Cross-linking agents As shown in Table 1, cross-linking can be classified into three types; chemical, biological and physical cross-linking [9, 15]. Chemical Cross-linking There are two types of chemical cross-linkers; synthetic and naturally derived reagents. The most commonly employed cross-linking reagent for collagen-based biomaterials is glutaraldehyde (GA), a five carbon bifunctional aldehyde, bridging ɛ-amino group of lysyl residues present in the protein over a varying range of distances owing to its less expensive and higher efficiency properties [16]. The mechanical properties of glutaraldehyde-treated tissue is quite different from non-cross-linked, showing more stiffness and increased tensile strength. However, GA is associated …show more content…
N-hydroxysulfosuccinimide (NHS), 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) is responsible for mediating “self cross-linking” or “zero-length” between the collagen molecules and plays an important role in improving the mechanical properties of the scaffolds [15, 24]. Generally, NHS is used in order to provide stability to carbodiimides cross-linking [25]. Compared with GA, carbodiimides are less toxic because they are released as urea substitute that can easily be removed by washing [15]. Powell et al. investigated that EDC facilitates the growth of human keratinocytes, smooth muscle cells and fibroblasts …show more content…
Recently, several chemical synthetic cross-linkers have also been developed having superior cross-linking properties [27]. In particular, 4-aminoethanol-N-hydroxyethanyl-1,8- naphthalimide (AHN), a dual-hydroxyl naphthalimide derivative that have been utilized in fluorescent labeling and as the chemical cross-linking agent but with less toxicity [28]. Naturally derived cross-linking reagents are considered superior to chemical cross-linking demonstrating a low toxicity level after implantation [9]. Genipin (GIP), an aglycone of geniposide obtained from Gardenia jasminoides Ellis Plant, was first discovered by Huang et al. in 1998 [29]. GIP is found to be 10,000 times less toxic than GA. GIP-fixed tissues, usually show resistance against enzymatic degradation as compared to GA resulting in the development of biocompatible cross-linked products [30]. In a recent study, Wang et al. reported that GIP alleviated the xenogeneic host response of decellularized porcine liver scaffolds by reducing the proliferation of lymphocytes and their subsets, accompanied by a decreased release of both Th1 and Th2 cytokines. It was reported that cross-linking using GIP promotes the beneficial tissue repair through enhancing angiogenesis and cell migration
This experiment was conduct to investigate the fluorescent behaviour of Leucophor PAF and to investigate the quenching of QBS with NaCl. It was found that the Leucophor PAF indeed satisfied the characteristic to act as whitening agent. It was also found that the quenching of QBS with NaCl was a diffusion-controlled collision process.
It regulates the ratio between epithelial cells and collagen fibers as well as changes in their morphology. The imbalance of collagen metabolism and its arrangement is attributed to many factors which result in increased synthesis of collagen by fibroblasts and myofibroblasts, which in turn inhibit the activity of collagenase, leading to extensive scar hyperplasia. Matrix changes, mainly changes in fibronectin and mucopolysaccharides, result in scar stiffness. MEBO Scar Ointment can accelerate the re-arrangement of twisted collagen andreduce proliferation of fibroblasts, thus restricting scar hyperplasia. [11,13,14,15 ,21] The accumulation and synthesis of mucopolysaccharide can also be reduced once local tissues are compressed, thus reducing generation of collagen and the corresponding scar tissue. [11] Moreover, massaging the MEBO Scar ointment onto old scars can potentially reduce blood supply within scars, decrease synthesis of collagenous fiber, and,reduce α2-M (alpha 2-macroglobulin) globulin of collagenase in serum which facilitates collagenase activity and speeds up disintegration of collagen in old scars,this facility by applying MEBO scar ointment .
First, let’s brake it down. What is glucosamine? Glucosamine is an amino sugar that is produced naturally in our bodies. Glucosamine can also be found in the shells of shellfish. Glucosamine is necessary for the construction of connective tissue and healthy cartilage. It is the building block of proteoglycans, which are large protein molecules that act like a sponge to hold water thereby giving connective tissue elasticity and cushioning effects. It also provides a buffering action to help protect against impacts that could cause damage to the surrounding area. Glucosamine helps to form tendons, ligaments, skin, nails, bones, mucous membranes, and other body tissue. Many studies have been put together to determine whether it effectively supplements our bodies’ glucosamine needs. Studies have shown that it can replace what the body can not produce. For example in one study, oral glucosamine stimulate...
the dynamic characteristics that keep on changing due to aging, intrinsic and extrinsic factors. The resin-dentin bond are still less predictable resin-enamel bond. Recent research are trying to improve bonding with collagen crosslinking agents, and inhibiting enzymatic degradation
Laminin 332 can bind via the G domain to α6β4 and α3β1 integrins [144, 145]. It also has binding sites along its β-chain for laminin 311 and collagen VII [146], and other binding sites along the γ-chain for perlecan and different types of collagen (IV, VII, and XVII) [144, 146]. Several studies showed that laminin 332 is involved in various cellular processes, such as epithelial cell adhesion, spreading and migration [147, 148]. The
These kinds of polymers have both some advantages and disadvantages. Although they are bioactive and biodegradable and provide high comppressive strength, Degradation of such polymers leads to undesired tissue response due to producing acid formation in degradation process. Metallic scaffolds are another method for bone repair and regenaration. They provide high compressive strength and enormous permanent strength. Metallic scaffolds are mainly made of titanium and talium metals. The main disadvantages of metallic scaffolds are not biodegradable and also discharge metal ions. Recent studies in metallic scaffolds mainly focus on biodegradable materials which can be used improve bioactivity of metals such as titanium.
... the usage of bioresorbable scaffold involves by selecting certain phenotype of cell and implants it on permeable substance before being implanted to the pulmonary position. The scaffold is presume to degenerate as the cells grow. The last approach involves constructing a mold for leaflets similar to the aortic shape using the collagen constructs (Vesely 2005).
Referencing is a crucial part in a student’s academic activities, as it is required whenever a student completes a piece of academic literature with information from other sources apart from himself. Any piece of academic writing has to be properly referenced if it draws information from sources other than the original author of the paper. Referencing lends credibility to any form of academic writing whether it is an assignment, a term paper, or even a thesis. Therefore, it can be defined as the process of acknowledging the sources of various ideas used within a document that do not belong to the documents author. It is important to discus both referencing and plagiarism according to unit 4 of UR courses by summarizing the ideas contained in the unit (Smithson 2014).
Yadav, P. R., & Tyagi, R. (2008). Biotechnology of animal tissues. New Delhi, IN: Discovery Publishing House.
When I started High School, My only goal was to be a wife and a mother because
The next application of animal biotechnology in pharmaceutical is artificial organ for transplant. Organ transplant can be defined as “a surgical operation where a failing or damaged organ in the human body is removed and replaced with a new one” (Paul, Valapour, Bartele, Abbott-Penny, & Kahn, 2004, p.5). According to Paul, Valapour, Bartele, Abbott-Penny, and Kahn (2004), example of organs that can be transplanted are skin, cornea and bone marrow that are less invasive but require specialized procedures. Cooper and Ayares (2012) mentioned that xenotransplantation is cross-species organ transplantation from animal to treat human. Furthermore, every year human need organs, tissues and cells for transplantation but lack in number of deceased human organs, so the interest of using organs and cells from animal species are rises continuously (Cooper & Ayares, 2012). Other than that, Houdebine, Lena and Burachik (2012) had stated that the most likely species for clinical transplantation into human is pig. In human heart surgery, the pig heart valves have been used for almost 30 years and in 1960’s, the best result was achieved when a chimpanzee’s kidney was transplanted into one patient who lived for nine months after the surgery (Nairne et al., 1996).
Collagen a protein is required for keeping skin young and smooth. Matrixyl 3000 is responsible for increasing the production of collagen by the skin.
Alexandra Kaye 5/3/14 LAQ 2 IB Psychology SL. Q: Discuss two errors in attribution. Within the social-cultural level of analysis, researchers study the social context in which behavior occurs. Humans have the natural need to understand why things happen. In order to explain why things happen, humans use attribution.
In its nature, collagen is like the backbone of the skin and is responsible for its elasticity and structure. It’s also responsible for replacement of dead skin cells with new ones giving the skin a radiant
The field of regenerative medicine encompasses numerous strategies, including the use of materials and de novo generated cells, as well as various combinations thereof, to take the place of missing tissue, effectively replacing it both structurally and functionally, or to contribute to tissue healing[29]