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BACKGROUND: In the treatment of skin trauma with active repair, tissue engineering techniques are needed to generate new tissue to replace necrotic tissue. Skin scaffolds have a good application prospect in the field of wound repair. Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division. However, the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds. OBJECTIVE: To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites, and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters. METHODS: Oxidized nanocellulose whiskers at 10% concentration were extracted from Humulus scandens and then compounded with 5% gelatin to obtain gelatin/oxidized nanocellulose composites. The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined. Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material. Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters (filling gap 1.5-2.5 mm, uniform distribution of 0.1 mm; air pressure of 160-200 kPa), and the skin scaffold with a three-dimensional porous structure was prepared. The compressive performance of the skin scaffold was tested and compared with the finite element analysis results. The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. RESULTS AND CONCLUSION: (1) The elastic modulus of 5% gelatin was increased by 8.84 times by adding 10% oxidized nanocellulose whisker. A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa. When the filling gap increased from 1.5 mm to 2.5 mm, the theoretical porosity of the scaffold increased from 33% to 60%, but the compressive strength decreased from 230 000 Pa to 95 000 Pa. (2) These findings showed that the skin scaffold with theoretical porosity of 50% and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap. The scaffold had a clear threedimensional porous structure. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the existing evaluation system of tissue engineering scaffolds, it is usually necessary to test the mechanical strength of scaffolds in many aspects to ensure that they can meet the requirements of clinical application. However, because the measurement of mechanical properties of biological composite materials is a small deformation measurement, it is difficult to have professional measuring instruments on the market to meet the accuracy requirements. The commonly used hardness tester or tensile tester is difficult to meet the requirements of the mechanical properties of the scaffold. OBJECTIVE: To develop a device with the function of automatic detection of hardness and toughness to detect the mechanical properties of the biological scaffold. METHODS: This test system used two sets of differential bridges to realize the output of stress and strain respectively, and mechanical tests were conducted in different ways under constant temperature, humidity and strain rate to obtain various mechanical properties of the material. Aiming at the particularity of composite biomaterials, the equipment testing of biocomposite materials composed of nanocellulose and polycaprolactone was conducted to verify whether this test system can meet the requirements. RESULTS AND CONCLUSION: Through experiments, the test system could accurately reflect the mechanical properties of biomaterial scaffolds. Taking the slope of the “force displacement” loading curve of the tested scaffolds as the characterization of the toughness/hardness of the scaffolds, the mechanical properties of the scaffolds could be visualized, and the accuracy of the test system could reach 0.1 μm. It has theoretical basis and application value for the establishment of three-dimensional bioprinting in tissue damage repair. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Research & Exploration in Laboratory is the property of Research & Exploration in Laboratory and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are many potential safety hazards such as pollution, injury and fire in the process of disposal of laboratory animal corpse. By developing a scientific and rational safety management system, the infectiousness of experimental animals in the process of dead bodies and wastes can be under control. The system includes animal carcasses and waste disinfection and sterilization; equipment operation, maintenance and repair; work environment disinfection and sterilization; personal safety protection and education; fire prevention and other aspects of management.These measures avoid the occurrence of safety accidents, and provide a guarantee for the development of the disposal of laboratory animal corpse in universities and colleges. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: With the development of 3D printing technology, organ and tissue construction can be achieved by constructing a three-dimensional scaffold that is conducive to cell growth. OBJECTIVE: To solve the scaffold over-accumulation during 3D printing. METHODS: Fluent, a finite element analysis software developed by ANSYS Company in the United States, was used to analyze the extrusion process of print heads and to obtain suitable viscosity and extrusion pressure of materials for the 3D printing of cellulose gel composites. We then compared simulation results with experimental results. RESULTS AND CONCLUSION: The error between simulation results and experimental results was less than 5%. The simulated values at a kinetic viscosity of 45 and a pressure of 0.10-0.12 MPa solved the phenomenon of over-accumulation of cellulose gel composites during the 3D printing process, ensuring enough space for the 3D printed scaffold. [ABSTRACT FROM AUTHOR]

Copyright of Research & Exploration in Laboratory is the property of Research & Exploration in Laboratory and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Because the traditional laboratory construction project management pattern cannot adapt to the development of school，based on the analysis of the status, this paper puts forward a new idea for laboratory construction project management system to improve the laboratory construction project management，and help to make scientific decision，to improve laboratory management in university. By .Net + MVC, the management architecture is built to realize scientific laboratory construction project approval process. It includes project application, project examination，project execution, query and statistic. The system solves the many problems, such as information feedback in time， lack of basic information in examination and approval and so on. It can deal with the dynamic funding data of laboratory construction timely and accurately，and realize device security checking and warranty reminding during given period. [ABSTRACT FROM AUTHOR]