What is crosslinking in collagen?
Cross-linking of collagen refers to the ability of collagen fibrils to form strong chemical bonds with adjacent fibrils. In the cornea, collagen cross-linking occurs naturally with aging due to an oxidative deamination reaction that takes place within the end chains of the collagen.
What is cross-linking in polymers?
Polymer chemistry. Crosslinking is the general term for the process of forming covalent bonds or relatively short sequences of chemical bonds to join two polymer chains together.
What is degree of cross linking?
The degree of crosslinking that occurs is determined by the percentage of polymer chains that are interconnected in this network, or in other words, the density of the gel component. Higher crosslink density is the result of more linkages per length of polymer chain, resulting in larger property changes.
How does cross linking affect the properties of a polymer?
Introduction. Chemical cross-linking has been widely used to alter the physical properties of polymeric materials, the vulcanization of rubber being a prototypic example. Linking of polymer chains through chemical linkages gives a material a more rigid structure and potentially a better-defined shape.
How is polymer swelling measured?
Polymer swelling can be analysed by the Flory-Rehner equation which shows how the swelling is related to the MWt of chains between crosslinks – with larger values allowing more swelling. The swelling is shown as a ratio of volumes which is identical to 1/φ2 which is the concentration of polymer in the swollen gel.
How does cross-linking increase the strength of polymers?
By cross-linking, the structure of a polymer solution can be fixed. The resulting polymer networks (or gels) show elastic behavior and, depending on the system, good mechanical properties. Polymer networks are able to swell by uptaking water or organic solvents.
What is the type of cross-linking in collagen?
Cross-linking in the collagen molecule may be divided into two functionally separate groups. First, intramolecular cross-linking, in which two a chains within the same molecule may be covalently linked. Second, intermolecular cross-linking that involves the formation of covalent bridges between chains in different molecules.
What is intermolecular cross-linking?
First, intramolecular cross-linking, in which two a chains within the same molecule may be covalently linked. Second, intermolecular cross-linking that involves the formation of covalent bridges between chains in different molecules. This chapter describes the techniques for isolation and quantitation of intermolecular crosslinks in collagen.
How does cross-linking density affect Hydrogel swelling capacity?
Cross-linking density also influences the swelling capacity of a hydrogel. If a higher concentration of cross-linking agent produces the higher cross-link density, it results in additional network formation taking place.
Is collagen cross-linking effective in the treatment of diabetic keratoconus?
Clinical use of collagen cross-linking (CXL) can also be supported by the fact that young diabetics seldom have progressive keratoconus due to the natural cross-linking effect of glucose, which increases corneal resistance.