1,143 research outputs found

    Nanotechnology in drug delivery systems

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    Nanotechnology is the engineering of purposeful systems at the molecular scale. It has an impact on every industry counting semiconductors, manufacturing, and biotechnology. Biomedical nanotechnology, bionanotechnology and nanomedicine are increasing biomedicine offered hybrid fields. The oncoming generations of nanoscale biomedical/pharmaceutical products will have object specificity, carry multiple drugs, and potentially release the payloads at desired unreliable time periods. Nanotechnology is also opening up new opportunities in implantable delivery systems, which are often preferable to the use of injectable drugs, for the reason that the latter frequently show first order kinetics that may ground toxicity and decreased drug ability. Bioadhesive polymers have broadly been used in transmucosal drug delivery systems. These materials can be combined into pharmaceutical formulations, drug absorption by mucosal cells can be increased or the drug can be released at the position for an expanded duration of time. Over the past few years, nano particle ceramics have been broadly handled in a wide spectrum of biomedical requests, and drug delivery is one of the wildest developing and increasing areas for nanoceramics, drawing growing consideration. Certainly, researchers are recognizing that the amazing characteristics of nano particle ceramics exhibit excellent platforms for drug transportation and controlled release compared with polymeric platforms. This review defines various nano particle ceramics and bio/mucoadhesive polymers used in drug delivery. The presented data displays that these systems can be used excellently for continued release applications. They assure the basic demands of biocompatibility, drug loading and tolerated release sketches spreading to several weeks, and are proper materials for present implant technologies

    Shape Memory Polyurethane-Based Smart Polymer Substrates for Physiologically Responsive, Dynamic Pressure (Re)Distribution.

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    Shape memory polymers (SMPs) are an exciting class of stimuli-responsive smart materials that demonstrate reactive and reversible changes in mechanical property, usually by switching between different states due to external stimuli. We report on the development of a polyurethane-based SMP foam for effective pressure redistribution that demonstrates controllable changes in dynamic pressure redistribution capability at a low transition temperature (∼24 °C)-ideally suited to matching modulations in body contact pressure for dynamic pressure relief (e.g., for alleviation or pressure ulcer effects). The resultant SMP material has been extensively characterized by a series of tests including stress-strain testing, compression testing, dynamic mechanical analysis, optical microscopy, UV-visible absorbance spectroscopy, variable-temperature areal pressure distribution, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, differential scanning calorimetry, dynamic thermogravimetric analysis, and 1H nuclear magnetic resonance spectroscopy. The foam system exhibits high responsivity when tested for plantar pressure modulation with significant potential in pressure ulcers treatment. Efficient pressure redistribution (∼80% reduction in interface pressure), high stress response (∼30% applied stress is stored in fixity and released on recovery), and excellent deformation recovery (∼100%) are demonstrated in addition to significant cycling ability without performance loss. By providing highly effective pressure redistribution and modulation when in contact with the body's surface, this SMP foam offers novel mechanisms for alleviating the risk of pressure ulcers

    Exceptional rigidity and biomechanics of amyloid revealed by 4D electron microscopy

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    Amyloid is an important class of proteinaceous material because of its close association with protein misfolding disorders such as Alzheimer’s disease and type II diabetes. Although the degree of stiffness of amyloid is critical to the understanding of its pathological and biological functions, current estimates of the rigidity of these β-sheet–rich protein aggregates range from soft (10^8 Pa) to hard (10^(10) Pa) depending on the method used. Here, we use time-resolved 4D EM to directly and noninvasively measure the oscillatory dynamics of freestanding, self-supporting amyloid beams and their rigidity. The dynamics of a single structure, not an ensemble, were visualized in space and time by imaging in the microscope an amyloid–dye cocrystal that, upon excitation, converts light into mechanical work. From the oscillatory motion, together with tomographic reconstructions of three studied amyloid beams, we determined the Young modulus of these highly ordered, hydrogen-bonded β-sheet structures. We find that amyloid materials are very stiff (10^9 Pa). The potential biological relevance of the deposition of such a highly rigid biomaterial in vivo are discussed

    Experimental Investigation of a Novel Formulation of a Cyanoacrylate-Based Adhesive for Self-Healing Concrete Technologies

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    The selection of an appropriate healing agent is critical to the success of vascular and mini-vascular networks. In self-healing concrete technology, commercially available cyanoacrylate (CA) adhesives have been shown to produce good strength recoveries; however, their rapid curing rate and short shelf-life make them unsuitable for site application. The aim of this study was to develop a modified cyanoacrylate (n-CA) with an extended shelf-life suitable for incorporation in a self-healing system. A series of n-CAs were formed from a commercial Ethyl Cyanoacrylate adhesive mixed with acrylic acid (AA) and nitro-anthraquinone (nAq) in varying ratios. When encapsulated within 3D printed mini-vascular networks (MVNs), the n-CAs remained dormant in liquid form for up to 5 days. The contact angle between the n-CAs and the cement mortar substrate, as measured via the sessile drop technique, decreased significantly with increasing AA content. The mechanical properties (bond strength) and the polymerization hardening of the n-CAs were evaluated over a curing period of 7–21 days, via a series of pull-off tests using cement mortar cubes. The 4:1:02 (CA:AA:nAq) n-CA formulation showed a significant increase in bond strength from 14 to 21 days, with a ceiling value of 2.6 MPa, while the 2:1 (CA:AA) n-CA formulation exhibited a good bond strength after 21 days (1 MPa). Nuclear Magnetic Resonance (NMR) conducted on the n-CAs suggested the formation of several new polymeric species, whilst differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) on the pre- and post-printed MVN material confirmed no significant changes in chemistry with no evidence of polymer degradation. Considered together, the experimental results show the potential for different n-CA formulations to act efficiently as a healing agent

    A COMPREHENSIVE REVIEW ON HYDROGELS

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    Polymers play a vital role in pharmaceutical development. Efforts have been continuously made to search a polymer that act in a controlled& desired way. Hydrogel development has solved many such issues. Hydrogels are hydrophilic, three-dimensional networks. Which are able to imbibe large amounts of water or biological fluids & thus resembles to a large extent, a biological tissue. They are insoluble due to the presence of physical or chemical crosslinks such as entanglements& crystallites. These materials can be synthesized to respond to a number of physiological stimuli present in the body, such as PH, ionic strength, temperature. The main aim of this article is to give a concise review on introduction, preparation methods, types, & various applications of hydrogels in the pharmaceutical field
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