DEVELOPMENT OF ELECTROSPUN POLY(VINYLPYRROLIDONE) (PVP) NANOFIBER MATS LOADED BY CALENDULA OFFICINALIS EXTRACT AND COENZYME Q10

2021 ◽  
Author(s):  
Sanja Rackov ◽  
◽  
Aleksandra Nešić ◽  
Milan Vraneš ◽  
Branka Pilić

Electrospun systems can be applied to various areas, particularly in biomedicine for skin treatment. The fabricated nanofibers represent an interconnected three-dimensional network with a high surface area to volume ratio providing structural and morphological similarities with the extracellular matrix. Hence, facilitate the removal of exudates, promote gaseous exchange, conform to the contour of the treated area and in the case of drug-loaded nanofibers resulting in improved bioavailability. Polyvinylpyrrolidone was selected as a polymer carrier due to its biocompatible, hydrophilic nature with good chemical and mechanical properties, approved by the U.S. FDA (Food and Drug Administration) as a safe polymer for biomedical and food applications. Calendula officinalis or Marigold extract is one of the oldest medical plants with numerous proven pharmacological effects including anti-inflammatory, antibacterial/antifungal and wound healing activity related to the components of the flowers such as sesquiterpenes, saponins, triterpenes, flavonoids. Coenzyme Q10 (CoQ10, Ubiquinone) is a naturally occurring oil-soluble antioxidant and anti-inflammatory agent that supports collagen production, mostly popularized as an anti-aging ingredient in skincare products for topical use. Novel Marigold extract and CoQ10–loaded polyvinylpyrrolidone nanofibers intended for skin treatment and wound therapy were developed using the electrospinning technique. The presence of functional groups on the nanofibrous surfaces was confirmed by FTIR analysis, the SEM images show the average size of the obtained nanomats and the thermal properties were investigated via DSC analysis.

2017 ◽  
Vol 72 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Jose Ordonez-Miranda ◽  
Karl Joulain ◽  
Younes Ezzahri

AbstractWe demonstrate that the energy transport of surface phonon-polaritons can be large enough to be observable in a crystal made up of a three-dimensional assembly of nanorods of silicon carbide. The ultralow phonon thermal conductivity of this nanostructure along with its high surface area-to-volume ratio allows the predominance of the polariton energy over that generated by phonons. The dispersion relation, propagation length, and thermal conductance of polaritons are numerically determined as functions of the radius and temperature of the nanorods. It is shown that the thermal conductance of a crystal with nanorods at 500 K and diameter (length) of 200 nm (20 μm) is 0.55 nW·K−1, which is comparable to the quantum of thermal conductance of polar nanowires.


2020 ◽  
Vol 6 (40) ◽  
pp. eaba0931
Author(s):  
Wenyu Wang ◽  
Karim Ouaras ◽  
Alexandra L. Rutz ◽  
Xia Li ◽  
Magda Gerigk ◽  
...  

Scalability and device integration have been prevailing issues limiting our ability in harnessing the potential of small-diameter conducting fibers. We report inflight fiber printing (iFP), a one-step process that integrates conducting fiber production and fiber-to-circuit connection. Inorganic (silver) or organic {PEDOT:PSS [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate]} fibers with 1- to 3-μm diameters are fabricated, with the fiber arrays exhibiting more than 95% transmittance (350 to 750 nm). The high surface area–to–volume ratio, permissiveness, and transparency of the fiber arrays were exploited to construct sensing and optoelectronic architectures. We show the PEDOT:PSS fibers as a cell-interfaced impedimetric sensor, a three-dimensional (3D) moisture flow sensor, and noncontact, wearable/portable respiratory sensors. The capability to design suspended fibers, networks of homo cross-junctions and hetero cross-junctions, and coupling iFP fibers with 3D-printed parts paves the way to additive manufacturing of fiber-based 3D devices with multilatitude functions and superior spatiotemporal resolution, beyond conventional film-based device architectures.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2679
Author(s):  
Alessandra Toncelli

Electrospinning is an effective and inexpensive technique to grow polymer materials in nanofiber shape with exceptionally high surface-area-to-volume ratio. Although it has been known for about a century, it has gained much interest in the new millennium thanks to its low cost and versatility, which has permitted to obtain a large variety of multifunctional compositions with a rich collection of new possible applications. Rare-earth doped materials possess many remarkable features that have been exploited, for example, for diode pumped bulk solid-state lasers in the visible and near infrared regions, or for biomedical applications when grown in nanometric form. In the last few decades, electrospinning preparation of rare-earth-doped crystal nanofibers has been developed and many different materials have been successfully grown. Crystal host, crystal quality and nanosized shape can deeply influence the optical properties of embedded rare earth ions; therefore, a large number of papers has recently been devoted to the growth and characterization of rare earth doped nanofibers with the electrospinning technique and an up-to-date review of this rapidly developing topic is missing; This review paper is devoted to the presentation of the main results obtained in this field up to now with particular insight into the optical characterization of the various materials grown with this technique.


2019 ◽  
Vol 99 (8) ◽  
pp. 1697-1707 ◽  
Author(s):  
Su Xuan Gan ◽  
Ywee Chieh Tay ◽  
Danwei Huang

AbstractMacroalgae play important ecological roles, including as hosts for a wide range of epifauna. However, the diversity relationships between macroalgae and epifauna are poorly understood for most tropical host species and algal morphologies. This study aims to characterize and analyse the diversity of invertebrates present amongst macroalgae with three distinct morphologies (three-dimensional, filamentous and foliose) across different tropical intertidal sites in Singapore. Morphological and DNA barcoding tools were employed for epifaunal species identification, and ordination statistics and multiple linear regression were used to test the effects of algal morphology, species and site on community structure and diversity of epiphytic invertebrates. Overall, epifaunal communities were distinct among sites and algal morphologies, and diversity was affected significantly by algal morphology. In particular, filamentous macroalgae hosted the highest abundance of epifauna dominated mainly by amphipods, which were able to take advantage of the high surface area to volume ratio in filamentous algal mats as a consequence of their thinner forms. Foliose species showed a significantly negative effect on invertebrate diversity. Our findings highlight the diverse associations between intertidal macroalgae and invertebrates with high turnover between algal morphology and sites that contribute to the high biodiversity of tropical shores. Future studies should consider the effects of the host habitat, seasonality and more algal species on epifaunal diversity.


2011 ◽  
Vol 45 (24) ◽  
pp. 2537-2546 ◽  
Author(s):  
J.S. Snipes ◽  
C.T. Robinson ◽  
S.C. Baxter

Nanocomposite materials hold the power to revitalize and revolutionize the field of composite materials. Nanoscaled, even common materials can exhibit strikingly different material properties from the bulk counterparts. If these properties can be accessed at the bulk scale, not only can materials be better tailored to suit various applications, but the possibility of designing multi-functional materials expands exponentially. In this study, the Generalized Method of Cells (GMC) micromechanics model is used to model 3D nanoscale composite architecture, including an interfacial region between the included and matrix phases, and predict the effective viscoelastic properties of a gold nanorod, polymer matrix, nanocomposite. Scale is introduced by referencing the dimensions of the interface to those of the nanorods. Comparisons are made of micromechanical response based on volume fraction and number density, highlighting the scale effects resulting from the high surface area to volume ratio of nanoparticles. Effective composite viscoelastic properties were developed, for static creep, for varying interfacial elastic stiffnesses. These experiments suggest that an elastically stiff interface greatly increases the stiffness of the polymer in response to an ‘instantaneous’ step load, reduces the rapid creep response, and results in a rapid leveling off of the time-dependent strain curves. The response of the composite to increasing stiffness of the interface region eventually reaches a plateau or threshold value, where further increases in the stiffness of the interface produces negligible increases in stiffness, or further reduction in creep response.


2013 ◽  
Vol 821-822 ◽  
pp. 32-35
Author(s):  
Xiao E Wang ◽  
Wei Jie Gao ◽  
Kun Wang ◽  
Yong Liu ◽  
Jie Fan

Nanofiber nonwoven has been used in many fields due to the high surface area to volume ratio of the nanofibers and other extremely excellent properties. Nanofiber yarn, which is composed of long nanofiber with some twists for expanding nanofibers application, has been a challenging. A continuous nanofiber yarn was fabricated by a electrospinning technique with two oppositely charged spinnerets system in this work. The effect of process parameters such as applied voltage, the distance and the angle between the two spinnerets were examined in detail. The optimum parameters obtained included that the applied voltage was ±16kV, the distance and the angle between the two spinnerets were 8cm and 120o respectively. The nanofiber yarn has good potential applications in textile, medical, and biology.


Química Nova ◽  
2021 ◽  
Author(s):  
Luiza Mercante ◽  
Rafaela Andre ◽  
Juliana Macedo ◽  
Adriana Pavinatto ◽  
Daniel Correa

ELECTROSPUN NANOFIBERS AND THEIR APPLICATIONS: ADVANCES IN THE LAST DECADE. In recent years there has been an increasing interest in the development of nanomaterials with improved properties compared to their counterparts at the micro- and macroscopic scale. In this context, nanofibers obtained by electrospinning technique are highly attractive due to the unique combination of high surface area/volume ratio, porosity, flexibility, mechanical performance, simple processing and relatively low cost. In addition, the possibility to buildup nanofibers with different compositions, structures and properties allows the design of nanostructures for a wide range of applications. In this review, we will discuss the advances of the last decade in the use of the electrospinning to obtain nanofibers with different compositions and morphologies for varied applications. Specifically, we are interested in providing an overview of the state of the art in relation to the application of nanofibers in different areas, including healthcare, environment, sensing and energy. Finally, we will discuss the real perspective in terms of industrial application and future trends that have been pursued to improve the performance of electrospun nanofibers. This review will help researchers to understand the evolution and challenges of the area and will also stimulate even more interest in the development of new devices based on electrospun nanofibers


2013 ◽  
Vol 683 ◽  
pp. 307-313
Author(s):  
Jin Joo Jung ◽  
Do Hyung Kim

Novel 3D (three-dimensional) urchin-like WO2.72nanostructures were prepared by a template-free hydrothermal synthetic route using W(CO)6and ethyl alcohol reagents. The detailed morphology and crystallinity were dependant on the synthesis temperature and synthesis time. The potential use of WO2.72nanourchins as a cathode electrode for electrochromic devices was assessed. The WO2.72electrochromic films exhibited a rapid switching response time (coloring time ~5 s, bleaching time ~1.6 s), outstanding high coloration efficiency (~116 cm2/C), and durability in an acidic electrolyte. This performance was attributed to the high diffusion coefficient [~6.43×10-9 cm2/s (in the intercalation)] of the urchin-likeWO2.72with a high surface area to volume ratio and high crystallinity


2017 ◽  
Vol 37 (9) ◽  
pp. 933-941 ◽  
Author(s):  
Mohammad Mahdi Safikhani ◽  
Ali Zamanian ◽  
Farnaz Ghorbani ◽  
Azadeh Asefnejad ◽  
Mostafa Shahrezaee

Abstract Tissue engineering is a biotechnology that is used to develop biological substitutes to restore, maintain, or improve functions. Thus, the porous scaffolds are used to accommodate cells in tissue engineering. In this research, three dimensional (3D) bi-layered polyurethane (PU)-gelatin nanofibrous scaffolds were prepared by the electrospinning method, after which the capability of the released heparin as an anti-coagulation factor was evaluated. Electrospinning has been extensively investigated for the preparation of fibers that exhibit a high surface area to volume ratio. Results showed that scanning electron microscopy (SEM) micrographs exhibited a smooth surface as well as a highly porous and bead-free structure, in which fibers were distributed in the range of 100–600 nm. The modulus and ultimate tensile strength (UTS) decreased and increased, respectively, after crosslinking the reaction of polymers. This process also reduced swelling ratio, the hydrolytic biodegradation rate, and the release rate as a function of time. Moreover, an in vitro assay demonstrated that 3D nanofibrous scaffolds supported L929 fibroblast cell viability and that cells adhered and spread on the fibers. Based on the obtained results, the heparin-loaded electrospinning nanofibrous scaffolds have initial physicochemical and mechanical properties to protect neo-tissue formation.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 316
Author(s):  
Samantha Lo ◽  
Mh Busra Fauzi

Tissue engineering technology is a promising alternative approach for improvement in health management. Biomaterials play a major role, acting as a provisional bioscaffold for tissue repair and regeneration. Collagen a widely studied natural component largely present in the extracellular matrix (ECM) of the human body. It provides mechanical stability with suitable elasticity and strength to various tissues, including skin, bone, tendon, cornea and others. Even though exogenous collagen is commonly used in bioscaffolds, largely in the medical and pharmaceutical fields, nano collagen is a relatively new material involved in nanotechnology with a plethora of unexplored potential. Nano collagen is a form of collagen reduced to a nanoparticulate size, which has its advantages over the common three-dimensional (3D) collagen design, primarily due to its nano-size contributing to a higher surface area-to-volume ratio, aiding in withstanding large loads with minimal tension. It can be produced through different approaches including the electrospinning technique to produce nano collagen fibres resembling natural ECM. Nano collagen can be applied in various medical fields involving bioscaffold insertion or fillers for wound healing improvement; skin, bone, vascular grafting, nerve tissue and articular cartilage regeneration as well as aiding in drug delivery and incorporation for cosmetic purposes.


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