Effect of Green Tea Extract Encapsulated Into Chitosan Nanoparticles on Hepatic Fibrosis Collagen Fibers Assessed by Atomic Force Microscopy in Rat Hepatic Fibrosis Model

Applying bioactive ingredients in the formulation of foods instead of artificial preservatives is problematic because bioactive ingredients are unstable and sensitive to environmental conditions. The present study aimed to control the antioxidant activity of green tea extract (GT) through encapsulating in chitosan nanoparticles (CS-NP). The synthesized nanoparticles were analyzed by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The encapsulation efficiency (EE), particle size, zeta potential, and polydispersity index (PDI) of GT-loaded CS-nanoparticles (CS-NP-GT) were assessed. Based on the results, the particle size and zeta potential related to the ratio of CS to GT of 1 : 0.5 were obtained as 135.43 ± 2.52 nm and 40.40 ± 0.2 mV, respectively. Furthermore, the results of FT-IR and XRD confirmed the validity of encapsulating GT in CS-NP. In addition, the antioxidant activity of GT increased after nanoencapsulation since the IC50 value of CS-NP-GT decreased to 6.13 ± 0.12 μg/ml. Finally, applying these particles for delivering GT polyphenols in foods is regarded as promising.

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Atomic Force Microscopy Study of Atherosclerosis Progression in Arterial Walls

Microscopy and Microanalysis ◽

10.1017/s1431927616000039 ◽

2016 ◽

Vol 22 (2) ◽

pp. 311-325 ◽

Cited By ~ 4

Author(s):

Peter S. Timashev ◽

Svetlana L. Kotova ◽

Galina V. Belkova ◽

Ekaterina V. Gubar’kova ◽

Lidia B. Timofeeva ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Cross Sections ◽

Microscopy Study ◽

Collagen Fibers ◽

Lipid Core ◽

Force Microscopy ◽

Atherosclerosis Progression ◽

Plaque Type ◽

Atomic Force ◽

Thickened Intima

AbstractCardiovascular disease remains the leading cause of mortality worldwide. Here we suggest a novel approach for tracking atherosclerosis progression based on the use of atomic force microscopy (AFM). Using AFM, we studied cross-sections of coronary arteries with the following types of lesions: Type II—thickened intima; Type III—thickened intima with a lipid streak; Type IV—fibrotic layer over a lipid core; Type Va—unstable fibrotic layer over a lipid core; Type Vc—very thick fibrotic layer. AFM imaging revealed that the fibrotic layer of an atherosclerotic plaque is represented by a basket-weave network of collagen fibers and a subscale network of fibrils that become looser with atherosclerosis progression. In an unstable plaque (Type Va), packing of the collagen fibers and fibrils becomes even less uniform than that at the previous stages, while a stable fibrotic plaque (Vc) has significantly tighter packing. Such alterations of the collagen network morphology apparently, led to deterioration of the Type Va plaque mechanical properties, that, in turn, resulted in its instability and propensity to rupture. Thus, AFM may serve as a useful tool for tracking atherosclerosis progression in the arterial wall tissue.

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