109 research outputs found

    Bionanomaterials from plant viruses

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    Plant virus capsids have emerged as useful biotemplates for material synthesis. All plant virus capsids are assembled with high-precision, three-dimensional structures providing nanoscale architectures that are highly monodisperse, can be produced in large quantities and that cannot replicate in mammalian cells (so are safe). Such exceptional characteristics make plant viruses strong candidates for application as biotemplates for novel and new material synthesis

    Templated mineralization by charge-modified cowpea mosaic virus

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    Templated mineralization of virus particles provides routes to narrowly dispersed nanoparticles that are not readily prepared by other means. The templated mineralization of metal or metal oxide on the external surface of wild-type cowpea mosaic virus (CPMV), a plant virus, is facilitated by increasing the external surface negative charge. This is achieved by the chemical modification of surface lysine groups by succinic anhydride. Hence, for example, treatment of charge-modified CPMV succinamate with a 1:2 mixture of iron(II) and iron(III) salts, followed by raising the pH to 10.2, led to the formation of narrowly dispersed, CPMV-templated, magnetite (Fe3O4) nanoparticles

    Polyelectrolyte-modified cowpea mosaic virus for the synthesis of gold nanoparticles

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    Polyelectrolyte surface-modified cowpea mosaic virus (CPMV) can be used for the templated synthesis of narrowly dispersed gold nanoparticles. Cationic polyelectrolyte, poly(allylamine) hydrochloride, is electrostatically bound to the external surface of the virus capsid. The polyelectrolyte-coated CPMV promotes adsorption of aqueous gold hydroxide anionic species, prepared from gold(III) chloride and potassium carbonate, that are easily reduced to form CPMV-templated gold nanoparticles. The process is simple and environmentally benign using only water as solvent at ambient temperature

    Alginate: Enhancement Strategies for Advanced Applications

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    Alginate is an excellent biodegradable and renewable material that is already used for a broad range of industrial applications, including advanced fields, such as biomedicine and bioengineering, due to its excellent biodegradable and biocompatible properties. This biopolymer can be produced from brown algae or a microorganism culture. This review presents the principles, chemical structures, gelation properties, chemical interactions, production, sterilization, purification, types, and alginate-based hydrogels developed so far. We present all of the advanced strategies used to remarkably enhance this biopolymer’s physicochemical and biological characteristics in various forms, such as injectable gels, fibers, films, hydrogels, and scaffolds. Thus, we present here all of the material engineering enhancement approaches achieved so far in this biopolymer in terms of mechanical reinforcement, thermal and electrical performance, wettability, water sorption and diffusion, antimicrobial activity, in vivo and in vitro biological behavior, including toxicity, cell adhesion, proliferation, and differentiation, immunological response, biodegradation, porosity, and its use as scaffolds for tissue engineering applications. These improvements to overcome the drawbacks of the alginate biopolymer could exponentially increase the significant number of alginate applications that go from the paper industry to the bioprinting of organs

    Characterisation of ciprofloxacin-loaded polymeric fiber mats prepared by meltelectrospinning

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    Electrospun drug-loaded polymers are used to make formulations that slowly release medication. This study creates ciprofloxacin (Cip)-loaded fiber mats by melt electrospinning using polycaprolactone (PCL) and PEG4000 for controlled release of Cip. The increase in Cip concentration and PEG4000 percentages increases the mat thickness resulting in uniform morphology. The tensile strength of the PCL mat is significantly improved by adding higher concentrations of Cip while PEG inclusion reduced the tensile strength significantly. Differential Scanning Calorimetry (DSC) curves of PCL and PEG 4000 either as free components of after melt electrospinning are identical and both components shows a single endothermic peak at 63 and 61 °C respectively. Fourier transform infrared spectroscopy confirms the chemical stability of the raw materials, while X-ray diffraction shows the conversion of PEG and Cip from crystalline to amorphous structure following melt electrospinning. Cip is released gradually over 72 h, and the release is increased in the presence of PEG with a maximum Cip release ≈25% after 72 h. The study provides new insights into the development of controlled release fiber mats loaded with antibacterial agents. This can help to develop formulations for wound dressings that improve the clinical outcomes

    Circadian rhythm disruption and Alzheimer’s disease: The dynamics of a vicious cycle

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    All mammalian cells exhibit circadian rhythm in cellular metabolism and energetics. Autonomous cellular clocks are modulated by various pathways that are essential for robust time keeping. In addition to the canonical transcriptional translational feedback loop, several new pathways of circadian timekeeping - non-transcriptional oscillations, post-translational modifications, epigenetics and cellular signaling in the circadian clock - have been identified. The physiology of circadian rhythm is expansive, and its link to the neurodegeneration is multifactorial. Circadian rhythm disruption is prevelant in contamporary society where light-noise, shift-work, and transmeridian travel are commonplace, and is also reported from the early stages of Alzheimer's disease (AD). Circadian alignment by bright light therapy in conjunction with chronobiotics is beneficial for treating sundowning syndrome and other cognitive symptoms in advanced AD patients. We performed a comprehensive analysis of the clinical and translational reports to review the physiology of the circadian clock, delineate its dysfunction in AD, and unravel the dynamics of the vicious cycle between two pathologies. The review delineates the role of putative targets like clock proteins PER, CLOCK, BMAL1, ROR, and clock-controlled proteins like AVP, SIRT1, FOXO, and PK2 towards future approaches for management of AD. Furthermore, the role of circadian rhythm disruption in aging is delineated

    Monkeypox virus: An emerging epidemic.

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    INTRODUCTION A monkeypox outbreak is spreading in territories where the virus is not generally prevalent. The rapid and sudden emergence of monkeypox in numerous nations at the same time means that unreported transmission may have persisted. The number of reported cases is on a constant increase worldwide. At least 20 non-African countries, like Canada, Portugal, Spain, and the United Kingdom, have reported more than 57662 as of September 9th suspected or confirmed cases. This is the largest epidemic seen outside of Africa. Scientists are struggling to determine the responsible genes for the higher virulence and transmissibility of the virus. Because the viruses are related, several countries have begun acquiring smallpox vaccinations, which are believed to be very effective against monkeypox. METHODS Bibliographic databases and web-search engines were used to retrieve studies that assessed monkeypox basic biology, life cycle, and transmission. Data were evaluated and used to explain the therapeutics that are under use or have potential. Finally, here is a comparison between how vaccines are being made now and how they were made in the past to stop the spread of new viruses. CONCLUSIONS Available vaccines are believed to be effective if administered within four days of viral exposure, as the virus has a long incubation period. As the virus is zoonotic, there is still a great deal of concern about the viral genetic shift and the risk of spreading to humans. This review will discuss the virus's biology and how dangerous it is. It will also look at how it spreads, what vaccines and treatments are available, and what technologies could be used to make vaccines quickly using mRNA technologies

    Redox-active ferrocene-modified Cowpea mosaic virus nanoparticles

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    A naturally occurring nanoparticle, the plant virus Cowpea mosaic virus, can be decorated with ferrocene derivatives, of various linker lengths with amine and carboxylategroups, on the external surface using a range of conjugation strategies. The multiple, organometallic, redox-active ferrocene moieties on the outer surface of the virus are electrochemically independent with reduction potentials that span a potential window of 0.16 V that are dependent on the site of modification and the nature of the ferrocene derivative. The number of ferrocenes coupled to each virus ranges from about 100 to 240 depending upon the conjugation site and the linker length and these redox active units can provide multielectron reservoirs
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