocks, which implies non covalent interactions of protein monomers to form the quaternary structure of viral capsids. Plant virus based systems, in particular, are among the most advanced and exploited for their potential use as bioinspired structured nanomaterials and nanovectors. Plant viruses have a size particularly suitable for nanoscale applications and can offer several advantages. In fact, they are structurally uniform, robust, biodegradable and easy to produce. Moreover, many are the examples regarding functionalization of plant virus based nanoparticles by means of modification of their external surface and by loading cargo molecules into their internal cavity. This plasticity in terms of nanoparticles engineering is the ground on which multivalency, payload containment and targeted delivery can be fully exploited. This review aims primarily to summarize the most important plant virus based nanoparticles systems through their recent applications in biomedicine, such as epitope display for vaccine development and targeted delivery for diagnosis or therapy. In addition, their production in the most commonly used plant propagation and expression systems will be also reviewed
Characterization of blood–brain barrier crossing and tumor homing peptides by molecular dynamics simulations
No full textIntroduction: The new frontier of tumor diagnosis and treatment relies on the development of delivery strategies capable of allowing the specific targeting of the diagnostic agents/ chemotherapeutics, avoiding side effects. In the case of brain tumors, achieving this goal is made more difficult by the presence of the blood–brain barrier (BBB). Peptides have been revealed as excellent candidates for both BBB crossing and specific cancer homing. Nanoparticles (NPs), functionalized with BBB crossing and tumor homing (TH) peptides, are emerging as smart theranostic systems. However, there is still poor knowledge concerning the molecular structure and dynamical properties of these peptides, essential requirements for a suitable functionalization of the delivery systems themselves. Methods: In this work, by means of molecular dynamics (MD) simulations, we have extensively characterized the structural and dynamical behavior of several peptides, known to be endowed of BBB crossing and TH properties. Results: The simulations point out that, on the basis of their conformational dynamics, the peptides can be classified in two main groups: 1) peptides assuming a specific structural conformation, a feature that could be important for interacting with the molecular target but that may limit their use as functionalizing molecules and 2) highly flexible peptides whose interaction with the target may be independent of a particular structural conformation and that may represent good candidates for the functionalization of theranostic NP-based platforms. Discussion: Such findings may be useful for the de novo designing of NP-based delivery systems
Plant produced TBSV nanoparticles: a versatile, multivalent platform for nanobiotechnology
No full textPlant produced TBSV nanoparticles: a versatile, multivalent platform for nanobiotechnology
No full textViral nanoparticles are molecular cages derived from the assembly of viral structural proteins. They bear several peculiarities as proper dimensions for nanoscale applications, size homogeneity, an intrinsic robustness, a large surface area to mass ratio and a defined, repetitive and symmetric macromolecular organization. Recently, plant viruses derived nanoparticles have received much attention as molecular tools in different technological fields.
We will present the development of a novel viral nanoparticles system based on Tomato bushy stunt virus (TBSV), that we have functionalized using different strategies of modification. Genetic modification of the viral coat protein gene has allowed protein fusions up to 56 amino acids in length, leading to correctly assembled chimeric virus particles that display the peptide of interest on the virus outer shell. Moreover, the system has shown an extreme versatility also regarding chemical modifications: N-hydroxysuccinimide ester based chemistry has been successfully employed to biotinylate lysine residues on the TBSV surface. Finally, a method has been developed to entrap little exogenous molecules inside the viral nanoparticles cavity by reversible opening of virion gated pores, a structural transition induced controlling physicochemical parameters such as pH and concentration of metal ions
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