scholarly journals Synthesis of Antibacterial Gelatin/Sodium Alginate Sponges and Their Antibacterial Activity

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1926
Author(s):  
Yanyi Wen ◽  
Bing Yu ◽  
Zhongjie Zhu ◽  
Zhuoran Yang ◽  
Wei Shao

In the present study, sponges with the antibiotic tetracycline hydrochloride (TCH) loaded into alginate incorporated with gelatin (G/SA) were fabricated. The G/SA sponges were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) analysis. G/SA sponges show a three-dimensional network structure with high porosity. An excellent swelling behavior and a controlled TCH release performance are observed from G/SA sponges. Moreover, they exhibit good antibacterial activity against both Gram-positive and Gram-negative bacteria.

2000 ◽  
Vol 6 (2) ◽  
pp. 151-157 ◽  
Author(s):  
I. Hernando ◽  
I. Pérez-Munuera ◽  
M.A. Lluch

Electron microscopy has made a significant contribution to our knowledge of the structure of foods and the interaction among their components. In this paper, several electron microscopy techniques are applied to study the Burgos cheese microstructure. Burgos cheese samples fixed in glutaraldehyde and observed by scanning electron microscopy showed a continuous three-dimensional network of protein, with roundish empty spaces, which probably contained fat, whey or air in the original sample. Fixation in osmium tetroxide showed the distribution of fat, which is organized in globules (1-3 ltm in diameter). Water closely and uniformly interacting with proteins and the protein shells deposited around the fat globule membranes (0.2 pm thick) can be observed by cryo-scanning electron microscopy. Samples observed by transmission electron microscopy showed loosely or ' strongly aggregated proteins forming the continuous network. Furthermore, a core and lining structure were distinguished; this structure could be related to the presence of B-lactoglobulin. Finally, this technique allows observations of individual casein grains and the interstitial spaces among them.


2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Almendo G. Lasera ◽  
Henry Aritonang ◽  
Harry Koleangan

ABSTRAKNanopartikel CuFe2O4 disintesis menggunakan metode kopresipitasi. Material yang telah disintesis, kemudian dikarakterisasi dengan menggunakan Scanning Electron Microscopy (SEM) dan Xray-Diffraction (XRD) serta di uji aktifitasnya sebagai antibakteri dengan menggunakan bakteri Staphylococcus aureus (Gram positif) dan Escherichia coli (Gram negatif). Hasil citra SEM memperlihatkan morfologi nanopartikel CuFe2O4 berbentuk persegi yang tidak beraturan. Difraktogram XRD menunjukkan bahwa ukuran sampel CuFe2O4 yang diperoleh adalah sebesar 20,136 nm. Uji aktifitas antibakteri yang telah dilakukan menunjukkan bahwa, nanopartikel CuFe2O4  jauh lebih baik dalam menghambat pertumbuhan bakteri E. coli dibandingkan dengan bakteri S.aureus, masing-masing 24 mm dan 6,5 mm. ABSTRACTCuFe2O4 nanoparticles were synthesized using the coprecipitation method. The synthesized material was then characterized using Scanning Electron Microscopy (SEM) and Xray-Difraction (XRD) and tested as antibacterial activity using Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative) bacteria. SEM imaging showed morphology of CuFe2O4 nanoparticles shaped like a rod. XRD diffractogram showed that the size of CuFe2O4 nanoparticles that obtained at 20.13 nm. The antibacterial activity test that has been done shows, CuFe2O4 nanoparticles are much better in inhibiting the growth of E. coli bacteria compared with S. aureus bacteria, 24 mm and 6,5 respertivelly. 


2017 ◽  
pp. 17
Author(s):  
Aida Carrillo-Ocampo ◽  
E. Mark Engleman

The seed of huauzontle (Chenopodium berlandieri ssp. nuttalliae) was studied by light microscopy and scanning electron microscopy. When the outer integument arises around the young ovule, instead of covering the inner integument and the nucellus, it grows backwards and partially surrounds the funiculus . When the pericarp is removed from the mature fruit, the seed is straw colored, because only the tegmen covers the seed. The chalaza of this seed has the form of a truncate cone, with the elliptical base towards the nucellus. In this zone of contact between the chalaza and the nucellus. a cuticle is deposited that surrounds some cells and makes a three dimensional network. This chalazal network is in contact with a smooth nucellar cuticle that fom1s part of the seed coat. The inversion of the inner integument could represent a selected mutation during the process of domestication.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
R. I. Johnsson-Hegyeli ◽  
A. F. Hegyeli ◽  
D. K. Landstrom ◽  
W. C. Lane

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
Enyew Amare Zereffa ◽  
Aschalew Tadesse ◽  
H. C. Ananda Murthy

Abstract Metal oxide nanomaterials are one of the preferences as antibacterial active materials. Due to its distinctive electronic configuration and suitable properties, ZnO is one of the novel antibacterial active materials. Nowadays, researchers are making a serious effort to improve the antibacterial activities of ZnO by forming a composite with the same/different bandgap semiconductor materials and doping of ions. Applying capping agents such as polymers and plant extract that control the morphology and size of the nanomaterials and optimizing different conditions also enhance the antibacterial activity. Forming a nanocomposite and doping reduces the electron/hole recombination, increases the surface area to volume ratio, and also improves the stability towards dissolution and corrosion. The release of antimicrobial ions, electrostatic interaction, reactive oxygen species (ROS) generations are the crucial antibacterial activity mechanism. This review also presents a detailed discussion of the antibacterial activity improvement of ZnO by forming a composite, doping, and optimizing different conditions. The morphological analysis using scanning electron microscopy, field emission-scanning electron microscopy, field-emission transmission electron microscopy, fluorescence microscopy, and confocal microscopy can confirm the antibacterial activity and also supports for developing a satisfactory mechanism. Graphical abstract Graphical abstract showing the metal oxides antibacterial mechanism and the fluorescence and scanning electron microscopic images.


1994 ◽  
Vol 42 (5) ◽  
pp. 681-686 ◽  
Author(s):  
V Rummelt ◽  
L M Gardner ◽  
R Folberg ◽  
S Beck ◽  
B Knosp ◽  
...  

The morphology of the microcirculation of uveal melanomas is a reliable market of tumor progression. Scanning electron microscopy of cast corrosion preparations can generate three-dimensional views of these vascular patterns, but this technique sacrifices the tumor parenchyma. Formalin-fixed wet tissue sections 100-150 microns thick from uveal melanomas were stained with the lectin Ulex europaeus agglutinin I (UEAI) and proliferating cell nuclear antigen (PCNA) to demonstrate simultaneously the tumor blood vessels and proliferating tumor cells. Indocarbocyanine (Cy3) was used as a fluorophore for UEAI and indodicarbocyanine (Cy5) was used for PCNA. Double labeled sections were examined with a laser scanning confocal microscope. Images of both stains were digitized at the same 5-microns intervals and each of the two images per interval was combined digitally to form one image. These combined images were visualized through voxel processing to study the relationship between melanoma cells expressing PCNA and various microcirculatory patterns. This technique produces images comparable to scanning electron microscopy of cast corrosion preparations while permitting simultaneous localization of melanoma cells expressing PCNA. The microcirculatory tree can be viewed from any perspective and the relationship between tumor cells and the tumor blood vessels can be studied concurrently in three dimensions. This technique is an alternative to cast corrosion preparations.


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