Biologically Active Polymers: Modification and Anti-microbial Activity of Chitosan Derivatives

Abstract

The principal derivative of chitin is chitosan, which is obtained by deacetylation of chitin. Chemical modification of synthetic and natural polymers is a convenient way to obtain materials with unique chemical and physical properties. Chitosan has an amino group at C-2 which is important because amino groups are nucleophilic and readily react with electrophilic reagents. Chitosan modified under mild conditions often results in regioselectivity for the C-2 amino group. In the present work, this reactivity was exploited to attach biologically active moieties into the amino groups of chitosan to yield anti-microbial chitosans. Specifically, vanillin, p-hydroxybenzaldehyde, p-chlorobenzaldehyde, anisaldehyde, methyl 4-hydroxybenzoate, methyl 2,4-dihydroxybenzoate, propyl 3,4,5-trihydroxybenzoate and 2-hydroxymethylbenzoate were attached. The anti-microbial activity of these modified chitosans was explored against fungi such as Candida albicans SC5314, Aspergillus flavus and Fusarium oxysporium. Also, they were tested against bacteria such as Bacillus subtilis, Escherichia coli and Staphylococcus aureus. These modified chitosans were found to be highly active toward fungi species more than bacterial species.

Antibacterial Effects of Poly(2-(dimethylamino ethyl)methacrylate) against Selected Gram-Positive and Gram-Negative Bacteria

“…Numerous polymers have been found to have antimicrobial activities against Gramnegative and Gram-positive bacteria, yeast and viruses 3,4 . For this reason they have been investigated as potential antimicrobial coatings and inhibit bacterial growth when attached to glass, paper, plastic and metal [5][6][7][8] .…”

Synthesis and antimicrobial activity of some polymers derived from modified amino polyacrylamide by reacting it with benzoate esters and benzaldehyde derivatives

“…This was achieved by modification of PA to produce polymers with the suitable active functional groups. A series of modified polymers (MPA [1][2][3][4][5][6][7][8] ) were synthesized and their antimicrobial activity against different tested organisms was investigated.…”

“…[5][6][7][8][9][10] A possible approach to prevent biomaterial-centered infections is to render the biomaterial surface antimicrobial properties by functionalization with suitable functional groups such as quaternary ammonium or phosphonium groups, which are widely known as disinfectants. 3 Antimicrobial biomaterials would be a promising solution for the problems associated with dental applications of polymers for treatment of periodontal diseases. 11 Contact lenses represent another important area for application of antimicrobial polymers, which would be able to reduce or prevent the bacterially driven adverse response associated with the contact lens wear.…”

“…[1][2][3] Also, infections associated with biomaterials represent a significant challenge to the more widespread application of medical implants. 4 The presence of a foreign body such as a synthetic biomaterial provides a site for microbial attachment.…”

Preparation of Polycyclic Pendant Chalcone Moiety Based Antimicrobial Polyacrylamides

“…Therefore, it infers the need for modifications in biomaterials development. 18,19 The various synthetic biomaterials provide a good site for microbial attachment and also the synthetic biomaterials consisting of suitable functional groups such as quaternary ammonium and phosponium groups are widely known as disinfectants. 20 In addition to halogenated sulfonamide, Nhalogenated amines are also used as antimicrobial agents.…”