scholarly journals Fabrication of Sponges from Amnion Hydrogel to Apply as Wound Dressing

2021 ◽  
Vol 18 (20) ◽  
pp. 36
Author(s):  
Nghia Thi Hieu Phan ◽  
My Thi Ngoc Nguyen ◽  
Ha Le Bao Tran

A burn is a type of injury to the skin or other tissues. It can give rise to skin defects or even death. In this study, sponges derived from amnion hydrogel were generated to apply as a wound dressing. The sponges were created by combining crosslinking and freeze-drying methods. There were three types of the obtained sponges: MGA-0 (only washed with PBS), MGA-1 (washed in glycine 1 % for one day) and MGA-2 (washed in glycine 1 % for two days). These sponges were evaluated by scanning electron microscope (SEM), mechanical test, swelling, and cytotoxicity. The tensile strength of the sponges was about 1.8 MPa, and the absorption increased during 24 h. The relative growth rates (%RGR) of MGA-0, MGA-1, and MGA-2 were 88.8, 58.2 and 67.2 %, respectively. The obtained results suggested that the MGA-0 sponge has potential for wound dressing application. HIGHLIGHTS The sponges have been manufactured from human amnion hydrogel by combining crosslinking and freeze-drying methods Through the scanning electron microscope (SEM), the surface of the obtained sponges showed a fibrous-like structure These sponges have good absorbency, the tensile strength of the sponges is about 1.8 MPa like the tensile strength of human skin, and the MGA-0 sponge is not cytotoxic GRAPHICAL ABSTRACT

2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
Mbwana Suleiman Ndaro ◽  
Xiang-yu Jin ◽  
Ting Chen ◽  
Chong-wen Yu

This paper summarizes the investigations of hydroentangled islands-in-the-sea (PA6/COPET) fiber webs. An increase in water jet pressure improved the tensile strength and fiber splitting while elongation at break decreased. Scanning Electron Microscope (SEM) micrographs and ANOVA (MS Excel ™) were used for characterizing fiber splitting and data analyses respectively. It can be concluded that with a new innovation in spinnerette design and modification of co-polyester structure, PA6/COPET, fibers can be split in the hydroentanglement process without dissolution of the sea component.


2012 ◽  
Vol 554-556 ◽  
pp. 1835-1840 ◽  
Author(s):  
Lu Lu Han ◽  
Liang Wu Bi ◽  
Zhen Dong Zhao ◽  
Ya Li Xing

Squalene, a natural antioxidant, was microencapsulated by the method of ultrasonic spraying and freeze-drying using shell materials of gelatin and arabic gum. The suitable condition for ultrasonic emulsification before ultrasonic spraying and freeze-drying was frequency 28 kHz and running time 20 min. The reasonable condition for microencapsulation of squalene by ultrasonic spraying and freeze-drying was gelatin 3.0 %, arabic gum 5.0 %, maltodextrin 6.0 % and sucrose ester 0.9 %. The appearance and size of microcapsules of squalene were measured by scanning electron microscope and metallographic microscope. The microcapsules of squalene were smonth spheres at the diameter of about 10 μm.


2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu

In this paper, the Al-8.5Fe-1.3V-1.7Si alloys were fabricated by spray forming and extrusion process. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that the tensile strength of the extrued alloys can reach 353MPa, the yield strength 300MPa, elongation 19.12%, at room temperature. At 250°C, the tensile strength of the extrued alloys can reach 221MPa, the yield strength 208MPa, elongation 13.33%.


2011 ◽  
Vol 221 ◽  
pp. 289-294 ◽  
Author(s):  
Guo Hong Zhang ◽  
Jian Hui Qiu ◽  
Liang Shao ◽  
Xie Fu

Based on the novel USW method, the welds of Polylactide (PLA) - Polyformaldehyde (POM) and PLA - polymethyl methacrylate (PMMA) have been carried out. The interdiffusion processes of polymer chains have also been investigated according to the reptation theory and the hauling theory. The welding strengths are carried out by the universal tester and the rupture interfaces are observed using the scanning electron microscope. The best welding strength is 52MPa (90% compared with PLA of the PLA-POM system), which can reach the tensile strength of IPS. The molecules of POM are much easier to inter-diffuse than those of PLA and PMMA.


2012 ◽  
Vol 476-478 ◽  
pp. 1855-1861
Author(s):  
Xiao Lei Song ◽  
Chun Li Yao ◽  
Xiao Juan Jin

This study shows a optimization usage of SA and PAE on enhancing both wet and dry strength of paper. The influence of the dosage of PAE and the viscosity of SA on the binary system for strengthening of paper have been studied and compared with paper which use PAE alone as a wet strength additive. A optimization ratio of PAE/SA was obtained, and with this ratio unchanged the amount of PAE/SA and initial of pH of the pulp has been tested. Scanning electron microscope (SEM) was used as a assistant method to observe those influence. The results showes that PAE/SA binary strengthening system for paper has a better property than that of PAE alone as a wet strength additive. The optimal viscosity of SA is about 350 mPa•S and the optimal ratio of PAE and SA is 3:2 and the addition of PAE and SA are 0.75% and 0.5% respectively. SEM analyses confirm that the film-forming property of PAE is accelerated by SA and it is also noticeable that the PAE/SA film can stick to the suface of fibres uniformly in the aqueous pulp slurry environment. The reaserch on the effects of the slurries at different pH to the wet and dry tensile strength prove that PAE/SA strength system is more suitable for neutral and alkaline papermaking conditions.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.


Author(s):  
Nga Thi-Hong Pham

Ductility and tensile strength are among the basic mechanical properties of polymers. Generally, it is difficult to enhance the ductility without significantly reducing the tensile strength. In this study, thermoplastic polyurethane (TPU) is mixed with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% polyamide 6 (PA6). The results show that the sample containing 100% TPU has the largest elongation of 690.5%. When PA6 is added, the elongation decreases gradually to 635.0%, 623.1%, 529.5%, 476.0%, 391.3%, and 242.8%, corresponding to 2.5%, 5%, 7.5%, 10%, 12.5%, and 100% PA6, respectively. The tensile strengths are 36.7, 33.8, 29.4, 26.5, 23.1, and 24.9 MPa, corresponding to 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PA6 samples, respectively. The tensile strength decreases gradually when the PA6 content is increased. Notably, the tensile strength of the 12.5% PA6 sample increases compared to the 10% PA6 sample. In addition, the hardness of the TPU/PA blend increases slightly as the PA6 ratio is increased. Finally, scanning electron microscope images demonstrate that PA6 particles act as particles dispersed or dissolved in TPU/PA blends.


1980 ◽  
Vol 58 (15) ◽  
pp. 1700-1703 ◽  
Author(s):  
E. C. Quattlebaum ◽  
G. R. Carner

Vapor fixation for 96 h with 1% osmium tetroxide (OsO4) and 3–4 days air drying produced distortion-free specimens of Beauveria spp. for examination with the scanning electron microscope. A combination of 4 h OsO4 vapor fixation and freeze-drying also reduced disruption satisfactorily but specimens were not as well preserved as with the first method. Preparation methods that were ineffective in preventing collapse of hydrophilic structures were Cling Free® sprayed on specimens prior to examination, freeze-drying, critical-point drying (of unfixed material), and vapor fixation with glutaraldehyde.


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