Human enzymatic activities related to the therapeutic administration of chitin derivatives

Abstract

Three cases are presented where modified chitins have been extensively administered to volunteers, as dressings for wounded soft and bone tissues, as anticholesterolemic dietary foods, and in the controlled delivery of anti-inflammatory drugs. The interactions of the modified chitins with human enzymes is critically examined. In the context of drug carrier resorption and wound healing, chitooligomers and monomers, generated by lysozyme, N-acetylglucosaminidase and human chitinase, activate macrophages and stimulate fibroblasts, respectively; the effects are production of smooth, vascularized and physiologically normal tissues. In the dietary food area, lipase, amylase, 3-hydroxy-3-methylglutaryl CoA reductase, glucokinase and the enzymes of prostaglandin synthesis are involved in the oral administration of chitosan: lipid adsorption is depressed mainly because of the physical form of the chitosan-lipid aggregates, which are unsuitable as substrates. When chitosan is used as a drug carrier, chitosan-drug complexes are present. The uniqueness of chitosan among polysaccharides is underlined in terms of susceptibility to enzymatic depolymerization, cationicity, supply of cell-activating oligomers, and supply of N-acetylglucosamine for rebuilding of other biopolymers. Advances in molecular recognition and biocompatibility are also presented.

Facile Preparation of Biocomposite from Prawn Shell Derived Chitosan and Kaolinite-Rich Locally Available Clay

“…Chitosan (CHT), a deacetylated derivative of chitin, has numerous applications in different fields including photography [5], metal capture from waste water (Hg 2+ , Cr 3+ ) [6][7][8], and acid dye sorption [9]. The low cost of CHT compared with commercial activated carbon as well as its possible biodegradability made it suitable for removal of heavy metals from industrial effluent [10].…”

Sorbitol-Plasticized and Neutralized Chitosan Membranes as Skin Substitutes

“…Moreover, it is metabolized by certain human enzymes, especially lysozyme, and is considered biodegradable 9 . Due to its positive charges at physiological pH, chitosan is bio-adhesive, which increases its retention on the site of application 10 .…”

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

“…Activated macrophages increase the production of lysozyme, chitinase and N-acetyl-␤-d-glucosaminidase, which catalyse the total depolymerization to monomers. The monomeric aminosugars become available to fibroblasts which proliferate under the action of interleukin-1, for incorporation into chondroitin 4-and 6-sulfate, hyaluronan and keratin sulfate, thus guiding the ordered deposition of collagen and also accelerating the wound healing process (Muzzarelli, 1991(Muzzarelli, , 1997. All these properties, including its bioadhesivity, make chitosan an excellent biomaterial to treat wounds and scars.…”