scholarly journals Stability of Insulin on Polycaprolactone Nanoparticles as a Function of Surface Properties

Author(s):  
Nader I. Namazi

The purpose of this research was to formulate insulin-loaded polycaprolactone (PCL) nanoparticles and evaluate structural stability of the protein using fluorescence spectroscopy. The size and morphology of the nanoparticles were characterized using dynamic light scattering (DLS) and scanning electron microscopy (SEM). Fluorescence emission data revealed that insulin is most stable with multilayer adsorption at pH close to its isoelectric point (IEP). The obtained particle size ranged from 130-140 nm+22 (SD). The loading amount of insulin onto the PCL nanoparticles was low at pH 7.4 and relatively high at pH 5.3. The adsorption phenomenon of protein onto hydrophobic nanoparticles provides a promising noninvasive carrier system for insulin.

2012 ◽  
Vol 198-199 ◽  
pp. 99-102
Author(s):  
Qing Gang Kong ◽  
Hai Yan Qian

Magnesium nitrate was used as additive for synthesis of Mg(OH)2 (MH) nanoparticles at low temperature (70°C). Mg(OH)2 nanoparticles have platelet-like structure and approximately 40-60nm in thicknesses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase. The supersaturation degree of solution effects the size and morphology of MH nanoparticles.


2012 ◽  
Vol 545 ◽  
pp. 169-171 ◽  
Author(s):  
Mawar Hazwani Jasimin ◽  
Nurhanna Badar ◽  
Rusdi Roshidah ◽  
Norlida Kamarulzaman

Aluminium oxide is one of the metal oxides that can exist in many phases such as α, θ, η etc. All the phases obtained are affected by annealing temperature and synthesis route. In this research the Al2O3 powders were synthesized by the combustion method using triethanolamine as fuels. A pure η phase as well as a mixed α and η phases were obtained. The size and morphology of Al2O3 particles were studied using scanning electron microscopy (SEM).


2006 ◽  
Vol 309-311 ◽  
pp. 3-6 ◽  
Author(s):  
S. Bertazzo ◽  
Celso A. Bertran

In this work, Scanning Electron Microscopy (SEM) has been used to determine the size and morphology of bone mineral crystals obtained from hydrazine-deproteinated parietal bone and femur of Wistar rats aged 15 days, 1 month and 1 year. Apart from the Scanning Electron Microscopy study, crystal size was also determined by X-ray diffractometry, using the Debye- Scherrer equation. Analyzing the results obtained and those reported in the literature for isolated crystals, it is possible to evaluate the influence of age and type of bone on the nanostructure of bone mineral and also propose the existence of a fundamental morphological unit that repeats itself in bone mineral formation.


2014 ◽  
Vol 34 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Shan Wang ◽  
Minyan Zheng

Abstract A chitosan (CS)–HgS nanocomposite was synthesized by a simulating biomineralization method. The effect of HgS nanoparticles on the physical properties of the composite was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The glass transition temperature (Tg) of the composite was 22°C higher than that of CS. The thermal stability of the composite was higher than that of CS, which was evidenced by the shift of onset temperature of degradation by 22°C as measured by DSC. The SEM image of the HgS/CS nanocomposite film shows that the nanoparticle size was 100 nm. The fluorescence emission of nanocomposite films was found to be very sensitive to the presence of triethylamine; even a small amount of triethylamine dramatically increased emissions. By contrast, emission was hardly affected by other common ions in water. The films are predicted to have the potential to be developed into excellent sensing films for triethylamine.


2010 ◽  
Vol 177 ◽  
pp. 9-11 ◽  
Author(s):  
Jie Song ◽  
Bing Xu ◽  
De Xin Huang ◽  
Cai Xia Li ◽  
Qiang Li

In this paper, super fine LiMn2O4 powder was synthesized by mechanochemical method starting from Li2CO3 and Mn2O3. The structure, size and morphology of LiMn2O4 were explored with X-ray diffraction and scanning electron microscopy (SEM). The electrochemical properties of LiMn2O4 were studied in 2 mol/L (NH4)2SO4 solution. The result showed that pure spinel LiMn204 powder was prepared after 8h grinding with 3.0KW of power and the particle size was about 1µm. Cyclic vohammetry curve indicate LiMn2O4 electrode material has better capacitive performances.


2018 ◽  
Vol 226 ◽  
pp. 03012
Author(s):  
Elizaveta A. Mukhanova ◽  
Inna A. Suprunova ◽  
Yana A. Suprunova ◽  
Igor Yu. Zabiyaka

In this work, we study the influence of various molecular weights of polyvinylpyrrolidone (PVP) on synthesis substituted hydroxyapatite. Using the scanning electron microscopy we estimated the size and morphology of the particle. We studied the structural transformations of phosphates and the effect of polymer sizes on the structure and morphology. We revealed the thermodynamic stability of the structure of hydroxyapatite due to experimental results.


2020 ◽  
Vol 1003 ◽  
pp. 128-133
Author(s):  
Hong Qian Dai ◽  
Yuan Lu ◽  
Zhi Hin Ou ◽  
Min Xu

Fe3O4-APTES-CS2 was prepared by modification of Fe3O4 with 3-aminopropyltriethoxysilane (APTES) and carbon disulfide (CS2). Lipase was covalently bonded to Fe3O4-APTES-CS2 to obtain the immobilized lipase Fe3O4-APTES-CS2-lipase. The textural characteristic of Fe3O4-APTES-CS2-lipase was assessed by scanning electron microscopy. The optimal immobilization conditions were 2.5 mg/mL lipase, pH 7.0, 35 °C, 3 h. The loading amount of lipase was 119.0 mg/g carrier. The immobilization efficiency reached 57%. (R)-(+)-N-acetyl-1-methyl-3-amphetamine was synthesized by Fe3O4-APTES-CS2-Li- pase. The conversion, enantiomeric excess of (R)-(+)-N-acetyl-1-methyl-3-amphet-a- mine and E value reached 36.8%, 98.5% and 132, respectivel.


Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


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