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Marine Polysaccharides in Pharmaceutical Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Riyasree Paul, Sourav Kabiraj, Sreejan Manna, Sougata Jana
Sharma et al. employed alginate and gelatin to develop microfibers containing curcumin as a potential agent used for wound healing. The tensile strength of microfibers was reported between 1.08 and 3.53 N/mm2. A cumulative curcumin release of 85% was observed after 72 hours. An in vivo study performed on cutaneous wound indicated higher drug accumulation in compared to the marketed formulation (Sharma et al. 2020). Karavasili et al. developed alginate and methyl cellulose based 3D printable hydrogels for wound healing application containing naturally obtained bioactive compounds. The developed carbohydrate inks exhibited excellent swelling behavior in hydrated conditions along with required antimicrobial efficacy. The formulations demonstrated good biocompatible profile with the human dermis layer. The in vivo wound healing study confirmed the cellular growth after application (Karavasili et al. 2020). In a recent investigation, Koga et al. reported the synthesis of zinc ion cross-linked alginate dressings for rapid healing of wounds. Aloe vera was also incorporated in the dressing and subjected tovarious evaluations. The developed films exhibited sufficient mechanical strength and malleability. An in vivo study performed in two groups of Wistar rats indicated enhancement in type I collagen fibers, quickening the healing process (Koga et al. 2020).
The Inflammatory Response: A Bridge Between The Constitutive and Inducible Systems
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
The mediators of inflammation are all present in the blood plasma in inactive form. The initial event triggering activation is common for the clotting system, the kinin system and the fibrinolytic system but not for the complement system. When plasma enters damaged tissue, the first component of these blood-borne systems to be activated is Hageman Factor. Activation results from contact with and binding to collagen in the damaged tissue. Collagen is present throughout the body as collagen fibers make up the matrix of the body′s tissues. It is typically covered by other components of the extracellular matrix, namely, fibrinonectin and proteoglycans, which are stripped from it by the injury that initiates inflammation.
Functional Anatomy
Published in James Crossley, Functional Exercise and Rehabilitation, 2021
Collagen fibers act like tough threads, providing tensile strength, supporting and binding tissues together. Elastin is a rubber-like substance designed to resist distension, absorb load and recoil after stretch. Ground substance, a lubricating gel composed of proteoglycans, hyaluronic acid and water contains various cells, including fibroblasts that synthesize collagen and maintain the extracellular matrix. Fibroblasts play a critical role in wound healing by maintaining the health of connective tissue cells.
Bovine pericardium leaflet damage during transcatheter aortic valve crimping: a study of the mechanisms
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Wentao Feng, Xianda Yang, Jie Yao, Chenglong Feng, Lizhen Wang, Yubo Fan
Bovine pericardium represents a superior material of choice to serve as the leaflets. In this study, bovine pericardium samples were folded and compressed with various stresses. The results indicated that the elastic modulus began to decrease significantly at 2 MPa stress and the tensile strength began to decrease significantly at 2.5 MPa stress. The stress levels of 2–2.5 MPa might cause micro-damage to the bovine pericardium material and affect its mechanical properties. The significant differences in tensile strength and elastic modulus appeared at two different stress levels. The elastic modulus decreased ahead of the tensile strength. The lower level of stress might affect the structure of collagen fibers (irregular, delaminated, or cavitated) but with no fragmentation of the fibers. With the increased stress, the collagen fibers began to break and cause a decrease in tensile strength. This phenomenon could also be observed in the results of histological analysis (Figure 5), SEM observation (Figure 6), and TEM observation (Figure 7). Accordingly, this study assumed that 2 MPa stress would be the high-risk level of bovine pericardium leaflet damage. The leaflet damage in the compression-bending region was more serious. Therefore, the crimping size of the TAV should be controlled to avoid loading 2 MPa or higher stress on the leaflets during deployment.
Supporting the role of penile trauma and micro-trauma in the etiology of Peyronie’s disease. Prospective observational study using the electronic microscope to examine two types of plaques
Published in The Aging Male, 2020
Aldo Franco De Rose, Guglielmo Mantica, Bruna Bocca, Alexander Szpytko, André Van der Merwe, Carlo Terrone
In the five preparations relating to patients in Group 1, we found an inflammatory reaction of the tunica albuginea with a disorganized production of extracellular matrix (mainly collagen), however it was less than that found in the Group 2 preparations (Figure 1). The collagen fibers were well represented quantitatively and tightly packed in small blocks. The periodicity of these fibers ranged between 32 and 42 nm (Figure 3). The ultrastructure of most fibroblasts was very similar to that found in Group 2 preparations: collagen fibrils exceeded the cell membrane, penetrating the cytoplasm structures (Figure 2). There were also numerous intracellular vacuoles containing collagen fibrils and amorphous substance or cellular debris. The normal structure of the elastic fibers was altered due to fragmentation and deformation phenomena.
Chronic cachaça consumption affects the structure of tibial bone by decreasing bone density and density of mature collagen fibers in middle-aged Wistar rats
Published in The Aging Male, 2020
José Renato Romero, Walter Krause Neto, Alexandre Sabbag da Silva, Everton Luiz dos Santos, Marco Aurélio Added, Eduardo Pianca, Eliane Florencio Gama, Romeu Rodrigues de Souza
The present work demonstrates that the density of collagen fibers in the newly formed bone tissue decreased by influence of cachaça. It is known that collagen fibers play a key role in maintaining the structural integrity of tissues [20]. When there are changes in collagen fibers, the structure of the tissue may exhibit modifications [32] which can be quantified by the polarization microscope. Collagen fibers are birefringent so that they appear bright, allowing it to be quantified by the intensity of birefringence [20–23,33]. Mature collagen fibers (Type I) may be recognized by their greater thickness and for presenting a pattern of birefringence ranging from yellow to deep red. When immature they show some disorganization in their shape and size, are thinner with weak birefringence, showing greenish hues [15,34].