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This study was designed and conducted to investigate the mechanical and physical properties of fish gelatin films and the effect of Glutaraldehyde crosslinking on antimicrobial control of poly-l-lysine. In this study, the film was prepared by casting method and then 0.05% Glutaraldehyde and 0.05% poly-l-lysine added to fish gelatin film. After that, physical and mechanical properties, antimicrobial activity and release of poly-l-lysine from the film were observed. The results showed that the addition of glutaraldehyde to the fish gelatin film increased tensile pressure (6.80 MPa) and reduced solubility (38.51%), moisture (8.05%), and water vapor permeability (2.03 mm/h mm²kpa×10^-6­). The fish gelatin film with glutaraldehyde as a crosslinking agent was showed a smooth surface without porosity according to the SEM results. Moreover, the release of poly-l-lysine from the biopolymer containing the Glutaraldehyde was slower and more continuous due to crosslinking. Considering the mechanical and physical properties of the films and release control of the antimicrobial compound, it seems that films containing crosslinking agents can be used in food storage.

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Given the widespread use of heart valve prostheses, examining these prostheses in terms of biological function and biocompatibility is of particular importance. Mechanical valves have excellent durability; however, due to long-term use of anticoagulant medications, there is a risk of thromboembolism and bleeding. In this regard, biological valves are preferable. On the other hand, biological valves made from bovine pericardium have a shorter lifespan. The performance of biological valves depends on the collagen structure and mechanical behavior of the selected tissue. Therefore, it is necessary to choose suitable tissue for constructing these prostheses. The purpose of this study is to investigate the compatibility of stresses, strains, and the opening degree of a biological valve made from glutaraldehyde-stabilized donkey pericardial tissue compared to a biological valve made from decellularized donkey pericardial tissue. In this study, after chemical preparation of the tissue, uniaxial tests were performed on the tissues. Then, a finite element model was used with the extracted mechanical properties to evaluate tissue valve degradation and stress under physiological loading. The stress at peak systole in the valve with a glutaraldehyde-stabilized leaflet was 1.72 MPa, which was 1.17 MPa for the decellularized valve. The results indicate that the stress in decellularized tissue is relatively lower than in glutaraldehyde-stabilized tissue. The results of this study can be used in designing and constructing biological heart valves